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Macronutrient deficiency and its effect on coniferous growth Murison, William Forbes 1960

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' M C ^ N U T R I E N T D E F I C I E N C Y A N D I T S E F F E C T O N C O N I F E R O U S GROWTH b y F i l l i a m F o r b e s M u r i s o n B . S . F . , U n i v e r s i t y o f B r i t i s h C o l u m b i a , 1951 M . F . , H a r v a r d U n i v e r s i t y , 1956 A t h e s i s s u b m i t t e d i n p a r t i a l f u l f i l l m e n t o f t h e r e q u i r e m e n t s f o r t h e d e g r e e o f D o c t o r o f P h i l o s o p h y i n t h e D e p a r t m e n t . o f B i o l o g y a n d B o t a n y We a c c e p t t h i s t h e s i s a s c o n f o r m i n g t o t h e r e q u i r e d s t a n d a r d T h e U n i v e r s i t y o f B r i t i s h C o l u m b i a J u n e , i 9 6 0 0 In presenting t h i s t h e s i s i n p a r t i a l f u l f i l m e n t of the requirements f o r an advanced degree at the U n i v e r s i t y of B r i t i s h Columbia, I agree that the L i b r a r y s h a l l make i t f r e e l y a v a i l a b l e f o r reference and study. I f u r t h e r agree that permission f o r extensive copying of t h i s t h e s i s f o r s c h o l a r l y purposes may be granted by the Head of my Department or by h i s r e p r e s e n t a t i v e s . I t i s understood that copying or p u b l i c a t i o n of t h i s t h e s i s f o r f i n a n c i a l gain s h a l l not be allowed without my w r i t t e n permission. Department of Biology and Botany The U n i v e r s i t y of B r i t i s h Columbia, Vancouver 8, Canada. Date I» I960. FACULTY OF GRADUATE STUDIES PROGRAMME OF THE FINAL ORAL EXAMINATION FOR T H E D E G R E E O F DOCTOR OF PHILOSOPHY of W I L L I A M F O R B E S M U R I S O N B.S.F., University of British Columbia, 1951 M.F . , Harvard University, 1956 F R I D A Y , S E P T E M B E R 23, 1960, A T 3:00 P . M . IN R O O M 3332, B I O L O G I C A L SCIENCES B U I L D I N G COMMITTEE IN CHARGE D E A N G . M . S H R U M , Chairman G . S. A L L E N V . J. K R A J I N A J. E . BIER G . E . R O U S E J. S. C L A R K D . J. W O R T P. G . H A D D O C K J. G . S P A U L D I N G External Examiner, DR. R. B. W A L K E R Professor of Plant Physiology, University of Washington M A C R O N U T R I E N T D E F I C I E N C Y A N D ITS E F F E C T O N C O N I F E R O U S G R O W T H A B S T R A C T This study was designed to throw some light upon the nutritional requirements of certain commercially important species of the western coniferous forests of Canada. Five species, coastal Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. menziesii), interior Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco var. glauca), Engelmann spruce (Picea engelmannii (Parry) Englm.), ponderosa pine (Pinus ponderosa Dougl.) and western white pine (Pinus monticola Dougl.) were grown in sand cultures in a greenhouse and artificially subjected to macronutrient deficiency for a period of nineteen months. The quantitative effects of such deficiencies on shoot and root growth, shoot/root ratios, chlorophyll content, vigor, specific gravity of the wood, foliar content of reducing sugars and foliar content of copper and zinc were studied and described. Chlorotic and necrotic symptoms were compared with the use of a coded color chart and keys to the various deficiencies constructed on the basis of these color comparisons. The foliar symptoms of deficiency were completely documented by color photography. A concurrent study of the growth of the same five species on four different soil types was also undertaken. Apart from affording useful information on the suitability of the soils for the growth of the species studied, this portion of the experiment confirmed the fact that the sand culture technique is an acceptable experimental method for growing conifers. The concept of tolerance was discussed and a method proposed for its objective determination. In essence, then, this study established a dependance between five coniferous species and an adequate supply of macrometabolic elements for normal development and growth. The imposition of deficiencies of any one of six elements studied resulted in reduced growth and arrested development. Quantitative and qualitative confirmation is given of the reality of these effects. G R A D U A T E S T U D I E S Field of Study: Forest Ecology Forest Autecology V . J. Krajina Forest Synecology V . J. Krajina Advanced Plant Physiology (I and II part) D . J. Wort Other Studies: General Forestry Seminar .... P. G . Haddock and J. H . G . Smith Forest Tree Seed G . S. Allen Soil Chemistry J. S. Clark Soil-Plant Relationships J. D . Beaton P U B L I C A T I O N Limiting edaphic factors evidenced by deficiency symptoms of some conifers. Abstract of joint paper with V . J. Krajina and J. G . N . Davidson, published in V o l . II Abstracts to the Proceedings of the I X International Botanical Congress, Montreal, 1959: p. 203. ABSTRACT This study was designed to throw some light upon the nutritional requirements of certain commercially important species of the western coniferous forests of Canada. Five species, coastal Douglas-fir (Pseudotsaga menziesii (Mirb*) Pranco var. menziesii), interior Douglas-f i r (Pseudotsuga menziesii (Mirb.) Franco var. glauca)» Engelmann spruce jjPlcea engelmannll (Parry) Engelnw), ponderosa pine (Pinus ponderosa Dougl.) and western white pine (Pinus monticola Dougl.) were grown in sand cultures in a greenhouse and artificially subjected to macro-nutrient deficiency for a period of nineteen months. The quantitative effects of such deficiencies on shoot and root growth, shoot/root ratios* chlorophyll content, vigor, specific gravity of the woodt foliar content of reducing sugars and foliar content of copper and zinc were studied and described. Chlorotic and necrotic symptoms were compared with the use of a coded color chart and keys to the various deficiencies constructed on the basis of these color comparisons. The foliar symptoms of deficiency were completely documented by color photography. A concurrent study of the growth of the same five species on four different soil types was also undertaken. Apart from affording useful information on the suitability of the Boils for the growth of the species studied* this portion of the experiment confirmed the fact that the sand culture technique is an acceptable experimental method for growing conifers. The concept of tolerance was discussed and a method proposed for its objective determination. In essence, then, this study established a dependence between five coniferous species and an adequate supply of macrometabolic elements for normal development and growth. The imposition of deficiencies of any one of six elements studied resulted in reduced growth and arrested develop-ment. Quantitative and qualitative confirmation is given of the reality of these effects. ACKNOWLEDGMENT A work of this nature owes much to many people who have gisren of their time and resources in order that i t should have every chance of completion. Dr. V. J. Krajina, for his i n i t i a l and continual encouragement throughout the course of this study, is deserving of especial thanks. The work was carried out under the auspices of the National Research Council .of Canada (N.R.C. Grant Uo. T-92; V. J. Krajina, Ecology of the Forests of the Pacific Northwest). My present employer, Dr. H. M. Raup» Director of the Harvard Forest, has "been most generous in allowing me time to complete the. manu-script. For advice and the opportunity for helpful discussion, I wish to thank Dr. T. M. C. Taylor, Dr. E, M. Gould, Jr., Mr. Dharam B. Mullick, Mr. B. Connelly, Dr. H. Y. Warren, Dr. M. H. Zimmermann and Dean G. S. Allen. The following were kind enough to help in the actual establishment of the experiment and in the running of i t over a two-year periodj Miss Trudy Pentland, Mrs. Y. J. Krajina, Mr. Slavoj Eie, and Mr. John Davidson. The measurement of the experimental plants was a task of no mean pro-portions and I was ably assisted in i t by Mr. Josef Ronetz, Mr. James Kayl, Mr. Kenneth Crombie and Mr. John Davidson. The many photographs that are a part of this work are the work of Dr. Y. J. Krajina, Mr. John Davidson and Mr. Kenneth Crombie. Dr. J. Clark, Dr. D. J. Wort, Dr. M. H» Zimmermann, Dr. H. Y. Warren and Mr. William Hancock generously allowed me to use their laboratory facilities to undertake the analyses reported in this paper. The seed used in this study were supplied, free of charge, by the Manning Seed Company, Seattle., Washington. T A B L E O F C O N T E N T S P a r t I I H i s t o r y o f t h e g e n e r a l f i e l d o f p l a n t n u t r i t i o n 1 I I F o r e s t t r e e n u t r i t i o n 8 I I I T h e d e f i n i t i o n o f e s s e n t i a l i t y 13 I V T h e f u n c t i o n a l r o l e o f m a c r o n u t r i e n t s i n t h e m e t a b o l i s m o f h i g h e r g r e e n p l a n t s 1 . G e n e r a l 17 2. N i t r o g e n 18 3. S u l f u r 20 4. M a g n e s i u m 23 5- C a l c i u m 27 6. P h o s p h o r u s 31 7. P o t a s s i u m 39 V M e t h o d s o f a r t i f i c i a l c u l t u r e u s e d i n t h e s t u d y o f p l a n t n u t r i t i o n 1 . W a t e r c u l t u r e 43 2. S a n d c u l t u r e 45 Y I T h e c o m p o s i t i o n a n d e f f e c t i v e n e s s o f n u t r i e n t s o l u t i o n s 49 P a r t I I I O b j e c t o f t h e p r e s e n t e x p e r i m e n t 57 I I M a t e r i a l s a n d m e t h o d 1. M a t e r i a l s 61 2. S o l u t i o n s 63 3- S e e d s o u r c e a n d p l a n t i n g 63 4. D e s i g n o f t h e e x p e r i m e n t 67 5. E x p e r i m e n t a l p r o c e d u r e s • 69 I I I T e m p e r a t u r e a n d h u m i d i t y d u r i n g t h e c o u r s e o f t h e e x p e r i m e n t 72 I V T h e q u a l i t a t i v e e f f e c t s o f m a c r o n u t r i e n t d e f i c i e n c y 1 . I n t r o d u c t i o n 73 2. T h e u s e o f c o l o r i n d i a g n o s i n g d e f i c i e n c y 75 3. C o l o r k e y s t o t h e f o l i a r s y m p t o m s o f m a c r o -n u t r i e n t d e f i c i e n c y • 79 4. D i c h o t o m o u s k e y t o f o l i a r s y m p t o m s o f d e f i c i e n c y 80 5. D e s c r i p t i o n o f d e f i c i e n c y s y m p t o m s d e v e l o p e d 83 6. P h o t o g r a p h i c r e c o r d o f s y m p t o m s d e v e l o p e d 95 V T h e q u a n t i t a t i v e e f f e c t s o f m a c r o n u t r i e n t d e f i c i e n c y A . M o r p h o l o g i c a l e f f e c t s 97 1. C o a s t a l D o u g l a s - f i r 103 2. I n t e r i o r D o u g l a s - f i r 109 3 • P o n d e r o s a p i n e 115 4 . W e s t e r n w h i t e p i n e 120 5- E n g e l m a n n s p r u c e 127 6. G r o w t h i n s a n d c u l t u r e s r e c e i v i n g d i s t i l l e d w a t e r o n l y 134 B . E f f e c t s o n f r e s h a n d d r y w e i g h t p r o d u c t i o n , s h o o t / r o o t r a t i o a n d m o i s t u r e c o n t e n t 136 C E f f e c t s o n m o r t a l i t y a n d v i g o r 150 D . E f f e c t s o n c h l o r o p h y l l - c o n c e n t r a t i o n 155 E . E f f e c t s o n t h e s p e c i f i c g r a v i t y o f w o o d 160 F . E f f e c t s o f m a c r o n u t r i e n t d e f i c i e n c y o n t h e f o l i a r c o n t e n t o f c o p p e r a n d z i n c 1 6 4 G . E f f e c t s o n t h e c o n c e n t r a t i o n o f r e d u c i n g s u g a r s 172 V I S p e c i e s d i v e r s i t y a n d t h e c o n c e p t o f t o l e r a n c e 177 V I I G r o w t h i n s o i l c u l t u r e 183 V I I I D i s c u s s i o n 200 T X C o n c l u s i o n s 217 B i b l i o g r a p h y 2 2 1 A p p e n d i x PART I 1 I History of the General Field of Plant Nutrition The abbreviated historical account that follows is based on the writings of Reed (19^2)» Sherman (1933) and Meyer (1891) and these sources may be consulted for a more comprehensive treatment of the statements made* In broaching this subject, one must begin with no less eminent a person than Aristoteles(384-322 B.C.) for the f i r s t recorded considerations of mineral nutrition in plants. Coupled with a vitalistic philosophy which attributed to plants selective habits only found in higher forms of animal l i f e * Aristoteles erroneously held that* prior to their uptake and use by plant8, foods from the soil were previously elaborated and made applicable to the purposes of growth* Such a formulation was considered necessary to ex-plain the observed absence of any excretory mechanism in plants. Andrea Cesalpino (1519-1603), a dedicated follower of Arietoteles, per-petuated the notion of the "plant soul" but found this postulate lacking when brought to bear on the problems of moisture uptake. Like Arietoteles, Cesalpino was more given to philosophical divination than impartial obser-vation when seeking to explain plant function. The f i r s t major advance toward a more realistic understanding of plant nutrition arose from the efforts of Joachim Jung (1587-1657) who gave no credence to the previously conceived ideas concerning nutrition but rather emphasized the essential functions of the plant root in control-ling the uptake of mineral matters from the soil* In a word, he was able to ascribe chemical activity to the plant without adumbrative allusions to the existence of a plant soul. The supposed similarity between animal and plant nutrition was seri-ously questioned by the now famous experiment of Van Helmont (1577-1644) 2 with a willow branch and* with this as background, the stage was set for yet another substantial advance in knowledge concerning the true nature of plant nutrition, Marcello Malpighi (1628-169*0 in his "Anatomia Plantarum," published in l6?5» discussed sap movement and nutrition and was led to con-clude that the fibrous elements of wood convey upwards to the leaves the crude substances* yet tuxelaborated, which are absorbed by roots. Though emphasizing the anatomical features that permit of translocation and move-ment* Malpighi further removed the actualities of mineral nutrition from subjective speculation and his published work doubtless gave fundamental support to the thought processes of one Edme Mariotte (c. 1620-1684) who, although a physicist, shed considerable light on the chemistry of nutrition* Speaking of the "elements" or "principes" of plants, Mariotte pro-pounded three hypotheses. a. There are many fundamental stuffs in plants, such as water, sulfur, common salt, etc., and each of these, in turn, is compounded of simpler principles or elements. He further noted an inherent tendency on the part of these elements for congregation or aggregation and that such a proclivity owed nothing to vitalistic f i r s t causes. In essence, he skirted the borders of our modern atomic theory and* in so doing* put considerable distance be-tween himself and past Aristotelian entelechies* b. Every plant contains several "principes grossieres11 or elemental substances that originate in the air* are carried by rain to the soil, and thence by roots to the plants. c. The varying combinations of the basic elements account for the differences in composition that exist between the sap of distinct species such as pear and oak. Prior elaboration of plant juices in the soil, a view s t i l l held valid in Mariotte*s time, was largely discounted by this 3 proposition although, as a hypothesis, i t was not to be finally dispelled until the time of Liebig. The contributions of Mariotte and Malpighi, when compounded, are seen to constitute a greatly improved rationality and objectivity concerning the phenomenon of mineral nutrition. After a frustrating lapse of years following these notable contribu-tions, there appeared a work by one Stephen Hales (l677-176l) entitled "Vegetable Statieks" which hy many is considered the f i r s t authoritative work in the fi e l d of plant physiology. Hales* much steeped in Newtonian principles* sought to explain the internal processes found in plants in terms of fundamental mechanico-physical laws as then understood. His tools of trade were observation and experimentation upon, which he placed complete reliance, and the value of his work reflects the acuity of his insight into the results that such methods afforded him. His, two greatest contributions to plant nutrition stem from his eluci-dation of the existence and mechanisms of transpiration and an appreciation of the part that air plays in the synthesis of the materials incorporated in the plant body. With a nod in the direction of Joseph Priestley (1733-1804) for his observations on the exhalation of oxygen by plants* we must pass now to the work of Jan Ingenhousz (1730-1799) whose book "Experiments on vegetables* discovering their great power of purifying the common air in sunshine and of injuring i t in the shade and at night," as the title suggests* shed don-siderable light on. carbon dioxide assimilation by plants. He seems to have favored the idea that the atmosphere was the only source of carbon for plant growth. The ideas propounded by Ingenhousz* Priestley* Hales and others were incorporated into a general treatise on plant physiology "by Jean Senebier (17^ *2-1809) • That this work, which suffered from a profusion of words and a paucity of originality, received hut scant attention was due very largely to the appearance in 1804 of a scholarly and precise work by U. Th. de Saussure (1767-IM5) entitled "Eecherches chimiques sur la vegetation" (1804). Fundamental to a l l succeeding work on plant nutrition, this work set forth the following facts'. 1. The elements of water are fixed in the plant at the same time as the carbon.. 2* There is no normal nutrition of the plant without the uptake of nitrates and mineral matter.-3* The nitrogen in the plant substance comes, not from air, but from the soil. k* The small quantities of mineral matters found In the ash of plants is no Justification for considering them inessential to plant growth. 5» Plant roots are selective in that they absorb mineral substances in ratios that are proportionately different from those that exist in the soil. ^ 6, The quantities of water transpired by plants far exceeds the amounts required for growth. 7. Perhaps as a corollary to this latter fact, the concentration of mineral solutes entering a.plant and subsequently found in its sap is extremely dilute. The magnitude of de Saussure's contributions i s sometimes hard for us to appreciate, far removed in time as we are from such illuminating dis-coveries, but a measure of their importance may be deduced from the fact that i t was some forty years before his contemporaries caught up with his ideas. 5 There followed in 18^2 the work of Wiegmann and Polatroff who were able to conclude that 1* Plants grown in distilled water gained nothing in ash content* 2* Plant8 are capable of making some growth at the expense of mineral constituents contained in the plant seed but* having exhausted this supply* grow no further* 3* Inorganic constituents found in plant tissue are not a by-product of their metabolism* 4* Any quantitative increase in the amounts of mineral matter in plants must originate by absorption from the external medium* Thus after a lengthy period of years the correctness of the views pro-> mulgated by de Saussure were finally established beyond any possibility of doubt* Confirmation of de Saussure1s work also came from C. S* Sprengel (1787-1854). In a l l his various works Sprengel emphasizes the need of crops in obtaining from air and Boil a l l of the chemical elements necessary for their proper growth and maturity* The fifteen elements regarded by him as essen-t i a l for the growth of plants were oxygen, carbon, hydrogen, nitrogen, sulfur* phosphorus, chlorine-* potassium* sodium* calcium* magnesium, aluminum, silicon* iron and manganese* He considered i t likely that other elements such as fluorine* iodine* bromine* lithium and copper* not yet found to be essential* may yet prove to be so* thus foreshadowing the more modern discovery of trace elements, Sprengel* in many respects* anticipated the work of Liebig in his statements concerning minimum and maximum factors and the role of humus in plant nutrition. He concluded, as a result of extensive determinations of the mineral constituents of soils and crops* that the quantities of these 6 various elements In one and the same plant are always dependent upon the chemical composition of the soil in which the plant i s grown* Furthermore* he enunciated the principle that plants differ greatly In their preferences and requirements for the various elements present in soil* A curious adherence to medieval vitalistlc conceptions coupled with the oracular authority of Liebig'e writings which sought to discredit his find-ings has led to Sprengel1s work being largely ignored* a fate which* from its very real worth* i t does not deserve* Bouseingault (1802-8?) was first to make wider use of the known ability of plants to grow in a r t i f i c i a l soils of sand or charcoal that were suit-ably amended by the addition of mineral solutions of known composition* He used this technique to explain the assimilation of atmospheric nitrogen by leguminous crops* without entering into the question of how this was effected. These and other studies on the effect of inorganic fertilizers secure for Bousslngault an enviable position in the field of agricultural chemistry but the value of his scientific methods and insights is of signi-ficance to the wider field of plant nutrition* Other contemporary workers whose names are worthy of mention a^s having furthered man18 knowledge on the intricacies of mineral nutrition are Trinchinetti, Salm-Horstmar and Malder. That theBe workers receive no further mention here is no disparagement of their efforts* It is done rather to permit of an earlier discussion of Liebig's more comprehensive work which contained an evaluation* albeit a somewhat biased one* of a l l that was meritorious in the published writings of his predecessors* Justus von Liebig (1803-1873), a brilliant student of chemistry and scathing commentator on other peoples* findings, is chiefly remembered for 7 Ms overthrow of the theory that plants obtain their carbon supply from the soil. This and other concepts concerning soils* fertilizers* the role of humus* analytical techniques and the role of nitrogen found expression in his famous book "Organic chemistry in its applications to agriculture and physiology." The immense popularity of this book is indicated by the fact that before 1848* eight years after its appearance* i t had gone through seventeen different editions and translations* four in Germany* four in England* two in America* two in Prance and one each In Denmark* Hollands Italy, Poland and RuBsia. These figures attest to the startling impetus given by Liebig to a l l forms of research concerning the mineral nutrition of plants either as individuals or as crops. His Law of the Minimum and the so-called "Mineral Theory of Manures" became widely known and hotly discussed. Subsequent investigation of a more stringent nature has served to discredit many of his more dogmatic assertions but l i t t l e can now de-tract from his position as the instigator of modern scientific research in-to the problems attending the mineral nutrition of plants. 8 II forest Tree nutrition Any review of forest tree nutrition research must "begin with the pioneering studies conducted by German forest botanists. As with other fields of forestry, Germany made early and significant contributions to the growing discipline of forest science and much that was done in the latter half of the nineteenth century has not since been equalled for accuracy or soundness of result. The names of Hartig, Raaann, Bauer, Vater, Mdller and Cranner come readily to mind as men who made fundamental studies concerning the nutrition and effects of mineral fertilizers on the growth of forest trees. Ramann, for instance, in his 'Torstliche Eodenkunde und Standortelehre" published in 1893 (IS!), treats of the varying mineral requirements that characterize various tree species, the mineral content of wood and bark, the role of oxygen and nitrogen in tree growth and the mineral content of soil water. A. M«ller (1904) and H. Vater (1910) were among the first to observe the effects of mineral deficiency on the growth of pines. They noted that a shortage of nitrogen in one-year-old pines caused the loss of a f u l l green color in the foliage normally associated with healthy plants and brought about instead a light green or yellowish coloration. Pine needles thus de-prived were noted to be small and weak. In the absence of sulfur, pine needles remained small and delicate with pallid green foliage that differed essentially from the coloration induced by nitrogen deficiency. With a shortage of phosphorus, young pines were seen to develop a blue to bluish violet color which Vater suggested might be due to anthocyanin pigments. These and other symptoms were described for growth of pines in media de-ficient in magnesium and calcium but the authors were quick to assert that 9 such evidences of s o i l deficiency would not furnish, any incontr over table proof of depletion of a given element in the s o i l . It seems that even then they were aware of competitive ion absorption and antagonism. A reliable review of early German investigations i n forest tree nutrition i s to be found i n the English translation of a work by M. Bflsgen and E. Mtfnch entitled "The structure and l i f e of forest trees"!t(1929)» Mention must now be made of A. Nemec who,* for a period of over twenty years (1929-1951)* published extensively on forest tree nutrition and f e r -t i l i z a t i o n basing his writings upon work conducted in Czechoslovakia. A l i s t of the t i t l e s of some of his articles w i l l serve best to describe the wide compass of his investigations. The phosphoric acid content of forest humus. 1929* Deficiency symptoms in pine seedlings. 1936. The effect of liming on the growth and nutrition of f i r trees i n the nursery. 1938. Nutritional disturbances i n pines. 1939* Mineral nutrition of a dying spruce stand i n St. Thomas Forest i n the Sdhmerwald. 1940. The nutrition and f e r t i l i z a t i o n of elm. 194?. These are but a selected few from many informative works that originated from his hand* a l l having some bearing on the problems of forest tree nu-t r i t i o n . A series of important papers on forest tree nutrition emerged from studies conducted by E. L. Mitchell at the Black Bock Forest i n New Tork State (193^» 1939a* 1939b). Working with both coniferous and deciduous species native to the Northeastern United States* Mitchell employed s o i l and sand pot culture techniques to point up the relative requirements for phosphorus* nitrogen* potassium and calcium on the part of the trees studied* 10 The scope of his efforts in this field has not been equalled elsewhere on this continent and i t is curious that the excellent ends to which his techniques led did not encourage like efforts on the part of others* As i t is* his published works remain as a starting point for any work designed to further knowledge on the comparative mineraloglcal requirements of forest tree species* The years prior to World War II saw the publication of numerous works in various countries dealing either with the fundamental roles of the mineral elements in tree growth or with specific cases of soil mineral deficiency as i t affected the health and vigor of art i f i c i a l l y established.plantations* Kessell and Stoats (1936) in Australia studied the nutrition of Pinus radiata and made recommendations concerning fertilization procedures designed to correct mineral deficiencies* Pessin (1937) studied the effect of nutrient deficiency on the growth of Pinus palnstris while Addoms (1937) made studies on the mineral nutrition of another southern pine, Pinus taeda. Steinbauer (1932) studied the effect of varying light intensity and nutrient solution concentration upon the growth of tree seedlings. Howell (1932) concerned himself with the acidity of the culture solution in which western yellow pine seedlings were grown and the changes effected by the growing plants upon the pH of their liquid nutrient media. Hoagland and Chandler (1932) sought to measure the effects of phosphate and potash deficiency on the growth and composition of fruit trees under controlled conditions. In Germany, Jessen described symptoms of potassium and magnesium deficiency as found on various native and Introduced forest species and recorded the results of efforts to correct these deficiencies through the use of f e r t i -lizers (1938). 11 Poet-war activity in. mineral nutrition has been more widespread and the .impetus has come not unnaturally from difficulties being experienced, mainly in Europe, with a r t i f i c i a l l y established forests of both native and exotic species. The establishment of such plantations on nutritionally poor soils such as heath, moor or alluvial sands is now leading to difficulty as these stands reach pole size and make ever increasing demands on pedo-logical reserves that were scant at the outset and which they themselves have further depleted. Leyton (1948) in England has made some successful attempts to correlate growth and mineral content of the foliage and presum-ably hopes to use this information to establish minima beyond which a r t i f i -cially applied soil amendments must be resorted to i f healthy and vigorous growth of the growing stock is to be maintained. Van Goor (195^ ) ka B des-cribed an anomalous situation with regard to the nitrogen requirements of Larlx leptolepis. Hobbs (1944) in. his study of macronutrlent deficiency as i t develops on Pinus strobus* Pinus resinosa, Pinus rlglda (pitch) and Pinus echinata (shortleaf) used methods not unlike those to be reported in the present study. The work of Addoms on Pinus taeda was further • enlarged by the studies of Davis (1949) who made a careful analysis of the morphological effects of calcium deficiency in the same species. Wilde and Volgt (1952), Vlamis, Biswell and Schultz (1957)* Miyazaki, Sato and Gikawa (1956), Day and Robbins (1950), Erickson and Lambert (1958). Eerrell and Johnson (1956)* Toungberg and Austin (1954), Toungberg (1958)* Eeiberg and White (1951). Goacharov (1946), L. C. Walker (1956*)» Rennie (1955)» Purl (I951)t Stone (1952), Gessel and Walker (1956"), Purnell (1958). Walker, Gessel and Haddock (1955) among the authors whose recent publications-have a direct bearing on forest tree nutrition. A more complete listing is to be found in a recent bibliography* provided with abstracts, issued by the 12 State University College of Forestry at Syracuse University, Hew York (1956). A further valuable source of bibliographical information is to be found in a "Bibliography of tree physiology" prepared by T. T. Kozlowski and published in cooperation with the United States Forest Service (195^ )» Doubtless the field is a large one and the expenditure of much time and energy is needed to keep abreast of developments. A recent review (Broyer and Stout* 1959)* for instance* stated that more than a thousand publications concerning macronutrient nutrition had appeared in the past three years. This is a formidable amount of material for any one person to assimilate but* with the help of some excellent reviews (Broyer and Stout, 1959? Gauch, 1957* Pirson, 1955)» the task is not an impossible one. 13 III The Definition of Essentiality Autotrophic plants have the ability* given adequate supplies of min-erals, water and carbon dioxide, to synthesize a l l of their food require-ments. Such plants* however, are capable of absorbing a large number of elements indiscriminately with the result that chemical analyses of s o i l -grown plants afford no criteria of essentiality. It is patently obvious that for healthy growth of a higher plant a l l the essential elements must be present, but, since the time of Sachs and En op, i t has become common knowledge that not a l l the elements present are essential. By techniques, developed originally by these early workers* that dif-ferentially remove specific elements from the rooting environment, i t is possible to assess the relative importance of any one element for the growth of the test plant used, likewise, the addition of specific minerals or combinations thereof to sand or water cultures and the plant responses that result will yield equally valuable data. Of course the recognition of sources of contamination and stringent measures to counteract them must attend any such investigation for valid conclusions to be drawn. A straightforward approach to a definition of essentiality is not feasible with heterogeneous soil components* It is a difficult matter to remove an element entirely from a soil sample and impossible to do so with-out altering the availability and relative concentration of the other ele-ments present. The alternative, additive approach also poses problems. The fixative properties of soil colloids for both macro- and micrometabolic elements so governs and controls the availability of added minerals that any quantitative measure of uptake and response by test plants is rendered Impossible. Classic examples in this regard are afforded by phosphorus 14 and zinc. Even l f responses of a noteworthy nature do result from such soil amendments, uncertainty s t i l l exists whether these responses are due directly to the added mineral or to some secondary effect caused "by the addition. The work of Horner, Buck, Allison and Sherman (194-2) nicely i l l u s -trates this point. Here i t was shown that the addition of vanadium to a soil improves nitrogen fixation by Azotobacter. Taken at face value, the increased growth of test plants in the vanadium-treated soil might well have been construed as evidence enough of the essentiality of vanadium for growth when, in fact, the secondary effect of increased nitrogen availability was responsible. One can do no better, at this point, than to quote Amon (as reported in Truog, 1951) °n the advisability of using culture techniques in determinations of essentiality. He Btates "The a r t i f i c i a l culture technique continues to be a powerful and discriminatory tool in evaluating the in-dlspensabillty of inorganic nutrients in plant nutrition." In the minds of those faced with a l i s t of elements determined to be essential for plant growth by culture techniques, there frequently arises the question as to the applicability of these results when considering plants grown in soil. This crit i c a l reservation was valid enough to warrant investigation and i t has now been shown by Hoagland and Arnon (1938) that thetrelative Inorganic composition of the various plant organs remains the same whether they be grown in soil, sand or water culture. Over the years there have emerged certain criteria which must be met for the definitive establishment of essentiality. It must be shown, for any element under scrutiny, that 1. Failure to grow in the absence of the element and resump-tion of growth on addition of the element holds for a l l plant8 tested. 15 2.. A deficiency of the element makes i t impossible for the test plant or plants to complete vegetative growth* or the reproductive stage of the l i f e cycle. . 3. Such deficiency is specific to the element in question and can be prevented or corrected only by supplying this element. 4. The element is directly involved in the nutrition of the plant quite apart from its possible effects in correcting some unfavorable microbiological or chemical condition of the soil or other culture medium. Such criteria of essentiality as above stated should have rather wide applica-tion in the plant kingdom. The other approach to the question of essentiality is through the study of function. A convincing demonstration that a given element is indispen-sable to some vital metabolic process would suffice to establish its essen-tiali t y even in the absence of appropriate growth experiments or corroborative analytical evidence on plant constituents. If*for instance* i t can be shown that a metal is the prosthetic group of an essential enzyme and that no other element can substitute for i t in this function* this Is evidence enough of its essential nature. The roles of zinc in carbonic anhydrase and copper in polyphenoloxidase may be cited* The establishment of essentiality through identification of an element with a specific internal function in plants in no way detracts from other essential roles in which the element features. The essentiality of mag-nesium as an activator of many enzyme systems together with its role as a functional constituent of the tetrapyrollic chlorophyll molecule is illustrative of this point. 16 In the present investigation of forost tree nutrition* i t was i n i t i a l l y assumed that the elements determined to he essential for other forms of plant l i f e would he equally essential for the growth of conifers. The present limited study partially confirmed this i n i t i a l premise. The longevity of the trees under study rendered i t impossible to study the reproductive phases of the l i f e cycle. Nor was l t possible to test the effects of resupplying . elements to plants previously affected by macronutrient deficiencies. 17 IV The Functional Role of Macronutriente In the Metabolism of Higher Green Plants General An attempt to make a comprehensive review of the functional roles of the various macrometabolic ions is made difficult by Incomplete knowledge concerning their specific part in the internal processes of plants. Although i t has long been generally known that major physiological processes such as respiration* chlorophyll synthesis* protein synthesis* ce l l division* cell elongation* osmotic pressure and others are intimately bound with mineral nutrition* yet the specific effects of a deficiency or excess of any one element in a particular species have been infrequently studied. Several specific roles of ions in metabolic developments have been elucidated in the recent literature and have been thoroughly reviewed (Hewitt* 1951)* Much remains to be done* however* in the functional-dynamic aspects of mineral nutrition. Coupled with this void in our knowledge of fundamental participation on the part of mineral elements in plant metabolism* any review of the functional aspects of nutrition is hampered by a plethora of documented evidence which* while germane* i s so diversified and scattered throughout other fields of research that a collation or synthesis of the available data at a particular point in time is a task of marathon proportions. The comments of Pirson (1955) this regard are worth recording. "Eeviewers in the field of mineral nutrition of plants have always been faced with a particular d i f f i -culty. Mineral research is a fi e l d which is hard to delimit* since i t branches far into the various spheres of plant physiology. The more a particular problem is delineated and a solution to i t sought* the more i t appears to belong to other fields, such as physiology of metabolism, physical ce l l physiology or enzymological biochemistry." 18 In view of this difficulty and in an attempt to remain concise and* at the same time, logical, the remarks that follow will he restricted to those aspects of functional metabolism and growth which seem most likely to he of more immediate moment to a fuller appreciation of the physiology of forest trees under conditions of deficient nutrient supply. The Role of Nitrogen The presence of nitrogen in protein molecules and the fundamental part that the latter occupy in the synthesis and elaboration of protoplasm* establishes, beyond any doubt, a high priority of requirement for nitrogen in plant metabolism. Its inclusion in nucleoproteins, nucleic acids, amides, the chlorophyll molecule, and numerous alkaloids substantiates this claim. Any deficiency of nitrogen is bound to have an influence on one or a l l of the above and, furthermore, will be measurable by its effect on an organism's ability to form enzymes. Virtanen (as quoted in Pirson (1955))bas noted that, under conditions of nitrogen deficiency, the ability to form adaptive enzymes is f i r s t reduced, whereas the final complement of vital enzymes Is maintained. The synthesis of the latter has absolute priority. This may, in part, ex-plain why mortality under conditions of reduced nitrogen supply is not invariably encountered. As further proof of its essentiality* one might cite the integration of nitrogen into many of the vitamin molecules or* more important* the inclusion of nitrogen in adenosine triphosphate which features so largely in a l l energy transformations in. living cells, both chlorophyllous and otherwise. The work of Kraus and Kraybill (1918), since corroborated by others, emphasized the effects of deficient nitrogen supply upon the carbohydrate 19 (notably reducing sugar) content of the foliage of affected plants. A paucity of nitrogen depresses the rate of synthesis of protoplasm with the result that there is an accumulation of excess carbohydrate in the leaves* Such an effect may increase resistance to adverse climatic conditions through an elevation of the osmotic pressure of the plant sap. A defici-ency of nitrogen in the rooting medium has decided effects on the shopt/root ratio, and, since the effect of such deficiency has more significance for shoot as opposed to root development, the probability of a reduction in ratio is high. That this differential effect of nitrogen deficiency with regard to shoot and root occurs, i s explainable on two counts. First, a reduced nitrogen supply will increase the amounts of carbohydrate available for down-ward translocation to the root. Second, such deficiency has been shown to be effective In reducing the amounts of auxin synthesized and transportable to the roots. The differential effects of such low auxin concentration on root and shoot growth have been illustrated by Leopold and Thimann (19^9). MOLAL CONCENTRATION IMDOLACETIC ACID Fig. 1. Auxin concentration and its effect on development. 20 The onset of maturity, susceptibility to fungal attack and the time of f r u i t i n i t i a t i o n are similarly and causatively linked to nitrogen nutrition. . Bosemark (195*0 has presented an excellent review of the effects of nitrogen supply on root growth. Hraus and Krayblll (1918) are to be con-sulted for the effect of nitrogen on fruitfulness while disease incidence as dependent on nitrogen* supply i s f u l l y covered i n the reviews of Wingard (1941), Walker (1946) and Mcllew (1953). Hewitt (1951) on the role of nitrogen as an enzyme activator, Mulder (1950), Pirson (1955)* Wallace (1932), Eroyer and Stout (1959) for a general review of nitrogen nutrition and the more-recent lines, of current research and Pessin (1937)* Hobbs (1944), Wallace (1932)* Gessel, Walker and Eaddock (1950), Worley, Lesselbaum and Matthews, (1941), Krajina (1959)» Pumell (1958), Mitchell (1939b) and Leyton (1952) are to be consulted for the effects of nitrogen deficiency on the growth of forest tree species. The Role of Sulfur Sulfur i s a constituent of the amino acids cystine, cysteine and methi-onine and of the vitamins thiamine and blotin. It features in thioctic acid and other cyclic S-S compounds in photosynthesis as well as being a constituent of the mustard o i l glycosides* Although sulfur i s usually absorbed i n the oxidized form by plants (SO^ ), i t i s reduced to sulfhydryl groups (-SH) prior to inclusion i n amino acids of which i t i s a part. The site and mechanisms of this reduction are unknown. Olsen (1957) working with cotton plants (Gossypium hlreutum var. Acala) has shown that 10 p.p.m. of sulfate i n the culture medium i s required for plants to reach maximum growth. He has also shown that such plants are 21 able to obtain significant quantities of their sulfur requirements from the sulfur dioxide of the atmosphere and that such supply was roughly proportional to the size of the plant and vras presumed to be a function of the effective leaf surface. According to the data» under conditions of balanced nutrient supply, the plants were able to obtain about 30 percent of their sulfur from the atmosphere* Over 50 per cent was obtained from the same source by plants gro'.-m in a nutrient solution deficient in elemental sulfur* Atmospheric amounts, however, were not able to compensate completely for deficiencies in the rooting medium. Katz, McCallum, Lathe et al. (1939) have reported on the effect of sulfur dioxide fumes on the vegetation in the neighborhood of the smelters at Trail, British Columbia, and they conclude that concentrations of over 1 per cent are toxic to most plants but that, below this level, plants are able to utilize considerable quantities of atmospheric sulfur for growth. Among the species reported on was Douglas-fir. Thomas, Hendricks and Hil l (1950) summarizing available data on the sulfur content of vegetation present.the following data. Table I Sulfur Content of Conifers (pine, f i r , spruce and Juniper) Growing in Non-industrial Areas throughout 11 Western States Plant Part Number of Samples Min. Sulfur Content Max. Avs. First year needles 66 o.oi* 0*25 0*11 Second year needles 73 0.07 0.37 0.11 Third year needles 28 0.06 0.26 0*10 fourth year needles 28 0.04 0.22 0.10 Fifth year neeHes 22 0*05 0.22 0*11 22 Bukovac and Wittwer (1957) l i s t sulfur as a mobile element in their tripartite classification of nutrient mobility but Biddulph et a l . (1956) qualify this statement by a note to the effect that circulation is rapidly curtailed by metabolic capture* particularly in young leaves. Sulfur deficiency symptoms and effects have been studied by numerous workers, among them Baton (1935* 194-1* 194-2). Ergle and Baton (1951)» Marsh (1923). Storey and Leach (1933). Wood (194-2) and Nightingale (1932). Gilbert (194-9) has made a comprehensive review of the field of sulfur nutrition. An attempt will be made to summarize the most cogent observations from the pub-lished writings of these and other workers. 1. There is a rather constant relationship between dry matter yield and sulfur content of the plant (Phase olus sp.) throughout the nutrient range 0.125 to 1.0 milimolar sulfur (1958). 2. pH of the medium in which plants grow has l i t t l e effect on sulfur uptake. 3. Omitting sulfur from the diet affects the tops more than the roots. Top/root ratios for sulfur-deficient plants are likely to be lower, on aver-age* than those receiving a complete, balanced supply of a l l elements. 4-. Stems of low sulfur plants tend to accumulate soluble nitrogenous compounds such as amides. That this is so may indicate proteolysis. This accretion of organic nitrogenous compounds in deficient plants is accompanied by an increase in inorganic nitrogenous compounds* e.g.* ammonia and nitrates (1941). 5. Polysaccharides, through sulfur deficiency, may accumulate but there is. a concomitant decline in reducing sugar concentration (194-1). 6. Sulfur deficiency increases elongation* and the subsequent height of plants grown in deficient sulfur cultures often exceeds that of plants grown in cultures containing sulfur. 23 ?• Sulfur deficiency interferes directly in the process of photo-synthesis (Pirson, 1955) "by i * e apparent effect on the protein level and the chlorophyll content of the chloroplasts. Low sulfur supply greatly de-creases leaf protein although the percentage of sulfur in leaf protein re-mains higher than elsewhere in the plant, indicating that a. In an unusually high proportion of plants available sulfur is localized in the chloroplasts* b. Some mechanism* as yet unknown* renders chloroplastic sulfur peculiarly impervious to changes in mineral supply, c. Competitively speaking* the chloroplasts are advan-tageously equipped to draw upon available sulfur sup-plies already absorbed. 8. An insufficiency of sulfur is effective in increasing the thickness * of cell walls (19*4-2). It has been noted that green stems become quite woody and leaves brittle under minus-sulfur growth conditions. The Role of Magnesium The very obvious part, played by magnesium in the chlorophyll molecule would seem, at f i r s t sight, to secure for magnesium a unique functional importance among the cations absorbed by higher plants. Due largely to the fact that magnesium is the-most effective activator in.a whole complex of enzymatic reactions, however, there are many correlative effects of magnesium deficiency which are equally important and independent of decreasing chloro-? phyll content. • Many of these effects are likely to make their appearance in the earlier stages of magnesium deficiency. * Eaton (1942). Zk Fleischer (1935)» using suspensions of Chlorella, noted that magnesium deficiency seemed to have a dual effect in that i t affected both the amount of chlorophyll present as well as the photosynthetic rate and that both these effects are independent* Following the publication of these results, Kennedy (1940) studied the effects of magnesium deficiency on similar material but used an intermittent rather than a continuous source of light. He found that at dark intervals of 0.02 seconds duration the yield per flask in m i l l i -meters of oxygen per hour was twice as great with the non-deficienct as with the deficient cultures. With intervals of 0.04 seconds, no significant differences were observable. The explanation lies in the fact that magnesium-deficient cultures in the short-interval series seemed unable to complete reduction of the C02 present but that this was possible i f the dark interval was increased. The enzymatic reactions presumably operative in the Blackman reaction are, i t would seem, retarded by the absence of sufficient magnesium. It seems to be generally held that magnesium deficiencies are among the most difficult to correct and that response to corrective influences is tardy. Sensitivity to magnesium deficiency varies greatly from plant to plant and has been shown to be conditioned by a single gene* Mulder (1950) has shown that a close positive correlation exists between the uptake of magnesium and that of phosphate. Mention was made earlier of the significantly large number of enzymatic reactions which were stimulated by the presence of magnesium. Since this facet of magnesium's function in plants is very widespread, a tabulated l i s t is appended to illustrate this diversity. Table R o l e o f M a g n e s i u m i n E n z y m e S y s t e m s E N Z Y M E SOURCE SUBSTRATE R E F E R E N C E P h o s p h a t a s e P h o s p h a t a s e P h o s p h o g l u c o m u t a s e H e x o k i n a s e E n o l a s e P y r u v i c o x i d a s e C a r b o x y l a s e N u c l e o t i d a s e s O x a l a c e t i c L e u c y l p e p t i d a s e A s p e r g i l l u s  o x y s a z Y e a s t W i d e l y d i s t r i b u t e d Y e a s t P h o B p h o g l y c e r o m u t a s e Y e a s t Y e a s t P r o t e u s  v u l g a r i s P e a , b e a n , l u p i n , e t c . M o l d s , r i c e , b r a n , s e e d s , e t c . M i c r o c o c c u s  l y z o d e i k t i c u s L e a v e s g l y c e r o p h o s p h a t e * ( M g + + ) ( a t p H 3-4) H 3 P 0 4 f%- g l y c e r o p h o s p h a t e ( M g + + , M n ^ + , * C o - H - ) .3. 4, G l u c o s e - 1 - P : ^ G l u c o s e - 6 - P A T P -( M g - H - , M n - H - , Co++) • A D P + G l u c o s e - 6 - P (Mg++) 3 ? - p h o s p h o g l y c e r i c a c i d —*• 2 - p h o s p h o g l y c e r i c a c i d ( M g + + , Z n - H - ) 2 - p h o s p h o g l y c e r i c a c i d >• e n o l p h o s p h o p y r u v i c a c i d (Mg++) P y r u v i c a c i d • a c e t i c a c i d (Mg++) R . C - C O O H < - R . C = 0 + 00o II I; 2 0 (Mg++) H D i a l y z e d c a r b o x y l a s e i s i n a c t i v e . M g - H - r e a c t i v a t e s . A d e n y l i c a c i d — — — * - a d e n o s i n e + ^-jPO^ T h o s e a c t i n g a t a l k a l i n e p H ' s r e q u i r e M g - H - . COOH I C H 0 f 3 CO + 00 r CO COOH I COOH ( M g - H - ) L e u c y l a m i d e L e u c i n e F o l l e y a n d K a y . E r g e b . E n z y m f o r s c h . 5:159 (1936) M a s s a r t a n d V a n d e n d r i e s s c h e . N a t u r w i s s e n s c h a f t e n 28 :143 ( 1 9 4 0 ) S u t h e r l a n d e t a l . J . B i o l . C h e m . 140:309 ( 1 9 4 1 ) K a l c k a r . J . B i o l . C h e m . 143:299 ( 1 9 4 2 ) W a r b u r g a n d C h r i s t i a n . N a t u r w i s s e n s c h a f t e n 29:589 (1941) W a r b u r g a n d C h r i s t i a n . N a t u r w i s s e n s c h a f t e n 29:589 (1941) S t u m p f . J . B i o l . C h e m . 159:529 (1945) G r e e n e t a l . J . B i o l . C h e m . 135:795 (1940) B o d n a r . B i l c h e m . Z . 73:193 (1916) S u m n e r . E r g e b . E n z y m f o r s c h . 7:105 (1938) K r a m p i t z a n d W e r k m a n n . B i o c h e m ; J . 35:595 ( 1 9 4 1 ) (Mg++) B e r g e r a n d J o h n s o n . J . B i o l . C h e m . 130:655 (1930) 26 The chemical work of Willstatter (1913) early established the presence of magnesium in chlorophyll as well as the empirical formula, C^H^^I^O^Mg, of chlorophyll a. The removal of magnesium from the molecule is possible by treatment with a weak acid, such as oxalic, with the ultimate production of pheophytins. HydrolysiB of chlorophyll a with strong acid removes both magnesium and the phytol groups to yield pheophorbide a. Ruben, Frankel and Kamen (1942) determined that the magnesium is not liberated by strong alkali, nor does pure chlorophyll exchange its magnesium for radioactive magnesium in the presence of magnesium salts. Magnesium plays a role in the phosphate metabolism of plants, and, consequently, in the respiratory mechanism. The work of Jordon and Chibnall (1933) is helpful in determining,:the role played by magnesium in fat synthesis. Working with runner beans (Phaseolue  multiflorus), they isolated the phosphorus containing compounds from cotyle-dons, embryo axes, prophylls and pinnate leaves of the germinating plants, and found magnesium present as a salt of phosphatidic acid. The ratio of this salt to the combined lecithin and cephalin content was 1:20. On germination, the relative amounts of this salt in the growing organs in** creased rapidly until* with mature pinnate leaves, calcium phosphatidate was the chief component salt. It is interesting to note, as the authors point out, that the replacement of magnesium by calcium takes place at the onset of chlorophyll synthesis. In conclusion, one must mention that magnesium is also to be found in vegetable gums, usually as a salt of uronic acid and in seeds as inositol hexaphosphoric acid and magnesium phosphatidate. Analyses reveal that the highest concentration of magnesium occurs where active growth is taking 27 place and nucleoprotelns are "being formed. When "both lecithins and nucleo-protelns are present in the cell, i t is not uncommon to find a higher con-centration of magnesium there. The Role of Calcium The Effects of Ca on Root Growth Haynes and Robbins (1948), using tomato plants, have shown that Ca is necessary for normal root development. Deficient cultures "brought about aberrant root development which was effective in causing malformation and discoloration of tops. Presley and Leonard (1948) demonstrated the importance of Ca in the development of the radicle of cotton seedlings. When calcium is withheld from water cultures, the size of the rootB of plants growing therein is greatly reduced. Reed and Haas (1923) showed that the roots of citrus seedlings, grown in the absence of calcium, were injured as indicated by the gelatinization of the superficial layers of root tissue and their ultimate death under conditions of insufficient supply. It was noted by Bamford (1931) that lateral root development was severely curtailed in low Ca cultures. The same author reports upon studies made.on the deficiency of Ca on the growth and cytological structure of the root tips of young wheat and corn seedlings growing in water cultures. Under such conditions, the cells of the root apices gradually lost a l l their stain** able contents, although ce l l walls remained intact. The protoplasm seemed to undergo a gradual disintegration, until i t completely disappeared. At f i r s t the nucleus remained normal, but eventually i t degenerated into a heterogeneous mass and disappeared. A very complete series of investigations into the effects of calcium on root growth have been conducted by Burstrflm (1952* 195*0 and. i t is his 28 contention that there is a triple division of function of the available calcium absorbed by roots; a minimal amount (10~^ M in the external medium) is necessary for cell division, a tenfold increase in amount is necessary for cell elongation and s t i l l higher concentrations are necessary for the detoxification of hydrogen ions. Canions act, i t would seem, as anti-auxins and as such further the elongation of root cells by their ability to reduce the effective concentration in the rooting medium. The direct relationship between Ca and the uptake of nitrate has been long known and often proved. Skok (19^1) and Eckerson (1932) showed that calcium was necessary to the incorporation, reduction and use of nitrate by plants and that, lacking i t , there is a measurable decrease in reductase activity. Urea and ammonium salts have been shown to be alternative sources of nitrogen which, due to their less oxidized condition, are more readily assimilable by plants otherwise influenced externally by deficiencies of calcium. Jones et al, (1957) found toxicity symptoms of Na and K, rather than deficiency symptoms of Ca, when the exchangeable Ca was relatively low and exchangeable Ha and K relatively high. Ekdahl (as reported in Broyer and Stout, 1959) states that wheat roots in a minus-calcium growth medium will not extend and that, when added, calcium induced extensive root hair formation. He postulates an inhibitory function for H* ions at low base saturation levels. Other Effects of Calcium on Growth With regard to the essentiality of calcium for cell division, the data of Sorokin and Sommer (19^ +0) are proof enough. These workers found that mitosis in apical meristems was seriously hampered by an absence of calcium. 29 The beneficial effect of calcium in mitosis above mentioned must be set against the inhibitory effect of Ca on the ce l l elongation as illustrated by the work of Cooil and Bonner (1957) on Avena coleoptiles. With such material i t was shown that elongation rates were greatly reduced by the presence of calcium salts and that such inhibition was slowly reversed by treatment with calcium-free solutions containing indolacetic acid and rapidly reversed by solutions containing potassium. Chelating compounds, such as BDTA-Na, are known to form complexes with Ca and the introduction of such material would promote elongation by removing the inhibitory calcium. In some cases, a deficiency of calcium has led to a dislocation in the translocation of carbohydrates with the resultant accumulation of abnormal amounts of starch in the tissues. The effects of Ca deficiency are thought to act rather through a disruption of the translocatory system rather than an interference with the actual synthesis of carbohydrate. Nightingale et al . (1931) showed that calcium-deficient plants accumulated large quantities of carbohydrate and they were able to relate this fact to a decrease in nitrate absorption, which, in turn, depressed the rate of incorporation of available carbohydrate into protoplasmic constituents. Much of the calcium in plants is in a fixed condition and so incorpor-ated into organic or inorganic compounds that i t can no longer represent a source for future metabolism. The intercellular secretions of calcium oxalate and the intermolecular position of calcium in the middle lamella are two examples of such immobilization. Kertesz (1951) gives a very f u l l discussion of pectic compounds and treats of methods for qualitative and quantitative estimation of calcium content in them. This well-known im-mobility of Ca once absorbed has lately been verified by Biddulph et a l . 3 0 (1958) in a study of Red Kidney bean. The i n i t i a l delivery of Ca-45 by the transpiration stream was not followed by any recirculation. This is further proof of the theory, consistently held, that calcium is normally immobile in phloem conductive systems. The result of such a conclusion can only mean that, for the normal, healthy growth of plants, a continuous rather than an intermittent supply of calcium is essential. An interesting exception to the above findings, and one that is peculiarly pertinent to the present thesis, is provided by the work of Ferrell and Johnson (1956) who found that there was substantial movement of previously deposited Ca-45 into newly developed buds of western white pine. Considering the specific activity of the radio-active calcium in the foliage and buds at various periods after trunk injec-tion, the one-year-old buds were found to have appreciably more calcium than the foliage. Florell (1956) has noted a distinctive increase in the amount of mito-chondria as calcium supplies increased. Coupling this fact with others previously mentioned, namely cel l elongation, cell division and the uptake of nitrate, one is -led to conclude that these energy-requiring processes, dependent as they are on calcium availability, may suffer more directly from an impaired effectiveness on the part of ce l l mitochondria occasioned by a reduction of this availability. In other words, an adequate supply of calcium in the rooting medium would seem to favor an increased respiratory rate which then results in an acceleration of the endergonic plant reactions mentioned above. The letter's dependence on calcium appearB to be indirect. The stimulatory effect of Ca on K absorption (Albrecht, 19^1)* the inherent tolerance and ability to extract calcium common to plants indigenous to serpentine soils (Walker* Walker and Ashworth, 1955) the ease with which 31 magnesium can substitute for calcium in certain aspects of tung metabolism (Reuther, Embleton and Jones, 1958. Drosdorff, Barrows, Lagasse and Shear, 1955) and. the effect of calcium on the development of root hairs (Cormack, 19**9) have a l l received attention in the recent past. fhe Role of Phosphorus The unique part that phosphorus plays in many of the vital plant func-tions endows i t with an importance which has been fully recognized in the past and has led to an enormous amount of literature on soil availability, uptake, transport in the plant, incorporation into the products of photo-synthesis, its role in carbohydrate and fat metabolism, respiration, etc. In fact, one is hard put to i t to find a functional process in which phos-phorus, as phosphate (POjj,), does not feature largely. By a description of the main groups of inorganic and organic compounds of which i t is a part, i t is hoped that adequate coverage of its numerous functions will result. The review that follows i s freely adapted from accounts of the func-tional role of phosphorus contained in Black (1957)» Amon (1953)» Kornberg (1951), Pirson (1955) and Bonner (1950), to which reference should be made for amplification of some of the statements made. Phosphorus Compounds in Plants 1. Inorganic Phosphate PO^ , unlike the other two anions, N0^ ~~ and SO^ , is not re-duced in plants. It is found in plant and animal as a phosphate radical, never as phosphite or elemental phosphorus. 32 2. Phospholipids Phospholipids are distinguishable from other lipids by being insoluble in acetone. Three groups are known: a. lecithin — glycerol, fatty acids, phosphoric acid, choline b. cephalin — glycerol, fatty acids, phosphoric acid* cholamlne c. sphingomyelin — fatty acid, phosphoric acid, choline and a complex amino alcohol, spingosine. H £ C — O — CO-^R H C — O — C O — R O h^C— O — P — O — CH E.CH a. M = (CH 3): OH OH LECITHIN 3. Phytic Acid Phytic acid is a form of organic phosphate of special interest to plants. It is the hexaphosphoric acid ester of inositol or hexahydroxy-cyclohexane. It is usually present in the form of Ca and Mg salts, known as phytin. Phytin serves as the storage form of PO/j, in seeds which contain very l i t t l e inorganic PO^ . 33 O H o 7 "OH \ / c PHYTIC ACID 4. Phosphorylated Sugars The participation of phosphorus as phosphate, as part of the adenylic acid system, and i n association with hexoses, points up i t s impor-tance for a l l transformations involving carbohydrate anaboliBm and catabolisnu both in the glycolytic cycle and the aerobic Krebs cycle. Its participation in an aerobic pathway of glucose-6-phosphate breakdown v i a ribose-5-phosphate has also been demonstrated. The recognition of the role played by phosphorus i n respiration and photosynthesis constitutes the major advance in plant bio-chemistry in our present age. 34 5.. Nucleoproteins and Nucleic Acid Nucleoproteins constitute a group of organic phosphorus compounds of especial significance to a l l living cells. As their name implies, these compounds are especially associated with cell nuclei. Nucleoproteins are conjugated proteins, i.e.. combinations of "simple" proteins, generally of basic character, with nucleic acid. Nucleic acid is a complex of purine and pyrimidine bases, sugar and phosphoric acid. Nucleoproteins are most intimately concerned with cellular organization, function and reproduction. They constitute a large part of the nucleus and are also present in the cyto-plasm. They are constituents of chromosomes and genes and are thus intimately concerned in the transmission of hereditary characteristics. Nucleic acids are made up of many nucleotides, and the phosphoric acid components of the latter are present in terminal ester linkages which can be split off by enzymatic hydrolysis leaving compounds called nucleosides. r— Nucleotidase (phosphatase) Nitrogenous base + sugar + phosphoric acid NUCLEOSIDE NUCLEOTIDE The nucleotides are usually designated according to the nature of the specific purine or pyrimidine base which they contain, e.g. Adenine nucleotide (Adenine * Sugar *• H^ PO^ ) « Adenylic acid. The corresponding nucleoside is adenosine (adenine' +• sugar). Since the 35 domponent sugars may be either rlbose or desoxyribose, the corresponding designations become ribonucleotide or desoxyribonucleotide and rlbonucleoside and desoxyribonucleoside. It appears that desoxyribonucleic acid occurs only in the nucleus, whereas ribonucleic acid is found in both nucleus and cytoplasm. 6. The Adenylic Acid System The adenylic nucleotides occupy a key position in the storage and transfer of energy in the metabolic reactions of living cells. They perform this function by accepting POj^  groups from metabolic intermediates, binding them in pyrophosphate linkage (P-)-P), and transferring them by reactions termed phosphorylations to other compounds. Adenylic acid is a nucleotide or better a ribonucleotide. Its single POjj, group, linked to riboee by ester linkage* i s not detached in transphbs-phorylation reactions. Adenylic acid combines with two molecules to form another compound of high significance, namely adenosine triphosphate (ATP). H MC c-o o o o N A D E N I N E N-l-C' H , ,~,C—C-O-p-O-vP- O ~ P — OH H O H I R I B O S E A D E N O S I N fr CH A D E N Y L I C A C I D C W ^ P ) OH A D E N O S I N E O I P H O S P H A T E C A D P ) OH A D E . N O S I N E , T R I P H O S P H A T E : C A T P ) 3 6 7. Pyridine nucleotides These compounds are among the most important coenzymes known* DPN (diphosphopyridine nucleotide) and TFN (triphosphopyridine nucleotide) have a similar structure with the exception that the latter has a third phos-phate group attached to the rihose of the adenylic acid moiety of the DPH molecule. A D E N I N E DIPHOSPHOPYRIDDIE NUCLEOTIDE (DPN) 37 DPN and TPN serve, in association with other dehydrogenases, as hydro-gen and electron carriers "by undergoing reversible oxidations and reductions in the nicotinamide part of the molecule as represented below. R R The oxidation-reduction of DPI! and TPN does not involve the PO^  groups of the molecule, It will be noted. Nevertheless, i t is well established that certain dehydrogenases are specific for DPN and others for TPN, and this suggests that the PO^ groups may play a role in the attachment of the coenzymes either to the substrate or to the apoenzyme. The general mode of DPN and TPN oxidation-reduction is presented below. A . H 2 + D P N ^ A + D P N M + H + CorTPN) (orTPNhj) metabolic s u b s t r a t e 38 8. Flavin Nucleotides These are compounds consisting of flavin, ribitol and phosphate. Flavoproteins are enzymes which are a combination of riboflavin phosphate or flavin mononucleotide (FMN) with the appropriate protein. In functioning, flavoproteins are readily reduced by accepting hydrogen from two sources a. reduced coenzymes I or II (DPNHor TFNH) b» other substrates or hydrogen donors such as sugars, aldehydes, amino acids. The reductions can be represented as follows: a) DPNH T B~ + Flavopfcojjein DPN + flavoprotein Hg b) A'Hg t flavoprotein flavoprotein Hg + A. 9. Other Phosphorus Compounds as Prosthetic Groups of Enzymes Uredine-diphospho-glucose (UDPG), an early photosynthate and pos-sible prosthetic group in the synthesis of sucrose, is an important compound in which phosphorus is present. Coenzyme A, which contains adenosine-5-phosphate, two additional phosphate groups, pantothenic acid and a sulfur-containing group, might also be men-tioned. Its fundamental metabolic role is well established. Pyridoxal phosphate has recently been shown to be a coenzyme of amino acid decarboxylases and certain transaminating enzymes. The intimate association of phosphate with photosynthesis, respiration, enzymatic hydrolysis and high energy transformations in plant metabolism makes:;it readily understandable why the early recognition of the essential role that phosphorus plays in plant l i f e has never been questioned but substantiated times without number. 39 The Role of Potassium By way of an introduction to a study of the functional role of potassium in plants, an excerpt from a recent paper by Broyer and Stout (1959) is worthy of mention. 'GPor. many years potassium has been the mysterious macro-nutrient. Por a l l the other macronutrients, incorporation into the structures of proteins, carbohydrates, porphyrins, and analagous components of living matter, make their uses understand-able. With potassium, there are no such compounds known. Even i f there were, there would always remain the question as to why a similar monovalent cation, such as sodium, should not be able to accomplish the same functions as potassium." Early work on potassium nutrition established the fact that, for normal carbohydrate formation to occur, an adequate and sizeable supply of potassium is necessary. Hov/ever, subsequent work on various plants brought to light the fact that a deficiency of potassium was closely correlated with an untoward increase in the concentration of sugars, notably reducing sugars, in affected tissue. In individual cases, however, there are exceptions and discrepancies. There is some doubt as to whether the increased concentration of reduc-ing sugars is not merely associated with the early onset of deficiency and that prolongation of deficiency will result in an ultimate reduction in a l l forms of carbohydrate (1952). Wall (1937t 1940a, 1940b) has suggested that the final drop in carbohydrate content in potassium-deficient plants may be due to a direct need for Z in carbon dioxide assimilation or to the indirect effects on protoplasm brought about by the interference, in K-deficient plants, with nitrogenous metabolism. This latter facet of his argument appears the more likely at present. Buzover (in Pirson, 1955) bas demonstrated that the reported increase in reducing sugar content is explainable on the basis of a marked increase in invertase activity which, he was able to show, occurred in plants grown in a medium deficient in potassium. * E a t o n ( 1 9 5 2 ) . 4o The very complex effects that any deficiency of potassium generates renders i t difficult to define, with any accuracy, its exact metabolic role. Perhaps this is due to the fact that i t has several, and* in a consideration of any one function such as carbohydrate synthesis, one is constantly obliged to consider others such as its effect on photosynthesis* nitrogen metabolism and respiration. If* as is suspected* potassium is involved in the adenylic acid system, in ATP - ADP transpositions in vivo or enzymologically with any phase of carbohydrate synthesis or the incorporative path taken by atmospheric carbon dioxide* then the precise elucidation of its role in plants i s s t i l l unanswered and will remain so until* as is presently being done, some of these reactions and pathways are explained. The contention that a deficiency of potassium must be proven to affect the translocatabillty of sugars already synthesized, thus leading to an excessive and abnormal accumulation, is invalid. The effects of potassium deficiency are sufficiently disruptive of nitrogen metabolism to permit of such an accumulation with l i t t l e or no alteration in translocation rates. When linked with the accelerated respira-tion that occurs in potassium-deficient plants (Gregory and Richards, 1929? Gregory and Sen, 1937. Richards, 1932), there can be l i t t l e doubt of their ability to accumulate such abnormal amounts of carbohydrate in situ. As has been mentioned above, a decrease in potassium supply is closely correlated with a progressive decline in photosynthetic ability (Eaton* 1952). Pirson has listed the effects of Z deficiency in the following manner. 1. Photosynthesis at light saturation a. during deficiency — inhibited b. during early recovery (1-2 hr.) — partially restored 2. Dark respiration (Endogenous) a. during deficiency — markedly increased b. during early recovery — restored 41 3* Short time oxidative assimilation of glucose — lowered 4. Nitrate reduction — inhibited, slowly reversed He has shown that a moderate deficiency can be rectified by an addition of potassium and there results an i n i t i a l rapid increase in photosynthesis (PQ, = Og/CO^ 1) which is followed by a slow but complete recovery of the assimilative mechanism* The accelerated respiratory rate under conditions of potassium deficiency, previously alluded to, is thought to be due to an uncoupling effect of respira-tion from its attendant energy transfers such as one can induce ar t i f i c i a l l y with 2, 4-dinitrophenol and arsenic... Precise details on the mechanisms of this process s t i l l require illumination* Wall (1937)» Eaton (1952) and others have shown that there is a distinct and measurable increase in soluble organic and inorganic nitrogen in E-deficient plants which is matched by a concurrent decline in protein. Low potassium plants have been shown to contain larger than normal amounts of ammonia, amides and amino acid compounds. Just where this potassium inhibition of nitrogen metabolism is effective is not known but the likelihood of an influence in the condensation of amino acids seems stronger than any present evidence directed to a consideration of its effect on reductive amination (Webster and Varner, 195*0-So far the emphasis has been on the effects of potassium deficiency as i t affedts plant metabolism. That this is the case is due to the undeniable absence of any known compound of which E is known to be an integral and inalienable part. Potassium has been everywhere shown to be an ionizable component of any organic compound with which i t is associated. In some lower forms of plant l i f e , even its removal seems to cause l i t t l e reduction in viability. 42 And so one is reduced to a puzzled compliance with the statements originally quoted concerning the functional role of this "mysterious nutrient." 7 Methods of Ar t i f i c i a l Culture The techniques of ar t i f i c i a l culture have proven suitable to the growth of a great many species of plant l i f e * Continuous refinement and adapta-tion of the methods have been suggested in the past and have led to an increasingly wide use of them both experimentally and commercially* Hewitt (1957)i Shive and Bobbins (19^ 0), Wood (19^ 2) and Mitchell (1939a) have re-viewed in some detail the different methods used and the merits of each. The accuracy of the results sought, the number of experimental plants used, the necessity for microchemical control in the nutrient medium, the importance of aeration* the permissible amounts of contaminants* the need for near-natural root development — a l l will govern the selection of the method chosen and the materials employed. The two types of a r t i f i c i a l culture most commonly used are water culture and sand culture. Water Culture If a close control of the nutrient environment is desirable, i t is likely that this method will be most advantageous* Since a l l the elements are in a soluble condition i t is presumed that they are continuously avails-able though, in actual fact, this will depend on the proportionate concen-tration of a given element in the solution and the attendant effects of light, heat and aeration on the metabolic plant processes which allow of its absorption and active uptake. The method is that usually adopted in attempts to assign essentiality to a given element since, apart from the container used and the purity of the water employed as solvent, a strict control can be kept over contamination from external sources. 44 By analysis of the residual solution, i t is possible "by this method to assess differential absorption of nutrient elements. The water-culture technique usually must be so devised as to allow of aeration of the nutrient solution since both root morphology and the ability to absorb mineral elements actively is adversely affected by anaerobic con-ditions. This inherent requirement can often be a decisive argument against its use in extensive commercial applications especially since, to be effective, introduced air must be broken up into very fine bubbles, which again requires special equipment. Ohmasa and Tsutsumi (1950) have shown that for the growth of Cryptomeria .laponica D. Don, such aeration is essential. Their results showed that aerated solutions made for better dry matter production and that, when ions are utilized as a source of nitrogen, aeration is essential. Gail and Long (1935) have noted the effects of soil saturation upon the root morphology of Pinus ponderosa and Pinus contorta and have shown that a r t i f i c i a l aeration of waterlogged soils can do much to correct the abnormalities previously induced. Olson (1944) investigated the possibility of growing forest tree species in solution cultures and was able to grow seedlings of American elm and red pine to proportions which far exceeded seedlings of similar age and species grown under similar experimental conditions in a well-fertilized soil. Seedling weights of the solution-grown elms exceeded those in soil by 410 per cent. Survival of the solution-grown seedlings when transplanted was very good, and was thought to be due to the improved root development shown by seedlings so raised. The solution, whose composition is outlined and differs from that used in the present work only by the inclusion of ammonium nitrate, was shown to be suitable for the growth of hard maple, white ash, catalpa, yellow birch, Norway spruce, white spruce and jack 45 pine in addition to the species mentioned above. A\ 40 per cent reduction in concentration was resorted to with Pinus spp. and found to be adequate for the growth of species with low nutrient demands. The inability of shortleaf pine seedlings to survive in culture solu-tions containing more than 500 p.p.m. 0a is noted by Chapman (l94l). It was concluded that herein lay an explanation for the species being largely restricted in its distribution to sandy. Piedmont soils of low base exchange capacity and reduced calcium content. The author attributes the toxic effects of calcium to an increase in permeability of the protoplasmic mem-branes, which results in a disorganization of the protoplasm in root cells. Hydrogen concentration in nutrient solutions and its effect on growth are discussed in papers by Hoagland and Anion (1938), Arnon, Pratzke and Johnson (1942) and Arnon and Johnson (1942). With certain reservations, i t would seem that, within the relatively wide range of pH between 4 and 8, hydrogen ion concentration -per se is not inimical to the welfare of the plants studied (lettuce, tomato and Bermuda grass). Sand Culture In essence, this method involves the use of an inert substrate for accomodation of the root systems of the test plants which derive their nutrient from salt solutions supplied them. Solid media chosen from in*r eluded quartz sand of varying purity, charcoal, vermiculite and gravel. In each case, the solid chosen functions merely as a support for the plants. Quartz sand, because of its purity and availability in graded particle sizes, is particularly suited to a r t i f i c i a l culture work and is the medium which has found greatest favor. Shive (1920) investigated the effect that 46 sand exerts on the concentrations of nutrients supplied in solution and found that different grades of washed sand gave .no evidence of salt or ion absorption in sufficient amount to alter materially .either the reaction or the total salt concentration of the solution in contact with the solid particles. Unwashed sand, or sand -that was not pretreated with acidified distilled water before use, reduced the total concentration of the solution (three-salt solution) from I.76 to 1.6l .atmospheres in 24 hours. Sand, as a medium in which to study growth and mineral uptake by forest tree species has been favored by many over solution cultures. Some have used both (Walker, Gessel and Haddock, 1955). The more natural conditions, that sand affords for the growth and development of root systems has led to its wider adoption. This has been particularly so in forest tree nutrition investigations where the gross effects of macrometabolic deficiency have been mainly studied. An unspoken belief that the applicability of sand culture results will, from the similarity that exists between sand and soil, be enhanced, has led to its wider adoption. Among those who have found this method useful in forest tree nutrition work are Addoms (1937)» Day and Bobbins (1950), Walker, Gessel and Haddock (I955)t Hobbs (1944), Krajina (1958, 1959). Krajina, Murison and Davidson (1959). Mitchell (1939a, 1939b), Pessin (1937)» Purnell (1958) and Worley et al . (194-1). Walker, Gessel and Haddock (1955) used a 20-30 mesh silica sand which had been washed with aqua regia and rinsed thoroughly with distilled water before use. Mitchell (1939a) in pot culture work used white Ottawa sand, 9 9 » 8 9 per cent pure silica, the particles of which were nearly spherical in shape. Size class distribution of the particles was as follows: 4? Through a 10 and on a 20 mesh screen — 0.3$ II II 20 " " « 28 » » — 16.2$ ti n 28 " «' » 35 » " — 74.0$ II " 3 0 " " " 4o " " — '9.5$ The pore volume was 39 per cent of total volume. In subsequent work (1939b), the same author reports using two kinds of sand, both pure silica. Pots were fi r s t f i l l e d to a depth of 5 inches with No. 4 Columbia sil i c a sand, which is angular and rather coarse. A mixture of 2 parts (by volume) of the Columbia silica and 3 parts of Ottawa, which is more rounded and spherical, was used in the upper parts of the pot. Drainage experiments proved this to be the best mixture. Methods for cleaning sand in small and bulky amounts, before and after use, are very extensively discussed by Hewitt (1957). Methods of applying solution to the sand cultures vary considerably but may be classified under three main heads, namely 1. Slop culture 2. Drip culture 3. Irrigation 1. Slop culture'involves nothing more than the addition of the nutri** ent solution to the sand surface by watering can and its subsequent collec-tion in drainage tanks provided. 2. Drip culture, usually by gravity, has been used by many people, among them Walker, Gessel and Haddock (1955)» and Hobbs (1944). Paddick (1944) and Meyer and Anderson (1955) describe useful and inexpensive methods of conducting small-scale experiments by this means. 3. Irrigation involves supplying nutrient solution, usually from 48 below, to the sand via conduits which have access to the sand in the crock by holes let into its base or lower side* The solution is allowed to flood to or near the surface where i t is stopped automatically or manually. Sub-sequent drainage is usually by gravity and the run-off is led to tanks or crocks which contain pumps primed to recirculate the' solutions twice or thrice daily. This method has the advantage of being adaptable to large commercial sand culture enterprises and is widely used in such cases. The use of sand and gravel cultures in horticultural greenhouses is widespread and there are many papers dealing with the extensive installation and use of sand pits and the methods for supplying solutions to them (Ellis and Swaney, 194?; Dunlap, 1936; Eaton, 1930; Eaton, 1936 and Laurie and Eiplinger, 1940). The extent to which such methods will be used in the future is largely a matter of economics. 49 VI The Composition and Effectiveness of Nutrient Solutions Historical Development and Use of Nutrient Solutions Sachs (i860), believing that the water culture method proposed by de Saussure and Liebig eliminated adhesion, absorption and other inter-fering effects encountered in soils, proposed that i t was possible to pre-pare a nutrient solution which would contain a l l the necessary elements for plant growth* He proposed a solution made up of two parts Part A (without phosphorus) contained MOy NaCl, CaSO^, MgSO^ , EeSO^ and MnSO^  Part B contained NagHPG^ , NaCl, KgSOjj, and NagSOj,,. This work was followed by that of Knop (1862). He» together with Sachs, was largely responsible for establishing a r t i f i c i a l nutrition on a sound, definable basis, and gave early credence to the idea that soilless culture of plants offered a useful means of dealing with many problems of mineral nutrition. Out of a continued series of works by these two workers and others that quickly followed their lead (Nobbe and Siegert, Wolf, Rautenberg, Mhn), • certain important results emerged. It was found that the optimal salt con-centration of nutrient solutions was of the order of 0«3 percent or lower and that, low as this might seem, for adequate and continuous ayailabilltyj such a salt solution had to be renewed frequently. Other facts which they were able to record, and which have since been corroborated, make mention of the selective ability of different plants of one species to absorb varying amounts of nutrients from the solution depending on size and maturity and the apparent wide latitude of concentration of the solution within which the plants seem to be able to make satisfactory growth. 50 Following upon the work of these early researchers, there developed a period of much active inquiry and investigation into the mineral requirements of various crop plants, the essentiality of the various mineral elements for growth and the relationships that exist between foliar content and mineral supply. Much attention was given to the concept of "physiological balance" between nutrients in the solution and i t was widely felt that imbalance would have deleterious effects on growth. A tabulated l i s t of some of the more commonly used nutrient solutions and their molecular composition is of interest. Table III A Comparison of the Molecular Composition of the More Commonly Employed Nutrient Solutions (after Tottingham, 191k) Author Total salt cone. { gram mols/liter E Ca Mg NO3 PO4. s o ^ Crone 0.200 .0050 .0022 .0010 .0050 .0017 .0020 Detmer 0.175 .0062 .0061 .0021 .0122 .0014 .0021 Hartwell 0.046 .0008 .0017 .0008 .0030 ,0005 .0008 Knop 0.140 .0035 .0049 .0017 .0117 .0015 .001? Pfeffer 0.150 .0033 ,004-9 .0017 .0117 .0015 .0017 Sachs 0.275 .0100 .0098 .0045 .0099 .0032 .0079 Schimper 0.416 .0114- .0129 .0044 .0311 .0031 .0044 Schreiner 0.025 .0007 .0001 .0000 .0020 .0001 .0003 Tollens 0.190 .0043 .0060 .0020 .0146 .0018 .0020 51 The comparative data of Table III show that great differences exist in the molecular concentrations and in the proportions of the nutrient salts. Excluding Sohreiner's, which contains no magnesium* the ratio of K is seen Mg to vary from 1:1 to 5:1, that of Ca from 2:1 to 3:1, that of NO3 from 3:1 Mg POZj, to 10:1 and that of HO3 from 1.3:1 to ?:1. There seems to have been l i t t l e SO4 agreement on what constituted "physiological balance." Tottingham (1914). after an exhaustive study of a l ! possible combina-tions of several of the above prescriptions, proposed a modified Knop's solu-tion as that which will most likely result in good dry weight production of test plants. Its composition is as follows: EH2P0^ - 0.0130M; Ca ( r r 0 3 ) 2 - 0.0144M MgSOjj, - 0 .0145M; KUO3 - 0.0049M. Shive (1915) proposed a solution using three salts only. It contained, however* a l l the elements needed for the growth of higher plants, except iron which had to be added separately, and was found not to precipitate when mixed in solution. The solution contained only KR^ PO^ , CaCNO^^ and MgSOjj,. The author claimed that* using buckwheat, there was a measurable improvement in growth in the, three-salt solution.as compared to Knop's solution or Tottingham's modification of i t . The controversy over "ideal" concentrations, "balanced solutions" and "average composition" continued unabated until there appeared a paper by Hoagland and Arnon (194-1) which made a cool and reasoned appraisal of the "best solution" quest and found i t to be misplaced and useless. In a rather succinct manner they pointed out that a. Under natural conditions plants do not grow in soil solutions of fixed composition; rather, the contrary is true. 52 b. Plant composition is a yardstick which is "by no means infallible in devising nutrient solutions, Not only do different species vary proportionately with regard to their Inorganic constituents but plants of the same species may exhibit wide variation in this regard with maturity. c. In addition to the considerations advanced above* the authors question the wisdom of predicating the composition of a nutrient solution on the mineral analysis of a plant that is itself dependent on the composition of the nutrient solution. By dint of some devastating reasoning, the same writers point out that to insist on stringent control over nutrient solution composition in the face of the relatively wide accommodation exhibited by plants towards fluc-tuations in osmotic concentration* pE value and salt concentration is i l l o g i -cal and unnecessary. They would emphasise rather an adequate supply of a l l nutrients required for plant growth* the avoidance of contamination in solu-tions designed to test the effects of deficiency upon growth and the adoption of a method of preparation and application best suited to the conduct of the experiment (Arnon, 1938 and Hoagland and Arnon, 1938)• They conclude by emphasizing the fact that the strict control of nutrient solution is made doubly difficult by the differential absorption of nutrients by plants. Such an effect results in considerable change in proportionate concentration shortly after use and the amount of such change is not subject to control. With the above in mind they propose a nutrient solution which they 53 found to be satisfactory for the culture and growth to maturity of tomato plants and which has since been widely adopted for work of a similar nature with other species. The solution composition is as follows: EHgPO^ - 0 .005M; EN03 - 0.005M; Ca ( N 0 3 ) 2 - 0.005M; MgSO^  - 0 .002M. Iron and micronutrients are added separately. It is a modification of this solution that was used by Gessel and Walker (195^) in a study of the mineral requirements of Thuja -plicata Donn. and a similarly modified composition was adopted in the present experiment. The Effect of Dilution on the Uptake of Ions Eaton ( 1 9 4 1 ) , Hoagland and Arnon ( 1 9 3 8 ) , Magistad, Ayers, Wadleigh and Gauch (1943) and Wall and Hartmann (1942) have variously published on the effects of nutrient concentration on water uptake and plant growth. It was shown by some of the early investigators that high concentrations of salt : in solution were not.conducive to. growth. Under conditions favoring active salt absorption, much greater amounts of ions, relative to concentration, are absorbed from very dilute solutions than from those of higher concen-tration, within a limited time. Absorption curves, at least for mobile ions like potassium, when plotted against concentration in the nutrient solution, rise very steeply in the low concentration range 0 .0001 to 0.001M. It has been found (Magistad, Ayers, Wadleigh and Gauch, 1943) that there is a fairly close correlation between dry matter production and oBmotic concentration (atmospheres) of the nutrient solution. 5 4 loo 80 60'-Relative Weight 40 (gme) 0.4 . " a-4 4-4 Osmotic concentration (atmos.) Figure 2 , The Relationship "between Relative Weight and Osmotic Concentration of Nutrient Solutions (after Magistad et a l . (1943) ) The relationship is almost as good between yield and conductance of the culture solution. Injury resulting from increased salt concentration is likely to he aggravated at high temperature. A "split root" experiment using corn (Zea Mays) conducted by Eaton (1941) illustrates the effectB of dilution on growth. He was able to show that more roots developed in the dilute solution regardless of what salt was reduced in amount to bring about such differences in concentration. Roots developed in dilute solutions were 1.6 times heavier than those grown in con-centrated solutions. Water uptake from the dilute solutions was alBO greater. Effects of Light and Temperature on Nutrient Uptake from Culture Solutions The principle that salt, accumulation is dependent upon metabolic activity suggests that the process of accumulation should have a high temperature coefficient over certain ranges of temperature. The Q^Q values for salt accumulation by excised roots have been shown to be of a high order ( 2»5 -5»0 ) between 6 and 24 degrees centigrade. Similarly high coefficients have been obtained with entire plants (Hoagland and Broyer. 1 9 3 6 ) . 55 Hayward and Long ( 1 9 4 1 ) , ^release and Livingston ( 1 9 2 4 ) and Trelease and Trelease ( 1 9 2 6 ) have shown that environmental conditions, notably tem-perature and light, may radically m o d i f y the action of salt solutions on plants. That this is so is not surprising when one considers that aerobic respiration in the root cells, upon which salt accumulation is dependent* is very largely conditioned by carbohydrate supply from aerial o r g a n B . Any conditions which markedly reduce the rate of photosynthesis, increase the rate of respiration or hinder the downward translocation of elaborated mater-ials will cause a diminution in the rate of salt accumulation. o 3 +» r-i 6 o 4 3 POTASSIUM / • / N l T R A T t / — - ^ O 1 1 1 M A U D E 18 Q £<} 30 O 6 l£ Temperature, 0 rC Figure 3 Relation between Temperature and Ion Accumulation (after Hoagland and Broyer (1936)) Root Aeration and Its Effect on Ion Uptake Most convincing evidence has been presented by Hoagland and Broyer ( 1 9 3 6 ) , Steward, Prevot and Harrison ( 1 9 4 2 ) and others of the necessity of an adequate oxygen supply for nutrient absorption. The former have shown that sand cultures and aerated water cultures gave considerably higher yields of fruits of tomato than a well-fertilized soil 56 in good physical condition under similar conditions of light and temperature. The suggestion is put forward that a limiting factor in nutrient absorption in soils may be the inadequate supply of Og and the inhibiting effect of excessive COg in the root vicinity. It is well to note* however* that the oxygen requirement of plants is extremely variable and there are evidences that some plants* e.g. willow, may have auxiliary means of circumventing anaerobic conditions in the rooting medium. Instances have been reported where excessive aeration of absorptive roots is. damaging. The detrimental effects of this treatment are magnified by increased temperature. It may be pertinent to our present discussion to recall that, for ade-quate amounts of water to be absorbed, a similar aeration of the roots is necessary. PART I I 57-I O b j e c t o f t h e P r e s e n t E x p e r i m e n t T h i s s t u d y w a s d e s i g n e d t o t h r o w s o m e l i g h t u p o n t h e n u t r i t i o n a l r e q u i r e m e n t s o f c e r t a i n c o m m e r c i a l l y i m p o r t a n t s p e c i e s o f t h e w e s t e r n c o n i -f e r o u s f o r e s t s o f C a n a d a . S u c h a n e n d e a v o u r w a s n o t w i t h o u t p r e c e d e n t . O t h e r s h a v e u n d e r t a k e n s i m i l a r s t u d i e s i n t h e p a s t a n d h a v e e l i c i t e d m u c h o f i n t e r e s t c o n c e r n i n g s o i l f e r t i l i t y l e v e l s c o n d u c i v e t o t h e b e s t g r o w t h o f v a r i o u s t r e e s p e c i e s , t h e e f f e c t o f s o i l a m e n d m e n t s o n t h e g r o w t h o f t r e e s i n f o r e s t s t a n d s , t h e i m p o r t a n c e o f m i c r o n u t r i e n t s f o r t h e s u c c e s s o f a r t i -f i c i a l l y e s t a b l i s h e d p l a n t a t i o n s a n d t h e r e l a t i v e p e r f o r m a n c e o f t r e e s p e c i e s u n d e r c o n d i t i o n s o f n u t r i t i o n a l s t r e s s . A p r e f e r e n c e f o r t h e l a t t e r t y p e o f s t u d y h a s e m e r g e d a m o n g i n v e s t i g a t o r s h a v i n g b e e n g i v e n o r i g i n a l i m p e t u s b y t h e v a l u a b l e w o r k o f M i t c h e l l (1939 a )• P e s s i n w o r k i n g w i t h l o n g l e a f p i n e (1937), H o b b s w i t h p i t c h , r e d , e a s t e r n w h i t e a n d s h o r t l e a f p i n e s ( 1 9 4 4 ) , W o r l e y e t a l . w i t h s p e c i e s o f C a t a l p a , A i l a n t h u s a n d U l m u s ( 1 9 4 1 ) , A d d o m s w i t h l o b l o l l y p i n e (1937), S t o a t e w i t h P i n u s r a d i a t a (1938), V a n G o o r w i t h J a p a n e s e l a r c h (1956), H o w e l l w i t h p o n d e r o s a p i n e o r w e s t e r n y e l l o w p i n e a c ^ w * ^ 1 4 m e r i a j a p o n i c a (1956), P u r n e l l w i t h P i n u s r a d i a t a (1958), a n d W a l k e r e t a l . w i t h w e s t e r n r e d c e d a r (1955) h a v e a l l h a d r e c o u r s e t o m e t h o d s o f a r t i f i c i a l c u l t u r e w h e r e i n c e r t a i n e l e m e n t s c o n s i d e r e d e s s e n t i a l t o g r o w t h h a v e b e e n s u p p l i e d i n d e f i c i e n t a m o u n t i n o r d e r t h a t , b y n o t i n g s p e c i e s r e s p o n s e t o s u c h d e f i c i e n c i e s , some m e a s u r e o f t h e r e l a t i v e e s s e n t i a l i t y o f t h e s e m a j o r e l e m e n t s f o r t h e g r o w t h o f t h e s e s p e c i e s m a y b e o b t a i n e d . T h e m e t h o d s a d o p t e d i n t h e p r e s e n t s t u d y a n d t h e i n i t i a l i d e a f o r u n d e r t a k i n g i t came f r o m t h e w o r k o f K r a j i n a (1958) w h o , j u s t p r e v i o u s t o t h e p r e s e n t i n v e s t i g a t i o n , s t u d i e d t h e e f f e c t s o f m a c r o n u t r i e n t d e f i c i e n c y (1932), Wemec w i t h S c o t s p i n e (1936, 1942), M i y a z a k i e t a l . w i t h C r y p t o -58. o n t h e g r o w t h o f c o a s t a l D o u g l a s - f i r , w e s t e r n r e d c e d a r , S i t k a s p r u c e a n d w e s t e r n h e m l o c k u s i n g s a n d c u l t u r e t e c h n i q u e s t h r o u g h o u t . T h e g r o w t h o f c o n i f e r s i n a r t i f i c i a l c u l t u r e h a s h i t h e r t o b e e n s h o w n t o h e a s g o o d a s a n d , m o r e o f t e n , b e t t e r t h a n t h a t o b t a i n e d i n s o i l s t h a t a r e O l s o n k n o w n t o b e h i g h l y f e r t i l e ( 1 9 4 4 ) . T h e t e c h n i q u e , t h e r e f o r e , p r o v i d e s a m e a n s o f c i r c u m v e n t i n g t w o o f t h e m o s t p e r s i s t e n t o b s t a c l e s t h a t a t t e n d a n y i n v e s t i g a t i o n i n t o t h e g r o w t h o f f o r e s t t r e e s i n t h e i r n a t u r a l e n v i r o n m e n t : b y r e m o v i n g t h e t e s t p l a n t s t o t h e g r e e n h o u s e a n d g r o w i n g t h e m i n a c o n -t r o l l e d m e d i u m f r e e f r o m c o m p e t i t i o n , o n e i s a b l e t o e l i m i n a t e m a n y o f t h e f a c t o r s t h a t m a k e t h e i n t e r p r e t a t i o n o f c a u s a l r e l a t i o n s h i p s d i f f i c u l t ; b y p l a c i n g t h e t r e e s u n d e r g l a s s t h e y m a y b e s u b j e c t e d t o c l i m a t i c c o n d i t i o n s t h a t i n c r e a s e t h e i r r a t e o f g r o w t h . T h u s t h e n a t u r a l c o m p l e x i t y o f t h e e n v i r o n m e n t a n d t h e s l o w r a t e o f g r o w t h a r e m o d i f i e d i n a m a n n e r t h a t r e n -d e r s e x p e r i m e n t a t i o n e a s i e r . H a v i n g d e c i d e d u p o n t h e m e t h o d s t o b e u s e d , t h e r e r e m a i n e d t h e q u e s t i o n o f w h a t e f f e c t s t o l o o k f o r a s e v i d e n c e s o f m a c r o n u t r i e n t d e f i c i e n c y . M o r p h o l o g i c a l d i f f e r e n c e s w e r e e x p e c t e d a n d l o o k e d t o a s i n d i c e s u p o n w h i c h t o b a s e c o n c l u s i o n s c o n c e r n i n g t h e d e g r e e o f e s s e n t i a l i t y o f t h e v a r i o u s e l e m e n t s f o r t h e g r o w t h o f t h e s p e c i e s s t u d i e d . N u t r i e n t c o n c e n t r a t i o n s d e c l i n e u n d e r c o n d i t i o n s o f d e f i c i e n t n u t r i t i o n . P l a n t a n a l y s e s h a v e i n d i -c a t e d t h a t t h e s e n u t r i e n t c o n c e n t r a t i o n s a r e o f t e n h i g h l y c o r r e l a t e d w i t h t h e a v a i l a b i l i t y o f t h e v a r i o u s e l e m e n t s i n t h e s o l u t i o n s s u p p l i e d . T h e r e i s a n i n c r e a s i n g t e n d e n c y a m o n g t h o s e e m p l o y i n g m e t h o d s o f a r t i f i c i a l c u l -t u r e , p a r t i c u l a r l y i n a g r o n o m y , t o i n v e s t i g a t e t h e u l t i m a t e e f f e c t s o f n u t r i e n t d e f i c i e n c y b y a t t e m p t i n g t o a n a l y z e t h e c o m p o s i t i o n a n d c o n t e n t o f o r g a n i c c o m p o u n d s t h a t a r e a p r o d u c t o f ' . p l a n t m e t a b o l i s m . V e r y o c c a s i o n -a l l y , a s w i t h p o t a s s i u m , t h e v a r i o u s m a c r o e l e m e n t s s e e m t o f u n c t i o n i n t h e 59-p l a n t w i t h o u t b e i n g i n c o r p o r a t e d , i n t o a n y o r g a n i c c o m p o u n d b u t i t i s c o m m o n e r f o r t h e s e e l e m e n t s t o b e a n e s s e n t i a l p a r t o f o n e o r o t h e r o f t h e m o r e i m p o r -t a n t o r g a n i c p l a n t c o n s t i t u e n t s a n d f o r a n y d e f i c i e n c y o f t h e m t o a l t e r t h e a n a l y z a b l e a m o u n t s o f t h e s e c o m p o u n d s . T h i s u l t i m a t e i n v o l v e m e n t o r m o d e o f f i n a l i n c l u s i o n i n t o t h e m e t a b o l i s m o f a n o r g a n i s m w a s c o n s i d e r e d t o b e t h e m o s t s i g n i f i c a n t p h a s e o f i n o r g a n i c n u t r i t i o n a n d t h e o n e w h e r e t h e e f f e c t s o f a n y a r t i f i c i a l l y i m p o s e d d e f i c i e n c y w o u l d b e m o s t a m e n a b l e t o a n a l y s i s . E a t h e r t h a n a t t e m p t t o m e a s u r e t h e i n o r g a n i c c o n t e n t o f t h e v a r i o u s e l e m e n t s i n t h e f o l i a g e o f t h e t r e e s g r o w n i n d e f i c i e n t c u l t u r e , t h e r e f o r e , p r e f e r -e n c e w a s g i v e n t o m e t h o d s o f a n a l y s i s w h i c h w o u l d m e a s u r e t h e e f f e c t o f m a c r o -n u t r i e n t d e f i c i e n c y o n t h e c o n t e n t o f r e d u c i n g s u g a r s , t h e c h l o r o p h y l l c o n -t e n t a n d t h e s p e c i f i c g r a v i t y o f t h e w o o d . T h e m o s t s t r i k i n g e v i d e n c e o f m a c r o n u t r i e n t d e f i c i e n c y i s i n t h e c h l o r o -t i c a n d n e c r o t i c s y m p t o m s t h a t d e v e l o p o n t h e f o l i a g e . D e s c r i p t i v e t e c h -n i q u e s n o w e x i s t w h i c h p e r m i t o n e t o d e f i n e p r e c i s e l y t h e s e v a r i o u s c o l o r a b e r r a t i o n s a n d i t w a s d e c i d e d t h a t e v e r y u s e s h o u l d b e m a d e o f t h e m i n t h e p r e s e n t s t u d y . M u c h a s t h e y i m p r o v e t h e a c c u r a c y o f v i s u a l o b s e r v a t i o n , t h e s e n e w m e t h o d s u s i n g s t a n d a r d c o l o r k e y s a n d a c o d i f i e d s e r i e s o f c o l o r d e s i g n a t i o n s a r e r e i n f o r c e d t o a c o n s i d e r a b l e d e g r e e b y t h e u s e o f c o l o r e d p h o t o g r a p h s . I t w a s i n t e n d e d t h a t t h e s e s h o u l d b e t a k e n i n c o n s i d e r a b l e n u m b e r t h r o u g h o u t t h e c o u r s e o f t h e e x p e r i m e n t a n d f u n c t i o n a s a v a l u a b l e v i s u a l r e c o r d o f t h e e f f e c t s o f m a c r o n u t r i e n t d e f i c i e n c y o n c o n i f e r o u s g r o w t h . T h e r e r e m a i n e d t h e c h o i c e o f s p e c i e s f o r t h e e x p e r i m e n t . I t w a s d e c i d e d t o s e l e c t c e r t a i n o f t h e m o r e i m p o r t a n t c o n i f e r o u s s p e c i e s t h a t c h a r a c t e r i z e t h e f o r e s t s o f t h e C o l u m b i a E i v e r b a s i n o f B r i t i s h C o l u m b i a . T h i s c h o i c e w a s m a d e f o r r e a s o n s t h a t f o l l o w . 60. 1. A s a g r o u p , t h e s e s p e c i e s g r o w t o g e t h e r n a t u r a l l y o n a w i d e v a r i e t y o f s i t e s a n d s o i l s . 2 . L i t t l e i s k n o w n c o n c e r n i n g t h e i r n u t r i t i o n a l r e q u i r e m e n t s o r t h e s o i l s u p o n w h i c h t h e y g r o w . J . T h e w r i t e r i s w e l l a c q u a i n t e d w i t h t h e m , h a v i n g w o r k e d f o r a n u m b e r o f y e a r s i n t h e r e g i o n w h e r e t h e y g r o w . 4. B e c a u s e o f f u t u r e c o m m e r c i a l d e v e l o p m e n t s i n t h e C o l u m b i a R i v e r r e g i o n , s c i e n t i f i c i n f o r m a t i o n o n o n e o f t h e m a j o r r e s o u r c e s i n t h e a r e a w o u l d b e v a l u a b l e . I t w a s d e c i d e d t o u s e a s e x p e r i m e n t a l g r o w i n g s t o c k i n d i v i d u a l s o f f o u r s p e c i e s , E n g e l m a n n s p r u c e [ P j L c e a e n g e l m a n n i i ( P a r r y ) E n g e l m . ] , w e s t e r n w h i t e p i n e ( P i n u s m o n t i c o l a D o u g l . ) , p o n d e r o s a p i n e ( P i n u s p o n d e r o s a D o u g l . ) , a n d t h e i n t e r i o r v a r i e t y o f D o u g l a s - f i r [ P s e u d o t s u g a m e n z i e s i i v a r . g l a u c a ( M i r b . ) F r a n c o ] . S i n c e c o n s i d e r a b l e e x p e r i e n c e w a s a t h a n d c o n c e r n i n g t h e g r o w t h o f t h e c o a s t a l v a r i e t y o f D o u g l a s - f i r i n a r t i f i c i a l c u l t u r e a n d s i n c e t h e r e s e e m e d t o b e m u c h v a l u e i n a c o m p a r i s o n b e t w e e n t h e t w o v a r i e t i e s o f t h i s s p e c i e s , i t w a s d e c i d e d t o i n c l u d e c o a s t a l D o u g l a s - f i r [ P s e u d o t s u g s  m e n z i e s i i ( M i r b . ) F r a n c o v a r - m e n z i e s i i ] i n t h e p r e s e n t s t u d y . I n s u m m a r y , t h e n , t h e p r e s e n t e x p e r i m e n t w a s d e s i g n e d t o m e a s u r e t h e e f f e c t s o f m a c r o n u t r i e n t d e f i c i e n c y o n t h e g r o w t h o f f i v e s p e c i e s , c o a s t a l D o u g l a s - f i r , i n t e r i o r D o u g l a s - f i r , E n g e l m a n n s p r u c e , p o n d e r o s a p i n e a n d w e s t e r n w h i t e p i n e . T h e e f f e c t s o f a r t i f i c i a l l y i n d u c e d d e f i c i e n c e s w e r e t o b e n o t e d o n . t h e m o r p h o l o g y o f t h e t e s t p l a n t s , t h e i r f o l i a r c h a r a c t e r -i s t i c s a n d t h e a b e r r a n t c o l o r s d e v e l o p e d , t h e c o n c e n t r a t i o n o f t h e c h l o r o -p h y l l s i n t h e f o l i a g e , t h e d e n s i t y o f t h e w o o d a n d t h e c o n t e n t o f r e d u c i n g s u g a r s . 61. I I M a t e r i a l s a n d M e t h o d T h e e x p e r i m e n t w a s c o n d u c t e d i n t h e h o r t i c u l t u r a l g r e e n h o u s e s l o c a t e d o n t h e c a m p u s o f t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , V a n c o u v e r , a n d l a s t e d f r o m F e b r u a r y 20, 1958 t o S e p t e m b e r 15, 1959, a p e r i o d o f a l m o s t n i n e t e e n ^ m o n t h s . 1. M a t e r i a l s A b e n c h 50 f e e t l o n g a n d 5 f e e t w i d e w a s u s e d , a n d o n i t w e r e p l a c e d 295 M e d a l t a g l a z e d s t o n e c r o c k s o f 1 - g a l l o n c a p a c i t y , a r r a n g e d b y t r e a t m e n t a n d c o n t e n t a s i n d i c a t e d b e l o w ( F i g . 4 ) . N o . o f C r o c k s C o n t e n t s S p e c i e s T r e a t m e n t 4 2 S a n d c o a s t a l D o u g l a s - f i r S o l u t i o n s 4 2 S a n d i n t e r i o r D o u g l a s - f i r S o l u t i o n s 4 2 S a n d p o n d e r o s a p i n e S o l u t i o n s 4 2 S a n d w e s t e r n w h i t e p i n e S o l u t i o n s 4 2 S a n d E n g e l m a n n s p r u c e S o l u t i o n s 5 215 S u b t o t a l S a n d a l l f i v e s p e c i e s D i s t i l l e d w a t e r 16 S o i l s c o a s t a l D o u g l a s - f i r D i s t i l l e d w a t e r 16 S o i l s i n t e r i o r D o u g l a s - f i r D i s t i l l e d w a t e r 16. S o i l s p o n d e r o s a p i n e D i s t i l l e d w a t e r 16 S o i l s w e s t e r n w h i t e p i n e D i s t i l l e d w a t e r 16 80 S u b t o t a l S o i l s E n g e l m a n n s p r u c e D i s t i l l e d w a t e r 295 G r a n d t o t a l E a c h s p e c i e s l o t o f 4 2 c r o c k s c o n t a i n e d 6 r e p l i c a t i o n s f o r e a c h o f t h e 7 s o l u t i o n t r e a t m e n t s . E a c h o f t h e s p e c i e s l o t s o f 16 s o i l c r o c k s c o n t a i n e d F i g . k. General view of the experiment showing arrangement of crocks on "bench and raised "bench supporting reservoir crocks of nutrient solution. (Photo: K r a j i n a ) Pig. 5' General view of the experiment showing longitudinal conduits, clamps and drainage crocks for used solutions, ( p h o t o : Krajina) 62. 4 r e p l i c a t e s f o r e a c h o f t h e f o u r s o i l t y p e s u s e d ( r a w h u m u s A Q , i l l u v i u m B , d u f f m u l l A Q , m e l a n i z e d a o i l A - | ) . M i t c h e l l G l a z e d c r o c k s w e r e u s e d t o p r e v e n t n u t r i e n t l o s s (1939a) * C r o c k s w e r e p r o v i d e d w i t h h o l e s l o c a t e d l o w o n t h e s i d e i n t o w h i c h w e r e i n s e r t e d N o . 6-1/2 h o l e d r u b b e r s t o p p e r s c o n t a i n i n g P y r e x g l a s s t u b i n g , t h e i n n e r o p e n i n g o f w h i c h w a s c o v e r e d b y p l a s t i c i n s e c t - m e s h t o p r e v e n t s a n d l e a k a g e . S i n c e i n t e r n a l c r o c k d i m e n s i o n s v a r i e d s o m e w h a t , a w e i g h e d a m o u n t o f O t t a w a w h i t e s i l i c a s a n d , s p h e r i c a l l y p a r t i c l e d , a n d g r a d e d t o p a s s c o m p l e t e l y t h r o u g h a 20-30 m e s h , w a s a d d e d t o e a c h c r o c k . S y n t h e t i c , t h i n - w a l l e d , N e o p r e n e t u b i n g 1_/, w h i c h i s s u l f u r - f r e e , w a s u s e d t o c o n d u c t t h e s o l u t i o n s t o t h e s a n d c r o c k s . T - j o i n t s o f b l a c k p a i n t e d P y r e x t u b i n g d i v e r t e d s o l u t i o n f l o w f r o m t h e m a i n f e e d i n g c h a n n e l s , t h a t r a n t h e l e n g t h o f t h e b e n c h , i n t o t h e a p p r o p r i a t e c r o c k s l o c a t e d i n r o w s o f s e v e n a c r o s s t h e w i d t h o f t h e b e n c h . C a r e w a s n e c e s s a r y i n l a y i n g t h e t u b i n g t o p r e v e n t t h e c r e a t i o n o f a i r p o c k e t s w h i c h m i g h t h a m p e r f r e e f l o w o f t h e s o l u t i o n . C o n s i d e r a b l e d i f f i c u l t y w a s e x p e r i e n c e d i n o b t a i n i n g a n e f f i c i e n t s e a l a t t h e r u b b e r - s t o p p e r e d c r o c k h o l e . L e a k a g e f r o m s p a c e s b e t w e e n s t o p p e r a n d c r o c k o r f r o m s p a c e s b e t w e e n t h e g l a s s t u b i n g a n d t h e s t o p p e r w a s c o m m o n . T h e m a t t e r w a s e v e n t u a l l y s o l v e d b y s e a l i n g t h e s e s p a c e s w i t h a m i x t u r e o f v e r y f i n e p u m i c e a n d l i n s e e d o i l . T h i s s e a l r e m a i n e d e f f e c t i v e t h r o u g h o u t t h e d u r a t i o n o f t h e e x p e r i m e n t . S o l u t i o n s w e r e g r a v i t a t i o n a l l y f e d t o t h e c r o c k s o n t h e b e n c h f r o m 5 - g a l l o n c r o c k s o f s i m i l a r m a n u f a c t u r e e l e v a t e d t o a h e i g h t o f 6 f e e t a t t h e i r b a s e ( F i g . 5). T h e d i f f e r e n c e i n h e i g h t b e t w e e n t h e r e s e r v o i r s a n d t h e c r o c k s w h i c h t h e y s u p p l i e d w a s a p p r o x i m a t e l y 3 f e e t . I n a l l , 18 s u c h c r o c k s w e r e u s e d t o c o n t a i n t h e s o l u t i o n s u p p l y a n d d i s t i l l e d w a t e r . E a c h w a s p r o v i d e d w i t h a l i d t o r e d u c e c o n t a m i n a t i o n f r o m t h e a t m o s p h e r e . T h e y d i d n o t p r e v e n t i t . Jj I t e m 14-171, F i s h e r S c i e n t i f i c C o . , 2 4 5 C a r l a w , T o r o n t o 8. 1952. 63. 2 . S o l u t i o n s T h e c o m p o s i t i o n o f t h e s o l u t i o n s u s e d w a s a s f o l l o w s : T a b l e I V C o m p o s i t i o n o f S a n d C u l t u r e S o l u t i o n s C o m p o u n d C o m p l e t e L o w - M L o w - M g L o w - C a L o w - F L o w - K L o w - S M 4 H 2 P 0 4 0.0005 0.000005 0.0005 0.0005 0.000005 0.0005 0.0005 K K O , 0.003 - 0.003 0.003 0.003 0 . 0 0 0 0 2 0.003 Ca(W03 )2 0 . 0 0 2 0.000035 0 - 0 0 2 0 . 0 0 0 0 2 0 - 0 0 2 0 . 0 0 2 0 - 0 0 2 M g S 0 4 . 0.001 0-001 0.00001 0-001 0.001 0-001 0 . 0 0 0 0 0 4 K ^ S 0 4 - 0.0015 -C a C l 2 - 0.001965 -H H 4 C 1 - - 0 . 0 0 0 4 9 5 H a H p P 0 4 - 0 . 0 0 0 4 9 5 - - . • -N a S 0 4 - - 0.00099 K a K O , - O.OO398 - O.OO298 M g C l g . - — - - - O.OOO996 ( a l l s o l u t i o n s i n m o l s p e r l i t r e ) M i c r o n u t r i e n t s w e r e a d d e d s e p a r a t e l y t o e a c h s o l u t i o n a n d i n t h e f o l l o w -i n g a m o u n t s . F e ( a s F e C l g ) 0.5 p p m C u ( a s C u C l 2 ) 0.005 p p m B ( a s H3BO,) 0.125 P P m Z n ( a s Z n C l 2 ) 0.0125 p p m M n ( a s M n C l 4 ) . 0.125 p p m . Mo ( a s N a 2 M o 0 4 ) 0.0125 p p m A d j u s t m e n t s o f p H t o a c o n s t a n t o f 5*5-0.1 w e r e m a d e i n e a c h n e w s o l u t i o n m i x b y d r o p w i s e a d d i t i o n o f e i t h e r 1N K a O H o r I K H C 1 . A B e c k m a n ( M o d e l N ) g l a s s e l e c t r o d e p H m e t e r w a s u s e d . C r o c k s c o n t a i n i n g t h e t e s t s e e d l i n g s w e r e s u b - i r r i g a t e d b y t h e a p p r o p r i -a t e s o l u t i o n a n d w a t e r e d f r o m a b o v e b y d i s t i l l e d w a t e r . 3- S e e d S o u r c e a n d P l a n t i n g L o t s * o f 2 4 0 0 s e e d s o f e a c h s p e c i e s w e r e s t r a t i f i e d i n p a r t i a l l y c l o s e d g l a s s j a r s c o n t a i n i n g m o i s t e n e d p a p e r t o w e l s a n d s t o r e d i n a r e f r i g e r a t o r h e l d a t 360 F . f o r a p e r i o d o f 6 w e e k s . T h i r t y s e e d s o f e a c h o f t h e f i v e s p e c i e s w e r e s o w n e v e n l y o v e r t h e s a n d o r s o i l s u r f a c e o f e a c h c r o c k u s i n g a p e g t e m p l a t e s p e c i a l l y c o n s t r u c t e d t o f i t c r o c k s o f 1 - g a l l o n s i z e . T h e s o u r c e , l o c a t i o n a n d d a t e o f c o l l e c t i o n o f e a c h o f t h e f i v e s e e d l o t s i s a s r e p o r t e d i n T a b l e V . 64. Table Y Seed Source and Date of Collection Species Source Crop Year Geographical Area Coastal Douglas-fir 3 1956 Nanaimo River Valley, Vancouver Island, B. C Interior Douglas-fir 1 1956 Shuswap Lake area, B. C Ponderosa pine 1 1957 . Merritt, B. C Western white pine 2 1957 Salmon Arm,. B. C Engelmann spruce 2 1957 Salmon Arm,.. B. C Source: 1. B. C. Forest Service 2. Manning Seed Co., Seattle, Washington 3. D. Mueller - Dombois . . . Seeds were sown in the sand of each crock which had previously been eluted several times with d i s t i l l e d water both as a precautionary measure against possible contamination and as a means of ensuring that the.medium for germination would be sufficiently moist. For the f i r s t 18 days follow-ing placement of the seed, the sand surface was kept continuously moist by frequent surface application of d i s t i l l e d water. Care was taken not to dis-lodge the seeds from their position or to expose them to the atmosphere by washing away the covering sand. No attempt was made to use solutions or the sub-irrigation method of supply at this early stage i n the experiment, for to have done so would have meant that many of the lighter seed would have floated from their positions i n the sand. Prior s t r a t i f i c a t i o n of the seed had the desired effect of accelerating germination considerably although, as can be seen from Table VE, there was considerable variation i n germinative a b i l i t y . 65-T a b l e 7 1 G e r m l n a t i v e A b i l i t y , b y S p e c i e s W o . S p e c i e s o f d a y s t i l l a p p e a r a n c e o f f i r s t g e r m i n a n t N o . o f g e r m i n a n t s . a f t e r 2 0 d a y s ' % g e r m i n a . t i p n a f t e r 2 0 d a y s C o a s t a l D o u g l a s - f i r 6 1 1 8 4 6 6 . 9 ' I n t e r i o r . D o u g l a s - f i r 4 1121 6 4 . 4 P o n d e r o s a p i n e 3 1132 63.9 w e s t e r n w h i t e p i n e . . 8 . 4 1 3 • - 23.3 E n g e l m a n n s p r u c e 9 ' 717 4 0 . 5 A f t e r t h r e e w e e k s , t h e n u m b e r o f s e e d l i n g s i n e a c h c r o c k w a s r e d u c e d t o s i x i n t h e c a s e o f p o n d e r o s a p i n e a n d s e v e n i n t h e c a s e o f t h e o t h e r f o u r s p e c i e s . I t w a s n e c e s s a r y , i n some c a s e s , t o m a k e u p t h e t o t a l i n some c r o c k s w i t h t r a n s p l a n t s f r o m o t h e r s w i t h a n e x c e s s . A l l s u c h t r a n s p l a n t i n g w a s d o n e b e f o r e t h e a d d i t i o n o f n u t r i e n t s o l u t i o n s . T o e f f e c t c o m p l e t e r e l e a s e o f t h e s e e d l i n g r o o t s y s t e m s w i t h o u t d a m a g e , i t w a s f o u n d t h a t b y f l o o d i n g t h e c r o c k s w i t h d i s t i l l e d w a t e r t h e s a n d w a s s o l o o s e n e d a s t o p e r -m i t o f e a s y e x t r a c t i o n . S u b s e q u e n t r e d u c t i o n s i n s e e d l i n g c o m p l e m e n t w e r e m a d e a s t h e l a t t e r g r e w l a r g e r a n d b e c a m e c r o w d e d . T h i n n i n g s w e r e m a d e i n M a y 1958 a n d J u n e 1959 (3 m o n t h s a n d 15 m o n t h s a f t e r s o w i n g ) w i t h t h e r e s u l t t h a t t h e r e r e m a i n e d o n l y o n e o r t w o s e e d l i n g s p e r c r o c k a t t h e t e r m i n a t i o n o f t h e e x p e r i m e n t . P l a n t s s e l e c t e d f o r r e m o v a l i n t h e t h i n n i n g o f M a y 1958 w e r e c h o s e n i n s u c h a m a n n e r t h a t t h o s e r e m a i n i n g , r e g a r d l e s s o f s i z e , w e r e a s w i d e l y s p a c e d a s p o s s i b l e . I n t h i s w a y , i t w a s h o p e d t h a t r o o t c o m p e t i -t i o n w o u l d b e d e l a y e d a n d i n d i v i d u a l p l a n t s w o u l d h a v e a g r e a t e r o p p o r t u n i t y o f g r o w i n g a s r a p i d l y a s t h e t r e a t m e n t a n d t h e i r o w n g e n e t i c c o n s t i t u t i o n w o u l d a l l o w . T h e r e d u c t i o n t o s i x s e e d l i n g s p e r c r o c k w i t h p o n d e r o s a p i n e , 66. r a t h e r t h a n s e v e n a s w a s t h e c a s e w i t h t h e o t h e r f o u r s p e c i e s , w a s b a s e d o n t h e a s s u m p t i o n t h a t t h e v i g o r o u s s h o o t g r o w t h t y p i c a l o f t h i s s p e c i e s i n d i -c a t e d a n e q u a l l y l a r g e e x t e n s i v e r o o t s y s t e m a n d , f o r t h e r e t o b e e q u a l i t y o f " f e e d i n g p r e s s u r e " b e t w e e n s p e c i e s , s u c h a r e d u c t i o n i n n u m b e r w a s c o n s i d e r e d d e s i r a b l e . T h e J u n e 1959 t h i n n i n g r e d u c e d t h e n u m b e r o f t r e e s p e r c r o c k t o o n e , i n - m o s t c a s e s , t o t w o i n t h o s e c r o c k s w h e r e p l a n t s w e r e s e v e r e l y a f f e c t e d b y t r e a t m e n t . T h e l a t e r t h i n n i n g o p e r a t i o n e n t a i l e d t h e c o m p l e t e r e m o v a l o f t h e s a n d a n d t h e t r e e s g r o w i n g i n i t . S u c h a p r o c e d u r e w a s n e c e s s a r y t o p e r m i t t h e r e m o v a l o f a l l t h e s a n d f r o m a r o u n d t h e s t r o n g l y a n a s t a m o s e d r o o t m a s s i n o r d e r t h a t t h e i n d i v i d u a l r o o t s y s t e m s c o u l d b e c a r e f u l l y t e a s e d a p a r t . T h e d e g r e e o f i n t e r g r o w t h a n d i n t e r m i n g l i n g w a s e x c e s s i v e i n t h e c a s e o f t h e l a r g e r p l a n t s a n d n e c e s s i t a t e d t h e e x p e n d i t u r e o f c o n s i d e r a b l e t i m e a n d p a t i e n c e t o e f f e c t t h e i r s e p a r a t i o n w i t h o u t u n d u e d a m a g e . C o n c e r n i n g t h e s u b j e c t i v e c h o i c e t h a t w a s m a d e r e g a r d i n g t h e t r e e s t o b e r e t a i n e d f o r t h e l a t t e r p h a s e o f t h e e x p e r i m e n t , a p r e f e r e n c e w a s s h o w n f o r t h o s e t r e e s , w h i c h b y t h e i r v i g o r a n d r e l a t i v e g r o w t h u n d e r s t r e s s , s e e m e d m o s t l i k e l y t o s u r v i v e a f u r t h e r t h r e e m o n t h s o f g r o w t h u n d e r c o n d i t i o n s o f d e f i c i e n t n u t r i -e n t s u p p l y . T h u s i t w a s t h a t p l a n t s t h a t w e r e t a l l e s t a n d h a d t h e m o s t e x t e n s i v e r o o t s y s t e m s w e r e s e l e c t e d f o r r e t e n t i o n a n d f u r t h e r e x p e r i m e n t a -t i o n . T h e e f f e c t s o f d e f i c i e n c y d e s c r i b e d o n t h e s e l a t t e r p l a n t s , t h e r e -f o r e , a r e t o b e j u d g e d a s b e i n g m i n i m a l i n e f f e c t s i n c e t h e i n d i v i d u a l s u p o n w h i c h t h e e f f e c t s a r e d e s c r i b e d a r e l i k e l y t o e x h i b i t . a g r e a t e r t h a n a v e r a g e t o l e r a n c e t o t h e m . T h e r e i s n o a t t e m p t t o d e n y t h e e x i s t e n c e o f a b i a s e d c h o i c e i n t h i s m a t t e r b u t i t i s h o p e d t h a t s u f f i c i e n t g r o u n d s h a v e b e e n e s t a b l i s h e d f o r m a k i n g i t . F u r t h e r m o r e , s i n c e t h e r e s u l t s o f t h i s s t u d y a r e l a r g e l y c o m p a r a t i v e i n n a t u r e a n d , s i n c e a l l t h e t h i n n i n g p r o c e d u r e s a b o v e d e s c r i b e d w e r e c o m m o n t o a l l s p e c i e s a n d t r e a t m e n t s o f s p e c i e s , i t i s 6 7 . c o n s i d e r e d t h a t t h e r e s u l t s s u f f e r e d l i t t l e f r o m s u c h d e c i s i o n s . A t a b u -l a t e d s u m m a r y o f t h e e x p e r i m e n t a l p o p u l a t i o n o v e r t i m e i s g i v e n i n T a b l e V I I . T a b l e V I I N u m b e r o f T r e e s b y S p e c i e s S a n d C u l t u r e s S p e c i e s F e b . - M a y '58 M a y '58 - J u n e '59 J u n e - S e p t . '59 C o a s t a l D o u g l a s - f i r 1 1 8 4 154 51 I n t e r i o r D o u g l a s - f i r 1121 156 53 P o n d e r o s a p i n e 1132 125 4 2 W e s t e r n w h i t e p i n e 4 1 3 • • 168 4 2 E n g e l m a n n s p r u c e 717 167 60 . 4567 770 2 4 8 T r e a t m e n t e f f e c t s w e r e s o s e v e r e i n t h e c a s e o f E n g e l m a n n s p r u c e g r o w n i n l o w p h o s p h o r u s c u l t u r e s , a n d t h e r e s u l t a n t m o r t a l i t y s o h i g h , t h a t n o a t t e m p t w a s m a d e t o r e m o v e a n y p l a n t s g r o w i n g i n t h i s t r e a t m e n t a f t e r M a y 1958. T h i s a c c o u n t s f o r t h e s l i g h t l y h i g h e r n u m b e r o f s p r u c e r e m a i n i n g a t t h e t e r m i n a t i o n o f t h e e x p e r i m e n t . 4 . D e s i g n o f t h e E x p e r i m e n t T h e d e s i g n o f t h e e x p e r i m e n t w a s d i c t a t e d , t o a g r e a t e x t e n t , b y t h e t e c h n i c a l i t i e s i n v o l v e d a n d t h e l i m i t a t i o n s o f s p a c e i n t h e g r e e n h o u s e . O r i g i n a l l y i t w a s i n t e n d e d t h a t t h e r e s h o u l d b e t w o r a n d o m i z e d b l o c k s w i t h t h r e e r e p l i c a t i o n s o f e a c h t r e a t m e n t o n e a c h s p e c i e s i n e a c h . R a n d o m p l a c e m e n t o f t h e c r o c k s , h o w e v e r , r e s u l t e d i n t h e r e b e i n g m o r e t h a n o n e t r e a t m e n t o n a n y o n e r o w a c r o s s t h e b e n c h . T h e c h a n c e s w e r e 1 i n 7 t h a t t h i s w o u l d b e s o . T h e p r o b l e m t h e n a r o s e o f t a p p i n g t h e m a i n l o n g i t u d i n a l 68. s o l u t i o n s u p p l y l i n e f o r m o r e t h a n o n e c r o c k a t o n e p o i n t i n t h e l i n e . A l t h o u g h t h i s m i g h t h a v e h e e n p o s s i b l e w i t h Y t u b i n g f i x t u r e s f r o m a s t a n d a r d T j o i n t , t h e r e r e m a i n e d t h e d i f f i c u l t y o f c r o w d i n g s e v e r a l c o n d u i t s i n t o t h e c o n f i n e d s p a c e b e t w e e n t r a n s v e r s e r o w s o f c r o c k s w i t h o u t p e r m i t t i n g a n y c r o s s - o v e r s a n d u n d u l a t i o n s i n t h e t u b i n g w h i c h m i g h t m a k e f o r f a u l t y d r a i n a g e . I t b e c a m e e v i d e n t t h a t , f o r a l l r o w s a c r o s s t h e b e n c h , o n l y o n e o f t h e s e v e n b r a n c h c o n -d u i t s c o u l d b e l e d o f f t h e m a i n l i n e s a n d t h a t i t w o u l d b e p r e f e r a b l e i f , b y j u d i c i o u s p l a c e m e n t o f t h e s o i l c r o c k s t h a t r e q u i r e d n o t u b i n g , l e s s t h a n s e v e n b r a n c h c o n d u i t s w e r e n e c e s s a r y i n a n y o n e r o w . S t a r t i n g a t t h e s o u t h e n d o f t h e b e n c h , t h e r e f o r e , a c r o c k c o n t a i n i n g a g i v e n t r e a t m e n t o f s p e c i e s A w a s s u c c e e d e d i n r o w 2 b y a c r o c k c o n t a i n i n g s p e c i e s B h a v i n g t h e same t r e a t -m e n t , r o w 3 c o n t a i n e d s p e c i e s C , 4 s p e c i e s D , 5 s p e c i e s E , a n d 6 s p e c i e s A a g a i n . T h e n e x t t r e a t m e n t w a s b e g u n w i t h s p e c i e s A a g a i n b u t t h i s t i m e t h e s e q u e n c e s t a r t e d o n r o w 2 a n d f o l l o w e d t h e same o r d e r a s a b o v e . T h e e a s t -w e s t p o s i t i o n i n g o f t h e c r o c k s a c r o s s t h e b e n c h w a s r a n d o m i z e d a s w a s t h e p l a c e m e n t o f t h e s o i l c r o c k s i n t h e s p a c e s t h a t r e m a i n e d a f t e r t h e s a n d c r o c k a r r a n g e m e n t h a d s y s t e m a t i c a l l y b e e n f i x e d i n t h e m a n n e r m e n t i o n e d a b o v e . B y t h i s m e a n s , i t w a s p o s s i b l e t o a r r i v e a t a s p a t i a l a r r a n g e m e n t p a t t e r n w h i c h w a s a s u n b i a s e d a s t h e t e c h n i c a l i t i e s o f t h e e x p e r i m e n t w o u l d a l l o w a n d w h i c h s p r e a d t h e v a r i o u s t r e a t m e n t / s p e c i e s c o m b i n a t i o n s s u f f i c i e n t l y w e l l o v e r t h e s u r f a c e o f t h e b e n c h t h a t f l u c t u a t i o n s i n l i g h t , t e m p e r a t u r e a n d h u m i d i t y w e r e e f f e c t u a l o n a l l . T h e l a r g e n u m b e r o f replicates w a s j u s t i f i a b l e o n t h e f o l l o w i n g c o u n t s : a . S t a t i s t i c a l s u p p o r t f o r t h e e x p e r i m e n t a l d e s i g n w a s l a c k i n g . b . T h e a r e a c o v e r e d b y t h e b e n c h w a s l a r g e a n d t h e e n v i r o n -m e n t a l c o n d i t i o n s a l o n g i t s l e n g t h s o m e w h a t v a r i a b l e . c . I t w a s a n t i c i p a t e d t h a t t h e r e w o u l d b e a w i d e h e t e r o g e n e i t y a m o n g i n d i v i d u a l s w i t h r e g a r d t o g r o w t h , v i g o r a n d t o l e r -a n c e o f d e f i c i e n c y . 69-d . B e i n g p l a c e d s o c l o s e t o g e t h e r , t h e s h a d i n g e f f e c t s o f o n e c r o c k u p o n a n o t h e r w e r e o f t e n q u i t e s e v e r e a n d h a d t o h e c o m p e n s a t e d f o r b y i n c r e a s i n g t h e s a m p l e p o p u l a t i o n . e . I t w a s n o t k n o w n h o w s e v e r e t h e m o r t a l i t y r a t e w o u l d b e a m o n g s e e d l i n g s r e c e i v i n g d e f i c i e n t n u t r i e n t s u p p l y a n d , t o a l l o w f o r u n t o w a r d d e v e l o p m e n t s i n t h i s r e g a r d , a l a r g e r n u m b e r o f t e s t p l a n t s w a s c o n s i d e r e d n e c e s s a r y . 5' E x p e r i m e n t a l P r o c e d u r e s H a v i n g o b t a i n e d a n a d e q u a t e n u m b e r o f p l a n t s o f a l l s p e c i e s i n a l l c r o c k s , b o t h s o i l a n d s a n d , s u b - i r r i g a t i o n b y n u t r i e n t s o l u t i o n o f t h e l a t t e r w a s b e g u n . C o n c e n t r a t e s w e r e a d d e d t o t h e r e s e r v o i r c r o c k s f i l l e d w i t h d i s t i l l e d w a t e r , p H ' s w e r e a d j u s t e d t o 5«5 a p p r o x i m a t e l y a n d t h e s y s t e m c o n n e c t e d i n s u c h a m a n n e r t h a t s o l u t i o n f l o w e d b y g r a v i t a t i o n , f r o m t h e c r o c k s , a l o n g t h e m a i n l i n e s r u n n i n g t h e l e n g t h o f t h e b e n c h a n d t h e n a t r i g h t a n g l e s t o i t , b e t w e e n t h e r o w s , t o t h e c r o c k s t h e m s e l v e s - . A s s o l u t i o n a p p e a r e d o n t h e s a n d s u r f a c e , r i s i n g f r o m b e l o w , t h e i n l e t c o n d u i t f r o m t h e m a i n f e e d l i n e w a s c l a m p e d a t t h e p o i n t w h e r e i t j o i n e d t h e l a t t e r o n t h e p a s s a g e w a y ( F i g . 5). T h i s a l l o w e d o n e o p e r a t o r t o c o n t r o l t h e i r r i g a t i o n o f t h e e n t i r e 210 c r o c k s b y m e r e l y m o v i n g b a c k a n d f o r t h a l o n g t h e b e n c h o n o n e s i d e a n d c l a m p i n g o f f c o n d u i t s a s t h e c r o c k s b e c a m e f u l l . W h e n a l l c r o c k s w e r e f u l l a n d f l o o d e d w i t h s o l u t i o n , t h e r e s e r v o i r t u b i n g w a s c l a m p e d a n d r e m o v e d . T h e i n l e t , b y w h i c h s o l u t i o n g a i n e d a c c e s s t o t h e i n t e r l o c k i n g s y s t e m t h a t f e d s i m u l t a n e o u s l y a l l c r o c k s o f a g i v e n s o l u t i o n , w a s a l s o c l a m p e d . T h e i n d i v i d u a l c r o c k c l a m p s w e r e o p e n e d a n d t h e e n t i r e s y s t e m d r a i n e d , b y i n d i v i d u a l s o l u t i o n , i n t o d r a i n c r o c k s p l a c e d a t i n t e r v a l s a l o n g t h e b e n c h . C o m p l e t e d r a i n a g e t o o k a b o u t o n e h o u r . T h e a p p l i c a t i o n o f t h e s e v e n d i f f e r e n t s o l u t i o n s t o t h e a p p r o p r i a t e c r o c k s o n t h e b e n c h t o o k a b o u t o n e a n d o n e - h a l f h o u r s . A t e a c h s o l u t i o n a p p l i c a t i o n , s o i l s w e r e w a t e r e d b y s p r i n k l i n g t h e m w i t h d i s t i l l e d w a t e r . N o a t t e m p t w a s m a d e t o p r e s e r v e t h e l e a c h a t e s . 70 T h i s o p e r a t i o n w a s r e p e a t e d e v e r y o t h e r d a y . O n a l t e r n a t e d a y s , s a n d s w e r e w a t e r e d f r o m a b o v e b y d i s t i l l e d w a t e r . F i v e s a n d c r o c k s , o n e o f e a c h s p e c i e s , r e c e i v e d o n l y d i s t i l l e d w a t e r t h r o u g h o u t t h e c o u r s e o f t h e e x p e r i -m e n t . O l d s o l u t i o n s w e r e d i s c a r d e d a n d n e w o n e s m a d e e v e r y 10 d a y s d u r i n g t h e g r o w i n g s e a s o n , e v e r y 15 d a y s w h i l e t h e p l a n t s w e r e d o r m a n t . A n y o n e b a t c h o f . s o l u t i o n s t h e n w a s u s e d n o t m o r e t h a n 8 t i m e s . I n t e r m s o f t i m e r e q u i r e d t o a t t e n d t h e p l a n t s , i t I s c o n s e r v a t i v e l y e s t i m a t e d t h a t , o v e r t h e 19 -month p e r i o d d u r i n g w h i c h t h e e x p e r i m e n t r a n , some 670 h o u r s o r a l m o s t 2 m o n t h s o f c o n t i n u o u s , 2 4 - h o u r l a b o r w a s r e q u i r e d f o r t h i s p a r t o f t h e o p e r a t i o n a l o n e . N o m o r e c o g e n t a r g u m e n t i s r e q u i r e d f o r t h e i n s t a l l a t i o n o f a m e c h a n -i c a l l y o p e r a t e d s y s t e m i n e x p e r i m e n t s o f t h i s k i n d . A l t h o u g h p H w a s s t a n d a r d i z e d a s e a c h n e w l o t o f s o l u t i o n s w a s m i x e d , n o a t t e m p t w a s m a d e t o c o r r e c t a n y d e v i a t i o n s a b o v e a n d b e l o w t h i s p o i n t a f t e r t h e s o l u t i o n s w e r e i n u s e . I t w a s k n o w n t h a t q u i t e c o n s i d e r a b l e f l u c t u a -t i o n s i n p H o c c u r r e d a f t e r e v e n o n e i r r i g a t i o n a n d a s e r i e s o f m e a s u r e m e n t s wae m a d e t o t e s t t h i s v a r i a t i o n ( T a b l e V I I l ) g i v e s s o m e i n d i c a t i o n o f t h e m a g n i t u d e a n d d i r e c t i o n o f s u c h c h a n g e . T a b l e V I I I N u t r i e n t S o l u t i o n s a n d p H A d j u s t m e n t s S o l u t i o n p H p r i o r t o u s e a n d c o r r e c t i o n b y a l k a l i p H a f t e r c o r r e c t i o n p H a f t e r 1 u s e p H a f t e r 2 u s e s p H a f t e r 3 u s e s C o m p l e t e 5.25 5.51 6.52 6 . 1 4 6.47 L o w N 5.29 5.52 6.08 5-85 6.03 L o w S 5-21 5.50 6.60 6.28 6.33 L o w M g 5.29 5.51 6.33 5-94 6.25 L o w C a 5-25 5.50 6.59 6.26 6 . 4 0 L o w P 5.56 ' 5.56 4.86 5.11 4.71 L o w K • 5.28 5.52 6.10 5.81 6.99 A v g . 5O0 5.51 6.15 5.91 6.02 7 1 . S i n c e w o r k o f C h a p m a n ( 1 9 4 1 ) a n d A r n o n , F r a t z k e a n d J o h n s o n ( 1 9 4 2 ) i n d i c a t e s t h a t o n l y a t e x t r e m e l y l o w o r e x t r e m e l y h i g h p H v a l u e s ( 3 ~ 9 ) a r e t h e r e l i k e l y t o b e a n y d e l e t e r i o u s e f f e c t s o n i o n u p t a k e , i t w a s n o t c o n s i d e r e d l i k e l y t h a t . t h e f l u c t u a t i o n s o b s e r v e d t o o c c u r i n t h i s e x p e r i m e n t w e r e o f a n y g r e a t s i g n i f i c a n c e . C a u t i o n h a d t o b e e x e r c i s e d , h o w e v e r , e s p e c i a l l y d u r i n g t h e h o t t e r s u m m e r m o n t h s , t o p r e v e n t a n a c c u m u l a t i o n o f s a l t s b y e v a p o r a t i o n . O n t w o o c c a s i o n s , a v e r y d i l u t e s o l u t i o n o f H C 1 w a s a p p l i e d t o l e a c h e x c e s s s a l t f r o m t h e c r o c k s . 72. I l l T e m p e r a t u r e a n d H u m i d i t y d u r i n g t h e C o u r s e o f t h e E x p e r i m e n t A r e c o r d i n g h y g r o t h e r m o g r a p h , p l a c e d i n a S t e v e n s o n s c r e e n , w a s u s e d t o r e c o r d f l u c t u a t i o n s i n t e m p e r a t u r e a n d h u m i d i t y i n t h e g r e e n h o u s e d u r i n g t h e c o u r s e o f t h e e x p e r i m e n t . A t i n t e r v a l s , t h e r e c o r d i n g n e e d l e s w e r e a d j u s t e d t o c o i n c i d e w i t h c h e c k r e a d i n g s o f r e l a t i v e h u m i d i t y a n d t e m p e r a -t u r e , m a d e w i t h t h e a i d o f a s l i n g p s y c h r o m e t e r a n d l a b o r a t o r y t h e r m o m e t e r r e s p e c t i v e l y . A t t h e c l o s e o f t h e e x p e r i m e n t , t h e a r e a s u n d e r t h e c u r v e s o f t e m p e r a -t u r e a n d h u m i d i t y f o r e a c h r e c o r d e d w e e k w e r e p l a n i m e t r e d , a n a v e r a g e f o r t h e w e e k c o m p u t e d a n d a r e c o n v e r s i o n t o t h e o r i g i n a l u n i t s o f d e g r e e s F a h r e n h e i t o r p e r c e n t m a d e b y i n t e r p o l a t i o n i n a g r a p h o f s t a n d a r d t e m p e r a -t u r e / a r e a o r r e l a t i v e h u m i d i t y / a r e a . T a b l e s I X a n d X c o n t a i n t h e m a x i m a , m i n i m a a n d a v e r a g e v a l u e s f o r t e m p e r a t u r e a n d h u m i d i t y o b t a i n e d i n t h i s f a s h i o n , w h i l e F i g u r e s 6 a n d 7 a r e g r a p h i c a l r e c o r d s o f t h e s a m e i n f o r m a -t i o n . T a b l e I X T E M P E R A T U R E A N D R E L A T I V E K U M I D I T Y D A T A F O R 1958 W E E K C O M M E N C I M G F E B . M A R . A P R . &4| 3; I O ! - f T i -2 4 3 1 — 7 -1 9 5 8 M A Y T U N . J U L . A U G . S E P . O C T . N O V r 14! £ 1 _2.fi . 5 12. 1 9 " 2 6 " 2 9 - 1 6 -2 3 SO 7 14 21 28 5 ' 12 19 -26 -1 8 _15._ 22 29 6 ~l'3r 2 d 2 7 — 3 D E C 1Q 17i _24 l i 8' 15J "22 2 9 T E M P E R A T U R E M A X . 7,<? 8,1 •80 " 8 0 " 8:1 S 3 - 6 5 -8.8 8 0 _7.8_ 7 7 8 7 8 8 " 8 8 " 8 7 7 8 - 9 1 -8 7 8 5 _94_ 91 8 8 91 " 8 6 " 8 8 8 4 - 8 3 -8 i l 8 0 _82_ 7 8 8.1 6.8 " 7 3 " 7 4 76 - 7 4 -7 7 74 _7:2_ 76 6S9 7 2 ~6J8" 7 0 M l M 61 61 61 "59 6 3 6 3 -62 ! 6 3 61 _6_4. 62! 6 4 65: "66 6S 6 4 - 6 7 62 6 3 „ 6 5 . 61 62 6 O "'"58' S 9 62 —S6: S 7 5 9 _6_4: 62 6 3 6 0 -6-CJ-6Q 61; —61 62 61 ___62 £ 6 61 62 "63* 52 AY_fii 6S.7J 64.7j 66 .2 ~"~6479j 67.3! 69 . 71 —€-6rS; 67 .7 68 .4 _6i)..3. 67.4 73.2 72. a "727ir T5.7; 70 .Q —76:6j-69.7: 73. Q _7.6, SI 7S.7; 73.41 73.6; ' _ 7 0 : 5 . ' 71 .8 72. l j —6-5.61-68.8: 7 0 . 5 _6.9..0_ 68 .4 68.O, 64.2: " " 6 5 . 7 " 66.2; 63 . 91 - 6 - 7 - e H 6 4 . 7 6 8 . 5 _6X_S_ 64.4J 6 5.0 65 .3 "6577 64.6 R E L A T I V E H U M I D I T Y M A X . 1 0 0 9 0 1 0 0 loo" 1 0 0 1 0 0 -l-ee-1 0 0 loo A.on.. loo loo loo l o o 1 0 0 1 0 0 -i-ee-1 0 0 l o o _LQO_ 1 0 0 l o o _ l o o _ l o o 1 0 0 1 0 0 - l e e -l o o l o o _ l o o _ l o o l o o l o o "loo"" l o o l o o l e e -l o o 9 8 _l_QO_ l o o 9 5 1 0 0 T0~0~ I O O M I N. 55 56 4 5 t T 3 7 4S -48-44 38 _4.2_ 51 3 0 46 " 4 3 " 36 5 4 -4-7-54 SO _54_ 43 45 54 ""43" 49 62 - 5 8 -49 52 _4_4_ SO 60 S2 " 5 5 " 53 S2 - 5 1 -38 68 _S.3._ 76 78 8 0 " 8 3 " 5 3 A V G. 8 2 . 3 79 .2 73.1 "9073" 7 8 . 3 7 9 . 7 -8-5.-0-8 6 . 8 74.4 „77.2._ 8 4 . 0 78 .4 8 9 . 3 ~9176~ 8 7 . 5 9 0 . 2 - 8 1 - 5 -8 7 . 7 8 4 . 4 _85..0_ 84.1 8S .O 8 6 . 8 ~8575" 8 2 . 3 8 9 . 7 - 9 2 T 4 -84 .1 93 .6 __90,_9_ 9 1 . 8 8 8 . 5 S3 .1 •""8872" 8 7 . 1 95 .4 -90.-2-74 .4 88 .6 _78.Q_ 88 .1 8 5 . 3 $ 5 . 0 "9372" . 77.2 T a b l e X T E M P E R A T U R E A D D R E L A T I V E H U M I D I T Y D A T A F O R 1959 WEEK C O M M E N C | N Q T E M P E R A T U R E IN *F R E L A T I V E H U M I D I T Y T A N . F E B . M A R . A P R T MAY. T U N . J U L r A U Q . 5! 12; ~ztr 2 1 -1-6-2 3 2 S__ 16 2 3 3 0 ~ 6 " 13 2 o 4 11 ..1.8_ 2 5 1 8 _ r s _ 22 2 i - -6-1 3 2 0 3 1Q 17: 31 MAX*. 1 1 5 1 7 5 76 7 3 " 7 3 " 7 4 7 8 - 7 2 76 7 7 8 3 7 5 7 8 "SO 76 7 8 - 7 7 81 88 ..78.. 78 8 7 7 8 - q 4 8 4 82 -8-6-8 5 q I _1 I_ 86 8 7 8 7 12 8 7 M l M. 6 3 6 3 5 8 " 60~ S S 6 0 6 4 -6 3 65 ..62. 62 6 3 65 51 6 0 6 0 - 5 4 54 6 3 62. 6 3 6 2 6 3 64" 65 63 6 0 66 6 3 .60. 6 0 61 62 6"2r" 6 0 A V G . ! 65.6 i i 65 .2 ! ! 6 6 . 2 ' 6 6 .7 65.2 65.6 • 66 .7 66 .8 6 7 6 _.-6.6..7 . 67 .0 66 .3 67 .7 "6'q.3 ' 67. 1 66 .8 -64 .7 • 65.6 68.2 68.5. 67.2 61 .2 68.8 73.4 " ' 72 .1 .71.3 • 7 1 . 9 ' 75.6 ; 73 .2 :_72,.o. 70 .1 72.1 71 .3 : 7 2 .0: 6 9 . 3 , M A V . l O O i l o o i ! i o o ! : ice ; l o o . : l o o • i ce -15 l O O . . : _ q . i . . . . 1 8 14 11 i c e l o o . i o o : l o o ••• i o o : i o o 1 o o . i o o IOO l o o ICC I C O IOO IOO • l o o IOO ICC .. IOO IOO 100 1 cc "" ; IOO M l M . 6 4 7 0 6 5 "76 " 6 5 5 4 - 6 4 56 '50 :48 46 6 0 4 7 "37 S 7 4 8 -51 ! 3 8 3 3 : 4 1 SO 45 46 "44 SO 51 : 41 56 . 4 4 . 4 2 41 . 4 7 SO ' 4 3 4 5 A V G . .4 .6 .3 .1 8 4 . 3 87 .4 8 7 5 "87.5 8 6 . 4 8 0 . 2 S 8-. 6 80. 2 82.6 7.6. 76. 77.1 7 1 . 7 72. 77 . 8 3 . 2 88 .0 7 0 . 7 8 5 . 0 7.7.5 80. 2 7 1 . 3 83 .2 8 1 . 5 7 8 . 8 8 3 . 1 75 .5 8 1 . 5 8 3 . 2 7 5 . 8 . 7 6 . 7 83.1 8 5 . 7 " 80 .6 8 5 . 6 | T I M E I N W E E K S •',o T I M E I N M O N T H S 73-I V T h e Q u a l i t a t i v e E f f e c t s o f M a c r o n u t r i e n t D e f i c i e n c y 1. I n t r o d u c t i o n T h e d a t e o f s e e d s o w i n g ( F e b r u a r y 2 0 , 1958) a l l o w e d t h e t e s t p l a n t s t o b e c o m e e s t a b l i s h e d b e f o r e t h e o n s e t o f t h e g r o w i n g s e a s o n , w i t h t h e r e s u l t t h a t f o r t h e f i r s t e i g h t m o n t h s t h e r e w a s c o n t i n u o u s a n d r a p i d g r o w t h . O n a l l s p e c i e s t h i s m a d e f o r a n e a r l y d e v e l o p m e n t a n d a p p e a r a n c e o f r e c o g n i z a b l e s y m p t o m s d u e t o t h e v a r i o u s d e f i c i e n c i e s . W i t h i n t h r e e m o n t h s , o b v i o u s s i z e d i f f e r e n c e s i n h e i g h t a n d d i a m e t e r g r o w t h w e r e n o t i c e d a n d i t w a s u s u a l f o r t h e s e t o b e a s s o c i a t e d w i t h c o n s i d e r a b l e v a r i a t i o n i n b r a n c h d e v e l o p m e n t . A p r o g r e s s i v e i n t e n s i f i c a t i o n o f t h e v a r i o u s d e f i c i e n c y s y m p t o m s f o l l o w e d w i t h t h e p a s s a g e o f t h e s u m m e r m o n t h s a n d b y O c t o b e r 195^ e v i d e n c e s o f d e f i c i e n c y w e r e d i s t i n c t i v e e n o u g h t o w a r r a n t c o m p l e t e m e a s u r e m e n t a n d d e s c r i p t i o n . T h e s e s u b j e c t i v e d e s c r i p t i o n s o f c o l o r , a n d s i z e d i f f e r e n c e s w e r e s u p p l e m e n t e d i n t h e f o l l o w i n g s p r i n g b y a d e s c r i p t i o n o f t h e r o o t s t r u c t u r e a n d h a b i t a s m o d i f i e d b y d e f i c i e n c y a n d t h i s w a s f o l l o w e d s h o r t l y t h e r e a f t e r b y a d e t a i l e d l i B t i h g o f f o l i a r s y m p t o m s u s i n g f o r c o m p a r i s o n a s t a n d a r d c o l o r n o t a t i o n . A s e t o f M u n s e l l 1/ c o l o r c h a r t s r i n g - b o u n d p o c k e t e d i t i o n c o n t a i n i n g 4 2 c h a r t s d e p i c t i n g 95^ c o l o r s w a s u s e d . A t f i n a l r e m o v a l , a v e r y c o m p l e t e a n d d e t a i l e d d e s c r i p t i o n o f t h e m o r -p h o l o g i c a l e f f e c t s o f m a c r o m e t a b o l i c d e f i c i e n c y w a s m a d e . A n a t t e m p t i s m a d e , i n t h e d e s c r i p t i o n s t h a t f o l l o w , t o c o n d e n s e a n d a b b r e v i a t e t h e r e c o r d e d i n f o r m a t i o n t o f a c i l i t a t e d i a g n o s i s o f v a r i o u s d e f i c i e n c i e s . T o f u r t h e r i n c r e a s e t h e u s e f u l n e s s o f t h e i n f o r m a t i o n c o l l e c t e d , a s e t o f f i v e d i c h o t o m o u s k e y s , o n e f o r e a c h s p e c i e s , i s a p p e n d e d w h i c h e n a b l e o n e t o d e t e r m i n e w i t h s o m e d e g r e e o f a c c u r a c y t h e p a r t i c u l a r e l e m e n t r e s p o n s i b l e f o r t h e s y m p t o m s o b s e r v e d . 7 7 M u n s e l l C o l o r C o m p a n y , I n c . , 2 4 4 1 W o r t h C a l v e r t S t . , B a l t i m o r e 18, M a r y l a n d , U . S . A . 7 4 . I n d e s c r i b i n g d e f i c i e n c y s y m p t o m s , t h e f o l l o w i n g l i m i t a t i o n s m u s t b e b o r n e i n m i n d . F i r s t l y , a l l d e s c r i p t i o n s o f c o l o r , s i z e d i f f e r e n c e s a n d m o r t a l i t y o c c a s i o n e d b y t h e d e f i c i e n c i e s o n l y a p p l y t o t h e s p e c i e s s t u d i e d . G e n e r a l i n f e r e n c e s r e g a r d i n g l i k e e f f e c t s o n o t h e r c o n i f e r o u s s p e c i e s s i m -i l a r l y a f f e c t e d a r e p o s s i b l e b u t c a n o n l y b e t e n t a t i v e . E a c h e l e m e n t i n d e f i c i e n t s u p p l y h a s a d i s t i n c t i v e e f f e c t o n d i f f e r e n t s p e c i e s . F o r e x a m p l e , m a g n e s i u m d e f i c i e n c y p r o d u c e s a s t r o n g c h l o r o t i c c o n d i t i o n o f t h e f o l i a g e o f p o n d e r o s a p i n e b u t g r o w t h i s o n l y m o d e r a t e l y r e t a r d e d a n d t h e r e i s l i t t l e a p p a r e n t e f f e c t o n t e r m i n a l g r o w t h o r b r a n c h d e v e l o p m e n t . E n g e l m a n n s p r u c e s u b j e c t e d t o a s i m i l a r d e f i c i e n c y g i v e s s t r i k i n g e v i d e n c e o f b e i n g s e v e r e l y a f f e c t e d b o t h i n f o l i a g e , b r a n c h a n d t e r m i n a l d e v e l o p m e n t a n d t h e c o n d i t i o n m a y b e d e t r i m e n t a l e n o u g h t o i n d u c e s t e m d i e - b a c k a n d s u b s e q u e n t m o r t a l i t y . A s e c o n d l i m i t a t i o n h a s t o d o w i t h t h e e x p e r i m e n t a l c o n d i t i o n s u n d e r w h i c h d e f i c i e n c y i s i n d u c e d ( T h o m a s , 1 9 4 5 ; L a w r e n c e , 1955) ' T h e i n t e n s i t y a n d d u r a t i o n o f t h e l i g h t s o u r c e , t e m p e r a t u r e a n d h u m i d i t y c o n d i t i o n s s u r -r o u n d i n g t h e t e s t p l a n t s , t h e l e n g t h o f t h e d o r m a n t p e r i o d , t h e d e g r e e o f a e r a t i o n o f t h e r o o t i n g m e d i u m — a l l w i l l a f f e c t t h e t y p e o f s y m p t o m s t h a t d e v e l o p . L a w r e n c e (1955)^ i n a s t u d y o f e x p e r i m e n t a l t e c h n i q u e s u s e d i n g r e e n h o u s e s t u d i e s , g i v e s f a c t u a l e m p h a s i s t o t h e n e e d f o r s u c h c a u t i o n . W i t h r e g a r d t o d i f f e r e n c e s i n l i g h t i n t e n s i t y , h e h a s n o t e d t h a t a v a r i a t i o n o f 1 0 0 f o o t c a n d l e s i s s u f f i c i e n t t o p r o d u c e s i g n i f i c a n t e r r o r s i n j u d g m e n t w h e n a n a l y z i n g t h e e f f e c t s o f t r e a t m e n t o n r a n d o m l y p o s i t i o n e d p o t c u l t u r e s . H e a t t r i b u t e s t h e v a r i a t i o n i n l i g h t g r a d i e n t t o s h a d o w s t h r o w n b y t h e s t r u c -t u r e o f t h e g r e e n h o u s e i t s e l f a n d b y t a l l p l a n t s g r o w n a d j a c e n t t o o n e s t h a t , b y r e a s o n o f t r e a t m e n t o r s p e c i e s , a r e c o n s i d e r a b l y s m a l l e r . H o r i z o n t a l g r a d i e n t s i n a m b i e n t t e m p e r a t u r e a r e a f e a t u r e o f a l l g r e e n h o u s e s a n d t h e s e m a y b e c o n s i d e r a b l y a c c e n t u a t e d b y t h e d e s i g n o f t h e h e a t i n g s y s t e m . I t 75 . s h o u l d h e n o t e d h e r e t h a t t h e r m o s t a t i c c o n t r o l o f t e m p e r a t u r e w a s n o t a f e a t u r e o f t h e g r e e n h o u s e a r e a u s e d i n t h i s s t u d y . 2 . T h e U s e o f C o l o r i n D i a g n o s i n g D e f i c i e n c y A m o n g t h e m o r e s t r i k i n g e f f e c t s o f m i n e r a l d e f i c i e n c y a r e t h e f o l i a r d i s c o l o r a t i o n s w h i c h i t p r o d u c e s . I n t h e m a j o r i t y o f c a s e s , t h e s e a r e t h e f i r s t d i s c e r n a b l e s i g n s o f n u t r i t i o n a l i m b a l a n c e i n t h e s o i l a n d i t i s u p o n t h e i r a p p e a r a n c e t h a t c o r r e c t i v e a c t i o n i s o f t e n i n i t i a t e d . T h e i d e n t i f i -c a t i o n o f t h e f o l i a r s y m p t o m s d u e t o d e f i c i e n c y h a s r e c e i v e d c o n s i d e r a b l e a t t e n t i o n f r o m a g r i c u l t u r a l s c i e n t i s t s f o r a n u m b e r o f y e a r s a n d t h e r e e x i s t s o m e v e r y e x c e l l e n t a c c o u n t s , d e s c r i p t i v e a n d p i c t o r i a l , w h i c h m a k e f o r q u i c k a n d a c c u r a t e i d e n t i f i c a t i o n o f t h e c o m m o n e r m a c r o n u t r i e n t a n d m i c r o n u t r i e n t d e f i c i e n c i e s a s t h e y a p p e a r o n m a j o r c r o p p l a n t s ( G i l b e r t , 19^9.» W a l l a c e , 1954) . T h e o n l y r e c e n t r e f e r e n c e t o t h e u s e o f c o l o r a s a m e a n s o f i d e n t i f y i n g m i n e r a l d e f i c i e n c y i n f o r e s t r y p r a c t i c e i s c o n t a i n e d i n a p a p e r b y W i l d e a n d V o i g t (1958) w h o m a k e u s e o f M u n s e l l c o l o r c h a r t s t o s t r e n g t h e n t h e i r d i a g -n o s t i c p r e d i c t i o n s c o n c e r n i n g t h e d e f i c i e n t n u t r i t i o n o f f o r e s t n u r s e r y g r o w -i n g s t o c k . O t h e r p a p e r s ( P u r n e l l , 1958; H e i b e r g a n d W h i t e , 1951) m a k e u s e o f c o l o r i n d e s c r i b i n g t h e e f f e c t s o f e x p e r i m e n t a l l y i n d u c e d d e f i c i e n c y b u t n o w h e r e , i n s u c h w o r k , h a s a n y u s e b e e n m a d e o f c o l o r c h a r t s t o d e s c r i b e t h e c o l o r s s o p r o d u c e d o n f o r e s t t r e e s . T h e d e s c r i p t i o n o f c o l o r i s a l w a y s a d i f f i c u l t m a t t e r a n d o n e w h i c h i s d e p e n d e n t t o a g r e a t e x t e n t o n t h e o b s e r v e r , h i s p o w e r s o f d e s c r i p t i o n , f a c i l i t y w i t h a d j e c t i v e s a n d a c u i t y o f v i s i o n . I t w a s f e l t t h a t a m o r e o b j e c t i v e d e s c r i p t i o n o f c o l o r w o u l d m a k e f o r a w i d e r u s e f u l n e s s o f t h e r e s u l t s o f t h i s s t u d y a n d , s i n c e t h e M u n s e l l n o t a t i o n i s n o w q u i t e w i d e l y r e c o g n i z e d a s a s t a n d a r d o f c o m p a r i s o n , i t w a s u s e d t h r o u g h o u t t h i s s t u d y 76. a s a n a d j u n c t t o t h e v e r b a l d e s c r i p t i o n o f s y m p t o m d e f i c i e n c y . T h e b r o a d - l e a v e d f o r e s t t r e e s p e c i e s a r e l i k e l y t o p r e s e n t l i t t l e d i f -f i c u l t y w h e n i t c o m e s t o m a k i n g c o l o r c o m p a r i s o n s w i t h t h e c h i p s t h a t a r e i n c l u d e d i n t h e v a r i o u s h u e c h a r t s , s i n c e t h e l e a f a r e a i s l a r g e e n o u g h t o p e r m i t o n e t o c o m p a r e c o m p a r a b l e a r e a s . F u r t h e r m o r e , t h e l a m i n a e a r e u s u a l l y o f s u c h a s i z e t h a t c o l o r s o f a f a i r l y c o n s i s t e n t h u e a r e e x t e n s i v e e n o u g h o n a n y o n e l e a f t o a l l o w o n e t o u s e t h e c u t - o u t w i n d o w c a r d s p r o v i d e d w i t h t h e s t a n d a r d c o l o r s e t s . C o n i f e r s , w i t h t h e i r t y p i c a l l y a c i c u l a r a n d s u b u l a t e l e a v e s o f s m a l l a r e a , p r e s e n t s o m e p r o b l e m s i n t h i s r e g a r d . I t w a s f o u n d t h a t t h e m o s t a c c u r a t e d e t e r m i n a t i o n o f t h e c o r r e c t c o l o r c o u l d b e h a d b y p l a c i n g t h e n e e d l e a d j a c e n t t o a n d a l o n g s i d e t h e c h i p s w h i c h i t c l o s e l y r e s e m b l e d . T h e n e e d l e s u r f a c e t h e n b e c o m e s a p a r t o f t h e c o l o r e d c h i p , a s i t w e r e , a n d a n y d i s c r e p a n c i e s i n h u e , l i g h t n e s s o r i n t e n s i t y o f c o l o r a r e q u i t e r e a d i l y o b s e r v e d . P e r h a p s i t w o u l d b e w e l l a t t h i s p o i n t t o g i v e a b r i e f e x p l a n a t i o n o f t h e c o m p o s i t i o n a n d c o l o r a r r a n g e m e n t u s e d i n t h e M u n s e l l s y s t e m . E s s e n -t i a l l y , t h e M u n s e l l s y s t e m i s a m e t h o d f o r d e s c r i b i n g c o l o r i n t e r m s o f t h r e e a t t r i b u t e s , h u e , v a l u e a n d c h r o m a . T h e s e t h r e e f e a t u r e s a r e a r r a n g e d i n o r d e r l y s c a l e s o f e q u a l v i s u a l i n t e r v a l i n s u c h a m a n n e r t h a t t h e y b e c o m e p a r a m e t e r s b y w h i c h c o l o r m a y b e a n a l y z e d a n d d e s c r i b e d u n d e r c o n d i t i o n s o f c o n s t a n t i l l u m i n a t i o n . C h r o m a t i c c o l o r s i n t h e M u n s e l l s y s t e m a r e d i v i d e d i n t o f i v e m a i n c l a s s e s w h i c h a r e g i v e n h u e n a m e s o f r e d ( K ) , y e l l o w ( y ) , g r e e n ( G ) , b l u e ( B ) , a n d p u r p l e ( P ) . A f u r t h e r d i v i s i o n y i e l d s t h e f i v e i n t e r m e d i a t e h u e n a m e s o f y e l l o w - r e d (YPO, g r e e n - y e l l o w ( G Y ) , b l u e -g r e e n ( B G ) , p u r p l e - b l u e ( P B ) a n d r e d - p u r p l e ( R P ) . T h e c h a r t s u s e d i n t h e p r e s e n t s t u d y w e r e f u r t h e r s u b d i v i d e d a c c o r d i n g t o h u e d i v i s i o n s 2.5, 5-0, 7.5, 10.0 a n d t h e s e a r e a p p l i c a b l e t o a n y o f t h e h u e c l a s s e s o r s u b c l a s s e s m e n t i o n e d a b o v e . 77-T h e v a l u e n o t a t i o n u s e d i n t h i s s y s t e m r e f e r s t o t h e d e g r e e o f l i g h t -n e s s o r d a r k n e s s o f a g i v e n c o l o r i n r e l a t i o n t o a n e u t r a l g r a y s c a l e , w h i c h e x t e n d s f r o m t h e o r e t i c a l l y p u r e b l a c k ( s y m b o l i z e d a s 0 / ) t o a t h e o r e t i c a l l y p u r e w h i t e . (10/ ) . T h e c h r o m a n o t a t i o n o f a c o l o r i n d i c a t e s t h e s t r e n g t h o r d e g r e e o f s a t u r a t i o n o f t h e c o l o r a s c o m p a r e d t o a n e u t r a l g r a y o f t h e same v a l u e . T h e s c a l e s o f c h r o m a e x t e n d f r o m /0 f o r a n e u t r a l g r a y o u t t o /10, /12, o r f a r t h e r , d e p e n d i n g o n t h e s t r e n g t h o f t h e c o l o r . T h e c o m p l e t e M u n s e l l n o t a -t i o n f o r a n y c h r o m a t i c c o l o r b e c o m e s t h e n h u e v a l u e / c h r o m a , o r s y m b o l i c a l l y H V / C F o r e x a m p l e , m a n y o f t h e b l u e - g r e e n s t h a t a r e s o m u c h a f e a t u r e o f c o n i f e r o u s f o l i a g e f a l l w i t h i n t h e r a n g e 7-5 GY ( h u e ) , 3/ ( v a l u e ) , / 4 ( c h r o m a ) o r 7-5 GY 3 /4 t o 5.0 GY 6/8. O f t h e t e n c l a s s e s a n d s u b - c l a s s e s o f h u e m e n t i o n e d e a r l i e r a s b e i n g t h e b a s i s o f t h e s y s t e m , o n l y f o u r , r e d ( R ) , y e l l o w - r e d ( Y R ) , y e l l o w ( Y ) , g r e e n - y e l l o w (GY ) ) c a m e i n f o r a n y e x t e n s i v e u s e . C u r i o u s l y , v e r y f e w n e e d l e s i n d e e d c o u l d , b y t h i s s y s t e m , b e c a l l e d g r e e n . W h e n a c t u a l c o m p a r i s o n s w i t h t h e c o l o r e d p l a t e s o r c h i p s a r e m a d e i t i s r e a d i l y s e e n t h a t t h e " g r e e n " o f c o n i f e r o u s t r e e s l i e s m o r e i n t h e m i d d l e o f t h e g r e e n - y e l l o w (GY) s u b - c l a s s . O n t h e w h o l e , t h e s y s t e m i s a s i m p l e o n e t o u s e a n d t h e c h a r t s a r e w e l l p r i n t e d a n d e a s i l y h a n d l e d . F o r t h e i n t e r p r e t a t i o n o f c o l o r d i f f e r -e n c e s o c c a s i o n e d b y m i n e r a l d e f i c i e n c y , i t w o u l d b e a n a d v a n t a g e t o h a v e a 10 -way s p l i t o n a n y o n e h u e r a t h e r t h a n t h e 4 - w a y s p l i t p r e s e n t l y u s e d . T h e r e w e r e c o l o r s w h i c h w o u l d n o t f i t a c c u r a t e l y o n t o a n y o f t h e h u e c h a r t s w h i c h a 2 . 5 , 5 . 0 , 7.5, 10.0 s u b d i v i s i o n p r o v i d e d . I t b e c a m e i m m e d i a t e l y a p p a r e n t t h a t , f o r t h e r e t o b e a n y c o n s i s t e n t b a s i s o f c o m p a r i s o n , s e p a r a t e c o l o r n o t a t i o n s w o u l d h a v e t o b e m a d e f o r o l d n e e d l e s ( i . e . , n e e d l e s p r o d u c e d i n p r e v i o u s g r o w i n g s e a s o n s ) , n e w n e e d l e s 78. c h l o r o t i c n e e d l e s a n d n e c r o t i c n e e d l e s . S y m p t o m s s u c h a s c h l o r o s i s a n d n e c r o s i s a r e p r e s e n t o n b o t h n e w a n d o l d n e e d l e s b u t a f u r t h e r s e p a r a t i o n i n t o c h l o r o t i c o l d a n d c h l o r o t i c new. n e e d l e s s e e m e d t o a f f o r d l i t t l e u s e f u l i n f o r m a t i o n , a n d s i n c e i n m a n y c a s e s t h e y w e r e v e r y a k i n t o o n e a n o t h e r , t h e f o u r c l a s s e s o f n e e d l e s o n w h i c h c o l o r d e t e r m i n a t i o n s w e r e m a d e r e m a i n e d o l d , n e w , c h l o r o t i c a n d n e c r o t i c . 1_/ 1 / C h l o r o s i s : a d i s e a s e d c o n d i t i o n o f l i v i n g c h l o r o p h y l l o u s c e l l s c h a r a c t e r i z e d b y a y e l l o w c o n d i t i o n o f p a r t s t h a t a r e n o r m a l l y g r e e n . N e c r o s i s : a s t a t e o f d e a t h a t t h e c e l l u l a r l e v e l ; s y m p t o m a t i c e v i d e n c e o f a d i s e a s e d c o n d i t i o n i n g r e e n p l a n t s u s u a l l y t a k i n g t h e f o r m o f b r o w n o r b l a c k d i s c o l o r a -t i o n s a c c o m p a n i e d b y s h r i n k a g e a n d d i s t o r t i o n . 7 9 , 3- C o l o r k e y s t o t h e f o l i a r s y m p t o m s o f m a c r o n u t r i e n t d e f i c i e n c y T h e c o l o r k e y s t h a t f o l l o w a r e s e l f - e x p l a n a t o r y . T h e c o d e a n d t h e m a n n e r o f i t s u s e h a v e "been p r e v i o u s l y e x p l a i n e d . T h e c o l o r s a r e a g a i n t a k e n f r o m t h e M u n s e l l c o l o r n o t a t i o n a n d c o m p a r i s o n s w e r e m a d e i n s u n l i g h t u n d e r g l a s s i n t h e m a n n e r p r e v i o u s l y d e s c r i h e d . T h e u s e o f s u c h a c o l o r c o d e t o d e s c r i b e f o l i a r c o l o r a t i o n s i n t r e e s h a s b e e n r e c e n t l y e n d o r s e d b y H a m i l t o n ( i 9 6 0 ) . A c a s e i s m a d e f o r t h e a d o p t i o n o f a c o l o r s c h e m e t h a t i s , i n m a n y r e s p e c t s , s i m i l a r t o t h e o n e t h a t f o l l o w s . C O A S T A L D O U G L A S F I E O l d N e e d l e s K e v N e e d l e s C h l o r o s i s K e c r o s i s C o m p l e t e 10.0 GY 4/2 I 5.0 GY 5/6 I L o v N | 7Q GY 5/6 i 2.5 GY 7/6 | 10-0 YP» 8/8 | 2.5 Y E 4/8 , L o w S t 7-5 GY 5/4 1 5-0 G Y 5/6 1 2.5 Y 8/8 1 5-0 Y B 5/8 , L o w M g 1 7-5 GY 5/4 1 5-0 GY 5/8 1 2.5 Y 8/8 1 10.0 g 4/6 , L o w C a I 7-5 G Y 5/4 1 5.0 GY 6/8 1 2.5 Y 7/6 | 10.0 § 4/8 | L o w P I 7-5 GY 5/4 1 5-0 G Y 5/6 1 M l 5-0 Y B 5/4 | Low K I 7.5 GY 3/4 1 5-0 GY 6/8 1 2.5 Y 8/6 1 10.0 B 5/4 I 5 T S R I 0 B I JOUGLAS F I R O l d N e e d l e s K e v N e e d l e s C h l o r o s i s N e c r o s i s C o m p l e t e l 7 . 5 GY 5 / 4 1 5 - 0 C Y 6 / 8 1 N i l I N i l _ 1 L o v N l 5 - 0 GY 5 / 4 1 2 . 5 G Y 7 / 6 1 1 0 . 0 Y R 7 / 6 , 1 0 - 0 R 4 / 6 | L o v S I 5 . 0 GY 4 / 4 I 5 - 0 GY 6 / 8 1 2 . 5 Y 8 / 8 1 2 . 5 Y R 3 / 4 | L o v M g I 5 . 0 GY 4 / 6 1 5 . 0 GY 7 / 1 0 l 2 . 5 Y 7 / 8 1 2 - 5 Y R 3 / 6 | L o v C a I 7.-5 GY I 5.0 GY 6 / 8 l 2 . 5 Y 6 / 8 1 7-5 R 2 / 2 1 Lov P 2 . 5 GY 5 / 2 1 5 - 0 GY 5 / 6 1 N i l 2 . 5 Y R 5 / 2 1 L o v K 5-0 CY 5/6 L P.5 GY" 7/6 P.ft Y 8/6 10.0 B ?/* P O N D E R O S A P I N E O l d N e e d l e s N e w N e e d l e s C h l o r o s i a flRnmals C o m p l e t e 7-f? GY 4/6 I 5 .0 GY 5/6 I mj I N i l L o w N I 5-0 GY 5/4 | 5.0 GY 6/6 | 10.0 YR 7/8 i 2.5 YR 5/6 i L o w S L o w M g 7-5 GY 4/4 i 5 . 0 GY 5/8 i 2.5 Y 8/10 i 2.5 YR 4/4 i L o w C a 7.5 GY 5/4 i 5 . 0 GY 5/6 , 2.5 Y 7/6 I 7.5 YR 6/6 i L o w P L o w K 7-5 GY 4/4 5.0 GY 5/8 10.0 YR 7/8 I n d e f i n i t e W E S T E R N VI TTTO P T T T O O l d N e e d l e s N e w N e e d l e s C h l o r o s i s N e c r o s i s Complete I Z*5 GY 4 / 6 I -7.0 GY 6 / 8 i i l l I N i l L o v N | Same a s n e v i 5.0 G Y 6 / 8 , 10.0 Y R 7/6 , 2 . 5 Y R 4 / 6 L o v S 5TQ GY 5/4 I 5«Q GY 5/6 i 7-5 YB 6 / 8 , 2.5 YR 3/2 , L o v M g I 5 . 0 GY 5 / 6 i 5 . 0 GY 6 / 8 , 10.0 Y R 6 / 8 i 2 . 5 Y R 5 / 6 , L o v C a 7.5 GY 4 / 6 i 5.0 GY 6 / 8 , 5.0 Y 6 / 8 i 2.5 Y R 5 / 6 i L o v P 7.5 GY 5 / 4 i 5.0 GY 4 / 6 , 10.0 Y R 6 / 8 i 5.0 Y R 6 / 6 , L o v K 5.0 GY 4 / 6 , 5.0 GY 5 / 8 , 2.5 Y 6 / 8 i 5.0 YR 5 / 6 | E N G E L M A M S P R U C E O l d E e e d l e s K e v K e e d l e s C h l o r o s i s N e c r o s i s C o m p l e t e Same a s n e v , 7-5 GY 3/4 i K i l | K i l L o v H i Same a s n e v I 5.0 GY 6/6 I K i l i K i l | L o v S i Same a s n e v L o v M g i Same a s n e v I L o v C a S a m e a s n e v I 2.5 G 5/2 I 5.0 Y 3/8 I 2.5 Y R 4/6 | L o v P 7-5 GY 4/4 , 5.0 GY 6/6 | 2.5 GY 5/6 , 2.5 Y R 3/4 | L o v E Same a s n e v , 7-5 GY 5/4 i K i l i 10.0 R 6/8 80. 4 . A d i c h o t o m o u s k e y t o f o l i a r s y m p t o m s o f d e f i c i e n c y H a v i n g a c o l o r n o t a t i o n f o r e a c h d e f i c i e n c y o n e a c h s p e c i e s , i t i s p o s -s i b l e t o d r a w u p n u m e r o u s k e y s w h i c h w i l l f a c i l i t a t e f u t u r e d i a g n o s i s . O n l y o n e s u c h p o s s i b l e k e y f o r e a c h o f t h e f i v e s p e c i e s i s p r e s e n t e d a n d i t w a s s e l e c t e d b e c a u s e o f t h e s i m p l i c i t y o f t h e i n f o r m a t i o n u s e d i n i t s c o m -p i l a t i o n . D i c h o t o m o u s K e y s t o F o l i a r S y m p t o m s o f D e f i c i e n c y a s T h e y D e v e l o p o n C o a s t a l . D o u g l a s - f i r , I n t e r i o r D o u g l a s - f i r , P o n d e r o s a P i n e , W e s t e r n W h i t e P i n e a n d E n g e l m a n n S p r u c e C h a r a c t e r i s t i c s u s e d : (1 ) M u n s e l l c o l o r c o d e n u m b e r ; (2) N e e d l e l e n g t h . C o a s t a l D o u g l a s - f i r N e e d l e s c o n s i d e r a b l y r e d u c e d i n l e n g t h A . N e e d l e s n o t s i g n i f i c a n t l y r e d u c e d i n l e n g t h B . A . L i g h t y e l l o w - g r e e n c h l o r o t i c (10.0 Y R 8/8) a n d f r e q u e n t l y l i g h t - b r o w n n e c r o t i c (2.5 Y R 4/8) N i t r o g e n A . L i t t l e c h l o r o s i s e v i d e n t , b u t a n e a r l y o n s e t o f d a r k r e d n e c r o s i s u s u a l (5.0 Y R 3 / 4 ) P h o s p h o r u s B . P r o n o u n c e d y e l l o w c h l o r o s i s (2.5 Y 8/8 w i t h d i s t i n c t i v e b l a c k " b a r s " i n c h l o r o t i c a r e a s M a g n e s i u m B . Y e l l o w c h l o r o s i s p r e s e n t b u t n o b l a c k " b a r s " o b v i o u s C . C N e c r o s i s 2.5 Y R 4/8 S u l f u r C . N e c r o s i s . 10.0 R h u e D . D . C h l o r o s i s g e n e r a l o n n e w a n d o l d n e e d l e s (7.5 Y R 6/6) P o t a s s i u m D . C h l o r o s i s r e s t r i c t e d t o o l d e r n e e d l e s (2-5 Y 7/6) C a l c i u m I n t e r i o r D o u g l a s - f i r N e e d l e s c o n s i d e r a b l y s h o r t e r t h a n n o r m a l A . N e e d l e s n o t s i g n i f i c a n t l y s h o r t e r t h a n n o r m a l B . A . O l d n e e d l e s d a r k b l u e - g r e e n (2.5 GY 3/2) b e c o m i n g b r o w n n e c r o t i c e a r l y (2.5 Y R 3/2) w i t h l i t t l e i n t e r m e d i a t e c h l o r o s i s P h o s p h o r u s 81. A . O l d n e e d l e s g r e e n (5.0 GY 5 / 4 ) b e c o m i n g v e r y c h l o r o t i c (10.0 Y E 7/6) a n d d a r k - b r o w n n e c r o t i c (10.0 E 4/6) N i t r o g e n B . D a r k g r e e n f o l i a g e o f o l d (5-0 G Y 4/6-4/8) a n d n e w n e e d l e s (5.0 GY 6/8) C . B . L i g h t g r e e n f o l i a g e o f o l d (5-0. GY 7/10) a n d e s p e c i a l l y n e w n e e d l e s (2.5 GY 7/6) D . C . C h l o r o s i s (2.5 Y 6/8), n e c r o s i s (7«5 R 2/2) C a l c i u m C C h l o r o s i s (2.5 Y 8/8), n e c r o s i s (2-5 Y E 3 / 4 ) . . . S u l f u r D . C h l o r o s i s b e g i n s o n t i p o f n e e d l e s (2.5 Y 7/8-5.0 Y 8/8) a n d r e m a i n d e r o f n e e d l e r e m a i n s g r e e n M a g n e s i u m D . E n t i r e n e e d l e p a l e s t o a n o v e r a l l y e l l o w - g r e e n c o l o r (2.5 Y 8/6) P o t a s s i u m P o n d e r o s a P i n e N e e d l e s l e s s t h a n h a l f t h e i r n o r m a l l e n g t h A . N e e d l e s m o r e t h a n h a l f t h e i r n o r m a l l e n g t h B . A . C h l o r o s i s 2.5 GY 6/8 P h o s p h o r u s A . C h l o r o s i s 10.0 Y E 7/8 N i t r o g e n B . O l d n e e d l e s v e r y d a r k g r e e n (7.5 G Y 3 / 4 ) , m a y b e p i n k - t i p p e d a n d h o o k e d ,. C a l c i u m B . O l d n e e d l e s n o t d a r k g r e e n (7.5 GY 4 / 4 - 4/6), a n d w i t h n o h o o k i n g o r : . p i n k d i s c o l o r a t i o n C . C . D i s t i n c t i v e b r i g h t y e l l o w c h l o r o s i s o f f a s c i c l e n e e d l e t i p s (2.5 Y 8/10) M a g n e s i u m C . C h l o r o s i s p r e s e n t b u t n o t r e s t r i c t e d t o t h e n e e d l e t i p s a n d n o t s u c h a b r i g h t y e l l o w c o l o r (10.0 Y R 7/10) D . D . C h l o r o s i s m i n o r , r e s t r i c t e d t o o l d e r s e c o n d a r y a n d p r i m a r y n e e d l e s . N e c r o s i s p r e s e n t (2.5 Y R 4/6) S u l f u r D . C h l o r o s i s g e n e r a l , m i x e d w i t h n e c r o t i c a r e a s o n n e e d l e s , u s u a l l y s t r i k i n g . N e c r o s i s v e r y a b u n d a n t (10.0 R 3 / 4 -2.5 Y R 3 / 4 ) P o t a s s i u m 82. W e s t e r n W h i t e P i n e N e e d l e s l e s s t h a n h a l f " t h e i r n o r m a l " l e n g t h A . N e e d l e s s h o r t e r t h a n n o r m a l h u t n o t l e s s t h a n t w o t h i r d s t h e i r n o r m a l l e n g t h B . A . F a s c i c l e n e e d l e s l i g h t - g r e e n (5 .0 GY.6/8), a n d s t r o n g l y c h l o r o t i c - ( 1 0 . 0 Y E 7/6) b e c o m i n g n e c r o t i c (2.5 Y E 4/6), e s p e c i a l l y ' a t t i p s . . . . . . . . . . . . . . . . . . . . . N i t r o g e n A l F a s c i c l e n e e d l e s d a r k p u r p l e - g r e e n (7.5 G Y " 3 / 4 ) w i t h o n l y s p o t t y c h l o r o s i s ( 1 0 . 0 - Y R 6/8), b u t w i t h c o n s i d e r a b l e n e c r o s i s (5.0 Y R 6/6), s o m e t i m e s o f l a r g e n e e d l e p o r t i o n s .- i . . . P h o s p h o r u s B . S t r o n g n e e d l e d e v e l o p m e n t , l o n g , s t o u t ^ w i t h * a d i s -t i n c t i v e o c h r e - y e l l o w c h l o r o s i s (7.5 Y R 6/8) . . . . . S u l f u r B . W e a k e n e d n e e d l e g r o w t h , " s l e n d e r n e e d l e s , a n d c h l o r o s i s i n t h e 5.0 Y - 2 . 5 Y - 10.0 Y R h u e s . . . . . . . . . C . C . O l d n e e d l e s d a r k b l u i s h g r e e n - (5 .0 GY 4/6), f o l i a g e s p a r s e , c h l o r o s i s (2.5 Y 6/8) a n d n e c r o s i s (5 .0 Y R 5/6) u s u a l l y e x t e n s i v e a n d s e v e r e ^ P o t a s s i u m C . O l d n e e d l e s g r e e n (7>5 G Y ) , f o l i a g e r e l a t i v e l y d e n s e , " c h l o r o s i s n o t 2 . 5 Y a n d n e c r o s i s d a r k e r b r o w n i n t h e 2.5 .YR 3/6 r e g i o n D . D . T i p c h l o r o s i s g e n e r a l a n d o f t e n s t r i k i n g , q u i t e y e l l o w ( 10 .0 Y R 6/8) . . . . . . . M a g n e s i u m D . T i p c h l o r o s i s i n f r e q u e n t , e v i d e n c e d o n l y b y a s l i g h t l i g h t e n i n g o f g r e e n c o l o r (5-0 Y 6/8) C a l c i u m E n g e l m a n n S p r u c e N e e d l e s b e c o m e n e c r o t i c ; (2.5 Y R 3/4-5.0 Y R 3 / 4 ) e a r l y a n d . f a l l p r e m a t u r e l y . E f f e c t s o f d e f i c i e n c y v e r y s e v e r e . . . . A . N e e d l e s b e c o m e c h l o r o t i c o r p a r t i a l l y n e c r o t i c a n d o n l y o c c a s i o n a l l y f a l l p r e m a t u r e l y B . A . S t r o n g , b r i g h t y e l l o w c h l o r o s i s o f a l l n e e d l e s (7.5 Y 8/6) M a g n e s i u m A . O n l y m i n o r c h l o r o s i s a n d t h a t s o m e w h a t d u l l y e l l o w - g r e e n (2.5 G Y 5/6) P h o s p h o r u s 83. B . D i s t i n c t i v e a n d w i d e s p r e a d g r e e n - y e l l o w c h l o r o s i s ( 2 . 5 G Y 6/6 - 5-0 GY 6/6) C . B . C h l o r o s i s p r e s e n t , y e l l o w t o y e l l o w - w h i t e ( 5 . 0 Y 7/6 -5.0 Y 8/8) ................... D . C . K e c r o s i s 5 . 0 Y E 3 /4 N i t r o g e n C N e c r o s i s a d i s t i n c t i v e - p u r p l e - p i n k .(.10.0 R 6/8) P o t a s s i u m D . O l d n e e d l e s v e r y d a r k g r e e n ( 2 . 5 G 3/2) b e c o m i n g b r o w n n e c r o t i c (2 .5 Y R 4/6) . . . . , C a l c i u m D . O l d n e e d l e s g l a u c o u s (7«5 GY ,3./4 b e c o m i n g d a r k b r o w n , n e c r o t i c (2 .5 Y R 2/2) . . . . . . . . . . . .' S u l f u r 5. D e s c r i p t i o n o f d e f i c i e n c y s y m p t o m s d e v e l o p e d T h e d e f i c i e n c y - s y m p t o m s t h a t f o l l o w a r e g r o u p e d b y d e f i c i e n t e l e m e n t r a t h e r . t h a n s p e c i e s t o i l l u s t r a t e - t h e u n i f o r m i t y o f r e s p o n s e b e t w e e n s p e c i e s t o a g i v e n d e f i c i e n c y . E f f e c t o f a d e f i c i e n c y o f n i t r o g e n o n d e v e l o p m e n t o f s h o o t s a n d f o l i a g e C o a s t a l D o u g l a s - f i r T e r m i n a l g r o w t h r e d u c e d i n l e n g t h , a s a r e n u m b e r . • , • o f - b r a n c h e s . N e w n e e d l e s l i g h t y e l l o w - g r e e n , c o n s i d e r a b l y s h o r t e r t h a n c o n t r o l s . O l d n e e d l e s y e l l o w , c h l o r o t i c , o f t e n p a r t i a l l y o r w h o l l y n e c r o t i c , f a l l i n g e a r l y i n m a n y c a s e s . C o t y l e d o n s s h o w e a r l y n e c r o t i c s y m p t o m s a n d f a l l v e r y e a r l y . I n t e r i o r D o u g l a s - f i r R e d u c e d t e r m i n a l g r o w t h , s h o r t b r a n c h e s r e d u c e d i n n u m b e r a n d i n o r d e r o f b r a n c h i n g . L e a d e r g r o w t h o f t e n l o o k s b r u s h y d u e t o c l o s e r ' s p a c i n g - o f - n e e d l e s o n s h o r t e n e d s t e m . N e w n e e d l e s s m a l l , s h o r t e r t h a n c o n t r o l s , y e l l o w - g r e e n c h l o r o t i c t o p a l e y e l l o w c h l o r o t i c , e s p e c i a l l y a t - t i p s . • O l d n e e d l e s s t r o n g l y c h l o r o t i c b e c o m i n g p r o g r e s s i v e l y n e c r o t i c , l i g h t r e d d i s h b r o w n i n c o l o r , f a l l i n g p r e m a t u r e l y . • C o t y l e d o n s b e c o m e n e c r o t i c a n d f a l l e a r l y . 8 4 . P o n d e r o s a p i n e ' . R e d u c e d h e i g h t g r o w t h a n d - a m a r k e d r e d u c t i o n i n n u m b e r a n d s t o . u t n e s a o.f b r a n c h e s . N e e d l e s , p a r t i c u l a r l y p r i m a r y o n e s o n l o w e r s t e m , p a r t i a l l y c h l o r o t i c / n e c r o t i c a n d f a l l i n g e a r l y . . M o r e r e c e n t l y d e v e l o p e d . p r i m a r y n e e d l e s . n e a r t h e t e r m i n a l e n d a r e v e r y m u c h s h o r t e n e d a n d l i g h t y e l l o w - g r e e n i n c o l o r . F a s c i c l e n e e d l e s , e s p e c i a l l y o l d e r o n e s , a r e d i s t i n c t l y . c h l o r o t i c y e l l o w - g r e e n w i t h y e l l o w t i p s . N e e d l e s g e n e r a l l y a r e m u c h m o r e s l e n d e r t h a n c o n t r o l s a n d o f t e n u n d u l a t i n g . W e s t e r n w h i t e p i n e R e d u c e d . g r o w t h o f t e r m i n a l s c o m m o n a n d a c o n s i d e r a b l e reduction.in t h e n u m b e r . o f b r a n c h e s . Some s e e d l i n g s d i d n o t h a v e a n y . N e w n e e d l e s a r e o f a c o n s p i c u o u s i i g h t r g r e e n h u e , . s o m e y e l l o w t i p p e d . O l d e r f a s c i c l e n e e d l e e x t r e m i t i e s s t r o n g l y y e l l o w - o r a n g e c h l o r o t i c a n d f a l l i n g . F e w n e e d l e s remain. N e c r o s i s i s o f o n l y m i n o r o c c u r r e n c e . E n g e l m a n n s p r u c e V e r y m u c h r e d u c e d b r a n c h d e v e l o p m e n t a n d t e r m i n a l g r o w t h . C u r r e n t y e a r ' s g r o w t h m u c h reduced a n d , i n s o m e c a s e s , n o . n e w t e r m i n a l g r o w t h m a y o c c u r . V e r y s t r o n g y e l l o w c h l o r o s i s o f n e w n e e d l e s ; o l d n e e d l e s a d i s t i n c t reddish b r o w n c o l o r , s o m e p a r t i a l l y c h l o r o t i c . T h e s e f o l i a r s y m p t o m s a r e s e v e r e s t i n l o w e r s t e m a n d b r a n c h a r e a s . N e e d l e f a l l i s s e v e r e . E f f e c t o f a d e f i c i e n c y o f n i t r o g e n o n r o o t d e v e l o p m e n t C o a s t a l D o u g l a s - f i r U s u a l l y v e r y f i n e l y f i b r o u s , l i g h t b r o w n i n c o l o r , l o n g e r t h a n n o r m a l , s l i g h t t o m o d e r a t e l y d e n s e . G r o w i n g t i p s p r e s e n t i n c o n s i d e r a b l e n u m b e r a l t h o u g h r e s t r i c t e d t o u p p e r p a r t s o f t h e s y s t e m . D e c a y m o d e r a t e , i n c l i n e d t o b e h e a v y a t d e p t h . S t r o n g s u l f u r o u s s m e l l f r o m d e e p e r , b l a c k e n e d r o o t s . I n t e r i o r D o u g l a s - f i r M o d e r a t e t o s p a r s e l y b r a n c h e d , l o n g e r t h a n c o n -t r o l s , s p i n d l y a n d o n l y m o d e r a t e l y f i b r o u s a t b e s t . W o o d y p o r t i o n s o f t e n w h i t i s h . R e d u c e d n u m b e r o f r o o t e n d s e x h i b i t i n g a c t i v e g r o w t h , u s u a l l y p r e s e n t i n g r e a t e r a m o u n t i n u p p e r p a r t o f s y s t e m . L a r g e r , w o o d i e r l a t e r a l s a r i s e f r o m relatively d e e p p o s i t i o n s o n t a p r o o t . R o o t s a r e c o v e r e d b y n u m e r o u s h a i r s . D e c a y o f t e n v e r y s e v e r e w i t h s t r o n g s u l f u r o u s s m e l l c h a r a c t e r i s t i c . D e c a y e d p o r t i o n s b l a c k a s i s t h e s a n d w i t h w h i c h t h e y c o m e i n c o n t a c t . D e c a y e d r o o t s q u i t e g e l a t i n o u s a n d f o r m i n g m a t s . D e c a y m o s t s e v e r e i n l o w e r t a p r o o t a n d i t s d e e p p l a c e d e x t e n s i o n s . 85-P o n d e r o s a p i n s M o d e r a t e l y d e n s e s y s t e m , f i n e l y , f i b r o u s , n o t v e r y w o o d y . L a t e r a l g r o w t h l o n g w i t h m a n y f i n e , w h i t e - t i p p e d r o o t l e t s b u t l a t t e r n o t s w o l l e n . B o o t s g e n e r a l l y s l e n d e r w i t h l i t t l e o r n o t e n d e n c y t o w o o d i n e s s . D e c a y v e r y s e v e r e c o m m o n l y . L o w e r p o r t i o n s o f s y s t e m c o m p l e t e l y b l a c k e n e d , a s i s s u r r o u n d i n g s a n d . S o m e t i m e s o n l y u p p e r t h i r d o f r o o t s y s t e m r e m a i n s v i a b l e . W e s t e r n w h i t e p i n e S l i g h t l y t o m o d e r a t e l y f i b r o u s , n o t d e n s e , r a t h e r s p a r s e s y s t e m w i t h l i t t l e w o o d y d e v e l o p m e n t o f l a t e r a l s . L i t t l e n e w g r o w t h . W h e r e p r e s e n t , n e w r o o t s a r e l i g h t b r o w n i n c o l o r , f i n e l y d i v i d e d , a n d u s u a l l y p r e s e n t i n u p p e r p o r t i o n s o f s y s t e m . . D e c a y i s m o d e r a t e t o v e r y h e a v y e s p e c i a l l y a t d e p t h . B o o t s s t a i n e d a n i n k y b l a c k c o l o r , g e l a t i n o u s , a n d a p p a r e n t l y f u n c t i o n l e s s . S a n d i s s i m i l a r l y s t a i n e d . E n g e l m a n n s p r u c e S p a r s e , f i n e l y f i b r o u s s y s t e m . M a n y f i n e , w h i t e r - t i p p e d g r o w i n g l a t e r a l s d e v e l o p i n g e s p e c i a l l y a t m a j o r w o o d y , l a t e r a l e x t r e m i t i e s . N e w r o o t s l i g h t b r o w n i n c o l o r . D e c a y s l i g h t t o m o d e r a t e , u s u a l l y s e v e r e s t o n f i b r o u s e x t e n s i o n s o f t h e t a p r o o t . D e c a y e d a r e a s b l u e - b l a c k i n c o l o r . E f f e c t o f a d e f i c i e n c y o f s u l f u r o n d e v e l o p m e n t o f s h o o t s a n d f o l i a g e C o a s t a l D o u g l a s - f i r S h o o t a n d b r a n c h d e v e l o p m e n t n o r m a l . N e w n e e d l e s d a r k g r e e n , n o r m a l . N e w n e e d l e s n o t s o g l a u c o u s b u t l a c k i n g a n y c h l o r o t i c o r n e c r o t i c s y m p t o m s . I n t e r i o r D o u g l a s - f i r B r a n c h d e v e l o p m e n t g o o d a s i s t e r m i n a l g r o w t h , e s p e c i a l l y i n s e c o n d y e a r . L a t e r a l b r a n c h e s o f t e n v e r y l o n g . N e w n e e d l e s n o r m a l , d a r k g r e e n , o c c a s i o n a l l y , h o w e v e r , a d a x i a l s u r f a c e s a r e r u p t u r e d , e s p e c i a l l y a l o n g m i d - r i b . O l d n e e d l e s , p a r t i c u l a r l y t h o s e o n l o w e r s t e m a n d b r a n c h e s , h a v e a d i s t i n c t i v e d u l l y e l l o w d i s c o l o r a t i o n a n d a r e v e r y f r e q u e n t l y r u p t u r e d l o n g i t u d i n a l l y . O n l y m i n o r n e c r o s i s . 86. P o n d e r o s a p i n e T e r m i n a l g r o w t h , g o o d a n d b r a n c h d e v e l o p m e n t a s g o o d a s c o n t r o l s . S t o u t , w o o d y d e v e l o p m e n t , g e n e r a l l y v i g o r o u s . F a s c i c l e n e e d l e s l o n g , h e a l t h y , g l a u c o u s , s t i f f . N e w p r i m a r y n e e d l e s o n m a i n s t e m d a r k e r b l u e - g r e e n a n d s h o r t e r . O l d p r i m a r y n e e d l e s y e l l o w c h l o r o t i c o r p a r t n e c r o t i c . P e r s i s t e n t . W e s t e r n w h i t e p i n e G o o d s t e m a n d b r a n c h d e v e l o p m e n t , a l m o s t a s g o o d a s c o m p l e t e s o l u t i o n . N e w f a s c i c l e n e e d l e s a r e a h e a l t h y , b l u e - g r e e n c o l o r , a n d f o l i a g e g e n e r a l l y d e n s e . O l d f a s c i c l e n e e d l e s a n d l o w e r p r i m a r y n e e d l e s o n m a i n s t e m a r e p a r t o c h r e - y e l l o w c h l o r o t i c , p a r t n e c r o t i c . S u c h s y m p t o m s a r e m i n o r i n e x t e n t . E n g e l m a n n s p r u c e T e r m i n a l g r o w t h s h o r t e r t h a n n o r m a l , b r a n c h d e v e l o p -m e n t a s g o o d a s c o n t r o l s . N e e d l e s i n s u b - t e r m i n a l s t e m p o r t i o n s u p s w e p t a r o u n d t h e s t e m . N e w n e e d l e s l o n g , s t o u t , d a r k b l u e - g r e e n . O l d n e e d l e s g r a y - g r e e n w i t h a d i s t i n c t y e l l o w i s h - w h i t e c h l o r o s i s e x t e n d i n g f r o m t i p t o a p o i n t h a l f w a y " d o w n n e e d l e l e n g t h . N e c r o s i s m i n o r . Some o f o l d m a i n s t e m n e e d l e s a r e f a l l i n g p r e m a t u r e l y . E f f e c t o f a d e f i c i e n c y o f s u l f u r o n r o o t d e v e l o p m e n t C o a s t a l D o u g l a s - f i r V e r y d e n s e , w e l l - b r a n c h e d s y s t e m s . N u m e r o u s a c t i v e g r o w i n g t i p s w e l l d i s t r i b u t e d t h r o u g h o u t t h e s y s t e m . D e c a y s l i g h t t o v e r y s l i g h t . I n t e r i o r D o u g l a s - f i r C o a r s e , w o o d y , m u c h b r a n c h e d , d e n s e l y f i b r o u s . G e n e r a l l y , a l a r g e a n d v i g o r o u s s y s t e m . M a n y n e w , a c t i v e l y g r o w i n g , w h i t e - t i p p e d r o o t s , m a i n l y a r i s i n g a s o u t g r o w t h s o f l a t e r a l s . D e c a y o f t e n v e r y s e v e r e , g i v i n g s y s t e m a b l a c k a p p e a r a n c e . D e c a y c o n c e n t r a t e d o n o l d l a t e r a l g r o w t h n e a r t h e s u r f a c e . P o n d e r o s a p i n e N o r m a l l y v e r y d e n s e , c o a r s e l y f i b r o u s , e x t e n s i v e s y s t e m w i t h m a n y w o o d y l a t e r a l s . T a p r o o t s h o r t , m a i n f u n c t i o n i n g r o o t i s a p a r t o f w i d e l a t e r a l s y s t e m . N e w g r o w i n g t i p s n u m e r o u s a n d w h i t e . D e c a y v e r y m i n o r . 87-W e s t e r n w h i t e p i n e D e i i s e , c o a r s e l y f i b r o u s s y s t e m w i t h e x t e n s i v e w o o d y l a t e r a l d e v e l o p m e n t w h i c h s u r p a s s e s t h a t o f c o n t r o l s . H e a l t h y p o r t i o n s o f t h e r o o t s y s t e m a r e c h a r a c t e r i z e d b y a y e l l o w / b r o w n d i s -c o l o r a t i o n , l e w r o o t d e v e l o p m e n t i s c o m m o n a n d f e a t u r e s m a n y l a r g e , a c t i v e l y g r o w i n g w h i t e t i p s . V e r y v i g o r o u s s y s t e m o n t h e w h o l e . B o o t h a i r s c o m m o n a t d e p t h . D e c a y o n l y m i n o r i n a m o u n t . G e n e r a l l y d e c a y f r e e . E n g e l m a n n s p r u c e F i n e t o m o d e r a t e l y c o a r s e , m o d e r a t e l y d e n s e s y s t e m w i t h s t o u t l a t e r a l d e v e l o p m e n t . H e w g r o w t h o n t h e r o o t i s a c h a r a c t e r i s t i c p a r s n i p - b r o w n c o l o r . N e w r o o t e n d i n g s w h i t e a n d n u m e r o u s e s p e c i a l l y i n u p p e r l a t e r a l b r a n c h e s . C o n s i d e r a b l e p o r t i o n s o f t h e r o o t s y s t e m e x h i b i t d e c a y , e s p e c i a l l y i n t h e l o w e r h a l f . G e n e r a l l y , s e v e r e a n d d a m a g e d r o o t s t u r n b l a c k , g e l a t i n o u s . E f f e c t o f a d e f i c i e n c y o f m a g n e s i u m o n d e v e l o p m e n t o f s h o o t s a n d f o l i a g e C o a s t a l D o u g l a s - f i r B r a n c h e s s h o r t a n d b r u s h y - l o o k i n g a t t i p s . A m o d e r a t e d e g r e e o f b r a n c h i n g . N e w n e e d l e s d a r k g r e e n , s o m e w h a t s h o r t e r t h a n c o n t r o l s , w i t h o n l y s l i g h t c h l o r o s i s . O l d n e e d l e s a l l s h o w some s i g n s o f d e f i c i e n c y . C h l o r o t i c n e e d l e s w i t h p a r t i a l n e c r o s i s o f o u t e r e x t r e m i t i e s a r e c o m m o n . B l a c k b a r -l i k e a r e a s o c c u r q u i t e f r e q u e n t l y i n n e c r o t i c a r e a s a n d a r e t y p i c a l f o r t h i s d e f i c i e n c y o n l y . C o t y l e d o n s c o m p l e t e l y n e c r o t i c a n d f a l l i n g e a r l y . I n t e r i o r D o u g l a s - f i r T e r m i n a l g r o w t h s h o r t e r b u t b r a n c h e s n u m e r o u s a n d w e l l d e v e l o p e d . S t e m s w e a k a n d t a p e r i n g r a p i d l y . O n l y s l i g h t c h l o r o s i s g e n e r a l l y o f n e w n e e d l e s . O l d n e e d l e s s h o w h e a v y c h l o r o t i c a n d n e c r o t i c s y m p t o m s e s p e c i a l l y o n l o w e r s t e m a n d b r a n c h a r e a s . M o d e r a t e t o s e v e r e p r e m a t u r e l e a f f a l l . C o t y l e d o n s n e c r o t i c a n d f a l l i n g e a r l y . P o n d e r o s a p i n e M o d e r a t e l y g o o d l e a d e r g r o w t h a n d b r a n c h d e v e l o p m e n t . S y m p t o m s o f d e f i c i e n c y a r e m o s t s t r i k i n g o n f a s c i c l e n e e d l e s w h i c h s h o w p r o -n o u n c e d e a r l y y e l l o w c h l o r o s i s w h i c h i s b o t h s t r i k i n g a n d u n i f o r m . T h i s g i v e s w a y t o a n e c r o t i c c o n d i t i o n a n d c h l o r o s i s a p p e a r s l o w e r d o w n o n . n e e d l e . 8 8 . N e e d l e s g e n e r a l l y . q u i t e l o n g a n d s l e n d e r . P r i m a r y n e e d l e s p a r t c h l o r o t i c , p a r t n e c r o t i c h u t a l l a f f e c t e d t o a d e g r e e . P r e m a t u r e n e e d l e f a l l m o d e r a t e l y h e a v y . C o t y l e d o n s e x h i b i t e a r l y c h l o r o s i s , b e c o m e q u i c k l y n e c r o t i c ( t a w n y b r o w n ) , ' b u t p e r s i s t . D i s t i n c t i v e p u r p l e b a n d s s e p a r a t i n g c h l o r o t i c f r o m n e c r o t i c ^ a r e a s a n d w i t h i n t h e n e c r o t i c a r e a s a r e c o m m o n . W e s t e r n w h i t e p i n e M a n y s h o r t l a t e r a l b r a n c h e s i n t h e t e r m i n a l b u d r e g i o n . T e r m i n a l g r o w t h f a i r . V i g o r r e m a i n s g o o d e v e n t h o u g h t h e r e a r e o b v i o u s s i g n s o f d e f i c i e n c y . E o l i a g e g e n e r a l l y d e n s e ; n e w n e e d l e s g l a u c o u s e x c e p t a t t i p s w h e r e a l i g h t g r e e n c o l o r p r e d o m i n a t e s a t f i r s t . • T h i s f a d e s t o a w h i t i s h - y e l l o w ( a l s o l e m o n ) c h l o r o s i s , w h i c h i s c o m m o n . Some n e c r o s i s p r e s e n t . S y m p t o m s s e v e r e r - - o n l o w e r , o l d e r n e e d l e s a n d t h e s e , l i k e p r i m a r y n e e d l e s , h e a v i l y a f f e c t e d . M a n y o f t h e l a t t e r f a l l . E a r l y t y p i c a l b l a c k M g b a r s h e r e p r e s e n t a l s o . E n g e l m a n n s p r u c e T e r m i n a l g r o w t h v e r y m u c h r e d u c e d a n d i n some c a s e s t h e r e i s s t r o n g d i e - b a c k o f a f f e c t e d l e a d e r s . B r a n c h e s a r e r e d u c e d b o t h i n n u m b e r a n d s i z e > a n d f e w , i f a n y , a r i s e i n u p p e r s t e m p o r -t i o n s . A n e a r l y a p p e a r a n c e o f a s t r o n g c h l o r o t i c c o n d i t i o n o f n e w n e e d l e s i s e v i d e n t . O l d n e e d l e s ( c h l o r o t i c p r e v i o u s l y ) t u r n a d i s t i n c t i v e r e d d i s h - b r o w n c o l o r , a l t h o u g h some m a y r e m a i n p a r t i a l l y c h l o r o t i c . S y m p t o m s a r e s e v e r e s t o n l o w e r s t e m a n d b r a n c h a r e a s . E f f e c t o f a d e f i c i e n c y o f m a g n e s i u m o n r o o t d e v e l o p m e n t C o a s t a l D o u g l a s - f i r U s u a l l y q u i t e d e n s e , a n d v e r y f i b r o u s w i t h m a n y f i n e r r o o t s . I n c l i n e d t o b e s h a l l o w e r t h a n n o r m a l . N u m e r o u s ' n e w . g r o w i n g t i p s e v i d e n t I n m o s t s y s t e m s . D e c a y i s o n l y s l i g h t a n d r e s t r i c t e d t o d e e p l y p l a c e d l a t e r a l s w h i c h m a y n o t h a v e r e c e i v e d p r o p e r a e r a t i o n . I n t e r i o r D o u g l a s - f i r D e n s e l y f i b r o u s , v i g o r o u s s y s t e m w i t h m a n y w e l l -d e v e l o p e d l a t e r a l s . New g r o w t h i s p l e n t i f u l , e s p e c i a l l y i n t h e r e g i o n o f t h e u p p e r l a t e r a l s . S y s t e m l i k e l y t o b e l i g h t b r o w n a b o v e , d a r k e r a n d s l o w e r g r o w i n g b e l o w . T h e r e s e e m s t o b e a r a p i d t u r n o v e r i n r o o t d e g e n e r a t i o n a n d r e n e w a l . T h i s i s e v i d e n c e d b y a c t i v e l y g r o w i n g , w h i t e - t i p p e d r o o t s b e i n g p r e s e n t a d j a c e n t t o t h o s e t h a t a r e b l a c k , s t r i n g y a n d g e l a t i n o u s . D e c a y m o d e r a t e • t o s e v e r e . j 89-P o n d e r o s a p i n e V e r y f i n e l y f i b r o u s , i n t e r t w i n i n g d e n s e s y s t e m u s u a l l y o f f i n e s l e n d e r r o o t l e t s . G r o w t h c o n t i n u o u s a n d a c t i v e a s e v i d e n c e d b y m a n y w h i t e - t i p p e d , a c t i v e l y g r o w i n g , l i g h t - b r o w n r o o t l e t s . N o t a s w o o d y a s n o r m a l . D e c a y i s m o d e r a t e t o s e v e r e w i t h a s t r o n g s u l f u r o u s s m e l l c o m m o n l y p r e s e n t . L o w e r p a r t s o f t e n m u c h b l a c k e n e d a n d s t r i n g y , c o m p l e t e l y n o n - f u n c t i o n a l . W e s t e r n w h i t e p i n e S p a r s e , c o a r s e , f i b r o u s s y s t e m . N o t m o r e t h a n m o d e r a t e l y d e n s e . M a n y n e w r o o t s u s u a l l y a p p a r e n t e s p e c i a l l y i n u p p e r p a r t s o f s y s t e m . P r o l i f i c r o o t h a i r d e v e l o p m e n t u s u a l , e s p e c i a l l y o n l i g h t b r o w n n e w r o o t s . L a t t e r a l s o w h i t e - t i p p e d . D e c a y i s s l i g h t o n l y a n d r e s t r i c t e d v e r y l a r g e l y t o l o w e r p a r t s o f s y s t e m . S t r o n g s u l f u r o u s s m e l l o f s u c h r o o t s a n d a d j a c e n t s a n d . E n g e l m a n n s p r u c e S p a r s e , f i n e l y f i b r o u s s y s t e m . M a n y f i n e , w h i t e -t i p p e d , a c t i v e l y g r o w i n g l a t e r a l s e s p e c i a l l y a t t h e o u t e r e x t r e m i t i e s o f t h e w o o d y l a t e r a l s . N e w r o o t s l i g h t b r o w n i n c o l o r . D e c a y s l i g h t t o m o d e r a t e , m o s t c o m m o n l y f o u n d o n l o w e r l a t e r a l e x t e n s i o n s o f t h e t a p r o o t . D e c a y e d a r e a s b l u i s h - b l a c k . E f f e c t o f a d e f i c i e n c y o f c a l c i u m o n d e v e l o p m e n t o f s h o o t s a n d f o l i a g e C o a s t a l D o u g l a s - f i r B u d s c u r i o u s l y s w o l l e n a n d g i v i n g e v i d e n c e o f a n i n a b i l i t y t o b r e a k d o r m a n c y . E m e r g e n t n e e d l e s o f t e n m u c h f o l d e d . T e r m i n a l g r o w t h r e d u c e d a n d o n l y a m o d e r a t e d e g r e e o f b r a n c h i n g u s u a l . W h a t b r a n c h e s d o d e v e l o p a r e w e a k a n d r e d u c e d i n w o o d i n e s s . N e w n e e d l e s a r e n e a r l y n o r m a l , a n d d a r k g r e e n i n c o l o r . O l d n e e d l e s c o m p l e t e l y c h l o r o t i c , d i s t i n c t l y o c h r e - y e l l o w c h l o r o t i c , some s h o w i n g p a r t i a l n e c r o s i s . I n t e r i o r - D o u g l a s - f i r L e a d e r g r o w t h i s r e d u c e d i n a m o u n t a n d a g a i n h y p e r t r o p h i e d b u d d e v e l o p m e n t c o m m o n . N e w n e e d l e s g e n e r a l l y d a r k g r e e n . O l d n e e d l e s d i s t i n c t l y c h l o r o t i c a n d n e c r o t i c . 90. P o n d e r o s a p i n e B r a n c h a n d t e r m i n a l d e v e l o p m e n t g o o d , s h o w i n g l i t t l e o r n o e v i d e n c e o f d e f i c i e n c y . F a s c i c l e n e e d l e s s t o u t , d a r k g r e e n , s o m e w h a t r e d u c e d i n l e n g t h . C h l o r o s i s o f t i p s o f o l d e r o n e s , l o c a t e d i n l o w e r s t e m a r e a s , u s u a l . P r i m a r y n e e d l e s s t r o n g l y n e c r o t i c / c h l o r o t i c b u t p e r s i s t e n t . L i t t l e o r n b n e e d l e f a l l . S o m e -t i m e s t h e p r i m a r y n e e d l e s a r e p u r p l i s h - p i n k - t i p p e d a n d h o o k e d . T h i s c o n d i -t i o n i s t o b e s e e n m o r e c o m m o n l y a r o u n d t e r m i n a l b u d . W e s t e r n w h i t e p i n e N o e v i d e n t s y m p t o m s o f d e f i c i e n c y . C o n s i d e r a b l e b r a n c h d e v e l o p m e n t m a i n l y o f a p r i m a r y b r a n c h i n g h a b i t . N e w f a s c i c l e - n e e d l e s v e r y c o n s i d e r a b l y s h o r t e r t h a n p r e v i o u s y e a r ' s g r o w t h . S y m p t o m s o t h e r w i s e m i n o r a n d l i m i t e d t o a l i g h t , l i m e - g r e e n c o l o r a t i o n o f t i p s o f n e e d l e s t h a t a r e o t h e r w i s e d a r k b l u e ^ - g r e e n . F o l i a g e v e r y d e n s e . N e c r o s i s m o d e r a t e o n l y a r i d r e s t r i c t e d t o o l d p r i m a r y n e e d l e s o n m a i n s t e m . L a t t e r p e r s i s t . E n g e l m a n n s p r u c e N e a r n o r m a l d e v e l o p m e n t , o n l y s l i g h t r e d u c t i o n i n t e r m i n a l g r o w t h a n d b r a n c h d e v e l o p m e n t . S m a l l e r , m o r e s e v e r e l y a f f e c t e d i n d i v i d u a l s e x h i b i t some s i g n s o f d i f f i c u l t y i n b r e a k -i n g t e r m i n a l b u d . N e w n e e d l e s g e n e r a l l y v e r y d a r k , g l a u c o u s . O l d n e e d l e s l i g h t e r g r e e n a n d m a r k e d l y c h l o r o t i c i n o u t e r p a r t s ( y e l l o w - g r e e n ) . N o n e e d l e f a l l . T e n d e n c y f o r n e e d l e s t o b e m u c h c o n t o r t e d i n l o w e r p o r t i o n o f c r o w n o f . m o r e v i g o r o u s p l a n t s . M o r t a l i t y h i g h , d e a t h s u d d e n . E f f e c t o f a d e f i c i e n c y o f c a l c i u m o n r o o t d e v e l o p m e n t C o a s t a l D o u g l a s - f i r M o r p h o l o g i c a l l y w e l l d e v e l o p e d t o a p o i n t a n d t h e n s e e m t o b e c o m e s u b j e c t t o d e c a y w h i c h m a k e s t h e m s t r i n g y . O n l y a m i n o r a m o u n t o f n e w g r o w t h e v i d e n t u s u a l l y . N e w r o o t t i p s w h i t i s h -b r o w n , d i s c o l o r e d , m u c h s w o l l e n , a n d r e s t r i c t e d t o u p p e r p a r t s o f r o o t s y s t e m . D e c a y , o f t e n s e v e r e e s p e c i a l l y i n l o w e r r o o t p a r t s . L a t t e r a r e e a r l y r e d u c e d t o a b r o w n / b l a c k s t r i n g y m a s s , a n d t h e i r d e c o m p o s i t i o n i s e v i d e n t e v e n f r o m t h e c o l o r o f t h e l e a c h a t e s d r a w n f r o m c r o c k s . F u n c t i o n a l r o o t a r e a m u c h r e d u c e d a n d m a i n l y i n s u r f a c e p o r t i o n s . R o o t c o n d i t i o n m u c h w o r s e t h a n f o l i a g e s y m p t o m s w o u l d i n d i c a t e . I n t e r i o r D o u g l a s - f i r M o d e r a t e l y f i b r o u s o n l y , o f t e n o n l y s l i g h t l y f i b r o u s i n m o r e a f f e c t e d s p e c i m e n s . G r o w t h t a k e s t h e f o r m o f f a t n e w l a t e r a l d e v e l o p m e n t w h i c h u s u a l l y a r i s e f r o m t h e l a r g e r l a t e r a l s a l r e a d y e s t a b l i s h e d . C o m m o n f o r t h e r e t o b e a p r o n o u n c e d s w e l l i n g o f a c t i v e l y g r o w i n g r o o t e n d s . 91. D e c a y o f t e n v e r y s e v e r e , d e e p e r r o o t s o f t e n m u c h b l a c k e n e d . C r o w n s y m p t o m s a r e s y m p t o m a t i c o f a v e r y s e r i o u s b r e a k d o w n o f r o o t , s t r u c t u r e . P o n d e r o s a p i n e M o d e r a t e l y d e n s e s y s t e m u s u a l l y w i t h m a n y n e w f i n e r l a t e r a l r o o t s b e i n g c o n t i n u a l l y p r o d u c e d i n u p p e r p a r t s o f s y s t e m . G r o w t h i s r e s t r i c t e d m a i n l y t o t h e u p p e r p a r t o f t h e s y s t e m . G r o w i n g t i p s a r e w h i t i s h a n d c o n s i d e r a b l y s w o l l e n . M o d e r a t e t o s e v e r e d e c a y o f l o w e r r o o t p a r t s n o t i n f r e q u e n t . T a p a n d l o w e r w o o d y l a t e r a l s s o m e t i m e s c o m p l e t e l y b l a c k , r o t t e n , l e a v i n g o n l y u p p e r t h i r d o f s y s t e m f o r f u n c t i o n a l a b s o r p t i o n . W e s t e r n w h i t e p i n e C o a r s e , s l i g h t t o m o d e r a t e l y d e n s e w i t h m a n y l a r g e , w o o d y l a t e r a l s w h i c h t e r m i n a t e i n a r e d u c e d n u m b e r o f f i n e r l a t e r a l e x t e n s i o n s . G r o w t h r e s t r i c t e d t o u p p e r o n e t h i r d o f s y s t e m . T a p r o o t c o m p l e t e l y r o t t e n . A g a i n l a r g e w h i t e s w o l l e n t i p s i n d i c a t i v e o f t h i s t r e a t m e n t . H e w r o o t s l i g h t b r o w n , a n d c o a t e d w i t h f i n e , s m a l l h a i r s . D e c a y v e r y h e a v y , s e r i o u s l y r e d u c i n g e f f e c t i v e n e s s o f t h e s y s t e m . M o s t s e v e r e i n l o w e r h a l f o f s y s t e m . E n g e l m a n n s p r u c e F i n e t o m o d e r a t e l y c o a r s e l y b r a n c h e d , m o d e r a t e l y d e n s e s y s t e m w i t h v e r y e x t e n d e d l a t e r a l r o o t d e v e l o p m e n t . M u c h l o n g e r t h a n c o n t r o l s . H e w g r o w t h o f t h e r o o t s y s t e m c h a r a c t e r i s t i c a l l y a p a r s n i p - b r o w n c o l o r . N e w r o o t e n d s a r i s i n g f r o m u p p e r l a t e r a l s w h i t e - t i p p e d a n d q u i t e n u m e r o u s . C o n s i d e r a b l e p o r t i o n s o f t h e r o o t s y s t e m a f f e c t e d b y d e c a y , a n d t h i s i s e s p e c i a l l y s o o f l o w e r h a l f . G e n e r a l l y s e v e r e r e s u l t i n g i n b l a c k , g e l a t i n o u s , f u n c t i o n l e s s r o o t s . E f f e c t o f a d e f i c i e n c y o f p h o s p h o r u s o n d e v e l o p m e n t o f s h o o t s a n d f o l i a g 9 C o a s t a l D o u g l a s - f i r L o w e r s t e m p o r t i o n s b l a c k e n e d , s h o r t , s p a r s e l y c l a d b r a n c h e s , f e w i n n u m b e r . T e r m i n a l g r o w t h s l i g h t a n d s t e m s e v i d e n t l y w e a k a n d p l i a b l e . A f f e c t e d p l a n t s v e r y u n i f o r m l y s t u n t e d . N e e d l e s v e r y d a r k p u r p l e ^ g r e e n , o f t e n q u i t e h o o k e d a t t i p s ; e s p e c i a l l y i s t h i s t r u e o f n e e d l e s a r o u n d t h e t e r m i n a l b u d . N e e d l e s v e r y s h o r t . C o t y l e d o n s b e c o m e e a r l y b r o w n a n d f a l l . 92. I n t e r i o r D o u g l a s - f i r T e r m i n a l g r o w t h m u c h r e s t r i c t e d . N u m b e r o f b r a n c h e s m u c h l e s s t h a n n o r m a l . S m a l l , s t u n t e d g r o w t h . N e w n e e d l e s e i t h e r r u s t y y e l l o w i s h - g r e e n o r d u l l b l u i s h - g r e e n , , t h e l a t t e r c o n d i t i o n b e i n g m o r e c o m m o n o n t h e l e s s s e v e r e l y a f f e c t e d p l a n t s . New a n d o l d n e e d l e s c o m m o n l y h e a v i l y n e c r o t i c . N e e d l e l e n g t h m u c h r e d u c e d ( a b o u t 75$ r e d u c t i o n i n s i z e ) . P r o n o u n c e d h o o k i n g o f t h e n e e d l e t i p s . C o t y l e d o n s s h e d e a r l y . P o n d e r o s a p i n e M u c h r e d u c e d s t e m a n d b r a n c h d e v e l o p m e n t , s t u n t e d , a n d l a c k i n g i n n o r m a l v i g o r . F a s c i c l e n e e d l e s a r e g e n e r a l l y s h o r t e r t h a n p r i m a r y . V e r y f e w f a s c i c l e n e e d l e s . W h e r e p r e s e n t t h e y a r e v e r y d a r k , g l a u c o u s , s o m e t i m e s y e l l o w -t i p p e d , s h o r t e r t h a n n o r m a l . P r i m a r y n e e d l e s h e a v i l y c h l o r o t i c a n d e x h i b i t i n g m u c h t a w n y b r o w n n e c r o s i s . C o t y l e d o n s o f t e n c o m p l e t e l y , n e c r o t i c b u t p e r s i s t e n t . W e s t e r n w h i t e p i n e S t u n t e d g r o w t h a n d a r e d u c e d n u m b e r o f b r a n c h e s c h a r a c t e r i z e t h i s d e f i c i e n c y . B r a n c h e s a r e o n l y a f e w c e n t i m e t r e s l o n g a n d r e s t r i c t e d t o t h e t e r m i n a l b u d a r e a . F a s c i c l e n e e d l e s f e w i n n u m b e r , s h o r t , p u r p l i s h - g r e e n , u s u a l l y n e a r t e r m i n a l b u d . O l d f a s c i c l e n e e d l e p a r t i a l l y n e c r o t i c , o n l y s h o w i n g s l i g h t c h l o r o s i s . P r i m a r y n e e d l e s o n u p p e r s t e m p o r t i o n s l i g h t g r e e n , p a r t i a l l y n e c r o t i c , l o w e r s t e m c o m p l e t e l y n e c r o t i c . C o t y l e d o n s p e r s i s t e n t a n d - o f t e n a p p e a r h e a l t h i e r t h a n some o f t h e p r i m a r y n e e d l e s . E n g e l m a n n s p r u c e V e r y r e d u c e d i n s i z e . B r a n c h e s d o d e v e l o p b u t o n l y o c c a s i o n a l l y a n d t h e n a r e s h o r t . N e e d l e s d a r k p u r p l i s h - g r e e n a n d v e r y s h o r t . S o m e t i m e s n e e d l e s d e v e l o p a y e l l o w - g r e e n c h l o r o s i s b u t t h i s i s q u i c k l y s u c c e e d e d b y a d a r k b r o w n n e c r o s i s w h i c h e x t e n d s o v e r t h e l e n g t h o f a f f e c t e d n e e d l e . C o t y l e d o n s a r e l o n g e r t h a n t h e n e e d l e s a n d a r e p e r s i s t e n t , e v e n t h o u g h , a s i s c o m m o n l y t h e c a s e , t h e y a r e c o m p l e t e l y d e a d a n d n e c r o t i c . E f f e c t o f a d e f i c i e n c y o f p h o s p h o r u s o n r o o t d e v e l o p m e n t C o a s t a l D o u g l a s - f i r - T h e r e i s a c o n s i d e r a b l e r e d u c t i o n i n t h e n u m b e r o f i a i e r a l b r a n c h e s o f a n y s i z e a n d t h e r e i s b u t s l i g h t t o m o d e r a t e d e v e l o p m e n t o f f i b r o u s r o o t l e t s o n t h o s e t h a t a r e p r e s e n t . P e c u l i a r m y c o r r h i z a l " o u t g r o w t h s q u i t e c o m m o n l y o c c u r o n s m a l l e r r o o t l e t s . T h e y a r e s w o l l e n , d i c h o t o m o u s l y b r a n c h e d , g e l a t i n o u s a n d w h i t e . G r o w t h i s g r e a t l y r e d u c e d i n a m o u n t . A c t i v e l y g r o w i n g r o o t t i p s f e w . 93-. D e c a y s e e m s m i n o r i n t h o s e s y s t e m s t h a t a r e r e l a t i v e l y s t i l l f u n c t i o n a l . W h e r e d e c a y a p p e a r s , u s u a l l y e n t i r e s y s t e m i s r a p i d l y a n d s e v e r e l y r e d u c e d t o a f e w n a k e d s t r a n d s . I n t e r i o r D o u g l a s - f i r V e r y s p a r s e l y f i b r o u s , o n l y a s l i g h t l y b r a n c h e d s y s t e m w i t h some f e w s m a l l r o o t l e t s n e a r t h e u p p e r p a r t o f t h e s y s t e m . N e w r o o t s t h a t d o d e v e l o p , a n d t h e y a r e f e w , a r e l o c a t e d i n u p p e r p a r t s o f s y s t e m . T h e y a r e q u i t e . h a i r y a n d a g a i n a r e p o s s e s s e d o f t h e a b o v e - m e n t i o n e d s w o l l e n r o o t l e t s t h a t s o r e s e m b l e t h e m y c o r r h i z a l r o o t l e t . D e c a y o f t e n v e r y s e v e r e , s o m e t i m e s o n l y m o d e r a t e . R e d u c e d s y s t e m i s o f t e n r e n d e r e d u s e l e s s b y d e c a y o f m a j o r l a t e r a l s . P o n d e r o s a p i n e S l i g h t l y d e n s e , m o d e r a t e l y f i b r o u s , s o m e w h a t s p a r s e s y s t e m s a r e c o m m o n w i t h a c o n s i d e r a b l e r e d u c t i o n i n t h e n u m b e r o f b r a n c h e s . O n l y s l i g h t a n d i n s i g n i f i c a n t a m o u n t o f g r o w t h , o n l y v e r y f e w r o o t l e t s s h o w -i n g a n y e v i d e n c e o f a c t i v e g r o w t h . W h i t e g r o w i n g t i p s , u n c o m m o n . T h e r e i s m o r e o f t e n t h a n n o t m o d e r a t e t o h e a v y d e c a y o f r o o t l e t s , e s p e c i a l l y a t d e p t h . T h i s c o n d i t i o n I s f u r t h e r m a d e n o t a b l e b y t h e o c c u r r e n c e o f s m a l l p i n k r u p t u r e s i n t h e w o o d i e r p a r t s o f t h e a f f e c t e d r o o t s . W e s t e r n w h i t e p i n e E x t r e m e l y s h o r t r o o t s y s t e m s , s h o r t i n l e n g t h a n d h e a v i l y r e d u c e d i n t h e n u m b e r o f l a t e r a l b r a n c h e s t h e y p o s s e s s . A f f e c t e d r o o t s m a d e l i t t l e o r n o g r o w t h i n t h e s e c o n d y e a r . T h e r e a r e b u t a f e w n e w g r o w i n g t i p s ; t h e n e w e r o n e s a r e q u i t e h a i r y a n d h a v e s m a l l , s h o r t c o r a l l o i d - l i k e b r a n c h e s w h i c h a r e m u c o u s - c o v e r e d a n d t o w h i c h s a n d p a r t i c l e s a d h e r e . L a t t e r a r e a f e a t u r e o f t h e u p p e r h e a l t h i e r l a t e r a l s o n l y . T h e r e i s o n l y a v e r y s m a l l a m o u n t o f d e c a y g e n e r a l l y . B l a c k d i s c o l o r a t i o n o f a f f e c t e d r o o t s a n d s u l f u r o u s s m e l l a b s e n t . . O n l y a f e w o f t h e l o w e r p l a c e d r o o t s h a v e l o s t t u r g i d i t y a n d a p p e a r n o n - f u n c t i o n a l . E n g e l m a n n s p r u c e E x t r e m e l y s p a r s e , s h o r t , s p i n d l y , a l m o s t h a i r - l i k e s y s t e m , m u c h r e d u c e d i n l e n g t h v e r t i c a l l y a n d l a t e r a l l y . V e r y l i m i t e d a m o u n t o f g r o w t h ; o n l y o n e o r t w o f i n e , h a i r - l i k e r o o t l e t s p o s s e s s w h i t e t i p s i n d i c a t i v e o f t h e i r a c t i v e g r o w t h . T h e r e a r e n o c l u s t e r s o f f i n e r o o t s a n d n o d i c h o t o m o u s l y b r a n c h e d , m y c o r r h i z a l - l i k e o u t g r o w t h s o n t h e r o o t s . D e c a y g e n e r a l l y s e v e r e , r e d u c i n g f u r t h e r w h a t i s a l r e a d y a m u c h a f f e c t e d . s y s t e m . 9 4 . E f f e c t o f a d e f i c i e n c y o f p o t a s s i u m o n d e v e l o p m e n t o f s h o o t s a n d f o l i a g e C o a s t a l D o u g l a s - f i r T e r m i n a l g r o w t h n e g l i g i b l e . W h a t g r o w t h t h e r e i s s e e m s t o b e o n t h e l a t e r a l b r a n c h e s a r i s i n g f r o m b a s a l p a r t s o f s t e m . T h e s e m a y m a k e r a t h e r s p e c t a c u l a r g r o w t h , a n d t h e t e r -m i n a l b u d r e m a i n d o r m a n t . C h l o r o s i s e v i d e n t , c o m m o n t o a l l n e e d l e s , n e w a n d o l d , g i v i n g t o t h e f o l i a g e g e n e r a l l y a y e l l o w = g r e e n c a s t . T h i s c o n d i t i o n i s r a t h e r q u i c k l y f o l l o w e d b y a d i s t i n c t i v e p u r p l e - r e d , b r o w n n e c r o s i s o f o l d e r n e e d l e s w h i c h u s u a l l y f a l l p r e m a t u r e l y a s a r e s u l t . I n t e r i o r D o u g l a s - f i r T e r m i n a l g r o w t h i r r e g u l a r a n d r e d u c e d i n a m o u n t w h e n o c c u r r i n g . T h e r e i s a t e n d e n c y f o r g r o w t h t o b e c o n c e n t r a t e d o n s u b - t e r m i n a l l a t e r a l s o r . l o w e r p l a c e d l a t e r a l s h o o t s . T h e n e e d l e s o n t h e l a t t e r a r e l i k e l y t o b e l o n g e r t h a n e l s e w h e r e o n a f f e c t e d p l a n t . P r i m a r y b r a n c h i n g h a b i t o n l y f o u n d . P e r s i s t e n t t e r m i n a l b u d s c a l e s a t b a s e o f c u r r e n t y e a r ' s g r o w t h o f t e r m i n a l s h o o t a n d l a r g e r b r a n c h e s . F o l i a g e h a s g e n e r a l l y a y e l l o w c h l o r o t i c a p p e a r a n c e . N e w n e e d l e s s h o r t e r t h a n n o r m a l , y e l l o w ; o l d e r o n e s , p a r t i c u l a r l y t h o s e o n l o w e r s t e m , c o m p l e t e l y n e c r o t i c a n d f a l l i n g r a p i d l y . P r e m a t u r e n e e d l e f a l l g e n e r a l l y h e a v y . P o n d e r o s a p i n e C o n s i d e r a b l e r e d u c t i o n i n t e r m i n a l g r o w t h a n d b r a n c h d e v e l o p m e n t . V e r y h e a v y c h l o r o s i s a n d n e c r o s i s o f p r i m a r y a n d s e c o n d a r y n e e d l e s . T a w n y b r o w n o u t e r h a l f o f f a s c i c l e n e e d l e s s u b t e n d e d b y d i s t i n c t d u l l y e l l o w c h l o r o s i s a n d t h i s i n t u r n s u b t e n d e d b y a s t r a w - y e l l o w / g r e e n c o ^ - o r n e a r n e e d l e b a s e . T o g e t h e r w i t h c o n s i d e r a b l e r e d u c t i o n i n n e e d l e , s i z e , t h e f o l i a r e f f e c t s o f t h i s t r e a t m e n t a p p e a r s e v e r e . W e s t e r n w h i t e p i n e S e v e r e l y r e d u c e d i n b r a n c h d e v e l o p m e n t a n d p h y s i c a l s i z e g e n e r a l l y . N e w n e e d l e s a r e t i n g e d w i t h a c h a r a c t e r i s t i c o r a n g e - y e l l o w c h l o r o s i s w h i c h g i v e s t o a l r e a d y s p a r s e f o l i a g e a s t r i k i n g h u e . F a s c i c l e n e e d l e s g e n e r a l l y t i g h t l y a p p r e s s e d i n t h e b u n d l e , o l d e r o n e s n e c r o t i c u p t o h a l f t h e i r l e n g t h . F o l i a g e g e n e r a l l y s p a r s e a n d l a c k i n g i n t h e c o m m o n b l u e - g r e e n h u e s t y p i c a l o f h e a l t h i e r i n d i v i d u a l s o f t h i s s p e c i e s . P r i m a r y n e e d l e s r e l a t i v e l y b r o a d , l i g h t g r e e n i n c o l o r a n d h o o k e d a t t i p . E n g e l m a n n s p r u c e B r a n c h d e v e l o p m e n t i s s e v e r e l y r e d u c e d a s i s t e r m i n a l g r o w t h . B o t h n e w a n d o l d n e e d l e s a r e h e a v i l y c h l o r o t i c , a n d c h a r a c t e r i z e d i n m a n y c a s e s b y a s t r i k i n g p u r p l i s h - p i n k c o l o r a t i o n , w h i c h g r a d u a l l y f a d e s t o a d a r k b r o w n n e c r o s i s , a l t h o u g h l e s s i n a m o u n t t h a n o t h e r s p e c i e s u n d e r s i m i l a r d e f i c i e n c y . N o w h e r e e l s e w a s t h i s p i n k c o l o r a t i o n o b s e r v e d . 95-E f f e c t o f a d e f i c i e n c y o f p o t a s s i u m o n r o o t d e v e l o p m e n t C o a s t a l D o u g l a s - f i r V e r y f i n e , h a i r - l i k e f i b r o u s r o o t s p a r t i c u l a r l y a t d e p t h o n l o w e r t a p r o o t . W h o l e s y s t e m h a s a w h i t i s h c o l o r a t i o n . H e w g r o w t h s p a r s e a n d o c c a s i o n a l . S l i g h t t o m o d e r a t e d e c a y b u t f i r s t e v i d e n c e s o f s e v e r e d e f i c i e n c y a p p e a r i n r o o t s w h i c h g e n e r a l l y a r e t h e m o r e s e v e r e l y a f f e c t e d b y t h i s d e f i c i e n c y . C o n s i d e r a b l e m o r t a l i t y , e s p e c i a l l y a f t e r t r a n s p l a n t i n g . I n t e r i o r D o u g l a s - f i r V e r y f i n e l y f i b r o u s u s u a l l y a n d n o t v e r y d e n s e . N e w r o o t l e t s a r e v e r y w h i t e , p a l e , b l e a c h e d - l o o k i n g a n d n o t a t a l l w o o d y e v e n n e a r t h e i r p o i n t s o f o r i g i n . R o o t l e t s a r e f i n e l y h i r s u t e . A p a r t f r o m v e r y m i n o r i n v a s i o n o f l o w e r s e c t i o n s o f t h e s y s t e m , r o o t s a f f e c t e d b y t h i s d e f i -c i e n c y a r e s u r p r i s i n g l y f r e e f r o m d e c a y , a f a t e t o w h i c h t h i s s p e c i e s s e e m e d p e c u l i a r l y s u s c e p t i b l e . P o n d e r o s a p i n e S p a r s e t o m o d e r a t e l y d e n s e , v e r y f i n e l y f i b r o u s s y s t e m . O n l y f a i r g r o w t h . M i n o r t o m o d e r a t e d e c a y o f l o w e r r o o t p a r t s n o t u n c o m m o n . R o o t s h a v e t h i s p e c u l i a r w h i t i s h - b r o w n a p p e a r a n c e . N e w , a n d a c t i v e l y g r o w i n g r o o t t i p s h a v e w h i t i s h - g r a y t i p s , n o t s w o l l e n . D e c a y i s o n l y m i n o r . W e s t e r n w h i t e p i n e S p a r s e l y f i b r o u s , n o t d e n s e , w i t h m a n y f i n e r o o t l e t s w h i c h a r e f i n e l y h a i r y a n d h a v e a f u z z y a p p e a r a n c e . T h e r e i s a r e d u c e d n u m b e r o f n e w r o o t s , a l t h o u g h some a r e c o n s t a n t l y b e i n g p r o d u c e d . W h o l e s y s t e m a g a i n c h a r a c t e r i s t i c a l l y b l e a c h e d t o a p a l e , w h i t i s h f a w n c o l o r . E n g e l m a n n s p r u c e A d e n s e , v e r y f i n e l y f i b r o u s s y s t e m u s u a l l y w i t h c l u m p s o r k n o t s o f f i n e r o o t l e t s a r i s i n g a t t h e e n d s o f w i d e -s p r e a d i n g , w o o d y l a t e r a l r o o t s . U n u s u a l l y g o o d a s e v i d e n c e d b y t h e n u m b e r o f w h i t e - t i p p e d , f i n e l y f i b r o u s r o o t l e t s . A g a i n w h i t i s h - b r o w n i n c o l o r . D e c a y i s v e r y m i n o r . 6". P h o t o g r a p h i c r e c o r d o f d e f i c i e n c y s y m p t o m s d e v e l o p e d T h e p h o t o g r a p h s t h a t f o l l o w a r e g r o u p e d b y d e f i c i e n t t r e a t m e n t r a t h e r t h a n s p e c i e s . T h e y w e r e t a k e n i n t h e s e c o n d g r o w i n g s e a s o n a n d s h o w , b e t t e r t h a n w o r d s c a n d e s c r i b e , t h e m o r p h o l o g i c a l e f f e c t s o f m a c r o n u t r i e n t d e f i c i e n c y . 96. T h e c h l o r o t i c a n d n e c r o t i c s y m p t o m s d e p i c t e d a r e r e p r e s e n t a t i v e o f t h e t y p e d e v e l o p e d o n o t h e r s p e c i m e n s o f t h e s a m e s p e c i e s b y a g i v e n e l e m e n t a l d e f i -c i e n c y . T h e o r i g i n a l p h o t o g r a p h s , f r o m w h i c h t h e e n l a r g e m e n t s i n c l u d e d i n t h e t e x t w e r e m a d e , w e r e 3 5 m m . K b d a c h r o m e t r a n s p a r e n c i e s . D u r i n g t h e d e v e l o p -m e n t a n d e n l a r g e m e n t p r o c e s s e s , e v e r y e f f o r t w a s m a d e t o m a i n t a i n c o l o r f i d e l i t y . T h e s c a l e s t i c k s a n d g r a d u a t e d r u l e r s b e h i n d t h e p h o t o g r a p h e d t r e e s a r e m a r k e d o f f i n c e n t i m e t r e s a n d m i l l i m e t r e s . Fig. 9 * Foliar symptoms of nitrogen deficiency on ponderosa pine. (Photo: Krajina) F i g . 10. " F o l i a r s y m p t o m s o f n i t r o g e n d e f i c i e n c y o n w e s t e r n w h i t e p i n e , ( p h o t o : K r a j i n a ) F i g . 11. F o l i a r s y m p t o m s o f n i t r o g e n d e f i c i e n c y o n w e s t e r n w h i t e p i n e . ( P h o t o : K r a j i n a ) F i g . 12. F o l i a r s y m p t o m s o f n i t r o g e n d e f i c i e n c y o n E n g e l m a n n s p r u c e . ( P h o t o : K r a j i n a ) F i g . 13. F o l i a r s y m p t o m s o f s u l f u r d e -f i c i e n c y o n c o a s t a l D o u g l a s - f i r . ( P h o t o : K r a j i n a ) l i g . 15. F o l i a r s y m p t o m s o f s u l f u r d e f i c i e n c y o n i n t e r i o r D o u g l a s - f i r . N o t e r u p t u r i n g o f n e e d l e s . ( P h o t o : K r a j i n a ) Fig. 17. Foliar symptoms of sulfur deficiency on western white pine. (Photo: Krajina) Fig. 18. Toiler symptoms of sulfur deficiency on western white pine. (Photo: Krajina) Fig. 19. Foliar 'symptoms of sulfur deficiency on Engelmann spruce. (Photo: Krajina) F i g . 20. F o l i a r s y m p t o m s o f m a g n e s i u m d e -f i c i e n c y o n c o a t s t a l D o u g l a s - f i r . ( P h o t o k i n d l y s u p p l i e d b y D r . V . J . K r a j i n a f r o m a n e x p e r i m e n t c o n d u c t e d i n 195?.) F i g . 21. P o l i a r s y m p t o m s o f m a g n e s i u m d e -f i c i e n c y o a i n t e r i o r D o u g l a s - f i r . ( p h o t o : K r a j i n a ) F i g . 22. F o l i a r s y m p t o m s o f m a g n e s i u m d e f i c i e n c y o n p o n d e r o s a p i n e . ( P h o t o : K r a j i n a ) F i g . 23. F o l i a r s y m p t o m s o f m a g n e s i u m d e f i c i e n c y o n p o n d e r o s a p i n e . U o t e , r o l a c k 1 3 X 6 " i n n e c r o t i c a r e a s a n d r e s i n e x u d a t i o n f r o m d e a d t i s s u e . ( P h o t o : K r a j i n a ) F i g . 2 4 . F o l i a r s y m p t o m s o f m a g n e s i u m d e -f i c i e n c y o n w e s t e r n w h i t e p i n e . N o t e p r e s e n c e o f " " b l a c k b a r s " i n n e c r o t i c a r e a s , ( p h o t o : K r a j i n a ) F i g . 25. C l o s e r v i e w o f magnesium deficiency symptoms o n ponderoBa p i n e . ( P h o t o : K r a j i n a ) . F i g . 26. F o l i a r s y m p t o m s o f m a g n e s i u m d e f i c i e n c y o n E n g e l m a n n s p r u c e . ( P h o t o : K r a j i n a ) F i g . 27. T h e e f f e c t o f a d e f i c i e n c y o f m a g n e s i u m o n t h e g r o w t h a n d f o r s i o f S i t k a s p r u c e . S i m i l a r l y e e r i o u s s y m p t o m s w e r e o b -s e r v e d o n E n g e l m a n n s p r u c e a t t h e e n d o f t h e s e c o n d g r o w i n g s e a s o n , ( p h o t o k i n d l y s u p p l i e d "by D r . V . J . K r a j i n a ) . F i g . 28. E f f e c t s o f a d e f i c i e n c y o f c a l c i u m t h e g r o w t h o f c o a s t a l D o u g l a s - f i r . N o t e s h o r t n e e d l e s o n s h o r t " b r a n c h e s . ( P h o t o : K r a j i n a ) F i g . 29* F o l i a r s y m p t o m s o f c a l c i u m d e -f i c i e n c y o n i n t e r i o r D o u g l a s - f i r . ( p h o t o K r a j i n a ) F i g . 31• S y m p t o m s o f c a l c i u m d e f i c i e n c y 011 p o n d e r o s a p i n e . N o t e m a n y s w o l l e n , u n b r o k e n b u d s a n d h o o k e d , d i s c o l o r e d n e e d l e t i p s , ( p h o t o : K r a j i n a ) Fig. 33» Foliar s y m p t o m s of phosphorus deficiency on coastal Douglas-fir. Hote dark blue-green color of short needles. (Photo: Krajina) Fig. 34. Appearance of foliage of interior DouglaB-fir affected by a deficiency of phosphorus. Illustrates the hooking of the needle tips which i s a common characteristic of this deficiency. (Photo: Krajina) Fig* 35» Foliar symptoms of phosphorus deficiency on ponderosa pine. Noteworthy i s the reduced number of fascicle needles, the short length, the pronounced blue-green color and heavy necrosis of affected needles. (Photo: Krajina) F i g . 36. A n o t h e r s a m p l e o f t h e e f f e c t s o f a d e f i c i e n c y o f p h o s p h o r u s o n t h e g r o w t h o f p o n d e r o s a p i n e . ( P h o t o : K r a j i n a } F i g . 37. A s p e c i m e n o f w e s t e r n w h i t e p i n e a f f e c t e d b y a d e f i c i e n c y o f p h o s p h o r u s . ( P h o t o : K r a j i n a ) F i g . 3 8 . F o l i a r s y m p t o m s o f p h o s p h o r u s d e f i c i e n c y o n w e s t e r n w h i t e p i n e , ( p h o t o : K r a j i n a ) F i g . 3 9 . T h e e f f e c t o f a d e f i c i e n c y o f p h o s p h o r u s o n t h e g r o w t h o f E n g e l m a n n s p r u c e . N o t e t h e g r e a t l y r e d u c e d size a n d d a r k " b l u e - g r e e n a p p e a r a n c e o f t h e f e w n e e d l e s d e v e l o p e d , ( p h o t o : K r a j i n a ) E i g . 4 0 . E n g e l m a n n s p r u c e g r o « i u n d e r t h e i n f l u e n c e o f a d e -f i c i e n c y o f p h o s p h o r u s . ( P h o t o : K r a j i n a ) l i g . 4 l . E o l i a r s y m p t o m s o f p o t a s s i u m d e f i c i e n c y o n c o a s t a l D o u g l a s - f i r . ( p h o t o : K r a j i n a ) F i g . 43. F o l i a r s y m p t o m s o f p o t a s s i u m d e f i c i e n c y o n p o n d e r o s a p i n e . ( P h o t o : K r a j i n a ) Pig. 46. Poliar symptoms of potassium deficiency on Bngelmann spruce. (Photo: Davidson) 97-V Q u a n t i t a t i v e E f f e c t s o f D e f i c i e n c y A . M o r p h o l o g i c a l E f f e c t s I t w a s t h e o b j e c t o f t h i s s t u d y t o m e a s u r e , t o t h e f u l l e s t p o s s i b l e e x t e n t / t h e q u a n t i t a t i v e e f f e c t s o f m a c r o m e t a b o l i c d e f i c i e n c y . T o t h i s e n d , a l l m e a s u r e m e n t s t h a t m i g h t s e r v e a s r e l i a b l e i n d i c e s o f t h e s e e f f e c t s w e r e t r i e d a n d , i f f o u n d u s e f u l , c o n d u c t e d o n a p r e c i s e a n d e x t e n s i v e s c a l e o n m o r e t h a n o n e o c c a s i o n d u r i n g t h e t e r m o f t h e e x p e r i m e n t . T h e f i r s t l a r g e s c a l e m e a s u r e m e n t o f t h e t e s t p l a n t s w a s u n d e r t a k e n a t t h e e n d o f t h e f i r s t g r o w i n g s e a s o n w h e n t h e r e w a s a b u n d a n t e v i d e n c e t h a t t h e p l a n t s w e r e i n a s t a t e o f d o r m a n c y a n d t h e r e s e e m e d l i t t l e l i k e l i h o o d t h a t a n y r a p i d g r o w t h w o u l d m a t e r i a l l y a l t e r t h e d i m e n s i o n s o f t h e p l a n t s a f t e r m e a s u r e m e n t s h a d b e g u n . T h i s w a s a f a c t o r t h a t h a d t o b e c o n s i d e r e d b e c a u s e t h e s e r i e s o f m e a s u r e m e n t s t o o k o v e r a m o n t h t o r e c o r d . A s e c o n d s e r i e s o f m e a s u r e m e n t s o f e v e n g r e a t e r s c o p e a n d i n c l u s i v e n e s s w a s c o n d u c t e d d u r i n g t h e e a r l y S p r i n g o f t h e s u c c e e d i n g y e a r (1959). Some g r o w t h h a d b e e n i n i t i a t e d b y a s m a l l p r o p o r t i o n o f t h e p l a n t s b u t t h e m a j o r i t y r e m a i n e d i n a s t a t e o f d o r m a n c y . I t w a s a t t h i s t i m e t h a t t h e n u m b e r o f p l a n t s p e r c r o c k w a s r e d u c e d t o o n e a n d t h e m e a s u r e m e n t s t h a t w e r e t a k e n a t t h i s t i m e - r e c o r d t h e d i m e n s i o n s a t t a i n e d b y t h e t h i n n e d p l a n t s o n l y . F o l l o w i n g d i r e c t l y u p o n t h e t h i n n i n g o p e r a t i o n a n d t h e m e a s u r e m e n t o f t h e t h i n n e d p l a n t s , t h o s e p l a n t s t h a t h a d b e e n r e t u r n e d t o t h e c r o c k s t o u n d e r g o a n o t h e r s e a s o n ' s g r o w t h w e r e r e m e a s u r e d i n t h e c r o c k s t o o b t a i n s o m e i d e a o f t h e i r s u b s e q u e n t i n c r e m e n t i n h e i g h t , d i a m e t e r , e t c . , a f t e r a f u r t h e r t h r e e m o n t h s * g r o w t h . I n A u g u s t 1959, a l l t h e p l a n t s g r o w i n g i n s o i l w e r e r e m o v e d , t h e i r r o o t s s e p a r a t e d a n d t h e p l a n t s m e a s u r e d a n d w e i g h e d . 98. I n S e p t e m b e r 1959> "the r e m a i n i n g s a n d c u l t u r e p l a n t s w e r e r e m o v e d a n d m e a s u r e m e n t s m a d e o f t h e c h a r a c t e r i s t i c s t h a t h a d a p p e a r e d m o s t s u b j e c t t o i n f l u e n c e t h r o u g h o u t t h e f i n a l g r o w t h r p e r i o d . T h u s t h e r e w e r e f o u r m a j o r a t t e m p t s t o m e a s u r e q u a n t i t a t i v e l y t h e e f f e c t s o f m a c r o m e t a b o l i c d e f i c i e n c y o n t h e g r o w t h o f t h e f i v e s p e c i e s s t u d i e d . T o r e p o r t a l l o f t h e f i g u r e s i n t h i s d i s c u s s i o n w o u l d h e a v i o l a t i o n o f t h e r e a d e r ' s p a t i e n c e a n d , s i n c e t h e f u n d a m e n t a l r e l a t i o n s h i p s m a d e c l e a r b y o n e s e t o f r e c o r d i n g s a r e s u b s t a n t i a t e d t o a v e r y h i g h d e g r e e b y a l l t h e o t h e r s , o n l y o n e s e t , t h e m o s t I n c l u s i v e , w i l l b e i n c l u d e d i n t h e t e x t . T h e r e m a i n d e r o f t h e d a t a c a n b e f o u n d i n t h e A p p e n d i x . T h e f o l l o w i n g c h a r a c t e r i s t i c s w e r e c o n s i d e r e d d u r i n g t h e c o u r s e o f t h e e x p e r i m e n t : h e i g h t o f t h e m a i n s t e m ; d i a m e t e r o f t h e s t e m a t t h e s a n d l e v e l a s m e a s u r e d b y s t e e l m i c r o - c a l i p e r ; t h e n u m b e r o f b r a n c h e s a r i s i n g f r o m t h e m a i n s t e m ; t h e b r a n c h i n g h a b i t , w h e t h e r s e c o n d a r y , t e r t i a r y , e t c . ; t h e l e n g t h o f t h e l o n g e s t b r a n c h ; t h e l e n g t h o f t h e l o n g e s t n e e d l e ; t h e v i g o r a s j u d g e d s u b j e c t i v e l y a n d e x p r e s s e d n u m e r i c a l l y a c c o r d i n g t o a s c a l e e x t e n d -i n g f r o m 0 t o 3 , o r f r o m d y i n g t o v e r y v i g o r o u s ; t h e l e n g t h o f t h e r o o t s y s -t e m ; t h e l e n g t h o f t h e l o n g e s t l a t e r a l r o o t ; t h e v o l u m e o f t h e r o o t s y s t e m a s m e a s u r e d b y w a t e r d i s p l a c e m e n t ; t h e f r e s h w e i g h t ; t h e d r y w e i g h t ; a n d t h e m o i s t u r e c o n t e n t a n d s h o o t / r o o t r a t i o d e r i v e d f r o m t h e l a t t e r t w o m e a s u r e s . O f t h e f o u r t e e n c h a r a c t e r i s t i c s m e n t i o n e d a b o v e , f o u r w e r e c a r r i e d c o n -s i s t e n t l y t h r o u g h o u t t h e s t u d y t o o b t a i n a m e a s u r e o f g r o w t h d e v e l o p m e n t . T h e s e w e r e h e i g h t , d i a m e t e r a t s t e m b a s e , n u m b e r o f b r a n c h e s a n d l o n g e s t b r a n c h . E o o t m e a s u r e m e n t s w e r e n o t p o s s i b l e u n t i l p l a n t s w e r e f i n a l l y r e m o v e d f r o m t h e e x p e r i m e n t . B y a c t u a l c o u n t , a t o t a l o f 12,700 m e a s u r e -m e n t s w e r e m a d e o n t h e 8 4 0 p l a n t s g r o w i n g i n s a n d c u l t u r e . 99-I t w a s d e c i d e d t o g r o u p t o g e t h e r t h e a b s o l u t e m e a s u r e m e n t s f o r a g i v e n c h a r a c t e r i s t i c , e . g . , h e i g h t , f o r a l l t h e . t r e e s f r o m a s i n g l e c r o c k , s i n c e t h e s e t r e e s r e c e i v e d t h e same t r e a t m e n t , w e r e t h e same s p e c i e s a n d w e r e e n v i r o n -m e n t a l l y c o n d i t i o n e d i n l i k e m a n n e r . T h i s p r o v i d e s c r o c k a v e r a g e s . F o r a n y o n e t r e a t m e n t , t h e n , a f f e c t i n g one* s p e c i e s s i x s u c h c r o c k a v e r a g e s a r e a v a i l -a b l e , t h e r e b e i n g s i x r e p l i c a t e s o f e a c h s p e c i e s / t r e a t m e n t c o m b i n a t i o n i n t h e s a n d c u l t u r e p a r t o f t h e e x p e r i m e n t . F o r e a c h s p e c i e s , t h e r e f o r e , a n d a d d i t i o n a l l y , f o r e a c h c h a r a c t e r i s t i c o f e a c h s p e c i e s m e a s u r e d , t h e r e w e r e 4 2 c r o c k a v e r a g e s (7 t r e a t m e n t s a n d 6 r e p l i c a t e s i n e a c h ) a n d i t w a s f r o m t h e s e d a t a t h a t t h e f i n a l a v e r a g e s r e p o r t e d i n t h e t e x t w e r e o b t a i n e d . A l s o , t h e s e 4 2 c r o c k a v e r a g e s w e r e t h e f i g u r e s u p o n w h i c h a n a l y s e s o f v a r i a n c e w e r e c o n d u c t e d . T o c l a r i f y t h e a b o v e e x p l a n -a t i o n , a s a m p l e c o n d e n s a t i o n w i l l b e g o n e t h r o u g h i n d e t a i l t o i l l u s t r a t e t h e s t e p s i n v o l v e d . S a m p l e C o n d e n s a t i o n o f t h e D a t a E x a m p l e u s e d : H e i g h t m e a s u r e m e n t o n t h i n n e d p l a n t s o f p o n d e r o s a p i n e , J u n e 1959. F i r s t : D a t a a s c o l l e c t e d — h e i g h t s i n c m s . C r o c k T r e a t m e n t ~ N o . C o m p l e t e L o w N L o w S L o w M g L o w C a L o w P L o w K 1 1.6; 6.7 3-0; 4.0 6.6; 4.1 6.5; 8.2 3-6; 6.5 3-4; 2.7 1 .8; 2.7 2 9-2; 8.2 4.5; 2.1 9.8; 6 .4 7-7; 2.5 10.4;11.8 2.0; 2.3 2.3; 3.0 3 8.5;14.0 2.1; 3-0 10.3J13.4 9-4; 7-4 4.9;10.0 2-5; 3-3 2-5; 2.6 4 6 . 4 ; 7.2 2.5; 1-7 10.0;10-3 6.9; 7-3 9-7; 9-1 2.5; 2.5 6.0; 2.7 5 5-7; 4.7 2 . 4 ; 2.1 9-3; 6.5 5.6;10.4 8.3; 6.7 2.9; 3-7 2.3; — 6 13.2; 8.2 2 . 1 ; . 4 . 5 7-5; 9-5 5-4; 5.5 6.5; 7-1 2.8; 2.1 3.3; 2.2 TOO. S e c o n d : C r o c k a v e r a g e s — h e i g h t s i n c m s . C r o c k n u m b e r T r e a t m e n t 1 2 3 4 5 6 C o m p l e t e 7.2 8-7 11.3 6 . 8 5-2 10.7 L o w N 3-5 3-3 2.6 2.1 2 .3 3 . 3 L o w S 5 - 4 8.1 11.8 10.2 7-9 8 . 5 L o w M g 7 . 4 5-1 8 . 4 7-1 8 . 0 5 . 0 L o w C a 5 -T 11.1 7-5 9 . 4 7-5 6 . 8 L o w P 3.1 2.1 2-9 2 . 5 3-3 2 . 5 L o w K 2-3' 2.6 2.6 4 . 4 2 . 3 2 .6 T h i r d : S t a t i s t i c a l a n a l y s i s o f t h e d a t a b y a n a l y s i s o f v a r i a n c e . T h e t o t a l v a r i a n c e b e t w e e n a n d w i t h i n t r e a t m e n t s f o i ? t h e 4 2 m e a s u r e m e n t s w a s f i r s t d e t e r m i n e d a n d a n e s t i m a t e m a d e o f t h e p r o b a b i l i t y t h a t d i f f e r e n c e s w e r e d u e t o t r e a t m e n t e f f e c t s . T h i s w a s f o l l o w e d b y a p a i r i n g o f e a c h o f t h e d e f i c i e n t t r e a t m e n t s w i t h t h e c o m p l e t e a n d , u p o n t h e p a i r e d s e t s o f m e a s -u r e m e n t s , a n o t h e r a n a l y s i s o f v a r i a n c e w a s c o n d u c t e d . . L e a s t s i g n i f i c a n t d i f f e r e n c e s ( L . S . D . ) i s a n a n l y t i c a l d e v i c e o f t e n u s e d t o o b v i a t e s u c h r e p e t i -t i o u s , w o r k b u t i t i s a m e a s u r e , t h a t i s o b j e c t e d t o b y m a n y a n d s o w a s n o t a d o p t e d i n t h e p r e s e n t i n s t a n c e . O n e a c h s e t o f m e a s u r e m e n t s o f a s p e c i f i c c h a r a c t e r i s t i c o n a g i v e n s p e c i e s , t h e n , o n e t o t a l a n d s i x s u b t o t a l a n a l y s e s o f v a r i a n c e w e r e r u n . T o c o n t i n u e t h e e x a m p l e , t h e c o m p u t e r t a b u l a t i o n s a p p e a r b e l o w : 101 . T r e a t m e n t iz2 ( * z ) 2 w C o m p l e t e 49-9 443.0 415.0 L o v W 17.1 50 .5 48 .7 L o v S 51.9 472.7 449.0 L o v M g 41 .0 290.7 280.2 L o v C a 47.4 396.3 374.5 L o v P 16 .4 45 .8 44 .8 L o v K 16.8 50.2 47-0 T o t a l 240.5 1,749.2 1,659-2 C o r r e c t i o n f a c t o r = ( G T ) 2 ( 2 4 0 . 5 ) 2 42 . 1,377.1 S o u r c e o f v a r i a t i o n D . f . S . s . M.S. V . r . B e t w e e n g r o u p s W i t h i n g r o u p s 6 35 282.1 900 .0 47 .0 25 .7 1.83 T o t a l 41 W i t h 6 a n d 35 d e g r e e s o f f r e e d o m , a v a r i a n c e r a t i o o f 2.38 o r o v e r i s i n d i c a t i v e o f r e a l d i f f e r e n c e . O u r v a l u e o f 1.83 i n d i c a t e s t h a t , t a k e n t o g e t h e r , t h e r e i s n o s t a t i s t i c a l j u s t i f i c a t i o n f o r p r e s u m i n g t h a t t h e d i f f e r -e n c e s I n h e i g h t o b s e r v e d a n d m e a s u r e d v e r a d u e t o t h e e f f e c t s o f t h e v a r i o u s d e f i c i e n t t r e a t m e n t s . H o v e v e r , a p a i r e d c o m p a r i s o n b e t w e e n l o v n i t r o g e n f i g u r e s a n d t h o s e i n c o m p l e t e s o l u t i o n g i v e s t h e f o l l o v i n g r e s u l t s : T r e a t m e n t 2 * z C o m p l e t e L o v N 49 .9 17.1 443.0 50.5 415.0 48 .7 T o t a l 6 7 . O 493.5 463.7 C o r r e c t i o n f a c t o r = ( C T ) = (67-0) - 374.1, E 12 102. S o u r c e o f v a r i a t i o n D . f . S . s . M.S. Y . r . B e t w e e n g r o u p s 1 89.6 89.6 29.9 W i t h i n g r o u p s 10 29.8 3.0 mmtm T D t a l 11 W i t h 1 a n d 10 d e g r e e s o f f r e e d o m , a f i g u r e g r e a t e r t h a n 1 0 . 0 4 i n d i c a t e s t h a t t h e r e i s a s t r o n g p r o b a b i l i t y t h a t t h e e f f e c t s o f t r e a t m e n t a r e o p e r a t i v e a n d r e s p o n s i b l e f o r t h e m e a s u r e d d i f f e r e n c e s . T h e s e p a i r e d c o m p a r i s o n s w e r e r e p e a t e d f o r e a c h p f i t h e s i x t r e a t m e n t s u n t i l f i n a l l y t h e f o l l o w i n g t a b l e c o u l d b e d r a f t e d : Q u a n t i t a t i v e E f f e c t s o f M a c r o n u t r i e n t D e f i c i e n c y P O K D E E O S A P I K E ( T a b u l a r c o m p a r i s o n b e t w e e n c o m p l e t e a n d d e f i c i e n t t r e a t m e n t s )  A v e r a g e s o f C r o c k A v e r a g e s K o . o f T r e a t m e n t H e i g h t D i a m . B r a n c h e s E t c . c m s . Tnmp. C o m p l e t e 8.3 L o w N 2.9 * * L o w S 8.6 K S L o w M g 6.8 K S L o w C a 7.9 K S L o w P 2.7 * * L o w K 2.8 * * w h e r e K S = n o t s i g n i f i c a n t , * = s i g n i f i c a n t a t t h e 5 $ l e v e l o f p r o b a b i l i t y , * * = s i g n i f i c a n t a t t h e 1 $ l e v e l o f p r o b a b i l i t y . T h e a b o v e i s t h e t y p e . o f t a b l e t h a t a p p e a r s i n t h e t e x t a n d A p p e n d i x . T h e q u a n t i t a t i v e e f f e c t s o f m a c r o n u t r i e n t d e f i c i e n c y a s i t a f f e c t s t h e m o r p h o l o g i c a l c h a r a c t e r i s t i c s o f t h e g r o w i n g p l a n t s w i l l b e d e s c r i b e d f o r e a c h o f t h e f i v e s p e c i e s i n t u r n . F i g u r e 4 7 R E L A T I V E GROWTH I N S A N D C u X T U R E ( a f t e r 15 m o n t h s o f g r o w t h ) F i g u r e 4 8 E E I A T I V E GKOWTH I N S A N D C u X T U R E ( a f t e r 1 5 m o n t h s o f g r o w t h ) F o r d e f i n i t i o n o f s y m b o l s , s e e F i g . 4 7 1 1 1 1 1 1 1 1 1 1 1 1 L i 1 1 1 1 1 • I F i g u r e 49 R E M T I - V J E GROWTH I N S A N D C U L T U R E ( a f t e r 15 m o n t h s o f g r o w t h ) F o r d e f i n i t i o n o f s y m b o l s , s e e F i g . 4 7 F i g u r e 50 R E L A T I V E GROWTH I N S A N D C U L T U R E ( a f t e r 15 i n o n t h s o f g r o w t h ) 10J. T a b l e X I Q u a n t i t a t i v e E f f e c t s o f M a c r o n u t r i e n t D e f i c i e n c y 1 . C O A S T A L D O U G L A S - F I R ( T a b u l a r c o m p a r i s o n b e t w e e n c o m p l e t e a n d d e f i c i e n t t r e a t m e n t s ) A v e r a g e s o f C r o c k A v e r a g e s T r e a t m e n t H e i g h t c m s . K o . o f D i a m . B r a n c h e s m m s -L o n g e s t B r a n c h c m s . L o n g e s t K e e d l e c m s . E o o t L e n g t h c m s . L o n g e s t L a t . R o o t c m s . R o o t Y o l u m e c . c . ' s a b c d e f R h C o m p l e t e 25.6 0.53 9 9-5 3.5 53-1 48.1 24.4 L o w K 6.6 ** 0.21 ** 3 ** 5.1 K S 2.7 ** 46.9 K S 35-1 * 7.5 ** L o w S 24.8 K S 0.50 K S 10 K S 8.7 K S 3.5 K S 53-4 K S 49.7 K S 21.5 K S L o w M g 17.0 ** 0.35 * 7 K S 4.5 * 3.3 K S 43.8 K S 39-3 K S 12.7 * L o w C a 19.8 K S 0 .42 K S 9 K S 6.6 K S 3.4 K S 43.4 K S 33.9 * 18.1 K S L o w P 2.1 ** 0.11 ** 1 *JH4* 0.1 ** 1.8 29.6 ** 20.8 ** 1.8 ** L o w K 8.2 ** 0.26 ** 3 ** 2-7 * 2.7 ** 37.8 ** 30.4 * 6.1 ** ( S e e F i g s . 4 7 a n d 4 8 . ) T h e t a b l e t h a t a p p e a r s a b o v e c o n t a i n s t h e d a t a f r o m t h e s e r i e s o f m e a s u r e m e n t s m a d e o n t h e t h i n n e d p l a n t s r e m o v e d i n J u n e 1959 a f t e r a g r o w t h p e r i o d - o f 15 m o n t h s d u r a t i o n . T h i s s e r i e s o f m e a s u r e m e n t s w a s c h o s e n f o r p r e s e n t a t i o n i n t h e t e x t f o r t h r e e m a i n r e a s o n s : o a . I t i s r e p r e s e n t a t i v e o f t h e t r e n d s a n d d i f f e r e n c e s o b s e r v a b l e i n o t h e r s e r i e s . b . I t c o n t a i n s t h e l a r g e s t n u m b e r o f s a m p l e t r e e s . c . I t w a s t h a t s e r i e s o f m e a s u r e m e n t s w h e n , b y v i r t u e o f t h e f a c t t h a t t h e p l a n t s w e r e b e i n g r e m o v e d , m e a s u r e m e n t s o n t h e r o o t s c o u l d a l s o b e m a d e . T h e s y m b o l s K S , * , a n d * * h a v e t h e same c o n n o t a t i o n a s b e f o r e . 104. A n a l y s i s o f r e s u l t s r e p o r t e d i n T a b l e X I a . H e i g h t d i f f e r e n c e s O f n o t e i s t h e s i m i l a r i t y i n h e i g h t b e t w e e n l o w s u l f u r c u l t u r e s a n d c o m p l e t e , t h e w i d e d i s c r e p a n c y e x i s t i n g b e t w e e n c o m p l e t e a n d l o w p h o s p h o r u s , t h e h i g h l y s i g n i f i c a n t d i f f e r e n c e t h a t e x i s t s b e t w e e n t h e s t a n d a r d c o m p l e t e s o l u t i o n p l a n t s a n d t h o s e g r o w n i n c u l t u r e s d e f i c i e n t i n N , P a n d K , a n d t h e l a c k o f s i g n i f i c a n c e b e t w e e n l o w c a l c i u m c u l t u r e p l a n t s a n d t h o s e i n c o m p l e t e s o l u t i o n . b . D i a m e t e r d i f f e r e n c e s C l o s e l y s u b s t a n t i a t i n g t h o s e o b s e r v e d f o r h e i g h t , d i a m e t e r d i f f e r -e n c e s a r e , i n t h i s c a s e , a s i n m o s t o t h e r s , a n e n d o r s e m e n t o f t h e s e v e r i t y a n d s i g n i f i c a n c e o f t h e t r e a t m e n t . A g a i n t h e l o w p h o s p h o r u s t r e a t m e n t a p p e a r s t o b e m o s t e f f e c t i v e i n r e d u c i n g t h e p h y s i c a l d i m e n s i o n s o f t h e t e s t p l a n t s . c . N u m b e r o f b r a n c h e s T h i s w a s a m e a s u r e t h a t w a s r e a d i l y m a d e o n p l a n t s o f s u c h s m a l l s i z e a n d o n e t h a t , w h i l e n o t a s s e n s i t i v e t o d i f f e r e n c e s i n n u t r i t i o n a l s t a t u s a s d i a m e t e r o r h e i g h t , g a v e a f a i r l y g o o d I n d e x o f r e l a t i v e g r o w t h p e r f o r m a n c e u n d e r c o n d i t i o n s o f m e t a b o l i c d e f i c i e n c y . T h e p r e v a i l i n g s e v e r i t y o f t h e e f f e c t s o f a d e f i c i e n c y o f e i t h e r N , P o r K i s a g a i n m a d e e v i d e n t b y t h i s m e a s u r e m e n t o f r e l a t i v e g r o w t h . d . L e n g t h o f l o n g e s t b r a n c h T h i s m e a s u r e m e n t i s g e n e r a l l y o f l e s s e r s i g n i f i c a n c e t h a n t h e o n e p r e v i o u s . I t i n d i c a t e s l i t t l e o r n o d e p a r t u r e f r o m t h e t r e n d s p r e v i o u s l y e s t a b l i s h e d b y h e i g h t , d i a m e t e r a n d t h e n u m b e r o f b r a n c h e s , a n d a s a m e a s u r e o f t h e d i f f e r e n c e s d u e t o t h e e f f e c t s o f m a c r o n u t r i e n t d e f i c i e n c y , i t i s t h e l e a s t s e n s i t i v e o f t h e m e a s u r e m e n t s m a d e o n t h e a b o v e - g r o u n d p o r t i o n s o f t h e t e s t p l a n t s . 105. e . L o n g e s t n e e d l e T h i s m e a s u r e m e n t w a s s u r p r i s i n g l y s e n s i t i v e t o t h e e f f e c t s o f a r t i -f i c i a l l y i n d u c e d d e f i c i e n c y a n d t h i s i s p a r t i c u l a r l y s o w i t h t h e P i n u s s p e c i e s w i t h t h e i r l o n g f a s c i c u l a r n e e d l e s , s o m e t i m e s c a l l e d s e c o n d a r y n e e d l e s . T h e l a t t e r a r e o f s u c h a s i z e t h a t t h e r e d u c t i o n s o c c a s i o n e d b y n u t r i e n t i m b a l a n c e a r e r e a d i l y n o t i c e a b l e . T h e r e l a t i v e e f f e c t s o f t h e v a r i o u s d e f i c i e n c i e s o n t h e p h y s i c a l s i z e o f t h e . a c i c u l a r l e a v e s o f D o u g l a s - f i r a r e n o t t h e l e s s s e v e r e b u t , b e c a u s e o f t h e i r r e l a t i v e l y s m a l l s i z e , t h e v i s u a l e v i d e n c e s o f d e f i c i e n c y a r e n o t s o s t r i k i n g . H o w e v e r , a s c a n b e s e e n f r o m t h e t a b l e a b o v e , t h e y a r e s i g n i f i c a n t e s p e c i a l l y w h e r e t h e d e f i c i e n c y i s N , P o r E . I t c a n b e s e e n t h a t n o t o n l y w a s t h e n u m b e r o f b r a n c h e s m u c h r e d u c e d b y l o w p h o s p h o r u s t r e a t -m e n t b u t t h e a c t u a l s i z e o f t h e f e w n e e d l e s d e v e l o p e d o n t h e m w a s a l s o s e r i -o u s l y r e d u c e d . f . R o o t l e n g t h T h i s w a s a m e a s u r e m e n t t h a t , o n t h e a v e r a g e , w a s o n l y m o d e r a t e l y r e l i a b l e a s a n i n d e x o f t h e e f f e c t o f m a c r o n u t r i e n t d e f i c i e n c y . L i k e t h e l e n g t h o f t h e l o n g e s t l a t e r a l r o o t g i v e n b e l o w , s u c h m e a s u r e m e n t s d i d n o t i n d i c a t e d i f f e r e n c e s t h a t w e r e r e a l a n d o b v i o u s t o t h e e y e . T h e f a c t t h a t t h e e x t e n t o f v e r t i c a l a n d l a t e r a l e x t e n s i o n o n t h e p a r t o f t h e r o o t s y s t e m s w a s l i m i t e d b y t h e p h y s i c a l d i m e n s i o n s o f t h e c r o c k s t h e m s e l v e s d i d m u c h t o l i m i t n a t u r a l v a r i a b i l i t y a n d t h e m a g n i t u d e o f t h e m o r p h o l o g i c a l r e s p o n s e s t o d e f i c i e n c y . T h e e f f e c t s o f p h o s p h o r u s a n d p o t a s s i u m r e m a i n e d s e v e r e , h o w -e v e r , e v e n a s m e a s u r e d b y r o o t l e n g t h . I t i s a l s o o f some i n t e r e s t t o n o t e t h a t n i t r o g e n d e f i c i e n c y d o e s n o t p r o d u c e a n y m a r k e d d e c r e a s e i n r o o t l e n g t h . I n f a c t , , t h e r e i s a s l i g h t i n c r e a s e . T h e e f f e c t s o f c a l c i u m d e f i c i e n c y o n r o o t d e v e l o p m e n t w e r e s e v e r e i n t h a t t h e r e r e s u l t e d a n i n c r e a s e d s u s c e p t i b i l i t y t o d e c a y , a n d e v i d e n c e o f t h i s b r e a k d o w n o f r o o t t i s s u e w a s p r e s e n t i n p r a c t i -106.. c a l l y e v e r y J e a c h a t e d r a w n f r o m t h e s a n d c u l t u r e a r e c e i v i n g s u c h t r e a t m e n t . B u t t h e s e v e r e d i s i n t e g r a t i o n o f r o o t t i s s u e w a s n o t t o o e v i d e n t f r o m t h e m e a s u r e m e n t s m a d e o n t h e r o o t s y s t e m s , l a r g e l y b e c a u s e t h e e f f e c t s o f t h i s t r e a t m e n t w e r e q u a l i t a t i v e r a t h e r t h a n q u a n t i t a t i v e . g . L e n g t h o f l o n g e s t l a t e r a l r o o t M e a s u r e s o f t h e l e n g t h o f t h e l o n g e s t l a t e r a l r o o t p r o d u c e d some i n t e r e s t i n g r e s u l t s . A s c a n b e s e e n f r o m T a b l e X I , t h e e f f e c t s o f l o w n i t r o -g e n a n d l o w c a l c i u m c u l t u r e a r e n o w s i g n i f i c a n t l y h i g h t o j u s t i f y t h e i r e l e v a -t i o n t o t h e . 9 5 $ l e v e l o f p r o b a b i l i t y . N o t e t o o t h a t t h e o u t c o m e o f t h e e f f e c t s o f l o w n i t r o g e n a n d l o w c a l c i u m d e f i c i e n c y i s a r e d u c t i o n i n t h e p h y s i c a l s i z e o f t h e l o n g e s t l a t e r a l r o o t . h . B o o t v o l u m e T h i s w a s m e a s u r e d b y p l a c i n g t h e r o o t s y s t e m i n a g r a d u a t e d c y l i n d e r o f a s i z e l a r g e e n o u g h t o c o n t a i n i t . P r i o r t o i m m e r s i n g t h e s y s t e m i n t h e c y l i n d e r , t h e l a t t e r w a s p a r t i a l l y f i l l e d w i t h w a t e r a n d t h e l e v e l n o t e d . S i n c e t h e r o o t s y s t e m s w e r e p r e v i o u s l y m o i s t e n e d , n o d e t e r g e n t w a s u s e d i n t h e w a t e r . T h e r o o t s y s t e m w a s c o m p l e t e l y I m m e r s e d , t h e n e w l e v e l r e a d o f f t h e g r a d u a t e d s c a l e o n t h e c y l i n d e r , a n d t h e t w o r e a d i n g s s u b t r a c t e d t o g i v e v o l -ume i n c u b i c c e n t i m e t r e s ( a c t u a l l y m i l l i l i t r e s ) . T h i s m e a s u r e m e n t w a s f o u n d t o b e a m o s t r e l i a b l e i n d e x o f s e e d l i n g r e s -p o n s e t o d e f i c i e n c y t r e a t m e n t a n d i t i s r e c o m m e n d e d t h a t w i d e r u s e b e m a d e o f i t i n s e e d l i n g , n u r s e r y s t o c k , f e r t i l i t y , p r o v e n a n c e a n d o t h e r s t u d i e s w h e r e t h e p h y s i c a l s i z e o f t h e r o o t a n d t h e r e l a t i o n s h i p e x i s t i n g b e t w e e n r o o t a n d s h o o t i s a m a t t e r o f s o m e i m p o r t a n c e . B e l y i n g o n l y o n a l i n e a r m e a s u r e m e n t o f t h e r o o t s y s t e m a s a n i n d e x o f t h e e f f e c t o f m a c r o n u t r i e n t d e f i c i e n c y , o n e w o u l d h a v e c o n c l u d e d f r o m t h e 107-d a t a i n T a b l e X I t h a t n i t r o g e n d e f i c i e n c y h a d n o a p p r e c i a b l e e f f e c t o n t h e g r o w t h a n d d e v e l o p m e n t o f r o o t s y s t e m s o f D o u g l a s - f i r . T h e s e c o n c l u s i o n s , h o w e v e r , m u s t b e f u r t h e r s c r u t i n i z e d i n t h e l i g h t o f t h e s t a t i s t i c a l l y s i g n i -f i c a n t s i z e d i f f e r e n c e s o b s e r v a b l e w h e n c o m p a r a t i v e m e a s u r e m e n t s a r e m a d e o f t h e r o o t v o l u m e s i n c o m p l e t e a n d l o w N c u l t u r e s . F o r h e r e i t i s s e e n t h a t t h e r e i s a s u b s t a n t i a l r e d u c t i o n i n r o o t v o l u m e i n c o n d i t i o n s o f p r e v a i l i n g n i t r o g e n d e f i c i e n c y . T h e n , t o o , t h e e f f e c t s o f m a g n e s i u m d e f i c i e n c y o n t h e r o o t s y s t e m s a r e mad© e v i d e n t b y a s t u d y o f r e l a t i v e r o o t v o l u m e . L i n e a r m e a s u r e m e n t s g a v e o n l y m o d e r a t e e v i d e n c e o f s u c h a n e f f e c t . L o w C a a n d l o w S t r e a t m e n t s , w h i l e c a u s i n g some r e d u c t i o n i n t h e v o l u m e o f t h e r o o t s y s t e m s o f D o u g l a s - f i r s e e d l i n g s , a r e l e a s t s e v e r e i n t h e i r e f f e c t o n r o o t d e v e l o p m e n t . I n s u m m a r y : T h e r e i s l i t t l e e v i d e n c e t o s u g g e s t t h a t s u l f u r d e f i c i e n c y i s e f f e c t i v e i n c a u s i n g a n y m a r k e d r e d u c t i o n i n t h e p h y s i c a l s i z e o f D o u g l a s - f i r a s g r o w n i n a r t i f i c i a l c u l t u r e i n t h e g r e e n h o u s e . T h i s c o n c l u s i o n g a i n s s t a t u r e f r o m t h e f a c t t h a t t h e p l a n t s g r o w n i n c u l t u r e s d e f i c i e n t i n e l e m e n t a l s u l f u r , r e c e i v e d o n l y 1 /250 o f t h e i r n o r m a l o r c o m p l e t e s u p p l y . T h e r e w a s some s u g -g e s t i o n t h a t t h e e f f e c t s o f c o n t a m i n a t i o n w e r e o b s c u r i n g t h e e f f e c t s o f t h e m a c r o n u t r i e n t c o n d i t i o n i n d u c e d . T h e a b s o r p t i o n o f a t m o s p h e r i c s u l f u r i s n o t a n i m p o s s i b i l i t y w h e n l o c a t e d s o c l o s e t o a l a r g e i n d u s t r i a l c e n t e r a s w e r e t h e g r e e n h o u s e s i n w h i c h t h e s t u d y w a s c o n d u c t e d . S e v e r a l f a c t s , h o w e v e r , s e e m e d t o a r g u e a g a i n s t p o s s i b l e c o n t a m i n a t i o n . 1• T h e N e o p r e n e t u b i n g u s e d i n t h e p r e s e n t e x p e r i m e n t i s s u l f u r f r e e . 2 . B i d d u l p h , C o r y a n d B i d d u l p h (1956) h a v e s h o w n t h a t t h e r e i s n o a p p r e c i a b l e d o w n w a r d m o v e m e n t o f f o l i a r a b s o r b e d s u l f u r u n t i l a d e q u a t e a m o u n t s a r e m a d e a v a i l a b l e i n t h e n u t r i e n t m e d i u m . 3. T h e s a n d u s e d c o n t a i n e d n o m o r e t h a n a t r a c e o f s u l f u r . 108. 4 . O t h e r s ( E a t o n , 1941) h a v e r e p o r t e d a n i n c r e a s e i n v e g e t a t i v e d e v e l o p m e n t a s a n e a r l y s i g n o f s u l f u r d e f i c i e n c y . T a k i n g f u l l c o g n i z a n c e o f t h e f a c t t h a t h e r e m a y w e l l h e c o n t a m i n a t i o n f r o m a n e x t e r n a l s o u r c e o p e r a t i v e i n t h e p r e s e n t c a s e , i t c a n h e s t a t e d w i t h s o m e a s s u r a n c e t h a t t h e s u l f u r r e q u i r e m e n t o f c o a s t a l D o u g l a s - f i r i s e x t r e m e l y l o w . T h e e f f e c t s o f l o w H , l o w P a n d l o w K a r e c o n s i s t e n t l y s e v e r e , a n d a n y s o i l d e f i c i e n c i e s o f t h e s e e l e m e n t s a r e l i k e l y t o h a v e c o n s i d e r a b l e e f f e c t o n t h e g r o w t h o f t h i s s p e c i e s . A d e f i c i e n c y o f C a o r M g i s a p p a r e n t l y o f m o d e r a t e s i g n i f i c a n c e o n l y f o r t h e g r o w t h o f t h i s s p e c i e s . K r a j i n a (1953) , i n a s t u d y o f t h e m a c r o n u t r i e n t r e q u i r e m e n t s o f t h i s same s p e c i e s , d e s c r i b e s s y m p t o m s t h a t i n d i c a t e t h a t C a a n d M g a r e c o n s i d e r a b l y m o r e i m p o r t a n t f o r t h e g r o w t h o f t h i s s p e c i e s t h a n t h e p r e s e n t s t u d y w o u l d s u g g e s t . T h e e x t e n d e d p e r i o d o f d o r m a n c y t h a t w a s a f e a t u r e o f t h e p r e s e n t e x p e r i m e n t a p p a r e n t l y a l l o w e d t h e a f f e c t e d i n d i v i d u a l s t o r e c o v e r q u i t e c o n s i d e r a b l y f r o m t h e d e f i c i e n t n u t r i t i o n i m p o s e d u p o n t h e m i n t h e p r e v i o u s g r o w i n g s e a s o n . 109-T a b l e X I I Q u a n t i t a t i v e E f f e c t s o f M a c r o n u t r i e n t D e f i c i e n c y 2 . I N T E R I O R D 0 U G L A . S - F I R ( T a b u l a r c o m p a r i s o n b e t w e e n c o m p l e t e a n d d e f i c i e n t t r e a t m e n t s ) T r e a t m e n t H e i g h t c m s . D i a m . m m s . N o . o f B r a n c h e s L o n g e s t B r a n c h c m s . L o n g e s t N e e d l e c m s . R o o t L e n g t h c m s . L o n g e s t L a t . R o o t c m s . R o o t V o l u m e c . c . * s a b c d e f P. h C o m p l e t e 7-8 0.23 1 1.3 2.9 36.3 28.6 4 .6 L o w N 5 -4 N S 0.19 N S 1 N S 2.2 N S 2.7 N S 40.1 N S 28 . 4 N S 4 . 6 N S L o w S 12.3 N S 0.31 N S 2 N S 4 . 0 N S 3.5 N S 4 0 . 6 N S 33-3 N S 10.9 * L o w M g 7-7 N S 0.21 N S 2 N S 2.1 N S 2.9 N S 35-8 N S 29.2 N S 4 . 9 N S L o w C a 10.5 N S 0.27 N S 2 N S 3.3 N S 3-2 N S 38 .4 N S 32.8 N S 8.9 N S L o w p 1 .2 * 0.09 .* 0 N S 0 N S 1 .7 * * 31 .3 N S 31-9 N S 0.8 *• L o w K 4 . 8 N S 0.20 N S 1 N S 3-2 N S 3.0 N S 36.6 N S 28.7 N S 3.7 N S . ( S e e F i g s 4 7 a n d 4 8 . ) R e p r e s e n t a t i v e o f t h e e f f e c t s o f t h e v a r i o u s d e f i c i e n c y t r e a t m e n t s a r e t h e r e s u l t s l i s t e d a b o v e i n T a b l e X I I . A s b e f o r e , t h e y a r e d r a w n f r o m a s e r i e s o f m e a s u r e m e n t s t a k e n a t t h e t i m e o f t h i n n i n g t h e p l a n t s t o o n e p e r c r o c k i n J u n e 1959. A n a l y s i s o f t h e r e s u l t s r e p o r t e d i n T a b l e X I I a . H e i g h t - g r o w t h T h e s a l i e n t f e a t u r e o f t h e d a t a t h a t i s a p p a r e n t w i t h t h i s m e a s u r e o f p l a n t r e s p o n s e , a s w i t h a l l t h e o t h e r s t h a t f o l l o w , i s t h e l a c k o f s i g n i f i -c a n c e b e t w e e n t h e v a r i o u s d e f i c i e n t c u l t u r e s a n d t h e c o m p l e t e . O n l y w i t h t h e m o s t s e v e r e t r e a t m e n t , l o w p h o s p h o r u s , d o t h e e f f e c t s a t t a i n t o a m a g n i t u d e t h a t p u t s t h e m b e y o n d t h e p r o b a b i l i t y o f c h a n c e o c c u r r e n c e . T h e r e l a t i v e f l u c t u a t i o n s i n e f f e c t b e t w e e n t r e a t m e n t s a r e s i m i l a r t o t h o s e s e e n w i t h t h e c o a s t a l v a r i e t y o f D o u g l a s - f i r , i . e . , s u l f u r d e f i c i e n c y i s l e a s t s e v e r e , n o . N , P a n d K t h e m o s t s e v e r e , M g a n d C a t r e a t m e n t s b e i n g i n t e r m e d i a t e i n t h e i r e f f e c t . B u t , i n a b s o l u t e t e r m s , t h e s e d i f f e r e n c e s a r e n o t m e a n i n g f u l w h e n c o m p a r e d t o t h e f i g u r e s o b t a i n e d f r o m t h e t r e e s g r o w n i n c o m p l e t e s o l u t i o n c u l t u r e . T h e l a t t e r w e r e c u r i o u s l y , r e t a r d e d i n t h e i r g e n e r a l d e v e l o p m e n t t h r o u g h o u t t h e l e n g t h o f t h e e x p e r i m e n t , a n d p a r t i c u l a r l y w a s t h i s s o d u r i n g t h e f i r s t g r o w i n g s e a s o n . T h e t r e e s , w h i c h t h e o r e t i c a l l y w e r e r e c e i v i n g a n u t r i e n t s o l u t i o n w h i c h , f r o m a l l c o n s i d e r a t i o n s a p p e a r e d a d e q u a t e f o r t h e i r g r o w t h , d e v e l o p e d v e r y l o n g , s t o u t s u b - t e r m i n a l l a t e r a l s a n d f e w o t h e r b r a n c h e s . T h e i r r o o t s y s t e m s w e r e b e l o w a v e r a g e i n d e v e l o p m e n t a n d d i d n o t r e a c h t h e d i m e n s i o n s o b t a i n e d b y m a n y o f t h e t r e e s g r o w i n g i n d e f i c i e n t c u l t u r e s . S u c h a b n o r m a l i t i e s a r e h a r d t o e x p l a i n . G r a n t e d t h e v a r i e t y w a s b e i n g g r o w n u n d e r e n v i r o n m e n t a l c o n d i t i o n s t h a t w e r e a b n o r m a l b u t , w i t h o t h e r s p e c i e s , t h i s a b n o r m a l i t y o n l y c a u s e d t h e m t o g r o w m o r e r a p i d l y . T h e t e m p e r a t u r e , h u m i d i t y a n d o t h e r c l i m a t i c f a c t o r s w e r e f o r e i g n t o t h e v a r i e t y a l t h o u g h t h e d a y l e n g t h s t o w h i c h i t w a s e x p o s e d w e r e n o r m a l . T h e s u g g e s t i o n w a s o f f e r e d t h a t p e r h a p s t h e v e r y h o t d a y t i m e t e m p e r a t u r e s w e r e I n j u r i o u s , b u t t h e r e i s m o r e l i k e l i h o o d o f a c o a s t a l s p e c i e s s h o w i n g t h e e f f e c t s o f s u c h e x c e s s i v e t e m p e r a t u r e s t h a n o n e w h i c h , t h r o u g h o u t i t s n a t u r a l r a n g e , i s e x p o s e d t o h o t , d r y s u m m e r s . T h e o n e e x p e r i m e n t a l c l i m a t o l o g i c a l f a c t o r w h i c h w a s a t v a r i a n c e w i t h t h o s e n o r m a l l y f o u n d t h r o u g h o u t t h e r a n g e o f i n t e r i o r D o u g l a s -f i r w a s t h e h u m i d i t y , w h i c h r e m a i n e d r e l a t i v e l y h i g h e v e n d u r i n g t h e h o t t e s t d a y . T h i s e x c e s s i v e h u m i d i t y m a y h a v e b e e n r e s p o n s i b l e f o r t h e a b n o r m a l i -t i e s i n f o r m a n d d e v e l o p m e n t o b s e r v e d b u t t h e r e s t i l l r e m a i n s t h e q u e s t i o n o f w h y i n d i v i d u a l s g r o w i n g i n o t h e r c u l t u r e s , d e f i c i e n t i n o n e o r o t h e r o f t h e m a c r o m e t a b o l i c e l e m e n t s r e q u i r e d f o r p l a n t g r o w t h , d i d n o t e x h i b i t l i k e e f f e c t s . P l a n t s i n l o w s u l f u r c u l t u r e s , f o r i n s t a n c e , w e r e l a r g e r , h a d a b e t t e r f o r m , a g r e a t e r n u m b e r a n d m o r e e x t e n s i v e s y s t e m o f b r a n c h e s a n d a l a r g e r r o o t s y s t e m t h a n t h e c o n t r o l . I f a n y c l i m a t i c d e t e r r e n t w e r e 111. o p e r a t i v e , i t w o u l d b e e x p e c t e d t o b e e q u a l l y d e l e t e r i o u s o n a l l p l a n t s o f t h e same v a r i e t y , n o m a t t e r w h a t t h e n u t r i e n t c o n d i t i o n s . Y e t s u c h w a s n o t t h e c a s e . T h e i n d i c a t i o n s a r e r a t h e r t h a t s o m e t h i n g i n t h e n a t u r e o f t h e c o m p l e t e s o l u t i o n , e i t h e r t h e a m o u n t o f o n e o f t h e c o n s t i t u e n t e l e m e n t s o r t h e b a l a n c e b e t w e e n a l l o f t h e m , w a s r e s p o n s i b l e f o r t h e g e n e r a l l a c k o f v i g o r n o t e d . A n e x a m i n a t i o n o f t h e . c o m p o s i t i o n o f t h e n u t r i e n t s o l u t i o n s ( T a b l e I Y , P « 63) g i v e s n o c l u e t o t h e i d e n t i t y o f t h e n u t r i e n t e l e m e n t r e s p o n s i b l e f o r t h e d i f f e r e n c e s . B o t h l o w C a a n d l o w S c u l t u r e s c o n t a i n a KO3- a n d r a d i c a l l i k e t h e c o m p l e t e s o l u t i o n . Y e t i n d i v i d u a l s g r o w i n g i n t h e s e d e f i -c i e n t ' s o l u t i o n s m a d e b e t t e r h e i g h t g r o w t h . S o d i u m w a s p r e s e n t i n t h e l o w c a l c i u m c u l t u r e s , a b s e n t i n t h e c o m p l e t e b u t a l s o a b s e n t i n t h e l o w S c u l t u r e s , s o n o s i g n i f i c a n c e c a n b e a t t a c h e d t o i t s a b s e n c e i n t h e c o m p l e t e s o l u t i o n . T h e p H d i f f e r e n c e s w e r e m i n o r . T h e f e e d i n g s c h e d u l e w a s s i m i l a r , t h e n u m -b e r o f p l a n t s p e r c r o c k t h e same a s o t h e r s p e c i e s , a n d t h e m i c r o n u t r i e n t d i e t i d e n t i c a l . - W h a t e v e r t h e c a u s a l f a c t o r , i t p r e s e n t l y e l u d e s a n a l y s i s . D u r i n g t h e s e c o n d g r o w i n g s e a s o n , t h e t e r m i n a l b u d s o f m a n y o f t h e t r e e s o f i n t e r i o r D o u g l a s - f i r , w h i c h h a d r e m a i n e d d o r m a n t d u r i n g t h e p r e v i o u s s e a s o n , g a v e r i s e t o t r u e l e a d e r s w h i c h g r e w w e l l a n d v i g o r o u s l y . T h e r e s u l t w a s t h a t w h i l e t h e b e l o w - n o r m a l p e r f o r m a n c e i n c o m p l e t e s o l u t i o n r e m a i n e d a f a c t , t h e d i f f e r e n c e s b e t w e e n t h e t r e e s g r o w i n g i n c o m p l e t e a n d t h e v a r i o u s d e f i c i e n t c u l t u r e s b e c a m e l a r g e e n o u g h t o w a r r a n t c a l l i n g t h e m s i g n i f i c a n t . F o r i n s t a n c e , b o t h a v e r a g e h e i g h t a n d d i a m e t e r m e a s u r e m e n t s w e r e s i g n i f i c a n t l y l o w f o r l o w N , P a n d K c u l t u r e s a t t h e t i m e o f f i n a l r e m o v a l ( A p p e n d i x T a b l e V I I ) . S i m i l a r l y , t h e a v e r a g e r o o t v o l u m e o f t r e e s g r o w i n g i n s u l f u r c u l t u r e s w a s s i g n i f i c a n t l y h i g h e r t h a n t h e c o m p l e t e s o l u -t i o n p l a n t s . W h a t e v e r t h e n a t u r e o f t h e a d v e r s e f a c t o r , t r e e s o f t h i s v a r i e t a l s t r a i n o f D o u g l a s - f i r w e r e n o t s o s e v e r e l y a f f e c t e d b y i t d u r i n g t h e s e c o n d g r o w i n g s e a s o n . 112. H a v i n g g i v e n some c o n s i d e r a t i o n , t h e r e f o r e , t o t h e a b n o r m a l i t i e s a t t e n d -i n g t h e g r o w t h o f t h e c o n t r o l c u l t u r e s i n t h i s s p e c i e s o r v a r i e t y , we c a n n o w b r i e f l y s t a t e t h a t t h e r e w a s a d e p r e s s i o n i n a v e r a g e h e i g h t g r o w t h i n l o w P , l o w K a n d l o w N c u l t u r e s , t h a t t h e r e w a s n o s i g n i f i c a n c e i n a n y o f t h e h e i g h t d i f f e r e n c e s n o t e d , w i t h t h e e x c e p t i o n o f p l a n t s g r o w n i n l o w P c u l -t u r e s , a n d t h e r e i s n o j u s t i f i c a t i o n f o r a s s u m i n g t h a t l o w C a a n d l o w S c u l -t u r e s a r e m o r e c o n d u c i v e t o t h e g r o w t h o f t h i s s p e c i e s u n t i l m o r e I s k n o w n c o n c e r n i n g t h e f a c t o r s w h i c h c a u s e d i n d i v i d u a l s g r o w i n g i n c o m p l e t e s o l u t i o n t o s u f f e r s u c h i l l e f f e c t s . b . D i a m e t e r g r o w t h A g a i n , o n l y t h e n e a r o m i s s i o n o f p h o s p h o r u s c a u s e d a n y s i g n i f i c a n t d e c r e a s e i n t h e a m o u n t o f d i a m e t e r i n c r e m e n t . P l a n t s g r o w n i n l o w c a l c i u m a n d l o w s u l f u r c u l t u r e s w e r e l a r g e r t h a n t h e c o n t r o l s i n t h i s r e g a r d , w h e r e a s t h o s e i n l o w p o t a s s i u m , l o w p h o s p h o r u s a n d l o w n i t r o g e n c u l t u r e s w e r e s m a l l e r . c . N u m b e r o f b r a n c h e s T h i s c r i t e r i o n w a s o f n o s i g n i f i c a n c e a s a n i n d i c a t o r o f t h e e f f e c t s o f m a c r o n u t r i e n t d e f i c i e n c y . B r a n c h d e v e l o p m e n t w a s m e a g e r a n d c o n s i d e r a b l y p o o r e r t h a n t h e c o a s t a l c o u n t e r p a r t o f t h i s s p e c i e s , d e s c r i b e d e a r l i e r . d . L e n g t h o f l o n g e s t b r a n c h L i k e w i s e , t h i s m e a s u r e m e n t w a s o f l i t t l e v a l u e . D i f f e r e n c e s e x i s t e d c e r t a i n l y , a n d t h e m a g n i t u d e a n d m o d e o f o c c u r r e n c e o f t h e s e d i f f e r e n c e s f o l -l o w e d t h e g e n e r a l p a t t e r n o f s p e c i e s s u s c e p t i b i l i t y o r s e v e r i t y o f e f f e c t . Y e t t h e g e n e r a l l y s m a l l s i z e o f t h e b r a n c h e s a n d t h e v a r i a b i l i t y t h a t o c c u r r e d w i t h i n a n y o n e t r e a t m e n t i n t h e i r l e n g t h , r e n d e r e d t h i s m e a s u r e m e n t i n a d e -q u a t e a s a m e a n s o f m e a s u r i n g t h e e f f e c t o f n u t r i t i o n a l d e f i c i e n c y . 113-e . L e n g t h o f l o n g e s t n e e d l e T h e v i t h i n - g r o u p v a r i a t i o n h e r e i s c o n s i d e r a b l y r e d u c e d f r o m i t e m d a n d , a s a c o n s e q u e n c e , t h e s i g n i f i c a n c e o f t h e l o v p h o s p h o r u s t r e a t m e n t , a s i t a f f e c t s n e e d l e l e n g t h , b e c o m e s a p p a r e n t . f . R o o t l e n g t h g . L e n g t h o f l o n g e s t l a t e r a l r o o t N e i t h e r o f t h e s e m e a s u r e m e n t s g a v e a n y i n d i c a t i o n o f r e a l d i f f e r e n c e a t t r i b u a t a b l e t o t r e a t m e n t e f f e c t s . h . R o o t v o l u m e C o n f i r m i n g o u r p r e v i o u s c o n t e n t i o n t h a t i n r o o t v o l u m e v e h a v e a m e a s u r e m e n t o f b e t t e r t h a n a v e r a g e w o r t h , i t i s s e e n f r o m t h e d a t a o f T a b l e X I I t h a t , a t t h e % l e v e l o f p r o b a b i l i t y , t h e r e a r e i n d i c a t i o n s t h a t t h e t r e a t m e n t e f f e c t s a r e o p e r a t i v e . I n l o v s u l f u r c u l t u r e s t h e r e i s a s i g n i f i c a n t i n c r e a s e i n t h e a v e r a g e r o o t v o l u m e , w h i l e i n l o v p h o s p h o r u s t h e r e i s a s i g -n i f i c a n t d e c r e a s e . I n s u m m a r y : T h e s i g n i f i c a n c e o f t h e t r e a t m e n t e f f e c t s a s t h e y a f f e c t e d t h e g r o v t h a n d v i g o r o f i n t e r i o r D o u g l a s - f i r w a s ' g r e a t l y i m p a i r e d b y 1 . T h e c u r i o u s i n c o m p a t i b i l i t y b e t w e e n p l a n t s o f t h i s s p e c i e s a n d t h e c h e m i c a l c o m p o s i t i o n o f t h e c o m p l e t e n u t r i e n t s o l u t i o n w h i c h r e s u l t e d i n a d i m i n i s h e d a m o u n t o f v e g e t a t i v e g r o w t h i n b o t h t o p s a n d r o o t s a s w e l l a s b e i n g r e s p o n s i b l e f o r s e v e r a l a b n o r m a l i t i e s o f f o r m a n d d e v e l o p m e n t ; 2 . T h e r e l a t i v e l y b e t t e r g r o w t h m a d e b y t h e same s p e c i e s i n c u l t u r e s t h a t w e r e d e f i c i e n t i n o n e o r o t h e r o f t h e m a j o r m a c r o e l e m e n t s ; 3 « T h e s m a l l e r p h y s i c a l s i z e a n d r e d u c t i o n i n t h e n u m b e r o f m e a s u r a b l e p a r t s . 114. H o w e v e r , some, d i f f e r e n c e s w e r e n o t e d a n d t h e y w e r e c o n s i s t e n t , b o t h i n m a g n i t u d e a n d i n t h e . m a n n e r o f t h e i r p r o g r e s s , e i t h e r u p o r d o w n . T h e r e l a -t i v e s u s c e p t i b i l i t y p a t t e r n w i t h r e g a r d t o t h e v a r i o u s m a c r o n u t r i e n t d e f i c i -e n c i e s i s s i m i l a r t o t h a t a l r e a d y n o t e d w i t h c o a s t a l D o u g l a s - f i r . F i g u r e 5.1 i l l u s t r a t e s t h e s i z e d i f f e r e n c e s o c c a s i o n e d b y t r e a t m e n t a n d g i v e s some i d e a o f t h e a b n o r m a l t y p e o f g r o w t h c h a r a c t e r i s t i c o f t h i s s p e c i e s i n c o m p l e t e s o l u t i o n c u l t u r e s . / F i g . 51* Relative performance of interior Douglas-fir i n cultures deficient i n one or other of the macrometabolic elements. (Photo: Crombie) Fig. 52. The effect of macronutrient deficiency on fascicle needle length (ponderosa pine). The scale i s six centimetres long. (Photo: Crombie) 115. Table XIII Quantitative Effects of Macronutrient Deficiency 3- PONDEROSA PINE (Tabular comparison between complete and deficient treatments) Averages of crock averages Treatment Height cms. No. of Diam. Branches Trims. Longest Branch cms. Longest Needle cms. Root Length cms. Longest Lat.Root cms. Root Yolume c.c. *s a b c d e f R h Complete 8-3 0.44 2 2.9 13.1 68.2 54.9 23-3 Low N 2.9 ** 0.26 ** 0 ** 0.0 ** 6.5 ** 59.7 NS 38.5 NS 8.1 ** Low S 8.6 NS 0.45 NS 2 NS 2.9 NS 11.0 NS 75-5 NS 66.4 NS 24-7 NS Low Mg 6.8 NS 0.41 NS 2 NS 1 .7 NS 10.6 NS 69.1 NS 60.9 NS 20.3 NS Low Ca 7.9 NS 0.43 NS 1 NS 1 -7 NS 11.7 NS 61 .0 NS 53-2 NS 21 -3 NS Low P 2.7 ** 0.24 ** 1 NS 0.2 ** 2.0 ** 52.5 NS 37.6 * 7.5 ** Low K 2.8 ** 0.26 ** 1 NS 1 .2 NS 6.7 ** 50.8 * 41.4 NS 6.7 ** (See Figs. 49 and 50) Analysis of the results reported in Table XIII a. Height growth This species, while not as t a l l as others experimented with, grew relatively well in a r t i f i c i a l culture. It was general for there to be stout leader development, few branches and a tendency for the secondary needles to be grouped around the region of the terminal bud. Although reduced, the variabil-ity in height growth was enough to indicate that low nitrogen, low phosphorus and low potassium cultures were highly significant in their effect on the height growth of this species. This finding is in accord with the measured effects of these deficiencies on the height growth of the two varieties of Douglas-fir. An increase in the severity of the effects of low potassium, how-ever, is a feature particular to this species. The effects of a K deficiency on this species were notably severe throughout as will become apparent as we continue to a discussion of the other indices of the effect of macronutrient deficiency. 116. I t w a s s o m e w h a t o f a s u r p r i s e t o n o t e h o w m i n o r t h e e f f e c t s o f l o w c a l -c i u m w e r e . A d e f i c i e n c y o f m a g n e s i u m a p p a r e n t l y w a s o f g r e a t e r c o n s e q u e n c e f o r t h e h e i g h t g r o w t h o f t h i s s p e c i e s t h a n c a l c i u m . S u l f u r a g a i n w a s a n e l e m e n t w h i c h h a d s e e m i n g l y l i t t l e e f f e c t o n t h e g r o w t h i n h e i g h t o f t h i s s p e c i e s s i n c e a v e r y c o n s i d e r a b l e r e d u c t i o n i n i t s a v a i l a b i l i t y h a d n o d e l e -t e r i o u s e f f e c t s . I f n u t r i e n t d e f i c i e n c y i s s u s p e c t e d o f h a v i n g a n a d v e r s e e f f e c t o n t h e g r o w t h o f p o n d e r o s a p i n e i n n a t u r a l f o r e s t c o n d i t i o n s , a c h e c k f i r s t o n t h e l e v e l s o f K a n d N a v a i l a b l e f o r g r o w t h w o u l d b e r e c o m m e n d a b l e . b . D i a m e t e r i n c r e m e n t T h e s t e m s o f t h e s e e d l i n g s o f t h i s s p e c i e s w e r e r e l a t i v e l y v e r y s t o u t a n d t h e y p o s s e s s e d o n l y m o d e r a t e t a p e r . A f t e r 15 m o n t h s o f g r o w t h i n a r t i f i c i a l c u l t u r e , t h e s t e m s w e r e l a r g e e n o u g h i n d i a m e t e r t o g i v e s t r o n g e v i d e n c e o f t h e e f f e c t s o f m a c r o n u t r i e n t d e f i c i e n c y . A n e x a m i n a t i o n o f t h e v a r i a n c e r a t i o o b t a i n e d o n a n a l y s i s o f t h e c r o c k a v e r a g e s f o r t h i s s p e c i e s a n d m e a s u r e m e n t i n d i c a t e s t h a t i t i s a r e l a t i v e l y s e n s i t i v e i n d e x o f s p e c i e s p e r f o r m a n c e . A g a i n t h e h i g h l y s i g n i f i c a n t e f f e c t s o f l o w H , P a n d K t r e a t -m e n t s a r e a p p a r e n t , a s i s t h e l a c k o f s i g n i f i c a n c e b e t w e e n t h e r e s u l t s o b t a i n e d i n l o w S , M g a n d C a c u l t u r e s a n d t h o s e i n t h e c o n t r o l c u l t u r e . c N u m b e r o f b r a n c h e s d e v e l o p e d L i k e t h e i n t e r i o r v a r i e t y o f D o u g l a s - f i r d i s c u s s e d p r e v i o u s l y , t h i s D r y B e l t p i n e g e n e r a l l y h a d f e w b r a n c h e s . T h e y a r o s e i n w s h o r l s i n g r o u p s o f o n e t o t h r e e . T h e r e s e e m e d t o b e a r e d u c t i o n i n b r a n c h d e v e l o p m e n t w h e n a p i c a l g r o w t h w a s r a p i d . I t i s n o t s u r p r i s i n g , c o n s i d e r i n g t h e i n f r e q u e n c y o f b r a n c h d e v e l o p m e n t r e g a r d l e s s o f d e f i c i e n c y , t h a t s t a t i s t i c a l s i g n i f i c a n c e c o u l d o n l y b e e s t a b l i s h e d f o r t h e m o r p h o l o g i c a l d i f f e r e n c e s o b s e r v e d b e t w e e n t h e l o w N a n d c o m p l e t e s o l u t i o n c u l t u r e s . 117-d . L e n g t h o f l o n g e s t " b r a n c h U s u a l l y , t h e d i f f e r e n c e s o b s e r v e d i n t h e n u m b e r o f b r a n c h e s d e v e l -o p e d i s m o r e t h a n a f a i r i n d i c a t i o n o f t h e e x t e n t o f d i f f e r e n c e e n c o u n t e r e d i n t h e l e n g t h s o f t h e l o n g e s t b r a n c h e s a s t h e y d e v e l o p i n t h e v a r i o u s d e f i c i e n t c u l t u r e s . . I n t h i s c a s e , h o w e v e r , t h e l e n g t h o f t h e l o n g e s t b r a n c h i s a m o r e s e n s i t i v e i n d e x o f t h e v a r i a b i l i t y i n i n d i v i d u a l r e s p o n s e t o t r e a t m e n t s i n c e i t b r i n g s t o l i g h t a s i g n i f i c a n t d i f f e r e n c e b e t w e e n t h e c o m p l e t e a n d l o w p h o s -p h o r u s c u l t u r e s . B o t h l o w m a n d l o w P c u l t u r e s a r e s u c h t h a t t h e y o c c a s i o n a s i g n i f i c a n t d e c r e a s e i n t h e a m o u n t o f l a t e r a l g r o w t h p u t o n b y t h e e s t a b l i s h e d b r a n c h e s . e . L e n g t h o f l o n g e s t n e e d l e A s c a n b e s e e n f r o m F i g u r e 52, t a k e n a t t h e e n d o f t h e e x p e r i m e n t s , t h e v a r i a t i o n i n n e e d l e l e n g t h d u e t o m a c r o n u t r i e n t d e f i c i e n c y i s s i z e a b l e a n d s e n s i t i v e t o t h e n u t r i t i o n a l l i m i t a t i o n s i m p o s e d . T h i s w a s f o u n d t o b e p a r -t i c u l a r l y t r u e o f t h o s e s p e c i e s , l i k e t h e p i n e s , w h i c h d e v e l o p l o n g , a t t e n u -a t e d s e c o n d a r y n e e d l e s i n f a s c i c l e s . T h e d i f f e r e n c e s i n p h o t o s y n t h e t i c c a p a c i t y d u e t o t h i s f a c t o r a l o n e m u s t b e c o n s i d e r a b l e . T h e r e s u l t s i n d i c a t e t h a t t h e e f f e c t s o f l o w n i t r o g e n , l o w p h o s p h o r u s a n d l o w p o t a s s i u m t r e a t m e n t s a r e a g a i n m o s t s e v e r e w h i l e t h o s e o f l o w c a l c i u m , l o w m a g n e s i u m a n d l o w s u l f u r a r e d e t r i m e n t a l b u t t o a n e x t e n t t h a t i s n o t s t a t i s t i c a l l y v a l i d . f . L e n g t h o f r o o t s y s t e m T h e i n d i c a t i o n s a r e t h a t m a c r o n u t r i e n t d e f i c i e n c y h a s b u t l i t t l e s i g n i f i c a n t e f f e c t o n t h e g r o w t h i n l e n g t h o f t h e r o o t s y s t e m s o f p o n d e r o s a p i n e . H o w t r u e t h i s d e d u c t i o n i s w i l l d e p e n d o n h o w s e v e r e l y t h e d i m e n s i o n s o f t h e c r o c k l i m i t e d t h e g r o w t h i n l e n g t h o f t h e m a i n t a p - r o o t s y s t e m . T h e 118. d o w n w a r d p e n e t r a t i o n o f t h e l i v i n g r o o t s y s t e m w a s u s u a l l y h a l t e d a t a p o i n t s o m e w h a t a b o v e t h e b o t t o m s u r f a c e o f t h e c r o c k i n a z o n e w h i c h w a s b e l o w t h e l o w e r r i m o f t h e s t o p p e r h o l e a n d t h u s w a s n e v e r a d e q u a t e l y d r a i n e d . T h e v e r y l a r g e r o o t s y s t e m s t h a t w e r e a f e a t u r e o f t h i s s p e c i e s a n d i t s g r o w t h i n a r t i f i c i a l c u l t u r e e l o n g a t e d m o s t l y i n a l a t e r a l p l a n e a n d m a n y s t o u t , w o o d y l a t e r a l r o o t s t h a t b r a n c h e d e x t e n s i v e l y w e r e o f c o m m o n o c c u r r e n c e ( F i g . 5 3 ) . B u t a s a n i n d e x o f t h e e f f e c t s o f m a c r o n u t r i e n t d e f i c i e n c y , t h e r e i s l i t t l e t o r e c o m m e n d t h i s m e a s u r e m e n t p e r s e . U s i n g i t , a n e s t a b l i s h e d s i g n i -f i c a n c e a t e t h e 5 $ l e v e l o f p r o b a b i l i t y w a s a p p l i c a b l e t o t h e e f f e c t s o f o n l y o n e o f t h e s i x t r e a t m e n t s , n a m e l y l o w p o t a s s i u m . g . L o n g e s t l a t e r a l r o o t . H e r e t h e e f f e c t s o f d e f i c i e n c y a r e m o r e e v i d e n t . A l o w n i t r o g e n c o n t e n t i n t h e n u t r i e n t s o l u t i o n h a s a n e f f e c t t h a t I s m o r e p r o f o u n d o n t h i s m e a s u r e o f r e l a t i v e r o o t d e v e l o p m e n t t h a n o n a n y m e a s u r e d e s i g n e d t o d e t e c t t h e e f f e c t s o n r o o t l e n g t h . S i m i l a r l y , t h e r e a r e c o n s i d e r a b l e r e d u c t i o n s i n t h e l e n g t h o f t h e l o n g e s t l a t e r a l r o o t d e v e l o p e d i n s o l u t i o n s d e f i c i e n t i n p o t a s s i u m a n d p h o s p h o r u s , a l t h o u g h o n l y t h e l a t t e r e f f e c t i s l a r g e e n o u g h t o b e s t a t i s t i c a l l y s i g n i f i c a n t . h . R o o t v o l u m e A c o m p a r i s o n b e t w e e n t h e d a t a r e p o r t e d i n c o l u m n h , T a b l e X I I a n d t h a t f o r a n y o t h e r s p e c i e s w i l l f u r n i s h r e a d y p r o o f o f t h e e x t e n s i v e n a t u r e o f t h e r o o t s y s t e m s d e v e l o p e d b y t h i s s p e c i e s . G e n e r a l l y , t h e y w e r e w o o d y , w i t h s t o u t l a t e r a l d e v e l o p m e n t a n d a n a b b r e v i a t e d t a p r o o t w h i c h m a y h a v e b e e n d u e t o t h e p h y s i c a l l i m i t a t i o n s o f t h e c o n t a i n e r s i n w h i c h t h e y g r e w . T h e c o n s i s t e n t l y s e v e r e e f f e c t s o f l o w N , P a n d E t r e a t m e n t s a r e h e r e m a d e q u i t e e v i d e n t . A l l h a v e a s i g n i f i c a n t l y b a d e f f e c t o n t h e g r o w t h a n d d e v e l o p m e n t 119-i n v o l u m e o f t h e r o o t s y s t e m s t h a t s u p p o r t t h e g r o w t h o f t h i s s p e c i e s . T h e p a r t i a l r e m o v a l o f M g , . C a a n d S f r o m t h e m e d i a i n w h i c h t h e y g r e w h a d l i t t l e e f f e c t o n t h e g r o s s m o r p h o l o g y o f t h e r o o t s y s t e m s d e v e l o p e d . I n s u m m a r y : H a l f o f t h e m e a s u r e m e n t s u s e d t o q u a n t i t a t i v e l y a s s e s s t h e e f f e c t s o f m a c r o n u t r i e n t d e f i c i e n c y o n t h e g r o w t h o f p o n d e r o s a p i n e g a v e i n c o n t r o v e r t i b l e e v i d e n c e o f t h e i l l e f f e c t s o f a n y d e c r e a s e i n t h e a m o u n t s o f p o t a s s i u m , p h o s -p h o r u s a n d n i t r o g e n s u p p l i e d . T h e s e t h r e e e l e m e n t s , i t i s s u g g e s t e d , a r e l i k e l y t o b e o f g r e a t e s t c o n s e q u e n c e t o t h e g r o w t h o f t h i s s p e c i e s i n n a t u r a l o r a r t i -f i c i a l c u l t u r e . T h e m e a s u r e m e n t s w h i c h f u r n i s h t h e b a s i s f o r s u c h c o n c l u s i o n s a l s o , o n i n t e r p r e t a t i o n , e m p h a s i z e t h e l a c k o f s i g n i f i c a n c e o f t h e e f f e c t s d u e d e f i c i e n c i e s o f C a , M g o r S . T h e s e c o n c l u s i o n s g a i n v e r i f i c a t i o n f r o m a n e x a m i n a t i o n o f F i g u r e 5 4 . Tig. 53. The effect of macronutrient deficiency on the growth of the roots of ponderosa pine. Note the absence of large woody lateral roots in the low Z treatment. Scale marked off in centimetres. (Photo: Crombie) Tig. 5k. Effect of macronutrient deficiency on the growth of ponderosa pine. The minus signs preceding the abbreviations for each of the elements imply a deficiency rather than a complete absence of the element. (Photo: Crombie) 120. T a b l e X I V Q u a n t i t a t i v e E f f e c t s o f M a c r o n u t r i e n t D e f i c i e n c y 4. W E S T E R N W H I T E P I N E ( T a b u l a r c o m p a r i s o n b e t w e e n c o m p l e t e a n d d e f i c i e n t t r e a t m e n t s ) A v e r a g e s o f C r o c k A v e r a g e s T r e a t m e n t H e i g h t N o . o f D i a m . B r a n c h e s L o n g e s t B r a n c h L o n g e s t N e e d l e R o o t L e n g t h L o n g e s t L a t . R o o t R o o t V o l u m e c m s • Trims • c m s . c m s . c m s . c m s . c . c . * s a b c d e f h C o m p l e t e 3-1 0.26 5 1.9 5-5 4 2 . 1 35.6 9.0 L o w N 2.4 N S 0.16 ** 1 ** 0.3 ** 5-3 K S 46.5 N S 34.9 N S 4.7 MS: L o w S 4.6 * 0.30 ** 6 N S 3-0 N S 5 .1 N S 41 .6 N S 33-4 N S 8.6 N S L o w M g 2.8 N S 0 . 2 4 N S 4 N S 1.6 N S 7-2 N S 38.5 N S 32.4 N S 7-5 N S L o w C a 3-3 N S 0.27 N S 4 N S £.5 N S 6.7 N S 50.3 N S 43.8 N S 7-9 N S L o w P 1 .3 ** 0.13 ** 0 ** 0.1 ** 1.5 ** 27.9 ** 16.6 ** 1 .7 ** L o w K 1.6 ** 0.17 ** 1 ** 0.2 ** 4.6 N S 32.1 ** 23.1 ** 2.2 ** ( S e e F i g s . 49 a n d 50) T h e e f f e c t s o f t h e v a r i o u s m a c r o n u t r i e n t d e f i c i e n c i e s o n s e v e r a l o f t h e m o r e s a l i e n t m o r p h o l o g i c a l f e a t u r e s a r e a s o u t l i n e d i n T a b l e X I V a b o v e . a . H e i g h t g r o w t h . P l a n t s o f t h i s s p e c i e s w e r e , r e l a t i v e l y s m a l l i n s i z e a n d a p p e a r e d t o b e o u t o f h a r m o n y w i t h t h e i r s u i r o u n d i n g s . E v e n t h o s e p l a n t s o f t h i s s p e c i e s r a i s e d i n c o m p l e t e s o l u t i o n p u t o n l i t t l e t e r m i n a l g r o w t h , e x h i b i t e d n o n e o f t h e u s u a l w h o r l e d b r a n c h d e v e l o p m e n t c o m m o n l y a f e a t u r e o f t h i s s p e c i e s , a n d w h a t b r a n c h e s w e r e d e v e l o p e d m a d e b u t m e a g e r l a t e r a l g r o w t h . L i k e i n t e r i o r D o u g l a s - f i r , w h i t e p i n e t h r i v e d l e s s w e l l i n t h e c o m p l e t e s o l u t i o n g e n e r a l l y t h a n i t d i d i n t h e l o w s u l f u r c u l t u r e s , f o r i n s t a n c e . T h i s p e c u l i a r i n c o m -p a t i b i l i t y b e t w e e n t w o i n t e r i o r s p e c i e s a n d a m o d e o f a r t i f i c i a l c u l t u r e w h i c h i s r e c k o n e d t o b e o p t i m a l c o u l d b e a c h a n c e o c c u r r e n c e b u t t h e c o i n c i -d e n c e i s s u g g e s t i v e o f some r e a l c a u s a l r e l a t i o n s h i p . T h e n a t u r e o f t h i s 121 . r e l a t i o n s h i p h a s b e e n s o u g h t , i n a n e a r l i e r d i s c u s s i o n , t o n o a v a i l . T o r e t u r n t o t h e h e i g h t g r o w t h m a d e b y t h e i n d i v i d u a l s o f t h i s s p e c i e s i n t h e v a r i o u s s a n d c u l t u r e s , t h e d a t a o f T a b l e X T V i n d i c a t e t h a t t h e e f f e c t s o f s u l f u r d e f i c i e n c y h a v e a n a c c e l e r a t i n g e f f e c t o n h e i g h t g r o w t h , w h i l e a d e f i c i e n c y o f e i t h e r P o r K r e d u c e s h e i g h t g r o w t h s i g n i f i c a n t l y . T h e n e a r a b s e n c e o f e i t h e r C a o r M g s e e m s t o h a v e n o p r o f o u n d e f f e c t o n h e i g h t g r o w t h a t a l l . N i t r o g e n d e f i c i e n c y w a s d e t r i m e n t a l t o t h e a m o u n t o f h e i g h t g r o w t h o f w h i c h t h e p l a n t s w e r e c a p a b l e , b u t t h e r e w a s n o s t a t i s t i c a l s u p p o r t f o r c o n c l u d i n g t h a t t h e o b s e r v e d d e p r e s s i o n i n h e i g h t g r o w t h w a s d u e t o t r e a t m e n t e f f e c t s . b . D i a m e t e r i n c r e m e n t A l t h o u g h n o t a s l a r g e a s p o n d e r o s a p i n e , i n d i v i d u a l s o f t h i s s p e c i e s r e s p o n d e d w e l l t o t h e e f f e c t s o f d e f i c i e n c y , i f t h i s m e a s u r e m e n t b e a n y c r i -t e r i o n f o r j u d g m e n t . F o u r o f t h e s i x d e f i c i e n t t r e a t m e n t s w e r e r e s p o n s i b l e f o r s i g n i f i c a n t c h a n g e s i n t h e a m o u n t o f r a d i a l i n c r e m e n t p u t o n b y t h e s t e m s o f w h i t e p i n e d u r i n g t h e 1 4 - m o n t h e x p e r i m e n t a l p e r i o d t h a t e l a p s e d b e f o r e t h e s e m e a s u r e m e n t s w e r e m a d e . O f t h e s e 4 c h a n g e s , 3 r e s u l t e d i n a n a v e r a g e d e c l i n e i n d i a m e t e r i n c r e m e n t ( l o w N , P a n d K ) w h e r e a s t h e f o u r t h ( l o w s) p r o d u c e d a s i g n i f i c a n t i n c r e a s e . D i f f e r e n c e s t h a t w e r e t h o u g h t t o b e i n d i c a -t i v e o f r e a l d e f i c i e n c y e f f e c t w h e r e h e i g h t g r o w t h w a s u s e d a s a m e a s u r e o f r e s p o n s e , n o w a p p e a r t o b e t r u l y s o o n a c o n s i d e r a t i o n o f d i a m e t e r g r o w t h . T h e h i g h s e n s i t i v i t y t h a t c h a r a c t e r i z e d t h i s m e a s u r e m e n t t h r o u g h o u t t h e e n t i r e e x p e r i m e n t w a s s u b s t a n t i a t e d i n t h e p r e s e n t i n s t a n c e . A d e f i c i e n c y o f M g o r C a a g a i n a p p e a r s t o b e o f l i t t l e c o n s e q u e n c e f o r t h i s a s p e c t o f w h i t e p i n e ' s m o r p h o l o g i c a l d e v e l o p m e n t . 122. c . N u m b e r o f b r a n c h e s d e v e l o p e d T h i s s p e c i e s , a s i t g r e w i n s a n d c u l t u r e i n t h e g r e e n h o u s e , d e v e l o p e d n u m e r o u s s h o r t b r a n c h e s , p a r t i c u l a r l y i n t h e r e g i o n s u b t e n d i n g t h e t e r m i n a l b u d . T h e s e b r a n c h e s w e r e s h o r t , p o s s e s s e d f e w n e e d l e s , a n d d i d n o t t h e m s e l v e s g i v e r i s e t o a n y s e c o n d a r y b r a n c h e s . I t w a s t h i s p e c u l i a r b r a n c h i n g h a b i t w h i c h i n d i c a t e d t h a t s o m e t h i n g i n t h e e n v i r o n m e n t a l c o n d i t i o n s s u r r o u n d i n g t h e g r o w t h o f t h i s s p e c i e s w a s i n i m i c a l t o i t s b e s t d e v e l o p m e n t . C o n j e c t u r e s o f t h i s n a t u r e a r e o f n o r e a l a n a l y t i c a l v a l u e , h o w e v e r , a n d w i l l n o t b e p u r -s u e d f u r t h e r , a t t h i s p o i n t . S u f f i c e i t t o s a y t h a t t h e b r a n c h d e v e l o p m e n t , w h e t h e r n o r m a l o r a b n o r m a l , s u p p o r t e d t h e c o n c l u s i o n s a l r e a d y d r a w n c o n c e r n i n g t h e s i g n i f i c a n c e o f t h e v a r i -o u s d e f i c i e n t t r e a t m e n t s a s t h e y a f f e c t e d t h e g r o w t h a n d d e v e l o p m e n t o f t h i s s p e c i e s . T h e n u m b e r o f b r a n c h e s d e v e l o p e d i n l o w N , P a n d K t r e a t m e n t s w a s s i g n i f i c a n t l y l o w , t h e n u m b e r d e v e l o p e d i n l o w S t r e a t m e n t s s l i g h t l y h i g h e r , a n d t h e r e w a s a m i n o r r e d u c t i o n i n b r a n c h n u m b e r s i n t h e l o w m a g n e s i u m a n d l o w c a l c i u m t r e a t m e n t s . d . L e n g t h o f l o n g e s t b r a n c h A s m e n t i o n e d p r e v i o u s l y , b r a n c h d e v e l o p m e n t i n t h i s s p e c i e s w a s a t y p i c a l a n d u n l i k e t h e b r a n c h d e v e l o p m e n t , i n f o r m a n d s i z e , s e e n i n p l a n t s g r o w n i n o u t d o o r c o n d i t i o n s . T h e e x p e c t a t i o n w a s t h a t , a s a r e s u l t , t h e e f f e c t s o f t r e a t m e n t w o u l d b e s o m e w h a t o b s c u r e d . T h e f i g u r e s o f a v e r a g e b r a n c h d i m e n s i o n b y t r e a t m e n t q u o t e d i n T a b l e X I V , h o w e v e r , s h o w t h a t t h e r e w a s a h i g h d e g r e e o f s e n s i t i v i t y t o t h e i n d u c e d d e f i c i e n c i e s . D e f i c i e n c i e s o f N , P a n d K w e r e a g a i n o f c o n s i d e r a b l e m o m e n t a n d c u r t a i l e d t o a s i g n i f i c a n t d e g r e e t h e l i n e a r d i m e n s i o n s o f t h e l o n g e s t b r a n c h d e v e l o p e d . D e f i c i e n c i e s o f t h e s e t h r e e m a c r o m e t a b o l i c e l e m e n t s a p p e a r e d t o b e e q u a l i n t h e s e v e r i t y o f t h e i r e f f e c t o n t h i s m o r p h o l o g i c a l c h a r a c t e r i s t i c . A r e d u c e d s u p p l y o f , 123. M g , C a o r S h a d n o s i g n i f i c a n t e f f e c t o n t h e l e n g t h o f t h e l o n g e s t b r a n c h ; i n f a c t , p l a n t s g r o w i n g i n t h e l a t t e r t w o d e f i c i e n t c u l t u r e s , C a a n d S , a c t u a l l y p o s s e s s e d , o n t h e a v e r a g e , l o n g e r b r a n c h e s t h a n t h e c o n t r o l . e . L e n g t h o f l o n g e s t n e e d l e T h e m e a s u r e m e n t s t a k e n a t t h i s t i m e a r e n o t a l t o g e t h e r i n d i c a t i v e o f some o f t h e d i f f e r e n c e s t h a t e v e n t u a l l y d e v e l o p e d i n t h e v a r i o u s d e f i c i e n t c u l t u r e s . A s c a n b e s e e n f r o m F i g u r e 5 5 , t h e s e d i f f e r e n c e s w e r e q u i t e m a r k e d . A l l d e f i c i e n c i e s , w i t h t h e u s u a l e x c e p t i o n o f s u l f u r , h a d t h e e f f e c t o f r e d u c -i n g t h e l i n e a r d i m e n s i o n s o f t h e d e v e l o p i n g s e c o n d a r y o r f a s c i c l e n e e d l e s . T h e p r e s e n t d a t a s h o w o n l y t h a t t h e d i m i n u t i o n i n n e e d l e l e n g t h o c c a s i o n e d b y a p a r t i a l a b s e n c e o f p h o s p h o r u s i s l a r g e e n o u g h t o b e s i g n i f i c a n t b u t t h e s e e f f e c t s w e r e i n t e n s i f i e d w i t h t h e p a s s a g e o f t i m e u n t i l , a t t h e t e r m i n a t i o n o f t h e e x p e r i m e n t , l o w N , l o w P a n d l o w K c u l t u r e s a l l h a d s e r i o u s e f f e c t s o n t h i s m o r p h o l o g i c a l c h a r a c t e r i s t i c . f . E o o t l e n g t h N o t e w o r t h y a m o n g t h e r e c o r d e d e f f e c t s o f m a c r o n u t r i e n t d e f i c i e n c y o n t h e l e n g t h s o f t h e r o o t s y s t e m s o f w h i t e p i n e a r e t h e f o l l o w i n g : 1 . L o w n i t r o g e n h a s t h e e f f e c t o f i n c r e a s i n g t h e a v e r a g e l e n g t h o f r o o t s y s t e m s d e v e l o p e d . 2 . A d e f i c i e n c y o f s u l f u r i n t h e r o o t i n g m e d i u m d o e s n o t i n c r e a s e t h e v e r t i c a l e x t e n t o f t h e r o o t s y s t e m s d e v e l o p e d b y t h i s s p e c i e s . I n o t h e r w o r d s , s u l f u r d e f i c i e n c y , I n t h i s r e s p e c t , h a s a d e c e l e r a t i n g e f f e c t o n g r o w t h . 3 . M a g n e s i u m c o n t i n u e s i n t h e l i m b o o f i n s i g n i f i c a n c e w h e n c o n -s i d e r a t i o n i s g i v e n t o i t s e f f e c t o n r o o t g r o w t h . 4 . C a l c i u m , l i k e w i s e , p r o d u c e s d i f f e r e n c e s i n r o o t l e n g t h t h a t a r e n o t v a l i d s t a t i s t i c a l l y . Y e t t h e f a c t o f i n t e r e s t h e r e i s n o t t h e m a g n i t u d e 1 2 4 . o f t h e c h a n g e b u t t h e d i r e c t i o n i n v h i c h i t t r e n d s . T h e a v e r a g e l e n g t h o f t h e r o o t s y s t e m s i n t h e c o n t r o l c o m p l e t e s o l u t i o n c u l t u r e w a s e x c e e d e d b y t h a t i n l o w c a l c i u m c u l t u r e b y a b o u t 20$, a n d , w h i l e s t a t i s t i c a l l y i n v a l i d , s u c h a n 5 i n c r e a s e i s reason e n o u g h f o r s p e c u l a t i o n . B u t r a t h e r t h a n resort t o t h i s , a n e x a m i n a t i o n o f r o o t l e n g t h m e a s u r e m e n t s t a k e n a t t h e e n d o f t h e e x p e r i m e n t ( A p p e n d i x T a b l e I X ) w i l l b e m a d e t o d e t e r m i n e w h e t h e r t h e r e i s a n y s u p p o r t f o r t h e t r e n d s h e r e e s t a b l i s h e d . F r o m T a b l e I X i n t h e A p p e n d i x , i t c a n b e readily s e e n t h a t t h e r e i s . A f t e r a f u r t h e r t h r e e m o n t h s o f g r o w t h , t h e l e n g t h o f r o o t s y s t e m s g r o w i n g i n l o w C a c u l t u r e e x c e e d e d t h e c o n t r o l s b y a n a v e r a g e o f g r e a t e r t h a n 60$, a n d s u c h a d i f f e r e n c e , o n a n a l y s i s , w a s s i g n i f i c a n t a t t h e 1 $ l e v e l o f p r o b a b i l i t y . T h i s i s t h e f i r s t r e c o r d e d i n s t a n c e o f s u c h a n e f f e c t o n c o n i f e r o u s r o o t s t h a t t h e w r i t e r h a s b e e n a b l e t o d i s c o v e r . C e r -t a i n l y t h e e f f e c t i s a c u r i o u s o n e a n d d i f f i c u l t t o e x p l a i n , a l t h o u g h a n a t t e m p t w i l l b e m a d e t o d o s o l a t e r ( p a g e 206 ) . F o r t h e p r e s e n t , t h e f a c t w i l l receive n o t i c e a s o n e o f t h e m o r e i n t e r e s t i n g o b s e r v a t i o n s t o e m e r g e f r o m t h e p r e s e n t s t u d y . ( S e e F i g u r e 56.) 5. B o t h P a n d K a r e e l e m e n t s w h i c h , w h e n removed f r o m t h e a m b i e n t n u t r i e n t s o l u t i o n , a p p e a r t o h a v e d e c i s i v e a n d d r a s t i c r e s u l t s u p o n t h e m a j o r i t y o f t h e m o r p h o l o g i c a l c h a r a c t e r i s t i c s m e a s u r e d i n t h e p r e s e n t s t u d y , a n d r o o t l e n g t h i s n o e x c e p t i o n . g . L e n g t h o f l o n g e s t l a t e r a l T h e r e i s a d e c i d e d s i m i l a r i t y b e t w e e n t h e r e s u l t s recorded u n d e r t h i s h e a d a n d t h o s e p r e v i o u s l y d i s c u s s e d u n d e r r o o t l e n g t h . T h e e f f e c t s o f t h e v a r i o u s d e f i c i e n c i e s a r e s i m i l a r a n d , i n t e r e s t i n g l y e n o u g h , a d e f i c i e n c y o f c a l c i u m a g a i n s e e m s t o h a v e t h e e f f e c t o f i n c r e a s i n g t h e p h y s i c a l d i m e n s i o n s o f t h e l a t e r a l l y d e v e l o p e d r o o t s . D a t a o b t a i n e d a t t h e t e r m i n a t i o n o f t h e 125. e x p e r i m e n t a g a i n u n d e r w r i t e t h e s i g n i f i c a n c e o f t h e t r e n d s h e r e n o t e d . F r o m t h i s l a t t e r s o u r c e ( A p p e n d i x T a b l e IX), i t b e c o m e s e v i d e n t t h a t t h i s i n c r e a s e i n l e n g t h o f t h e l o n g e s t l a t e r a l , w h i c h p r e s u m e s a n i n c r e a s e i n a v e r a g e l e n g t h o f a l l t h e o t h e r l a t e r a l r o o t s , i s s u b s t a n t i a l a n d t i g h t l y t i e d , s t a t i s t i c a l l y , t o t h e t r e a t m e n t e f f e c t s . C o u p l e d w i t h t h e o b s e r v a t i o n s n o t e d p r e v i o u s l y o n t h e e f f e c t s o f l o v C a c u l t u r e s o n r e l a t i v e a v e r a g e r o o t l e n g t h , t h e s e o b s e r -v a t i o n s o n l a t e r a l d e v e l o p m e n t u n d e r s i m i l a r c o n d i t i o n s c a n o n l y b e i n t e r p r e t e d t o m e a n t h a t t h e r e w a s a g e n e r a l , o v e r a l l i n c r e a s e i n r o o t d e v e l o p m e n t b o t h l a t e r a l l y a n d v e r t i c a l l y w h e n c a l c i u m w a s a l l b u t r e m o v e d f r o m t h e s o l u t i o n s t o w h i c h t h e r o o t s w e r e e x p o s e d . O n e c o u l d p o s t u l a t e t h a t a ) c a l c i u m h a s a n i n h i b i t i n g e f f e c t o n t h e e l o n g a t i o n o f t h e r o o t m e r i s t e m s o f w e s t e r n w h i t e p i n e ; b ) t h e i n c r e a s e d q u a n t i t i e s o f o t h e r i o n s a b s o r b e d i n t h e a b s e n c e o f t h e d i v a l e n t c a l c i u m i o n ( p a r t i c u l a r l y K i o n s ) m a y h a v e t h e e f f e c t o f i n c r e a s i n g t h e a m o u n t o f r o o t d e v e l o p m e n t ; o r c ) t h a t s o d i u m , t h e c o m p e n s a t i n g I o n i n t h e p r e s e n t c a s e , h a d s o m e a c c e l e r a t i n g e f f e c t o n r o o t g r o w t h . W h a t e v e r t h e r e a l e x p l a n a t i o n , t h e a u t h e n t i c i t y o f t h e r e s u l t s r e m a i n s a f a c t . C o n c l u d i n g o u r r e m a r k s o n t h e p r e s e n t m e a s u r e m e n t , we m u s t n o t e t h e s i g n i f i c a n t e f f e c t s o f r e m o v i n g a p r o p o r t i o n o f t h e a v a i l a b l e p h o s p h o r u s a n d p o t a s s i u m f r o m t h e c u l t u r e s o l u t i o n s . T h e l e n g t h o f t h e l o n g e s t l a t e r a l w a s a p p r e c i a b l y r e d u c e d a s a r e s u l t . h . R o o t v o l u m e A l l d e f i c i e n t c u l t u r e s w e r e r e s p o n s i b l e f o r r e d u c t i o n s , o f v a r y i n g m a g n i t u d e , i n t h e v o l u m e o f t h e r o o t s y s t e m s d e v e l o p e d . O n l y i n t h e c a s e o f l o w j? a n d l o w K , h o w e v e r , w e r e t h e r e d u c t i o n s l a r g e e n o u g h t o b e s i g n i f i c a n t . T h e p r e v i o u s l y n o t e d i n c r e a s e i n t h e l e n g t h o f t h e l o n g e s t l a t e r a l a n d i n t h e v e r t i c a l e x t e n t o f t h e l o w C a s y s t e m s d i d n o t r e s u l t i n a n y i n c r e a s e i n t h e 126. a v e r a g e p h y s i c a l v o l u m e o f t h e a f f e c t e d r o o t s y s t e m s . -I n s u m m a r y : A d e f i c i e n c y o f n i t r o g e n p r o d u c e s s i g n i f i c a n t r e d u c t i o n s i n d i a m e t e r i n c r e m e n t , h e i g h t g r o w t h a n d t h e n u m b e r a n d r e l a t i v e l e n g t h o f t h e b r a n c h e s d e v e l o p e d . L o w N a l s o h a s a d e t r i m e n t a l e f f e c t o n t h e l e n g t h o f t h e l o n g e s t n e e d l e . T h i s , t o g e t h e r w i t h t h e p r e m a t u r e l e a f f a l l t h a t r e s u l t s f r o m t h i s d e f i c i e n c y , i s i n d i c a t i v e o f t h e s e r i o u s n a t u r e o f t h e e f f e c t s w h i c h a d e f i -c i e n c y o f t h i s e l e m e n t c a n i n f l i c t . T h e r o o t s y s t e m s , g e n e r a l l y , a r e l e s s a f f e c t e d b y a d e f i c i e n c y o f t h i s e l e m e n t . A d e f i c i e n c y o f s u l f u r h a s a n a c c e l e r a t i n g e f f e c t o n h e i g h t a n d d i a m e t e r g r o w t h b u t t h e s e f a v o r a b l e e f f e c t s a r e n o t a f e a t u r e o f a n y d e f i c i e n c y o f t h i s e l e m e n t o n t h e g r o w t h o f t h e r o o t s y s t e m s o f w h i t e p i n e . A d e f i c i e n c y o f m a g n e s i u m , w h i c h i s s y m p t o m a t i c a l l y o b v i o u s a t a n e a r l y d a t e , c a u s e s o n l y m i n o r r e d u c t i o n s i n t h e d i m e n s i o n s o f b o t h s t e m a n d r o o t p a r t s . T h e e f f e c t o f l o w c a l c i u m c u l t u r e s i s n o t r e m a r k a b l e f o r i t s o r i g i n a l i t y w h e n c o n s i d e r a t i o n i s g i v e n o n l y t o m e a s u r e s o f h e i g h t , d i a m e t e r a n d b r a n c h d e v e l o p m e n t . B u t t h e s e e f f e c t s a s s u m e i m p o r t a n c e w h e n s t u d i e d w i t h r e g a r d t o t h e p h y s i c a l d i m e n s i o n s o f t h e r o o t s y s t e m s . T h e i n c r e a s e s n o t e d a r e s u p p o r t e d b y s u b s e q u e n t o b s e r v a t i o n s m a d e a t t h e e n d o f t h e e x p e r i m e n t . L o w P a n d l o w K t r e a t m e n t s w e r e u n i f o r m l y s e v e r e i n t h e i r e f f e c t o n g r o w t h r e g a r d l e s s o f t h e m o r p h o l o g i c a l c h a r a c t e r i s t i c s e l e c t e d t o m e a s u r e t h e s e e f f e c t s . O f t h e t w o , a d e f i c i e n c y o f p h o s p h o r u s w a s t h e m o r e s e v e r e t h r o u g h o u t . A n i m p r e s s i o n o f t h e e f f e c t t h e v a r i o u s d e f i c i e n c i e s h a d u p o n t h e g r o w t h o f w e s t e r n w h i t e p i n e c a n b e r e a d i l y h a d f r o m a n e x a m i n a t i o n o f F i g u r e 57. Pig* 55* The effect of macronutrient deficiency on fascicle needle length (western white pine). The scale i s six centimetres long. (Photo: Crombie) Pig. 56. The effect of macronutrient deficiency on the root growth of western white pine. Note the radical increase in length of the roots grown in a culture deficient in calcium. (Photo: Crorabie) F i g . 57* Gross differences caused by the various macronutrient deficiencies as they affect the growth and development of western white pine. (Photo: Crombie) Fig. 58. The effect of the various macronutrient deficiencies on the growth and development of reprecentative specimens of JSngel-nann apruee. (photo: Crombie) 12T< T a b l e X V Q u a n t i t a t i v e E f f e c t s o f M a c r o n u t r i e n t D e f i c i e n c y 5 . E H G E L M O H S P R U C E ( T a b u l a r c o m p a r i s o n o f c o m p l e t e a n d d e f i c i e n t t r e a t m e n t s )  A v e r a g e s o f C r o c k A v e r a g e s E o . o f L o n g e s t L o n g e s t R o o t L o n g e s t T r e a t m e n t H e i g h t D i a m . B r a n c h e s B r a n c h N e e d l e L e n g t h L a t . R o o t c m s . m m s . c m s • c m s • c m s * c m s • R o o t V o l u m e c . c . * s f fi- l l C o m p l e t e 6-5 0.20 1 1-5 1.8 33.0 28.4 5-1 L o w N 3.2 N S 0 . 14 * 0 N S 0.5 N S 1.6 N S 37.5 N S 28.6 N S 3.7 N S L o w S 5.1 N S 0.18 N S 2 N S 1 .6 N S 1.8 N S 28.8 N S 22.7 # 5-0 N S L o w M g 2.0 * 0.11 ** 1 N S 0.5 N S 1.3 ** 24 .3 ** 17.3 0.5 ** L o w C a 3-7 N S 0.17 N S 1 N S 0.6 N S 1 .7 N S 28.9 N S 22.7 * 6.6 N S L o w P 1.1 ** 0.08 ** 0 # 0 * 0.8 ** 18.3 ** 16.4 ** 0.1 ** L o w K 2.0 * 0.11 ** 1 N S 0.3 N S 1.2 ** 25.4 * * 17-3 *# 0.8 ** P r o c e e d i n g t o a v e r b a l a n a l y s i s o f t h e d a t a o u t l i n e d i n T a b l e X V , we m u s t c o n s i d e r f i r s t h e i g h t g r o w t h . a . H e i g h t g r o w t h A l l d e f i c i e n c i e s t e n d t o r e d u c e t h e a v e r a g e o f t h e h e i g h t s a t t a i n e d b y t h e t e s t p l a n t s . Some d e f i c i e n c i e s a r e m o r e e f f e c t i v e t h a n o t h e r s i n t h i s r e g a r d . P h o s p h o r u s , w h e n i n s h o r t s u p p l y , s e e m s a g a i n w i t h t h i s s p e c i e s t o b e m o s t d e t r i m e n t a l t o h e i g h t g r o w t h . L o w m a g n e s i u m a n d l o w p o t a s s i u m c u l t u r e s s h a r e s e c o n d p l a c e h o n o r s w h e n we c o n s i d e r t h e e f f e c t o f d e f i c i e n c y o n h e i g h t g r o w t h . A d e f i c i e n c y o f n i t r o g e n i s r e l a t i v e l y s e v e r e b u t s t a t i s t i c a l l y i n v a l i d i f we l i m i t o u r o b s e r v a t i o n s t o t h e p r e s e n t s e t o f m e a s u r e m e n t s . I f we d o n o t , a n d i n c l u d e t h o s e m a d e a t t h e t e r m i n a t i o n o f t h e e x p e r i m e n t ( A p p e n d i x T a b l e X ) , i t i s a p p a r e n t t h a t a d e f i c i e n c y o f n i t r o g e n i s o f s i g n i f i c a n c e f o r t h e g r o w t h i n h e i g h t o f t h i s s p e c i e s . B o t h c a l c i u m a n d s u l f u r d e f i c i e n c i e s a r e r e l a t i v e l y q u i t e e f f e c t i v e i n r e d u c i n g a v e r a g e h e i g h t g r o w t h . 128. A r a t h e r s u r p r i s i n g e f f e c t i s h e r e o b s e r v e d w h e n a d e f i c i e n c y o f m a g -n e s i u m i s o p e r a t i v e . H i t h e r t o t h i s e l e m e n t h a s s e e m e d t o b e o n l y m o d e r a t e l y e s s e n t i a l f o r t h e g r o w t h o f a n y o n e o f t h e . f o u r c o n i f e r o u s s p e c i e s p r e v i o u s l y d i s c u s s e d . I t m a y b e w r o n g t o t r y t o q u a l i f y e s s e n t i a l i t y s i n c e t h i s i s a n a t t r i b u t e w h i c h i s o r i s n o t . a p p l i c a b l e t o a g i v e n e l e m e n t , a n d i t i s o n e a w a r d e d o n t h e d e g r e e o f p h y s i o l o g i c a l i n v o l v e m e n t i n t h e m e t a b o l i s m o f t h e p l a n t s u s e d t o d e t e r m i n e i t s e s s e n t i a l c h a r a c t e r . B u t t h e r e a r e s h a d e s o r d e g r e e s o f e s s e n t i a l i t y . A n e l e m e n t s u c h a s p h o s p h o r u s , f o r i n s t a n c e , s e e m s t o b e h i g h l y e s s e n t i a l f o r t h e g r o w t h o f a l l s p e c i e s s t u d i e d n o m a t t e r w h a t m o r p h o l o g i c a l c h a r a c t e r i s t i c b e s e l e c t e d t o m e a s u r e t h e e f f e c t o f i t s p a r t i a l r e m o v a l . M a g n e s i u m , o n t h e o t h e r h a n d , w h i l e k n o w n t o b e e s s e n t i a l , d o e s n o t s e e m t o b e s o a c u t e l y i n v o l v e d i n t h o s e l i f e p r o c e s s e s w h i c h a r e f u n d a -m e n t a l t o g r o w t h a n d s u r v i v a l . T h e l e v e l o f i t s s u p p l y i n t h e p r e s e n t e x p e r i -m e n t w a s t h e same a s p h o s p h o r u s , 1/100 o f t h e c o m p l e t e l e v e l . Y e t , b a s i n g o u r d e c i s i o n s o n b o t h t h e q u a l i t a t i v e a n d q u a n t i t a t i v e e x p r e s s i o n s o f d e f i c i -e n c y e f f e c t , t h i s l e v e l o f s u p p l y a p p e a r s t o b e c o n s i d e r a b l y s u b o p t i m a l f o r p h o s p h o r u s a n d o n l y m o d e r a t e l y s u b o p t i m a l f o r m a g n e s i u m . T h i s , a t a n y r a t e , h o l d s f o r t h e t w o v a r i e t i e s o f D o u g l a s - f i r a n d t h e t w o s p e c i e s o f P i n u s a l r e a d y s t u d i e d . B u t i n E n g e l m a n n s p r u c e we a r e c o n f r o n t e d w i t h q u a n t i t a t i v e a n d q u a l i t a t i v e e v i d e n c e o f a m u c h i n c r e a s e d s e v e r i t y i n t h e e f f e c t o f a s i m i l a r d e f i c i e n c y o f m a g n e s i u m i n t h e c u l t u r e s o l u t i o n . H e i g h t g r o w t h , d i a m e t e r g r o w t h , n e e d l e l e n g t h a n d r o o t d e v e l o p m e n t a r e a l l s i g n i f i c a n t l y l e s s i n c u l -t u r e s o l u t i o n s d e f i c i e n t i n m a g n e s i u m . T h e e f f e c t o f a p a r t i a l r e m o v a l o f M g i s e v e n m o r e s e v e r e t h a n a s i m i l a r d e f i c i e n c y o f n i t r o g e n , a n d e q u a l l y a s s e v e r e a s a d e f i c i e n c y o f p o t a s s i u m . H e r e a g a i n , o n e I s i m p r e s s e d w i t h t h e v e r y s p e c i f i c n a t u r e o f t h e r e l a t i o n s h i p w h i c h a p p e a r s t o e x i s t b e t w e e n a n y d e f i c i e n c y o f a g i v e n e l e m e n t a n d t h e s p e c i e s a f f e c t e d b y i t . P r o g n o s t i c a -129-t i o n s o f p o s s i b l e e f f e c t a r e v a l u e l e s s j u s t b e c a u s e o f t h i s u n p r e d i c t a b i l i t y a n d u n c e r t a i n t y s u r r o u n d i n g t h e s e v e r i t y o f a g i v e n d e f i c i e n c y . C o n c l u s i o n s d e r i v e d r e g a r d i n g t h e e f f e c t o f a g i v e n d e f i c i e n c y o n t h e g r o w t h o f a g i v e n s p e c i e s m a y , w i t h c a u t i o n , b e a p p l i e d t o a n o t h e r s p e c i e s o f t h e same g e n u s t h a t r e s e m b l e s , i n some c o n s i d e r a b l e d e t a i l , t h e f i r s t s p e c i e s i n i t s r a n g e a n d e n v i r o n m e n t a l p r e f e r e n c e s . A n e v e n s e v e r e r e f f e c t o f m a g n e s i u m d e f i c i e n c y o n t h e g r o w t h o f S i t k a s p r u c e [ P i c e a sitchenBis ( B o n g . ) C a r r ] w a s r e p o r t e d b y K r a j i n a .( 1958) . A n e x p l a n a t i o n o f t h e s e e f f e c t s w a s o f f e r e d a t t h a t t i m e a n d w a s a s f o l l o w s : " T h e r e s u l t s o f t h i s e x p e r i m e n t h e l p t o e x p l a i n w h y , a l o n g . t h e c o a s t o f t h e P a c i f i c O c e a n , S i t k a s p r u c e , r e q u i r -i n g g r e a t a m o u n t s o f a v a i l a b l e M g , e s t a b l i s h e s p u r e s t a n d s u n d e r t h e i n f l u e n c e o f o c e a n i c s p r a y ; t h e r e f o r e , S i t k a s p r u c e g r o w s v e r y w e l l i n a l l u v i a l s o i l s , r i c h i n m a g n e -s i u m m a t e r i a l s , a n d m a y e v e n v e g e t a t e u n d e r t h e i n f l u e n c e o f b r a c k i s h w a t e r , r i c h i n M g . " T h e g e o g r a p h i c a l r a n g e s o f t h e s e t w o s p e c i e s d o n o t o v e r l a p . S i t k a s p r u c e i s t r u l y a t i d e w a t e r s p e c i e s a n d r e a c h e s i t s m a x i m u m s i z e i n t h e C o a s t f o r e s t s a b u t t i n g o n t h e P a c i f i c O c e a n . E n g e l m a n n s p r u c e i s t y p i c a l l y a m o n -t a n e s p e c i e s a n d i s p r i n c i p a l l y d i s t r i b u t e d t h r o u g h o u t t h e R o c k y M o u n t a i n c h a i n a n d t h e e a s t e r n s l o p e s o f t h e C a s c a d e M o u n t a i n s . I t i s o n l y i n f r e q u e n t l y f o u n d g r o w i n g a t v e r y h i g h a l t i t u d e i n a r e a s w h i c h a r e d i r e c t l y e x p o s e d t o o c e a n i c i n f l u e n c e . " W h i l e a d m i t t i n g t h e p o s s i b i l i t y o f t h e e x p l a n a t i o n b y K r a j i n a r e g a r d i n g t h e e f f e c t s o f a d e f i c i e n c y o f m a g n e s i u m o n S i t k a s p r u c e , i t i s h a r d t o s e e h o w s u c h e f f e c t s a r e o p e r a t i v e w i t h r e g a r d t o E n g e l m a n n s p r u c e . I n i t s n a t u r a l r a n g e , t h e l a t t e r s p e c i e s c a n b e l i t t l e a f f e c t e d b y . t h e p r e s e n c e o r a b s e n c e o f o c e a n i c s p r a y . Y e t t h e e f f e c t o f m a g n e s i u m d e f i c i e n c y i s j u s t a s r e a l . I f e c o l o g i c a l i m p l i c a t i o n s w e r e b e i n g s o u g h t t o e x p l a i n o r m a k e m o r e u n d e r s t a n d a b l e t h i s r e l a t i o n s h i p , t h e i n f l u e n c e o f t h e e x t e n s i v e d o l o m i t i c d e p o s i t s t h a t a r e p r e s e n t i n t h e R o c k y M o u n t a i n r e g i o n s m a y w e l l b e a s i m p o r -130. t a n t f o r t h e g r o w t h o f t h i s s p e c i e s a s i s t h e i n f l u e n c e o f o c e a n i c s p r a y f o r t h e g r o w t h o f S i t k a s p r u c e . T h e f a c t r e m a i n s , h o w e v e r , t h a t t w o s p e c i e s o f t h e g e n u s P i c e a h a v e b e e n s h o w n t o b e s t r o n g l y a f f e c t e d b y a d e f i c i e n c y o f m a g n e s i u m . T h e i n d i c a t i o n s a r e t h a t t h e r e i s a h i g h g e n e r i c r e q u i r e m e n t f o r t h i s e l e m e n t , a n d , r e g a r d l e s s o f s p e c i e s , m e m b e r s o f t h i s g e n u s a r e l i k e l y t o b e s i m i l a r l y a f f e c t e d . T h e o n l y o t h e r i n f o r m a t i o n t h a t t e n d s t o s u p p o r t t h i s c o n c l u s i o n r e g a r d i n g t h e i m p o r t a n c e o f t h e t y p e o f p l a n t s u b j e c t t o t h e e f f e c t s o f m a g n e s i u m d e f i c i e n c y i s t o b e f o u n d i n a p a p e r b y G a r n e r , W . W . e t a l . (1930 ) . T h e r e i t i s s t a t e d t h a t p l a n t s d i f f e r m a r k e d l y i n t h e i r r e s p o n s e t o m a g n e s i u m d e f i c i e n c y . E x a m -p l e s a r e g i v e n : b u c k w h e a t a n d s p i n a c h a r e v e r y s e n s i t i v e ; t u r n i p s , c o r n a n d t o b a c c o c o n s i d e r a b l y s o ; s m a l l g r a i n s , g r a s s e s , c l o v e r a n d p o t a t o e s o n l y s l i g h t l y s o . F u r t h e r , i t i s s t a t e d t h a t t h e e x t e n t t o w h i c h p l a n t s r e s p o n d t o m a g n e s i u m d e f i c i e n c y i s o n l y p o o r l y c o r r e l a t e d w i t h t h e c o n t e n t o f t h a t e l e m e n t i n t h e p l a n t i t s e l f , e . g . , t h e m a g n e s i u m c o n t e n t o f l e g u m e s i s h i g h ( 0 . 3 - 1-0$), y e t t h e y a r e r e l a t i v e l y ' i n s e n s i t i v e t o m a g n e s i u m d e f i c i e n c y . W a l l a c e (1932)' h a s a l s o n o t e d t h a t t h e r e i s a w i d e v a r i a b i l i t y i n t h e s e v e r i t y o f s y m p t o m s d e v e l o p e d b y w o o d y s p e c i e s a f f e c t e d b y a d e f i c i e n c y o f m a g n e s i u m . T h i s w o u l d i n d i c a t e t h a t t h e s e same s p e c i e s r e q u i r e d v e r y v a r i a b l e a m o u n t s o f t h i s e l e m e n t f o r n o r m a l g r o w t h . I n s h o r t , t h e ' h y p o t h e s i s i s a d v a n c e d t h a t t h i s s e e m i n g s u s c e p t i b i l i t y o n t h e p a r t o f t w o m e m b e r s o f t h e g e n u s P i c e a t o a d e f i c i e n c y o f m a g n e s i u m i s m o r e a n i n d i c a t i o n o f a p r e v a i l i n g g e n e r i c c h a r a c t e r i s t i c t h a n a n y s p e c i f i c i d i o s y n c r a s y e x p l a i n a b l e b y r e f e r e n c e t o e c o l o g i c a l c o n d i t i o n s p e c u l i a r t o t h e r a n g e o f t h e a f f e c t e d s p e c i e s . 131. b . D i a m e t e r g r o w t h i n c r e m e n t T h e i m p r e s s i o n s g a i n e d f r o m a s t u d y o f t h e e f f e c t s o f m a c r o n u t r i e n t d e f i c i e n c y o n t h e h e i g h t g r o w t h o f P i c e a E n g e l m a n n i i a r e s t r e n g t h e n e d c o n s i d e r -a b l y b y r e f e r e n c e t o t h e d a t a o n d i a m e t e r i n c r e m e n t . H e r e t h e s i g n i f i c a n c e o f t h e d i f f e r e n c e s i s e n h a n c e d . A d e f i c i e n c y o f p h o s p h o r u s , p o t a s s i u m o r m a g n e s i u m h a s a n e f f e c t o n t h e a m o u n t o f d i a m e t e r i n c r e m e n t t h a t i s h i g h l y s i g n i f i c a n t . L o w n i t r o g e n c u l t u r e s a r e a l s o e f f e c t i v e i n c a u s i n g r e s u l t s o f r e l a t i v e l y h i g h c o r r e l a t i o n . T h e e f f e c t s o f c a l c i u m a n d s u l f u r d e f i c i e n c y a r e n o t s i g n i f i c a n t . I t i s i n t e r e s t i n g t o n o t e t h a t t h e e f f e c t o f a d e f i c i e n c y o f m a g n e s i u m i s e v e n m o r e s e v e r e t h a n a s i m i l a r d e f i c i e n c y o f n i t r o g e n , a t l e a s t w h e r e d i a m e t e r i n c r e m e n t i s c o n c e r n e d . P h o s p h o r u s a g a i n a p p e a r s t o b e m o s t e s s e n t i a l f o r t h e g r o w t h o f t h i s s p e c i e s . T h e r e d u c t i o n i n s i z e o c c a s i o n e d b y a d e f i c i e n c y o f t h i s e l e m e n t w a s v e r y g r e a t , a s c a n b e s e e n f r o m t h e d a t a i n T a b l e X V . A n 83$ r e d u c t i o n i n h e i g h t , a 60$ r e d u c t i o n i n d i a m e t e r i n c r e m e n t , a 55$ r e d u c t i o n i n t h e l e n g t h o f t h e l o n g e s t n e e d l e , a 44.5$ r e d u c t i o n i n t h e l e n g t h o f t h e r o o t s y s t e m , a 4 2 . 2 $ r e d u c t i o n I n t h e l e n g t h o f t h e l o n g e s t l a t e r a l r o o t , a n d a . 98$ r e d u c t i o n i n r o o t v o l u m e a r e i n d i c a t i o n e n o u g h o f t h e d e g r e e o f e s s e n -t i a l i t y t h a t c a n b e a s s i g n e d t o t h i s m a c r o - m e t a b o l i c e l e m e n t . c . N u m b e r o f b r a n c h e s d . L e n g t h o f l o n g e s t b r a n c h N e i t h e r o f t h e s e c h a r a c t e r i s t i c s i s o f m u c h v a l u e a s a n i n d i c a t o r o f t h e e f f e c t o f m a c r o n u t r i e n t d e f i c i e n c y . T h e y d o s u b s t a n t i a t e t h e o u t -s t a n d i n g e f f e c t o f a d e f i c i e n c y o f p h o s p h o r u s b u t f o r t h e o t h e r e l e m e n t s , d u e l a r g e l y t o a s m a l l n u m b e r o f b r a n c h e s d e v e l o p e d a n d a w i d e i n t r a - g r o u p v a r i a n c e , t h e r e i s l i t t l e t o b e g l e a n e d f r o m t h e d a t a a s p r e s e n t e d . 132. © . L e n g t h o f l o n g e s t n e e d l e T h i s m e a s u r e m e n t a p p e a r s i n a b e t t e r l i g h t . I t i n d i c a t e s t h a t t h e r e i s s i g n i f i c a n c e t o t h e e f f e c t o f a d e f i c i e n c y o f p o t a s s i u m , p h o s p h o r u s a n d m a g n e s i u m . I t a l s o i n d i c a t e s t h e r e l a t i v e s e v e r i t y o f t h e s e e f f e c t s ; p h o s p h o r u s m o s t s e v e r e , f o l l o w e d b y p o t a s s i u m a n d l a s t l y m a g n e s i u m . A s u l f u r d e f i c i e n c y i s s e e n t o h a v e n o e f f e c t o n t h i s m o r p h o l o g i c a l c h a r a c t e r i s t i c , c a l c i u m o n l y t o a m i n o r d e g r e e a n d n i t r o g e n t o a d e g r e e t h a t i s s t i l l f a r f r o m b e i n g s i g n i f i c a n t . f . R o o t l e n g t h H e r e a g a i n a d e f i c i e n c y o f m a g n e s i u m c a u s e s a d e c l i n e i n t h e l i n e a r d i m e n s i o n s o f a p l a n t p a r t w h i c h i s n o t n o r m a l l y t a k e n t o b e m u c h a f f e c t e d b y t h i s e l e m e n t . I t m a y b e t h a t t h e e f f e c t s o n r o o t m o r p h o l o g y a r e t h e m o s t i m p o r t a n t o f a l l t h e k n o w n a n d m e a s u r e d e f f e c t s o f a d e f i c i e n c y o f M g a s a p p l i e d t o E n g e l m a n n s p r u c e a n d t h a t t h e v e g e t a t i v e e f f e c t s o b s e r v e d a r e s e c o n d a r y . - * g . L e n g t h o f l o n g e s t l a t e r a l r o o t ' A n y d e f i c i e n c y i n t h e a v a i l a b l e s u p p l y o f s u l f u r , m a g n e s i u m , c a l -s i u m , p h o s p h o r u s o r p o t a s s i u m i s s u f f i c i e n t t o c a u s e a d e c r e a s e i n t h e a m o u n t o f g r o w t h p u t o n b y t h e l o n g e s t l a t e r a l r o o t s o f E n g e l m a n n s p r u c e . O n l y n i t r o g e n s e e m s t o l a c k e s s e n t i a l i t y w i t h r e g a r d t o t h i s c h a r a c t e r i s t i c . N i t r o g e n , i n f a c t , s e e m s t o b e a n e l e m e n t t h a t r a n k s q u i t e l o w i n t h e s c a l e o f e s s e n t i a l i t y a p p l i c a b l e t o E n g e l m a n n s p r u c e . T h e h i g h c o r r e l a t i v e e f f e c t o f a d e f i c i e n c y o f p h o s p h o r u s , p o t a s s i u m o r m a g n e s i u m i s a g a i n a p p a r e n t . I n t e r e s t i n g l y e n o u g h , t h i s m e a s u r e m e n t i s t h e f i r s t e v i d e n c e a v a i l a b l e t h a t a d e f i c i e n c y o f s u l f u r d o e s h a v e a s i g n i f i c a n t l y d e l e t e r i o u s e f f e c t o n m o r p h o l o g i c a l d e v e l o p m e n t . Some e f f e c t s w e r e n o t i c e a b l e 133-u n d e r o t h e r h e a d s b u t o n l y h e r e i s t h e r e a n y s t a t i s t i c a l v a l i d i t y t o t h e m , h . B o o t v o l u m e T h e s a l i e n t f e a t u r e o f t h e s e r e s u l t s i s t h e t r e m e n d o u s r e d u c t i o n i n r o o t v o l u m e o c c a s i o n e d b y a d e f i c i e n c y o f p h o s p h o r u s . T h e m e a s u r e m e n t s o f r e l a t i v e r o o t v o l u m e c o n f i r m t h e v i s u a l i m p r e s s i o n s o b t a i n e d f r o m a n e x a m i n a t i o n o f t h e a f f e c t e d s y s t e m s . T h e l a t t e r w e r e a l m o s t h a i r - l i k e , s h o r t a n d w i t h o n l y o n e o r t w o f i l a m e n t o u s l a t e r a l s ; t h i s a f t e r 15 m o n t h s g r o w t h i n c o n d i t i o n s w h i c h w e r e e n v i r o n m e n t a l l y s u i t a b l e e x c e p t f o r a d e f i c i e n c y o f p h o s p h o r u s . T h e s e r o o t s y s t e m s w e r e l a r g e l y a s d e v e l o p e d f r o m t h e s e e d . T h e s u p p l y o f p h o s p h o r u s w a s s o f a r b e l o w m i n i m u m t h a t a c o m p l e t e c e s s a t i o n o f g r o w t h , e n s u e d a n d w a s m a i n t a i n e d u n t i l t h e t e r m i n a t i o n o f t h e e x p e r i m e n t . T h e o v e r r i d i n g i m p o r t a n c e o f p h o s p h o r u s f o r t h e g r o w t h o f E n g e l m a n n s p r u c e i s b e s t s u p p o r t e d b y a r e f e r e n c e t o t h e e f f e c t s o f a d e f i c i e n c y o f i t o n t h e v o l u m e o f t h e r o o t s y s t e m s d e v e l o p e d . T h e r e l a t i v e l y s e v e r e e f f e c t o f m a g n e s i u m d e f i c i e n c y i s h e r e m a d e c l e a r a g a i n . I n s u m m a r y : . U n l i k e t h e o t h e r s p e c i e s t h a t w e r e a p a r t o f . t h i s s t u d y , a n d f o r w h o s e g r o w t h a n d d e v e l o p m e n t t h e i m p o r t a n c e o f a d e q u a t e a m o u n t s o f N , P a n d K h a s b e e n e m p h a s i z e d , r e c o m m e n d a t i o n s f o r E n g e l m a n n s p r u c e b a s e d o n t h e s e v e r i t y o f r e s p o n s e t o d e f i c i e n c y m u s t p l a c e e m p h a s i s o n t h e e l e m e n t s P , M g a n d K a s b e i n g m o s t . c r i t i c a l f o r n o r m a l d e v e l o p m e n t . E n g e l m a n n s p r u c e s e e m e d t o b e m o s t s e n s i t i v e t o a . d e f i c i e n c y o f p h o s p h o r u s . T h e e f f e c t s o f a d e f i c i e n c y o f p h o s p h o r u s a r e b e s t m e a s u r e d b y a r e f e r e n c e t o r e l a t i v e r o o t v o l u m e s d e v e l o p e d . M a g n e s i u m , a n e l e m e n t . t h a t h i t h e r t o h a s n o t r a n k e d h i g h i n . t h e e s s e n t i a l i t y 1J4. s c a l e , g i v e s e v i d e n c e o f b e i n g o f c o n s i d e r a b l e i m p o r t a n c e t o t h e g r o w t h a n d s u r v i v a l o f E n g e l m a n n s p r u c e . T h e s u g g e s t i o n i s o f f e r e d t h a t t h e s e s p e c i f i c e f f e c t s a r e b u t a p a r t i a l i n d i c a t i o n o f a w i d e r , m o r e c o m p r e h e n s i v e g e n e r i c d e p e n d e n c e o n t h e a d e q u a c y o f t h e m a g n e s i u m s u p p l y . N i t r o g e n , a n e l e m e n t t h a t h a s f e a t u r e d s t r o n g l y i n t h e n u t r i t i o n a l r e q u i r e -m e n t s o f t h e o t h e r f o u r s p e c i e s s t u d i e d , a p p e a r s t o b e o f o n l y m i n o r s i g n i f i -c a n c e f o r t h e g r o w t h o f t h i s s p e c i e s . W h e t h e r t h e r e i s a n y j u s t i f i c a t i o n f o r h o l d i n g t h i s l o w H r e q u i r e m e n t r e s p o n s i b l e f o r t h e a b i l i t y o f t h e s p e c i e s t o i n h a b i t s o i l s a t h i g h a l t i t u d e w h e r e n i t r i f i c a t i o n i s m u c h r e t a r d e d c l i m a t o -l o g i c a l l y i s n o t k n o w n . C e r t a i n l y t h e i d e a h a s m e r i t a n d w o u l d b e w o r t h y o f f u r t h e r i n v e s t i g a t i o n . C a l c i u m a n d s u l f u r d e f i c i e n c i e s a r e o n l y o f m i n o r i m p o r t a n c e w h e n c o n -s i d e r i n g t h e g r o w t h o f E n g e l m a n n s p r u c e . P o t a s s i u m a p p e a r s t o b e o f h i g h s i g n i f i c a n c e f o r t h e g r o w t h o f t h i s s p e c i e s a s h a s p r o v e n t o b e t h e c a s e w i t h o t h e r s s t u d i e d . A l l b u t t w o o f t h e m o r p h o l o g i c a l c h a r a c t e r i s t i c s m e a s u r e d i n d i c a t e t h a t t h e e l e m e n t i s m u c h i m p l i c a t e d i n t h e m e t a b o l i s m o f t h i s s p e c i e s . A v i s u a l i m p r e s s i o n o f t h e e f f e c t s o f t h e v a r i o u s m a c r o n u t r i e n t d e f i c i -e n c i e s o n t h e g r o w t h o f E n g e l m a n n , s p r u c e c a n b e r e a d i l y h a d f r o m a n e x a m i n a -t i o n o f F i g u r e 58. 6. G r o w t h i n S a n d C u l t u r e s R e c e i v i n g D i s t i l l e d W a t e r O n l y I n c l u d e d i n t h e e x p e r i m e n t a l l a y o u t w e r e 5 c r o c k s , o n e f o r e a c h o f t h e 5 s p e c i e s , w h i c h r e c e i v e d n o n u t r i e n t s o l u t i o n s d u r i n g t h e e n t i r e d u r a t i o n o f t h e e x p e r i m e n t . T h e y w e r e w a t e r e d f r o m a b o v e w i t h d i s t i l l e d w a t e r o n l y . T h e p l a n t s g r o w i n g i n t h e m a n d s u b j e c t e d t o s u c h a t r e a t m e n t g e r m i n a t e d a n d w e r e a b l e t o d e v e l o p c o t y l e d o n s a n d a f e w p r i m a r y n e e d l e s b u t t h e s e v e r i t y o f t h e t r e a t m e n t a n d t h e t o x i c i t y o f t h e d e m i n e r a l i z e d w a t e r i t s e l f p e r m i t t e d n o f u r t h e r g r o w t h . T h e i r c o n d i t i o n a t t h e e n d o f t h e e x p e r i m e n t w a s e x t r e m e l y p o o r a n d m a n y d i e d a s a r e s u l t o f t h e i m p o s e d n u t r i t i o n a l l i m i t a -t i o n s . I n m a n y w a y s , i t w a s s u r p r i s i n g t h a t a n y p l a n t s s u r v i v e d a t a l l . T h e i r c o n d i t i o n i s h e s t i l l u s t r a t e d b y a r e f e r e n c e t o F i g u r e s 59 t h r o u g h 63 w h i c h a r e r e p r o d u c t i o n s o f p h o t o g r a p h s t a k e n a t t h e e n d o f t h e e x p e r i m e n t a l p e r i o d J / . T h e h i g h m o r t a l i t y r a t e a n d t h e e x t r e m e l y l o w v i g o r o f t h e i n d i -v i d u a l s s u b j e c t e d t o t h e d i s t i l l e d w a t e r t r e a t m e n t f u r n i s h e v i d e n c e o f a r a t h e r c o n c l u s i v e n a t u r e c o n c e r n i n g t h e s t e r i l i t y o f t h e s a n d u s e d a n d t h e a b s e n c e o f a n y m i n e r a l s i n i t w h i c h m i g h t c o n f o u n d t h e r e s u l t s h e r e r e p o r t e d . J_/ B y M r . X . G . K . D a v i d s o n . 59* A p p e a r a n c e o f s e e d l i n g s o f c o a s t a l D o u g l a s - f i r a f t e r n i n e t e e n m o n t h s g r o w t h i n s a n d c u l t u r e s w a t e r e d f r o m a b o v e w i t h d i s t i l l e d w a t e r o n l y . ( P h o t o : D a v i d s o n ) F i g . 60. Appearance of eeedlinge of interior Douglas-fir after nineteen months growth i n sand cultures watered from above with d i s t i l l e d water only. (Photo: Davidson) Fig. 6 l . Appearance of seedlings of western white pine after nineteen months growth i n sand cultures watered from above with d i s t i l l e d water only. (Photo: Davidson) Pig. 62. Appearance of seedlings of ponderosa pine after nineteen months growth in sand cultures watered from above with distilled water only. (Photo: Davidson) Tig. 63. Appearance of seedlings of Engelmann spruce after nine-teen months growth in sand cultures watered from above with die-ti l l e d water only. (Photo: Davidson) 136. B . E f f e c t s o n F r e s h a n d D r y W e i g h t P r o d u c t i o n , S h o o t / B o o t P a t i o a n d M o i s t u r e C o n t e n t _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ^ E f f e c t s o n F r e s h a n d D r y W e i g h t P r o d u c t i o n T h e r e l a t i v e f r e s h a n d d r y w e i g h t s o f t h e t r e e s g r o w n i n t h e v a r i o u s d e f i c i e n t c u l t u r e s w e r e a v a l i d i n d e x o f t h e e f f e c t s o f m a c r o n u t r i e n t d e f i c i -e n c y a n d b o r e o u t t h e t r e n d s e s t a b l i s h e d b y t h e v a r i a t i o n i n m o r p h o l o g i c a l d e v e l o p m e n t . O n r e m o v a l , t h e t r e e s w e r e w a s h e d f r e e o f a l l a d h e r i n g s a n d p a r t i c l e s , s h a k e n t o g e t r i d o f e x c e s s m o i s t u r e a n d w e i g h e d o n a t o r s i o n b a l a n c e , u s u a l l y t o t h e n e a r e s t t e n t h o f a g r a m . T h e r e u p o n , t h e p l a n t s w e r e s n i p p e d a t t h a t p o i n t o n t h e s t e m w h i c h m a r k e d t h e d i v i d i n g l i n e b e t w e e n t o p a n d r o o t a n d t h e t w o p a r t s w e r e s e p a r a t e l y s e a l e d i n p a p e r b a g s w i t h w i r e s t a p l e s . T h e d r y i n g s c h e d u l e w a s o f 2 4 h o u r s d u r a t i o n a n d t h e t e m p e r a t u r e s o f t h e o v e n f l u c t u a t e d b e t w e e n 80 .and 90 d e g r e e s C e n t i g r a d e . P l a n t s w e r e r e t a i n e d i n t h e b a g s d u r i n g d r y i n g . T h e d r i e d p l a n t p a r t s w e r e w e i g h e d s e p a r a t e l y , r o o t a n d t o p , a n d t o t a l d r y w e i g h t o f t h e p l a n t c o m p u t e d . T h e r e s u l t s t h a t f o l l o w a r e a g a i n o b t a i n e d b y a v e r a g i n g t h e c r o c k a v e r -a g e s f o r t h e g r o u p o f s i x r e p l i c a t e s t h a t r e p r e s e n t t h e s a m p l e f o r a g i v e n t r e a t m e n t o n a g i v e n s p e c i e s . T h e r e a r e f o u r c a t e g o r i e s r e p o r t e d f o r e a c h s p e c i e s i n t h e f o l l o w i n g t a b l e s : t h e a v e r a g e t o t a l f r e s h w e i g h t p e r p l a n t , t h e a v e r a g e d r y w e i g h t o f t h e s h o o t p o r t i o n p e r p l a n t , t h e a v e r a g e d r y w e i g h t o f t h e r o o t p o r t i o n p e r p l a n t , a n d t h e a v e r a g e t o t a l d r y w e i g h t p e r p l a n t . T h e r e i s a s e p a r a t e t a b l e f o r e a c h s p e c i e s . 1 3 7 -T a b l e X V T E f f e c t o f M a c r o n u t r i e n t D e f i c i e n c y o n F r e s h a n d . D r y W e i g h t P r o d u c t i o n - C O A S T A L D O U G L A S - F T P ( T a b u l a r c o m p a r i s o n b e t w e e n , c o m p l e t e a n d d e f i c i e n t t r e a t m e n t s )  A v e r a g e s o f C r o c k A v e r a g e s T o t a l f r e s h D r y w e i g h t D r y w e i g h t T o t a l d r y I n c r e m e n t o r T r e a t m e n t w e i g h t / p l a n t s h o o t / p l a n t r o o t / p l a n t w e i g h t / p l a n t D e c r e m e n t g m a . s i g n . g m s . s i g n , g m s . s i g n , g m s . s i g n . ( C o l , d ) j> a b c d e C o m p l e t e ; . 3 0 * 5 2 . 6 3 . 8 6 . 4 L o w N 8 . 8 .' 0 . 4 ** 0 . 9 ** 1 . 3 ** - 7 9 - 7 L o w S 2 8 . 7 N S 3 . 2 N S . 4 . 3 . N S - 7 - 5 N S + 1 7 . 2 L o w M g . 1 4 . . 8 * 1 - 5 2 . 1 ** 3 . 6 - 4 3 . 8 L o w C a 2 6 . 1 N S 2 . 4 N S ' . 2 . 9 N S 5 - 3 N S - 1 7 . 2 L o w P 2 . 2 0 . 1 0 - 3 **. 0 . 4 '** - 9 3 . 8 L o w K 8 . 2 *# 0 . 6 0 . 9 ** . 1 - 5 •# - 7 6 . 6 O v e r a l l s i g n i f i -c a n c e o f t r e a t -m e n t , d i f f e r e n c e s ** ** ** 'ft it1 T h e r e s u l t s o b t a i n e d f o r t h i s s p e c i e s a r e a s r e p o r t e d i n T a b l e X V T . T h e s y m b o l s u s e d t o i n d i c a t e s t a t i s t i c a l s i g n i f i c a n c e a r e t h e s a m e a s b e f o r e . T h e e f f e c t s o f l o w N , M g , P a n d K a r e o b v i o u s a n d s i g n i f i c a n t f o r a l l f o u r c a t e g o r i e s m e n t i o n e d . M a g n e s i u m , w h i c h f r o m o t h e r m e a s u r e m e n t s d i d n o t a p p e a r t o b e o f h i g h s i g n i f i c a n c e f o r t h e d e v e l o p m e n t o f t h i s s p e c i e s , n o w a p p e a r s a s a m o r e . t e l l i n g d e f i c i e n c y w h e n c o n s i d e r a t i o n i s g i v e n t o d r y w e i g h t p r o d u c t i o n . C o l u m n . e , t h e l a s t c o l u m n o f t h e t a b l e , p r o v i d e s i n f o r m a t i o n t h a t e n a b l e s o n e t o g r a d e t h e v a r i o u s d e f i c i e n c i e s a c c o r d i n g t o t h e s e v e r i t y o f t h e i r e f f e c t . R e a d i n g f r o m m o s t t o l e a s t s e v e r e , s u c h a g r a d e d l i s t o f s e v e r i t y o f e f f e c t f o r c o a s t a l D o u g l a s - f i r w o u l d ' b e a s f o l l o w s : P ; N ; K ; M g ; C a ; S . E a c h o f t h e f o u r c a t e g o r i e s o f m e a s u r e m e n t i s s i g n i f i c a n t a s a w h o l e f o r t h e t r e a t m e n t e f f e c t s . 138. T a b l e X V I I E f f e c t o f M a c r o n u t r i e n t D e f i c i e n c y o n F r e s h a n d D r y W e i g h t P r o d u c t i o n I N T E R I O R D O U G L A S - F I R ( T a b u l a r c o m p a r i s o n b e t w e e n c o m p l e t e a n d d e f i c i e n t t r e a t m e n t s )  A v e r a g e s o f C r o c k A v e r a g e s T o t a l f r e s h D r y w e i g h t D r y w e i g h t T o t a l d r y I n c r e m e n t o r T r e a t m e n t w e i g h t / p l a n t s h o o t / p l a n t r o o t / p l a n t w e i g h t / p l a n t D e c r e m e n t g m s . s i g n . g m s . s i g n , p m s . s i g n , g m s . s i g n . ( C o l , d ) j> a b - c . d r - e . C o m p l e t e 6.7 O.54 O.85 1.39 L o w N 6*1 N S 0.27 N S 0.79 N S 1.06 N S -23.7 L o w S 14.8 * 1.17 N S 1.78 N S 2.95 N S +112.2 L o w M g 6.0 N S 0.60 N S O.76 N S 1.36 N S -2.2 L o w C a 11.6 N S O.85 N S 1.30 N S 2.15 N S +54.7 L o w P 1.0 0.06 N S 0.16 N S 0.22 N S -84.2 L o w Z 4.9 N S 0.45 N S O.63 N S 1 .08 N S -22.3 O v e r a l l s i g n i f i -c a n c e o f t r e a t - -m e n t d i f f e r e n c e s ** •** ** ** T h e r e s u l t s w i t h t h i s s p e c i e s w e r e a g a i n m a r r e d b y t h e a b n o r m a l g r o w t h o f t h e p l a n t s i n t h e c o n t r o l c u l t u r e s . T h e w i d e d i v e r g e n c e e x i s t i n g b e t w e e n t h e g r o w t h p e r f o r m a n c e o f t h i s s p e c i e s i n c o m p l e t e a n d l o w s u l f u r c u l t u r e s i s p r o o f e n o u g h o f t h e u n s u i t a b i l i t y o f t h e former a s a m e d i u m f o r g r o w t h . I n s p i t e o f t h e r e d u c e d s i z e o f t h e a v e r a g e p l a n t i n c o m p l e t e s o l u t i o n c u l t u r e , c e r t a i n o f t h e d e f i c i e n t c u l t u r e s w e r e e v e n m o r e u n s u i t e d t o t h e g r o w t h o f t h i s s p e c i e s . T h e e f f e c t o f t h e s e d e f i c i e n c i e s i s a p p a r e n t f r o m a n e x a m i n a t i o n o f t h e d a t a i n T a b l e X v T I . T h e p r e v a i l i n g l a c k o f s t a t i s t i c a l s i g n i f i c a n c e i s a t t r i b u t a b l e t o o t o t h e s u b n o r m a l g r o w t h o f t h e c o n t r o l c u l t u r e s . A l t h o u g h o f l i t t l e u s e a s a m e a n s o f g a u g i n g p e r f o r m a n c e i n a n y s p e c i f i c d e f i c i e n t c u l t u r e , t h e r e s u l t s r e p o r t e d i n t h e t a b l e a r e s t i l l u s e f u l i n 139-f u r n i s h i n g i n f o r m a t i o n o n t h e r e l a t i v e s e v e r i t y o f t h e v a r i o u s n u t r i t i o n a l e f f e c t s . O r d e r e d i n a s e q u e n c e b e g i n n i n g w i t h m o s t s e v e r e a n d t e r m i n a t i n g i n t h e l e a s t ' s e v e r e , t h e v a r i o u s d e f i c i e n t c u l t u r e s c a n b e s e t d o w n i n ' t h e f o l l o w i n g m a n n e r , u s i n g t h e t a b u l a t e d d a t a i n t h e t a b l e : P ; N ; K ; M g ; C a ; S -I t w i l