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The biology and control of some turf weeds. Ho, Lee San 1964

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THE: BIOLOGY AND CONTROL OF SOME: TURF WEEDS by LEE SAN HO B.S.A. Taiwan P r o v i n c i a l Ghung H s i n g U n i v e r s i t y I 9 6 0 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE, REQUIREMENTS FOR THE' DEGREE OF MASTER OF- SCIENCE IN AGRICULTURE i n t h e D i v i s i o n o f PLANT SCIENCE We accept t h i s t h e s i s as co 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 THE, UNIVERSITY OF BRITISH COLUMBIA May, 1964 In p r e s e n t i n g 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 per-m i s s i o n 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 Plant Science The U n i v e r s i t y of B r i t i s h Columbia, Vancouver 8, Canada Date May 6, 1964 ABSTRACT T h i s s t u d y o f some common t u r f w e e d s o f t h e V a n c o u v e r a r e a c o n s i d e r s some a s p e c t s o f b i o l o g y a n d c o n t r o l . S e e d p r o d u c t i o n o b s e r v a t i o n s i n d i c a t e d t h a t s e e d s r a n g i n g f r o m 3 0 0 t o o v e r 2 6 0 , 0 0 0 p e r p l a n t w e r e p r o d u c e d e a c h s e a s o n b y d i f f e r e n t s p e c i e s . S e e d s o f S e n e c i o v u l g a r i s L . , S o n c h u s o l e r a c e u s L . a n d H y p o c h a e r i s r a d i c a t a L . g e r m i n a t e d i m m e d i a t e l y a f t e r h a r v e s t w h i l e o t h e r s r e q u i r e d s e v e r a l m o n t h s . JH . r a d i c a t a s h o w e d g o o d g e r m i n a t i o n i n l i g h t w h i l e C e r a s t i u m v u l g a t u m L . a n d L a m i u m  a m p l e x i c a u l e L . g e r m i n a t e d . b e s t i n a s h a d e d o r d a r k e n v i r o n m e n t . Two g e r m i n a t i o n p e a k s i n s p r i n g a n d f a l l o c c u r i n t h i s g r o u p o f t u r f w e e d s . H o w e v e r S t e l l a r i a m e d i a ( L . ) C y r i l l p r o d u c e d f l o w e r s a n d s e e d f o r m o s t o f t h e y e a r . Rumex a c e t o s e l l a L . a l s o h a d a l o n g f l o w e r i n g p e r i o d a s d i d P l a n t a g o l a n c e o l a t a L . a n d P . ma. jor L . T h e t h r e e l a t t e r s p e c i e s w e r e f o u n d t o r e q u i r e a l o n g t i m e t o m a t u r e i n t h e f l o w e r h e a d a n d so w e r e n o t s h e d d i n g s e e d o v e r t h e c o n s i d e r a b l e p e r i o d o f t i m e c h a r a c t e r i s t i c o f S_. m e d i a . L e a f a r e a d e v e l o p m e n t d i d n o t a p p e a r t o be a s s o c i a t e d w i t h r o o t d e v e l o p m e n t i n t h e s e e d l i n g w e e d s e x a m i n e d , a n d v a r i a t i o n s i n t h e r e l a t i v e l e a f a r e a s o f t h e d i f f e r e n t s p e c i e s o c c u r r e d w i t h t i m e . M a r k e d d i f f e r e n c e s i n f l o w e r i n g p e r i o d a n d c h a r a c t e r -i s t i c s w e r e a p p a r e n t i n o b s e r v a t i o n s o n t h e v a r i o u s w e e d s made o v e r a 17i . m o n t h p e r i o d . A p o m i c t i c s e e d s o f T a r a x a c u m o f f i c i n a l e L . w e r e f o u n d t o h a v e a g e r m i n a t i o n r a t e s i g n i f i c a n t l y l o w e r t h a n t h o s e p r o d u c e d b y a r t i f i c i a l p o l l i n a t i o n . I n h i b i t o r y m a t e r i a l s p r e s e n t i n l e a v e s a n d s t e m s o f w e e d s w e r e s h o w n t o d e l a y g e r m i n a t i o n o f b e n t g r a s s n e a r l y t h r e e w e e k s a n d t o d e f i n i t e l y r e d u c e t h e p e r c e n t a g e g e r m i n a t i o n . T h e s p e c i e s s h o w i n g t h e g r e a t e s t i n h i b i t o r y p r o p e r t i e s w e r e M a t r i c a r i a m a t r i c a r i o i d e s ( L e s s . ) P o r t e r , S_. m e d i a a n d P . l a n c e o l a t a i n t h a t o r d e r . F o u r t u r f g r a s s e s w e r e shown t o d i f f e r i n t h e i r r e s p o n s e s t o p r o p r i e t o r y m i x t u r e s o f t h e p h e n o x y t y p e h e r b i c i d e s , a n d w e e d s p e c i e s s i m i l a r l y d i f f e r e d i n t h e i r r e s p o n s e s t o t h e n e w e r h e r b i c i d e s w h i c h i n c l u d e d B a n v e l D ( d i c a m b a ) , T o r d o n , p h e n o x y p r o p i o n i c m a t e r i a l s a n d m i x t u r e s c o n t a i n i n g t w o a n d t h r e e c h e m i c a l s . ACKNOWLEDGEMENT I w o u l d l i k e t o t a k e t h i s o p p o r t u n i t y t o show ray a p p r e c i a t i o n a n d t h a n k s t o t h e f o l l o w i n g p e r s o n s . My s p e c i a l t h a n k s t o D r . A . J . R e n n e y , D i v i s i o n o f P l a n t S c i e n c e f o r h i s g u i d a n c e a n d s u p e r v i s i o n . My t h a n k s a r e a l s o due t o D r . V . C . B r i n k , C h a i r m a n o f t h e D i v i s i o n o f P l a n t S c i e n c e f o r h i s u n d e r s t a n d i n g a n d s y m p a t h y . T h a n k s a r e a c c o r d e d t o t h e o t h e r members o f my t h e s i s c o m m i t t e e : D r . B . A , E a g l e s , D e a n o f t h e F a c u l t y o f A g r i c u l t u r e D r . C . A . H o r n b y , D i v i s i o n o f P l a n t S c i e n c e D r . N . A . M a c L e a n , D i v i s i o n o f P l a n t S c i e n c e D r . K . B e a m i s h , D e p a r t m e n t o f B o t a n y M r . H . V a a r t n o u , D e p a r t m e n t o f B u i l d i n g s a n d G r o u n d s F i n a n c i a l s u p p o r t f r o m t h e P . E . 0 . S i s t e r h o o d h e l p e d t o make my s t u d i e s p o s s i b l e . I am g r a t e f u l a l s o t o M r . F . V r u g t m a n who t r a n s l a t e d the ' G e r m a n r e f e r e n c e s f o r me . TABLE OF CONTENTS Page ACKNOWLEDGEMENT LIST OF TABLE LIST OF FIGURES INTRODUCTION 1-2 REVIEW OF LITERATURE 3 -3 PROCEDURE I B i o l o g i c a l Studies 1. Seed andlplant studies 9-12 2 . Inhibitors as facto r s i n plant competition 12-13 II Control Studies 1. Tolerance of grass to two experimental phenoxy herbicides 13-14 2. Herbicidal t r i a l s on t u r f i n s i t u 14 RESULTS AND DISCUSSION 15-42 CONCLUSION 43-45 BIBLIOGRAPHY 46-49 APPENDIX 50-76 LIST OF TABLES Table Page 1. Seed production of some turf weeds 17 2. The number of frui t ing units and number of 19 seeds per fru i t ing unit of various weed species at f i r s t and last col lect ion. 3 . Seed production under greenhouse conditions 20 4. Seeds germinating after three storage periods 22 following harvest 5. The effect of grass competition and environ- 29 ment on the growth of 13 mature weed species 6. Dandelion seeds per head produced by different 30 treatments 7. Percentage germination of dandelion seeds 30 following different treatments 6*. Percentage germination of highland bent in 33 four concentrations of leaf extract 9. Tolerance of four turf grasses to varying rates 36 of NPH/112 10. Tolerance of four turf grasses to varying rates 3# of Supertox 11. Herbicidal effects on weeds and grass in a 40 mature bent-blue grass turf . 12. Weed control and grass injury, resulting from 41 herbicidal-applications to a fescue-bent establishing turf L i s t of figures Page 1. Leaf areas of seedling weeds three, 24 (a) f i v e and seven weeks afte r emergence 2. Weed growth andwgather conditions 26 (a) 3. Growth i n h i b i t i o n of bent grass caused 32 (a) by three concentrations of l e a f powder extract of various weeds 4. The germination of bent grass" i n sand 32 (b) as influenced by 1.7% concentrations of the dried l e a f powder of three weeds 5. Photographs of some weed seedlings 70 - 76 Appendix tables Table Page 1. Botanical names of weed species 50 2. Leaf areas of seedling weeds at three 52 growth stages , 3 . Leaf development of 13 weed species u n t i l 53-54 seven weeks after germination 4 . Root development of 13 weed species unt i l 55 seven weeks after germination 5. Stem development of 13 weed species unt i l 56-57 seven weeks after germination 6 . Flowering and seed production periods of 5$ 22 turf weed species in the Vancouver area 1962-63 7. Monthly mean teamperatures and precipitat ion, 59 U. B. C. Meteorological Station 1962 and January-June 1963 S. The germination of highland bent and Merion 60 blue grass in areas contaminated by root exudates of \arious weeds. 9 . (a) Germination and shoot length of highland 6 l . . bent grass in three concentrations of theeleaf extract of six weeds (b) Analysis of variance, percentage 62 germination (c) Analysis of variance, shoot length 62 1 0 . - Germination of bent grass in sand as influenced 63-65 by 1.7$ concentrations of the dried leaf powder of three weeds 11. Greenhouse experiment for competition studies (a) Plan and rates 5 5 (b) Analysis of\ariance, f i r s t harvest (three 5 7 weeks) (c) Analysis of variance, second harvest (six 6S - weeks) 12. Chemical names of herbicides • 69 I . INTRODUCTION 1 Man*s problems with weeds began when he decided to grow crops in one place rather than roam the wilds to collect roots, f ru i t s and seeds. As the centuries passed and he found time for le i sure , recreation and the improve-ment of his surroundings, the advantages of turf became apparent - and with the development of turf areas came the need to study and control turf weeds. Unfortunately playgrounds, golf courses, parks and playing f i e lds share with the home lawn the disadvantages of undesirable plant species. The study of weed biology has received attention only recently. Harper (IS) indicates that biological studies of th i s type have been evident only for the past ten to f i f teen years. L i t t l e i s known of the l i f e history of turf weeds, their rate and means of dispersal , or the nature of the competition they offer to the desirable grass species. Additional biological studies on weeds would probably aid in discovering more effective control measures whicti in turn would result in more pleasing and more useful grassed areas. With the advent of 2,4-D in 1945, an exciting new tool was available for weed control in tur f . However, not a l l broadleaf weeds were equally susceptible to this herbicide, and other phenoxy compounds as well as chemicals from closely associated groups have been appear-2. ing in recent years. Mixtures of herbicides are also proving useful where mixed weed populations exist . Two types of investigation were undertaken in the present work: biological studies and control studies. The emphasis was placed on weeds common to the Vancouver area and more part icularly to those found on the extensive grassed areas of the University of B r i t i s h Columbia. 3 . II . LITERATURE REVIEW The term "weed" suggests a plant which has use-less , harmful or objectionable habits or characteristics and which grows where i t i s not wanted ( 3 6 ) . Most weeds are vigorous in their growth habit, have a wide range of adaptation and often have the ab i l i ty to regenerate lost parts or spread by vegetative means. A turf weed could be considered as any plant other than the desired species or mixture (37) • Usually this means any plant other than the seeded grass species but this may not always be the case. A weed or turf i s usually characterized by having a growing point near the s o i l surface, often forming a rosette or mat. It may produce a large number of seeds ( 3 6 ) . The beauty of the lawn "the front door carpet of the house" can only be real ized when i t i s uniformly textured and evenly green. Weeds w i l l interfere with the development of this ideal and w i l l thus destroy the quality of the turf . They also offer competition to the grass for nutrients and water. In addition grassy weeds may act as hosts for insects and such diseases as rusts and smuts which attack the more desirable grass species ( 1 3 ) . Several workers, have reported on the large number of seeds produced by various weed species (36, 41* 2S, 40). Those plants considered to be injurious or unsightly to 4. turf , produced seeds ranging from less than 200 per plant to over 500,000, depending on the species. Climatic, edaphic and biot ic factors cause considerable variation in the number of seeds which a single species w i l l produce ( 9 ) . In addition to these environmental influences the constant mowing to which turf weeds are subjected res tr ic t s the production of seed to those species which are able to form seeds below the level of the mower blades or to those which have grown to maturity in nearby unmowed areas. |he ab i l i ty of weed seeds to remain viable over many years has been well established ( £ , lo", 26, 44, 3 , 2) and periodicy of germination has received attention from these workers and others. Of the weeds studied by Brenchley and Warrington (2) f eleven germinated in the autumn (September to December), nine in the winter (January to M§rch) and sixteen showed no regular peaks of germination. Thurston*s review (44) on this topic i s a very comprehensive one part icularly for conditions in England. Chepil (3) similarly covers many Canadian weeds, some of which are pests of turf areas. It i s apparent from his ;st.udy that although germination i s normally highest the f i r s t season after seed production, nevertheless a large fract ion of the seeds of most turf species w i l l germinate in the second, t h i r d , fourth and even the f i f t h year after pro-duction. Chepil 1 s data show germination peaks occurring mainly between A p r i l 15 and May 30, but germination of 5. Portulaca oleracea i s delayed, reaching a maximum between June 15 and June 3 0 t h . This species appears to reach a second major peak between August 15 and August 3 0 . Weeds such as Amaranthus retroflexus and Taraxacum officinale show germination patterns which are more or less uniform from May u n t i l September. Seed dormancy results from the inhibit ion of one or more of the processes preceding or accompanying germina-t ion ( 7 ) . Conversely seed germination is influenced by the physiology of the seed and environmental conditions (47)• Permeability of seed (46) influences the response of "hard seed" as does the seed*s ab i l i ty to absorb oxygen (43)• The duration of dormancy in grass seeds i s much longer than that of cereals (47)• Korsrao (29) gives an excellent description of 97 species of weeds including their ecology, and cross sections of root t i p s , stems and leaves. His text i s a useful reference for mode of action studies in weeds. L i t t l e information i s available on relative leaf areas of the individual weed species except indirect ly by reference to i l lus trat ions of seedlings. (29 , 1 6 ) . Kutschera (30) compared the development of weeds in d i f fer-ent habitats. His data included figures for rooting depths, root spread and top height. The l i terature on plant competition including the presence and effects of growth inhibit ing materials i s exten-sive. Recent reviews include those of Evenari ( 11) , Martin ( 3 5 ) , Tourneau ( 3 2 ) , Garb ( 1 5 ) . Of particular interest to turf investigators are reports on inhibit ion caused by-couch grass (37) 27, 33) chickweed ( 3 4 ) , and Matricaria spp. ( 3 5 ) . Weed control, as defined in the Report of the Terminology Committee of the Weed Society of America I960 i s "the process of l imit ing weed infestations so that crops can be grown profitably or other operations can be conducted eff ic ient ly". In their recently published text, Crafts and Robbins (6) l i s t four methods of weed control: mechanical cropping and competition biological chemical. A l l four of these are used in the control of weeds in turf although chemical control has received the greatest emphasis since 2,4-D ( 2 , 4 - dichlorophenoxy-acetic acid) was f i r s t marketed commercially in 1945* However, i t was known in the last 19th century that inorganic materials such as iron salts , sulphuric acid, sodium and copper nitrate and ammonium sulphate had selective weed k i l l i n g action when applied to broad leafed weeds in cereals. The organic chemicals nevertheless revolutionized weed control and turf workers have benefitted from their introduction as much as any other group. MCPA (2 methyl 4 chlorophenoxyacetic acid) appeared i n Europe at approximately the same time as 2,4-D appeared i n North America. These chemicals appeared to control a similar group of t u r f weeds including Taraxacum spp., Flantago spp., and many members of the Cruciferae family. 2,4,5-T (2,4,5-trichlorophenoxyacetic acid) appeared shortly a f t e r 2,4-D and MGPA and although i t some-times caused injury when applied to grass i t was often valuable i n helping to control some of thoese weeds which were re s i s t a n t to the other two herbicides. This chemical was used alone i n water, or with water and a small amount of d i e s e l or similar o i l , or was used i n 1:1 or 1:2 mix-tures with 2,4-D» Within the l a s t three years two other compounds belonging to t h i s group have come into common use. They are 2(MCPP) (2 methyl, 4 chlorophenoxypropionic acid) and silvex 2,4,5-trichlorophenoxypropionic a c i d ) , (21, 10).14, 42, 5). These chemicals enable an additional group of weeds such as the T r i f o l i u m spp., chickweeds, black medic and creeping Charlie to be controlled. Dicamba (2 methoxy-3'y, 6 dichlorobenzoic acid) which i s valuable for English daisy control i s the newest herbicide to be added to the recommended l i s t . Combinations of herbicides f o r broad spectrum weed control are beginning to appear (4$)• These usually include 2.4-D, 2 (MCPP) or Silvex and 2,4,5-T; or 2,4-D and Dicamba. s. Two t u r f w e e d s f o r w h i c h s a t i s f a c t o r y c o n t r o l s h a v e n o t b e e n a c h i e v e d s o f e r a r e s p e e d w e l l V e r o n i c a s p p a n d a n n u a l b l u e g r a s s P o a a n n u a . Some p r o m i s i n g r e s u l t s f o r V e r o n i c a s p p . h a v e b e e n r e p o r t e d (25, 4, 21, 17) i n w h i c h t h e c h e m i c a l e n d o t h a l ( d i s o d i u m 3,6, e n d o x o h e x a h y d r o p h t h a l a t e ) w a s u s e d . H o w e v e r g r a s s damage u s u a l l y r e s u l t s a t r a t e s w h i c h a r e n e c e s s a r y f o r w e e d c o n t r o l . I n a more r e c e n t t e s t z y t r o n (0-2,4; d i c h l o r o p h e n y l 0 - m e t h y l i s o p r o p y l p h o s p h o r a m i d e t h i o a t e ) w h i c h h a s b e e n used f o r c r a b g r a s s c o n t r o l i n t h e U n i t e d S t a t e s g a v e g o o d c o n t r o l o f V e r o n i c a f i l i f o r m i s (22). 9 . PROCEDURE; B i o l o g i c a l S t u d i e s A . S e e d P r o d u c t i o n T h e s e e d p r o d u c t i o n o f t h e i n d i v i d u a l w e e d p l a n t i s g o v e r n e d b y e n v i r o n m e n t a l f a c t o r s a s w e l l a s b y g e n e t i c f a c t o r s . T o s t u d y t h e e f f e c t s o f t h e s e f a c t o r s - t h e f o l l o w -i n g p r o j e c t s w e r e u n d e r t a k e n . 1 . Weed s e e d p r o d u c t i o n u n d e r n a t u r a l c o n d i t i o n s . T o s i m u l a t e s e e d p r o d u c t i o n u n d e r n a t u r a l c o n d i -t i o n s , w e e d s p e c i m e n s w e r e t a k e n f r o m l a w n a r e a s a t t h e f o u r t r u e l e a f s t a g e a n d t r a n s p l a n t e d i n t o a c o l d f r a m e w i t h o u t t h e s a s h . T r a n s p l a n t i n g w a s d o n e M a r c h 2 , 1 9 6 2 . S e e d s o f t h e s e p l a n t s w e r e c o l l e c t e d f r o m M a r c h 11 u n t i l A u g u s t 1 5 , 1 9 6 2 , i n c l u s i v e . A l t h o u g h t h e p r o j e c t s w a s i n i t i a t e d w i t h t h r e e p l a n t s e a c h o f e i g h t e e n s p e c i e s , i n a f e w c a s e s one p l a n t d i e d a n d o n l y t w o p l a n t a v e r a g e s w e r e p o s s i b l e . 2 . Weed s e e d p r o d u c t i o n u n d e r g r e e n h o u s e c o n d i t i o n s . S e e d s c o l l e c t e d f r o m p l a n t s g r o w n i n t h e c o l d f r a m e i n 1962 w e r e u s e d i n t h i s t r i a l . On F e b r u a r y 1 6 , 1 9 6 3 , s e e d s w e r e s o w n , 50 s e e d s p e r c r o c k ( 6 . 5 i n c h e s i n d i a m e t e r ) . A s t a n d a r d s t e r i l i z e d g r e e n h o u s e s o i l w a s u s e d . A f t e r t h e f o u r t h t r u e l e a f a p p e a r e d , s e e d l i n g s w e r e t h i n n e d 10. t o f i v e p e r c r o c k . The p l a n t s w e r e g r o w n i n t h e g r e e n h o u s e t h r o u g h o u t t h e t r i a l p e r i o d . The m i n i m u m t e m p e r a t u r e o b s e r v e d d u r i n g t h e t r i a l p e r i o d w a s 4 5 ° F . M o i s t u r e c o n d i -t i o n s w e r e k e p t u n i f o r m b y a p p l y i n g t h e same amoun t o f w a t e r t o e a c h c r o c k t w i c e a w e e k . F i v e p l a n t s e a c h o f 13 w e e d s p e c i e s w e r e u s e d i n t h i s s t u d y . C o l l e c t i o n s w e r e made May 1 a n d J u n e 26, 1963• B . G e r m i n a t i o n s r a t e s a n d p e r i o d i c i t i e s . G e r m i n a t i o n t e s t s w e r e s e t up a t r e g u l a r i n t e r v a l s t o d e t e r m i n e t h e s t a t e o f m a t u r i t y o f t h e w e e d s e e d s . F i f t y s e e d s o f e a c h o f s e v e n t e e n s p e c i e s c o l l e c t e d i n t h e g r e e n -h o u s e w e r e u s e d f o r e a c h t e s t b e g i n n i n g J u n e 26 , 1963 . The s e e d s w e r e p l a c e d i n c o v e r e d p e t r i d i s h e s o n f i l t e r p a p e r d a m p e n e d w i t h d i s t i l l e d w a t e r . R e a d i n g s w e r e t a k e n w h e n t h e f i r s t g e r m i n a t i o n o c c u r r e d a n d i n t h r e e d a y i n t e r v a l s t h e r e a f t e r . The f o l l o w i n g i n f o r m a t i o n w a s r e c o r d e d : d a t e o f s e e d c o l l e c t i o n d a t e o f s e e d i n g s e e d s g e r m i n a t e d p e r c e n t a g e g e r m i n a t i o n C . L e a f a r e a m e a s u r e m e n t s . A c o m p e n s a t i n g p o l a r p l a n i m e t e r ( K . & E . ) w a s u s e d t o m e a s u r e l e a f a r e a s . M e a s u r e m e n t s w e r e r e c o r d e d i n s q u a r e c e n t i m e t e r s , a t t h e t h r e e , f i v e and s e v e n w e e k g r o w t h p e r i o d . D . S e e d l i n g c h a r a c t e r i s t i c s . Weed s e e d l i n g s g r o w n i n p o t s i n t h e g r e e n h o u s e w e r e 1 1 . s a m p l e d e v e r y t w o w e e k s . M e a s u r e m e n t s o f l e a v e s , s t e m s a n d r o o t s w e r e r e c o r d e d a n d r e p r e s e n t a t i v e p l a n t s w e r e i l l u s t r a t e d . E , O b s e r v a t i o n s o f w e e d f l o r a a t t w o l o c a t i o n s i n V a n c o u v e r D u r i n g 1 9 6 2 a n d 1 9 6 3 m o n t h l y o b s e r v a t i o n s w e r e made o n t h e t u r f w e e d s o n t h e U n i v e r s i t y o f B . C . c a m p u s . D u r i n g 1 9 6 3 s i m i l a r n o t e s w e r e t a k e n o n t h e t u r f a t Q u e e n E l i z a b e t h P a r k ( L i t t l e M o u n t a i n ) . S p e c i a l a t t e n t i o n w a s g i v e n t o t h e t i m e o f r e a p p e a r a n c e o f new s e e d l i n g s , t o t h e m a i n f l o w e r i n g p e r i o d a n d t o t h e m a t u r i n g t i m e o f t h e f r u i t s . I n one s t u d y r o o t a n d t o p g r o w t h , a n d s e e d p r o -d u c t i o n o f w e e d s g r o w i n g i n t u r f w e r e c o m p a r e d w i t h g r e e n h o u s e p o t g r o w n p l a n t s . T e m p e r a t u r e a n d p r e c i p i t a t i o n f i g u r e s o b t a i n e d f r o m t h e U n i v e r s i t y o f B . G . m e t e o r o l o g i c a l r e c o r d s w e r e u s e d t o i l l u s t r a t e t h e r e l a t i o n b e t w e e n m o n t h l y maximum t e m p e r a t u r e s , m o n t h l y m i n i m u m t e m p e r a t u r e s , t o t a l m o n t h l y p r e c i p i t a t i o n a n d t h e i r c o m b i n e d e f f e c t o n w e e d g r o w t h . F . S e e d p r o d u c t i o n i n d a n d e l i o n s F i v e i n f l o r e s c e n c e s ( o n t h r e e p l a n t s ) w e r e a r t i f i c i a l l y p o l l i n a t e d a n d t h e n c o v e r e d i n d i v i d u a l l y w i t h s m a l l p o l y e t h y l e n e p l a s t i c b a g s . F i v e o t h e r b l o o m s w e r e b a g g e d i n t h e b u d s t a g e a n d a t h i r d s e t o f f i v e i n f l o r e s -c e n c e s wa . seused w i t h o u t c o v e r i n g a s c o n t r o l s . The n u m b e r 12. o f s e e d s w a s c o u n t e d t o c o m p a r e s e e d s e t i n e a c h c a s e . G . I n h i b i t o r s a s f a c t o r s i n p l a n t c o m p e t i t i o n . 1. U n d e r g r o u n d p a r t s . L a w n w e e d s e e d l i n g s w e r e c o l l e c t e d a n d p l a c e d o n w e t f i l t e r p a p e r i n o p e n p e t r i d i s h e s . F o u r t e e n w e e d s p e c i e s w e r e u s e d i n t h i s s t u d y . T w e n t y s e e d s o f h i g h l a n d b e n t g r a s s A g r o s t i s t e n u i s w e r e p l a c e d i n c l o s e p r o x i m i t y t o t h e r o o t s o f t h e w e e d i n e a c h c a s e . The s e r i e s w a s r e p e a t e d w i t h m e r i o n b l u e g r a s s P o a p r a t e n s i s . Two p e t r i d i s h e s w i t h h i g h l a n d b e n t a n d t w o w i t h m e r i o n b l u e g r a s s s e r v e d a s c o n t r o l s . 2 . A b o v e - g r o u n d p a r t s L e a v e s a n d s t e m s o f t h e w e e d s w e r e o v e n d r i e d a t ctO°G a n d g r o u n d i n t o p o w d e r i n a W i l e y m i l l . T e n p e r c e n t s o l u t i o n s w e r e p r e p a r e d u s i n g d i s t i l l e d w a t e r . A f t e r one d a y o f f r e q u e n t s t i r r i n g t h e m i x t u r e w a s f i l t e r e d . F o u r c o n c e n t r a t i o n s w e r e o b t a i n e d b y d i l u t i o n f r o m t h i s f i l t r a t e . S i x t e e n s p e c i e s w e r e e x t r a c t e d i n t h i s m a n n e r . F i v e m i l l i l i t r e s o f t h e a q u e o u s e x t r a c t w a s u s e d t o w e t t h e f i l t e r p a p e r i n e a c h p e t r i d i s h . T w e n t y s e e d s o f h i g h l a n d b e n t g r a s s w e r e p l a c e d f o r g e r m i n a t i o n i n e a c h c a s e . T h r e e d i s h e s w e t t e d w i t h d i s t i l l e d w a t e r w e r e u s e d a s c o n t r o l s . S i x w e e d s p e c i e s w e r e s e l e c t e d f o r a f u r t h e r t r i a l . T h r e e r e p l i c a t i o n s w e r e r u n f o r e a c h 13. concentration of plant extract. Again there were three controls. Similar t r i a l s were run with only three species. F . Weed-grass competition in s o i l . Fi f ty- four plots each one foot square, were l a id out on a greenhouse bench. Plots were separated by lath s tr ips . Ster i l i zed greenhouse so i l testing 18$ organic matter was used. Seeds of five weed species collected from the 1962 study were seeded with various rates of highland bent grass. A randomized block design was used . 1 with three seeding rates for the grass, three replications and nine control plots (no weed seeds). The so i l surface was treated with captan dust to prevent fungus growth. The plots were watered every two days. Grass and weeds were clipped one inch above ground level at definite intervals , air dried andweighed. Chemical Control Studies A. Tolerance of grass to two experimental phenoxy herbicides. Two of the more promising formulation in 1962 were NPH/ll^and Supertox. : An experiment was set up to test the tolerance of four turf grasses to these chemicals. Flats of high-land bent grass x and creeping red fescue. Chewing1s x See appendix for formulae and botanical names. 14. fescue and Merion blue grass were divided into three equal parts. Two parts of each f lat were sprayed with different rates of NPH/112 and Supertox using precautions to prevent spray d r i f t . In one series the grass was treated when growth was approximately one inch high; in a second series when growth was two inches. Dry weights were measured three weeks after treatment and the regrowth was harvested 44 days after the f i r s t clipping in the one inch series and 64 days later in the two inch series. B. Effects of certain herbicides on turf weeds. F i r s t t r i a l : Fourteen treatments replicated three times were applied to plots five feet by ten feet on land now occupied by dormitories on South-west Marine Drive. Scoring was done by visual estimate between July 19 and September 6 , 1962. Second t r i a l : Nineteen treatments replicated four times were applied to plots five feet by ten feet on a newly seeded creeping red fescue bent grass playing f i e ld in the Fort Gamp area of the University of B . C . Scoring was done visually from June 6 u n t i l September 13 , 1963. Spraying was done in each case with a L i t t l e Giant hand sprayer. Border areas were lef t adjacent to each sprayed plot and precautions were taken to avoid contamination of plots through d r i f t . 15. I V . R E S U L T S AND D I S C U S S I O N B i o l o g i c a l S t u d i e s A . S e e d P r o d u c t i o n T a b l e 1 s h o w s t h e s e e d p r o d u c t i o n o f e i g h t e e n w e e d s p e c i e s d u r i n g t h e t e s t p e r i o d M a r c h 11 - A u g u s t 15, 1962. The l e n g t h o f t h e f r u i t i n g p e r i o d o f t h e v a r i o u s w e e d s p e c i e s d i f f e r s w i d e l y , e . g . t h e t w o d a n d e l i o n p l a n t s p r o d u c e d a l l t h e i r s e e d s w i t h i n f i v e w e e k s , b u t t h e s e e d m a t u r a t i o n p e r i o d o f common c h i c k w e e d , mouse e a r c h i c k w e e d , g r o u n d s e l a n d s h e p h e r d * s p u r s e w a s d i s t r i b u t e d o v e r more t h a n t w e l v e w e e k s . I n g e n e r a l f e w s e e d s w e r e p r o d u c e d d u r i n g t h e s p r i n g m o n t h s b u t s e e d p r o d u c t i o n i n c r e a s e d t o w a r d t h e end o f t h e c o l l e c t i n g p e r i o d . V a r i a t i o n s b o t h i n t h e n u m b e r o f f r u i t i n g u n i t s ( c a p s u l e s , n u t l e t s , h e a d s , e t c . ) p e r p l a n t a n d i n t h e number o f s e e d s p e r f r u i t i n g u n i t w e r e o b s e r v e d . T h e s e v a r i a t i o n s w e r e m o s t e v i d e n t i n c o m p a r i n g t h e f i r s t a n d l a s t s e e d c o l l e c t i o n s ( T a b l e 2). D u r i n g M a r c h a n d A p r i l b o t h v e g e t a t i v e a n d r e p r o -d u c t i v e g r o w t h w e r e r e s t r i c t e d a n d s e e d f o r m a t i o n r e q u i r e d more t h a n one w e e k a f t e r t h e w e e d s f l o w e r e d , e ' . g . common c h i c k w e e d , mouse e a r c h i c k w e e d a n d c o r n s p u r r y . H o w e v e r , d u r i n g May a n d J u n e m a t u r e s e e d w a s p r o d u c e d i n t w o t o t h r e e d a y s . D a n d e l i o n a l t h o u g h l i s t e d a s a d a y n e u t r a l p l a n t (1) i s a n e x c e p t i o n — i t s s e e d p r o d u c t i o n p e r i o d t e r m i n a t e d t o w a r d s t h e m i d d l e o f M a y . 17. TABLE: 1 Seed production of some t u r f weeds. Co l l e c t i n g Period Collec-t i o n s Average seeds per plant ( t o t a l period) Dandelion 3/11 - 4/16 5 2,033 ; Shepherd 1 s purse 3/11 - 6/12 12 27,634 Common chickweed 3/11 - 6/14 13 90,711 Groundsel 3/11 - 6/28 12 43,739 Mouse ear chickweed 3/11 - 6/14 9 151,266 ; Annual, Blue Grass 4/6 - 5/30 5 362 ; Dead nett l e 4/6 - 5/16 7 556 Stork*s b i l l 4/11 - 6/28 10 5,093 Corn spurry 4/14 - 6/23 17 253,706 Yellow rocket 6/16 1 46,392 Narrow leaved Plantain 3/15 1 33,300 Sheep s o r r e l 6/23 1 48,779 Tumbling mustard 6/14 l l 127,498 Hedge mustard 6/28 1 3 ,333 Pineapple weed 3/14 1 24,333 Lambfs quarters 3/1 1 74,2.40 Smart weed 1 3,640 Cat*s ear 5/20;;- 6/15 4 2,329 # 2 plant averages, others a l l 3 plant averages In these t r i a l s maximum seed production was achieved by (1) growing the seed plants without competition and (2) removing the mature seeds from the plants p e r i -o d i c a l l y , thus stimulating l a t e r a l growth of the plant and subsequent seed production. Lawn weeds i n competition with t u r f grasses are l i k e l y to be l e s s productive. 19 . TABLE 2 The number of fruiting units and number of seeds per fruiting unit of various weed species at f i r s t and last collection. Number of fr u i t i n g Number of seeds per Species units per plant at f r u i t i n g unit at time of time of  f i r s t last f i r s t last collection collection collection collection Annual blue grass 3 - 4 8-12 3 - 5 3 - 5 Cat's ear 2 - 4 7 - H 78 - 92 137 - 150 Common chickweed 114 1829 8 - 12 10 - 22 Corn spurry 8 3213 18 - 20 20 - 35 Dandelion 3 20 - 30 80 - 120 110 - 181 Dead nettle 4 36 2 - 3 2 - 3 Stork's b i l l 2 418 5 5 Groundsel 3 - 4 96 50 - 80 70 - 90 Mouse ear chickweed 2 - 3 587 24 - 35 39 - 45 Shepherd's purse 24 979 12 - 16 12 - 21 .20. TABLE; 2 Seed production under greenhouse conditions (five plan averages) Species Fruit ing Units Seeds per fru i t ing unit Average seeds per plant Hedge mustard 1,080 IS 19,440 Dandelion 12 120 2,040 Cat T s ear 15 82 ' 1,230 Dead nettle 975 3 2,925 Broad leaved plantain 200 5 1,000 Narrow leaved plantain 270 7 1,750 Annual sow th is t le 25 80 2,000 Groundsel 146 SO 11,680 Yellow rocket 120 50 6,000 Stork*s b i l l 60 5 3,000 Common chickweed 1,493 12 17,976 Mouse ear chickweed 66S 35 23,380 Shepherd's purse 434 25 10,950 The data presented as five plant averages in Table 3 are sometimes at variance with the information of Table 2. These plants grown under greenhouse conditions 21. a p p a r e n t l y r e f l e c t e d t h e more f a v o u r a b l e g r o w i n g e n v i r o n m e n t b y t e l e s c o p i n g t h e s e e d p r o d u c t i o n p e r i o d t o a m a r k e d d e g r e e , a n d i n one c a s e ( S h e p h e r d ' s p u r s e ) s h o w e d a l a r g e r number o f s e e d s p e r f r u i t i n g u n i t . When a l l o w a n c e i s made f o r t h e f a c t t h a t o n l y one h a r v e s t w a s t a k e n f r o m t h e g r e e n h o u s e p l a n t s , d i f f e r e n c e s i n t o t a l s e e d p r o d u c t i o n w h i c h a r e g r e a t e s t i n t h o s e s p e c i e s s h o w i n g t h e g r e a t e s t amoun t o f i n d e t e r m i n a t e g r o w t h , a r e more u n d e r s t a n d a b l e . The e f f e c t o f t h e p e r i o d i c r e m o v a l o f t h e f r u i t i n g u n i t s r e m a r k e d u p o n e a r l i e r w o u l d n e v e r t h e l e s s a p p e a r t o be a d e f i n i t e f a c t o r i n i n c r e a s i n g t h e p r o d u c t i o n o f t h e o u t d o o r g r o w n s p e c i m e n s . T A B L E ; ^ Seeds germinating after three storage periods following harvest Species Seeded immedi-ately 1 month storage 2 months storage Total Germ % Corn spurry 0 0 5 4 .4 Hedge mustard 33 11 22 44.0 Lambs quarters 39 . 18 21 52.0 Groundsel 48 46 42 90.6 Dandelion 29 40 2 47.2 Stork*s b i l l 0 0 0 0 . 0 Shepherd's purse 1 0 0 0 .6 Dead nettle 0 4 3 4 .6 Annual Sow Thist le 20 36 4 40.0 Common Chickweed 6 1 1 5.4 Mouse ear Chickweed 29 0 45 49.3 Smart Weed 39 48 0 53.0 Pineapple Weed 5 4 12 14 .0 Cat's ear 34 29 2 43.3 Table 4 represents the influence of dry storage at room temperature on the seed embryos between the date 23. o f h a r v e s t J u n e 26 a n d A u g u s t 24 when t h e l a s t s e r i e s w a s s e t t o g e r m i n a t e . E l e v e n s p e c i e s a r e a p p a r e n t l y r e a d y t o b e g i n p r o d u c i n g new p l a n t s i m m e d i a t e l y t h e s e e d i s s h e d i f m o i s t u r e a n d t e m p e r a t u r e c o n d i t i o n s a r e f a v o u r a b l e . A l t h o u g h t h e s e c o n d s e r i e s , s e t a m o n t h a f t e r t h e f i r s t , b r o u g h t a b o u t no a p p r e c i a b l e c h a n g e i n t h e g e r m i n a t i o n b e h a v i o u s o f m o s t s p e c i e s , mouse e a r c h i c k w e e d w a s t h e one e x c e p t i o n w h e r e g e r m i n a t i o n d r o p p e d t o z e r o a n d t h e n r e v i v e d a g a i n i n t h e t h i r d s e r i e s one m o n t h l a t e r . D a n d e l i o n , c a t ' s e a r a n d a n n u a l sow t h i s t l e a l l d e c l i n e d . a p p r e c i a b l y i n t h e August s e r i e s f o l l o w i n g t w o m o n t h s o f s t o r a g e . T h i s t r i a l d e m o n s t r a t e s t h a t a l l s p e c i e s r e p r e s e n t e d e x c e p t s t o r k ' s b i l l w i l l show some g e r m i n a -t i o n w i t h i n a t w o m o n t h p e r i o d f o l l o w i n g t h e s h e d d i n g o f t h e s e e d . P o s s i b l y a g r e a t e r d i f f e r e n c e i n d a y / n i g h t t e m p e r a t u r e s o r some o t h e r c h a r a c t e r i s t i c o f t h e n o r m a l o u t s i d e e n v i r o n m e n t w o u l d h a v e e n c o u r a g e d e v e n t h i s t s p e c i e s t o g e r m i n a t e b u t w h e t h e r s o r k ' s b i l l g e r m i n a t e s f r o m s e e d l e s s t h a n t w o m o n t h s o l d i s n o t k n o w n . Many w e e d s e e d s , l i k e m o s t c r o p s e e d s , r e q u i r e a r e s t i n g s t a g e o r d o r m a n c y p e r i o d a f t e r t h e y a r e r i p e n e d . T h e l e n g t h o f t h i s p e r i o d v a r i e s w i t h d i f f e r e n t s p e c i e s a n d i n t h e p r e s e n t s t u d y r a n g e d f r o m l i t t l e o r none t o t h r e e m o n t h s a f t e r h a r v e s t f o r m o s t s p e c i e s w i t h f o u r r e q u i r i n g u n t i l F e b r u a r y b e f o r e g e r m i n a t i n g ( s t o r k ' s b i l l , 24. s h e p h e r d ' s p u r s e , d e a d n e t t l e a n d c o r n s p u r r y ) . S e e d m a t u r i t y p e r i o d s o n some w e e d s w e r e e x t e n d e d b e c a u s e s e e d f r o m b o t h c u r r e n t l y m a t u r e d p l a n t s a n d f r o m t h o s e m a t u r e d i n p r e v i o u s s e a s o n s showed c o n t i n u o u s g e r m i n a t i o n d u r i n g m o s t o f t h e summer . F o r e x a m p l e f r e s h l y h a r v e s t e d c a t ' s e a r s e e d h a s a h i g h g e r m i n a t i o n r a t e i n t h e w a r m summer m o n t h s . T h i s c h a r a c t e r i s t i c may e x p l a i n why t w o g e n e r a -t i o n s a y e a r f r e q u e n t l y a r e f o u n d . M a t u r e p l a n t s c a n be p r o d u c e d f r o m s e e d i n t w o m o n t h s u n d e r f a v o u r a b l e c o n d i -t i o n s . When t h e s e f a c t s a r e c o u p l e d w i t h t h e o t h e r w i s e p e r e n n i a l h a b i t o f t h e w e e d i t i s n o t d i f f i c u l t t o u n d e r -s t a n d why c a t ' s e a r h a s become s u c h a p e r s i s t a n t p e s t i n t u r f . G r o u n d s e l a n d a n n u a l sow t h i s t l e h a v e t h e same c h a r a c t e r i s t i c s b u t b e i n g a n n u a l s a n d h a v i n g a t a l l e r g r o w t h h a b i t a r e e a s i e r t o c o n t r o l b y m o w i n g t h a n i s c a t ' s e a r . I t w a s n o t e d a l s o t h a t c a t ' s e a r g e r m i n a t e s w e l l u n d e r s t r o n g l i g h t . Some o t h e r s p e c i e s e . g . mouse e a r c h i c k w e e d a n d d e a d n e t t l e g e r m i n a t e d b e t t e r i n s h a d e o r i n t h e d a r k . A s t h e e a r l y d e v e l o p m e n t o f a l a r g e p h o t o s y n t h e t i c a r e a . i s c o n s i d e r e d t o be a n i m p o r t a n t f a c t o r i n w e e d c o m -p e t i t i o n i t i s o f i n t e r e s t t o e x a m i n e f i g u r e 1 a n d a p p e n -d i x t a b l e s 2 a n d 3» The o r d e r o f s p e c i e s f r o m l e f t t o r i g h t i n f i g u r e 1 i n d i c a t e s t h e i n i t i a l ( 3 - w e e k ) m a g n i t u d e s TOTAL LEAF AREA (SQ. CMS.) Hedge bustard Yellow Rocket Dead Nettle Narrow Leafed Plantain Broad Leafed Plantain Mouse Ear Chickweed CO CD co CD CO 25. o f t h e l e a f a r e a s . H o w e v e r t h e o r d e r c h a n g e s a t t h e 5-week s t a g e a n d a g a i n a t t h e 7 -week s t a g e . T h u s a l t h o u g h s t o f e k ' s b i l l h a s t h e a b i l i t y t o p r o d u c e t h e g r e a t e s t i n i t i a l i . e . 3 -week l e a f a r e a o f t h e 13 s p e c i e s , i t i s r e l e g a t e d t o 4 t h p o s i t i o n w h e n m e a s u r e d a f t e r s e v e n w e e k s . C a t ' s e a r i s t h e o n l y p e r e n n i a l t o a p p e a r i n t h e f i r s t f i v e s p e c i e s - t h e o t h e r t h r e e p e r e n n i a l s a r e i n t h e t h r e e l o w e s t p o s i t i o n s . M o u s e e a r c h i c k w e e d i s t h e s l o w e s t s t a r t e r (0-5 w e e k s ) o f t h e w e e d s m e a s u r e d . I t a l s o s h o w s t h e l o w e s t r o o t m a s s ( A p p e n d i x t a b l e 4) a t f i v e w e e k s o f a g e . T h e f i r s t f i v e s p e c i e s a t f i v e w e e k s i n t h e o r d e r o f t h e i r r o o t d e v e l o p m e n t w e r e : A n n u a l sow t h i s t l e , h e d g e m u s t a r d , n a r r o w l e a v e d p l a n t a i n , common c h i c k w e e d a n d s t o r k ' s b i l l . T h e i r s u b s t a n t i a l l e a f a r e a s a t f i v e w e e k s a n d t h e s u b s e q u e n t l e a f g r o w t h o f g r o u n d s e l a n d s h e p h e r d ' s p u r s e m i g h t h a v e b e e n a c c o m p a n i e d b y e x t e n s i v e r o o t g r o w t h i n t h e s e t w o s p e c i e s . H o w e v e r t h i s i s n o t t h e c a s e . T h e i r r o o t m a s s e s a r e w e l l b e l o w t h o s e o f t h e f i v e s p e c i e s m e n -t i o n e d . I t w o u l d seem t h a t t h e r e i s v e r y l i t t l e c o r r e l a t i o n b e t w e e n r o o t m a s s a n d l e a f a r e a w h e n f i g u r e 1 a n d a p p e n d i x t a b l e 4 a r e c o m p a r e d . D e a d n e t t l e i s t h e f i r s t w e e d t o show d i f f e r e n -t i a t i o n i n t o more t h a n one s t e m . T h i s h a s o c c u r r e d b y t h e t h r e e w e e k s t a g e . F o u r o t h e r s p e c i e s h a v e b e g u n t o d i f f e r -e n t i a t e b y s e v e n w e e k s a n d common c h i c k w e e d a v e r a g e s 35 26. s t e m s b y t h i s t i m e ( a p p e n d i x t a b l e 5)• I t i s i n t e r e s t i n g t o c o m p a r e t h e t i m e s w h e n g r e a t e s t s t e m d e v e l o p m e n t o c c u r s i n t h e v a r i o u s s p e c i e s . Where s t o r k ' s b i l l h a s i n c r e a s e d o n l y f r o m 28 c m s . t o 32 c m s . i n s t e m l e n g t h b e t w e e n t h e 5th a n d 7th w e e k s , o t h e r s p e c i e s h a v e i n c r e a s e d b y s e v e r a l t i m e s t h e i r l e n g t h s a t f i v e w e e k s , e . g . c o r n s p u r r y o v e r t h r e e t i m e s , a n n u a l sow t h i s t l e o v e r f i v e t i m e s , common c h i c k w e e d o v e r f o u r t i m e s a n d t h e t w o p l a n t a i n s o v e r t h r e e t i m e s . T h e s e d i f f e r e n c e s i n g r o w t h h a b i t s h o u l d h a v e a n i m p o r t a n t b e a r i n g o n t h e c o m p e t i t i v e a b i l i t y o f t h e s p e c i e s s t u d i e d . M o r e o v e r t h e t i m i n g o f t h e m a j o r c o m p e t i t i v e e f f e c t s e x e r t e d b y t h e d e s i r e d t u r f g r a s s c o u l d be c r i t i c a l . Common c h i c k w e e d p r o d u c e d f l o w e r s a n d s e e d f o r m o s t o f t h e y e a r , b e g i n n i n g g r o w t h d u r i n g S e p t e m b e r a n d d e v e l o p i n g s u f f i c i e n t l y t o p r o d u c e s e e d mn O c t o b e r . O n l y d u r i n g J u l y a n d A u g u s t w h e n t e m p e r a t u r e s w e r e h i g h a n d m o i s t u r e ( p r e c i p i t a t i o n ) w a s l o w , w a s t h i s w e e d i n a c t i v e . ( F i g u r e 2, A p p e n d i x t a b l e 6). Common c h i c k w e e d p r o d u c e d s e e d s o v e r a l o n g e r t i m e t h a n a n y o t h e r w e e d f o r w h i c h r e c o r d s w e r e t a k e n . S h e e p s o r r e l a p p e a r s t o h a v e a l o n g e r s e e d i n g p e r i o d i n F i g u r e 3 b u t t h e s e e d s o f t h i s w e e d t a k e much more t i m e t o m a t u r e t h a n do t h o s e o f common c h i c k w e e d a n d v e r y f e w s e e d s a r e p r o d u c e d n e a r t h e b e g i n n i n g o f t h e s e e d m a t u r i n g p e r i o d . N a r r o w a n d b r o a d l e a v e d p l a n t a i n a r e s i m i l a r i n t h i s r e s p e c t . •• 26 ( ezzzza ezza zzzzzz J F M A M J J A S O N D J F M A M J >•••••" vegetative 70r 60 50' c 30 20 l i t t l e growth Broad leafed plantain Cat's ear Black medic, "clovers Common chickweed Dandelion B i t t e r cress Corn spurry Cudweed F a l l dandelion Grasses (annual) Knotweed Lamb's quarters .Mouse ear chickweed Narrow leafed plantain Pineapple weed Purslane Sheep sorrel Shepherd's purse Smartweed Speedwell Yellow rocket seeding / \ / ... X x <A A / N I J n il i i il J J n M I) J N A ii 10 5-1 3 2" it 1 1 • < H precipitation ndn. temps. max. temps. Figure 2 Weed growth and weather conditions, 1962-1963. 2 7 . S e v e r a l s p e c i e s p r o d u c e s e e d s a t t w o d i f f e r e n t p e r i o d s d u r i n g t h e y e a r - i n s p r i n g a n d f a l l . T h e s e i n -c l u d e d a n d e l i o n , c o r n s p u r r y a n d g r o u n d s e l . C o r n s p u r r y a c t u a l l y h a s t w o g e n e r a t i o n s i n a y e a r . B i t t e r c r e s s a p p e a r s t o be a v e r y e a r l y a n n u a l i n t h i s c l i m a t e . O n l y c h i c k w e e d , w h i c h i s a w i n t e r a n n u a l , p r o d u c e d s e e d a s e a r l y i n t h e s p r i n g . O f t h e s p e c i e s s t u d i e d a l l b u t t h r e e w e r e i n t h e s e e d p r o d u c i n g s t a g e i n t h e m o n t h o f J u l y . I n t h i s c l i m a t e J u l y p r o d u c e s t h e h i g h e s t a v e r a g e t e m p e r a -t u r e s a n d t h e l o w e s t p r e c i p i t a t i o n when l o n g t e r m a v e r a g e s a r e c o n s i d e r e d . C o n v e r s e l y o n l y one w e e d , c h i c k w e e d , w a s p r o d u c i n g s e e d d u r i n g D e c e m b e r a n d J a n u a r y w h e n a v e r a g e t e m p e r a t u r e s a r e l o w e s t a n d p r e c i p i t a t i o n h i g h e s t . L i t t l e i n f o r m a t i o n i s a v a i l a b l e o n t h e p h o t o -p e r i o d i c r e s p o n s e o f t h e w e e d s p e c i e s o b s e r v e d i n t h i s s t u d y . O n l y d a n d e l i o n a n d common c h i c k w e e d , w h i c h a r e r e p o r t e d t o be i n d e t e r m i n a t e i n t h e i r r e s p o n s e t o d a y l e n g t h a n d n a r r o w l e a v e d p l a n t a i n w h i c h i s a l o n g d a y p l a n t , a p p e a r i n t h e l i t e r a t u r e ( 1 2 ) . The o c c u r r e n c e a n d d i s t r i b u t i o n o f w e e d s i n t u r f r e s u l t f r o m a c o m p l e x i n t e r a c t i o n o f many f a c t o r s . I t w a s n o t e d f o r e x a m p l e t h a t t h e m i x t u r e o f g r a s s e s u s e d i n a p a r t i c u l a r a r e a a n d f o r a p a r t i c u l a r p u r p o s e seemed t o h a v e i t s a s s o c i a t e d w e e d s . W h e r e t h e f i n e -t e x t u r e d , l e s s r o b u s t H i g h l a n d b e n t a n d M a r i o n b l u e g r a s s w e r e s e e d e d , s o i l s h a d t o be m a i n t a i n e d i n a h i g h l y 28. f e r t i l e and moist condition. These conditions in turn seemed to attract the wet-tolerant, large-rooted weed species such as broad leaved plantain, dandelion, the clovers, creeping buttercup, and dead nettle. Fescures, which tolerate poorer so i l conditions, drought and mechanical injury to a greater extent than do the bents and bluegrasses seemed to share the ground with smartweed, lamb's quarters, cat's ear, bitter cress, and speedwell. Sandy or open textured so i l s , i . e . those near concrete walks usually featured cudweed, pineapple weed, purslane, groundsel, yellow rocket, sandwort and sheep sorre l . However many species had a broader adaptation and appeared generally throughout the area under observation. These included shepherd's purse, groundsel cat's ear, narrow leaved plantain, stork's b i l l , black medic, common chickweed, mouse ear chickweed and annual blue grass. Poorer so i l conditions and grass competition reduced the size of the weed and shortened i t s l i f e cycle. The nature of the competition offered by the grass i s indicated in Table 5. Top growth, root size and seed numbers are a l l reduced but some of our worst pests are affected the least e.g. dandelion, and cat's ear. A direct comparison of the data contained in Table 5 i s not possible of course because of the differences in the growing condi-tions represented, but the evident ab i l i ty of some species to do well in competition with grass i s of some interest. 2 9 . TABLE 5 The e f f e c t of grass competition and environment on the growth of 1 3 mature weed sp e c i e s . Weeds i n grass (3 p l a n t averages) Weeds i n greenhouse (3 p l a n t averages) Top (cms.) Root (cms.) Wo. seeds Top (cms.) Root (:cms.) No. seeds Hedge Mustard 48 2 5 548 1 4 5 80 19,440 Dandelion K 2 6 2 7 1050 2 5 2 4 2,040 C a t 1 s ear K 18 2 3 6 4 0 2 3 28 1,230 Dead n e t t l e 20 15 893 5 1 3 2 2 , 9 2 5 Broad leqved 3 5 p l a n t a i n 1 4 11 6 0 3 22 2 5 1,000 Narrow leaved 3 5 p l a n t a i n 2 3 : 2 5 1 , 4 5 0 35 3 0 1,750 Annual sow t h i s t l e 83 3 0 1 , 4 4 0 138 6 0 2,000 Groundsel 3 2 28 5 6 8 45 3 0 11,680 Y e l l o w rocket 6 2 48 4 2 3 85 51 6,000 Stork's b i l l * 40 ' 3 2 2 1 5 54 45 3 0 0 Common chickweed 3 4 21 12 780 48 3 2 1 7 , 9 7 6 Mouse ear chickweed 3 6 1 3 10 5,793 45 33 23,380 Shepherd's purse 45 28 1,704 <75 3 0 10,950 x weeds growing i n mowed t u r f . Others were i n unmowed grassed areas. Y Because t h e d a n d e l i o n i s such a common lawn weed, and because o f i t s a p p a r e n t l y a p o m i c t i c seed p r o d u c t i o n (19) i t was d e c i d e d t o check t h e seed set and g e r m i n a t i o n under t h r e e c o n d i t i o n s . TABLE 6 D a n d e l i o n seeds p e r head produced by d i f f e r e n t t r e a t m e n t s R e p l i c a t i o n s Average F v a l u e C o n t r o l - no t r e a t m e n t 102 L06 114 116 . .22 112 0.267 N.S. Hand p o l l i n c a t e d , bagged 102 106 117 126 L32 117 3agged a t bud stage 90 100 113 119 120 108 TABLE 7 P e r c e n t a g e g e r m i n a t i o n o f d a n d e l i o n seeds f o l l o w i n g d i f f e r e n t t r e a t m e n t s R e p l i c a t i o n s j ,verage F v a l u e C o n t r o l - no t r e a t m e n t 50 30 44 28 43 40 4.67 (.05x s i g . ) Hand p o l l i n a t e d , bagged 54 62 5^ 50 66 53 Bagged a t bud stage 26 30 32 22 30 23 31. Seed formation in the dandelion inflorescence usually requires one to two weeks after the development of the bud stage. This period varies with temperature, l ight and moisture conditions. The use of plast ic bags to isolate the flower head raises the moisture content of the surrounding a i r , often delaying seed formation unt i l two weeks haveeelapsed even when days are relatively sunny and warm. It i s apparent from tables 6 and 7 that although there was no difference in the seed set by the various treatments, the flowers which were denied pol l ination had a significantly lower production of seed which would germin-ate. However even a 28% germination w i l l allow a substan-t i a l increase in an infestation and th is germination i s possible, under conditions of this t r i a l , in the complete absence of pol l inating insects. The f i r s t attempts to determine the nature of inhibitory effects of weeds on associated grass species involved the possible exudates from the roots of fourteen weed species. Appendix tablw 7 shows the results of germinating seeds of two grass varieties on surfaces recently occupied by roots, of weeds. Any reduction observed in the germination rates appeared to be a result only of contamin-ation by fungi (Ascomycetes). As no gross toxic effect on seed germination could be observed, i t was decided to abandon this approach. 3 2 . T & b l e S s h o w s t h e r e s u l t s o f t e s t s i n w h i c h h i g h -l a n d b e n t g r a s s s e e d w a s g e r m i n a t e d i n t h e p r e s e n t o f v a r i -o u s e c o n c e n t r a t i o n s o f t h e l e a f e x t r a c t s o f 1/+ w e e d s . The 10% a n d t h e 5% c o n c e n t r a t i o n s o f a q u e o u s ' w e e d e x t r a c t s i n h i b i t e d t h e g r a s s s e e d g e r m i n a t i o n i n m o s t c a s e s . T h e r e w a s a l s o a d e l a y i n g e r m i n a t i o n a p p a r e n t i n many i n s t a n c e s . T h i s d e l a y c o u l d be c r i t i c a l i n t h e e s t a b l i s h m e n t o f new s e e d l i n g s i f t h e s o i l w a s c o n t a m i n a t e d b y s i m i l a r i n h i b i t o r y m a t e r i a l s . S t o r k ' s b i l l g a v e some i n d i c a t i o n o f s t i m u l a t o r y a c t i o n , w h i c h g e r m i n a t i o n o f t e n e x c e e d i n g t h e c o n t r o l s b u t t h i s o b s e r v a t i o n w a s n o t p u r s u e d f u r t h e r . A s a r e s u l t o f t h e d a t a o f T a b l e S , 6 s p e c i e s w e r e s e l e c t e d f o r f u r t h e r t e s t i n g . S h o o t l e n g t h w a s m e a s u r e d i n a d d i t i o n t o g e r m i n -a t i o n . T h e s e r e s u l t s a r e g i v e n i n F i g u r e 3 a n d A p p e n d i x t a b l e s 9 a , 9b a n d 9 c . A n i n h i b i t i v e e f f e c t w a s o b s e r v e d w i t h t h e e x t r a c t s o f p i n e a p p l e w e e d a n d n a r r o w l e a v e d p l a n t a i n a t 10%, 5% a n d 2.5%; w i t h t h e e x t r a c t s o f common c h i c k w e e d a t 10% a n d 5% a n d w i t h t h e e x t r a c t o f c a t ' s e a r a t 10% o n l y . I n a l l t h e s e c a s e s b o t h t h e g e r m i n a t i o n r a t e a n d t h e a v e r a g e l e n g t h o f t h e s e e d l i n g s h o o t s w e r e a f f e c t e d . D a t a f r o m t h e l a s t t r i a l i n t h i s s e r i e s a r e i l l u s t r a t e d i n F i g u r e 4« M a r k e d i n h i b i t i o n r e s u l t i n g i n a n a v e r a g e g e r m i n -a t i o n o f o n l y 2% p e r s i s t e d f o r 19 d a y s i n t h e d i s h e s c o n t a i n -i n g p i n e a p p l e w e e d l e a f p o w d e r w h e r e a s t h e c o n t r o l s h a d r e a c h e d .an a v e r a g e g e r m i n a t i o n o f 60% w i t h i n t h e f i r s t w e e k . 8 12 DATS 16 21 8 12 16 DATS 21 8 12 16 DATS 21 -* Cat's ear -. Q o m m o n chickweed Dandelion Narrow — • — •'- leaf plantain —" —*- Pineapple weed —*—*~ Control Groundsel Figure 3 Growth inhibition of bent grass caused by 3 concentrations of the leaf powder of various weeds. to. 32 (b) 70 601-50 c o 3 40 3 o3 30 W) 20 10 .control •h . l . plantain ^^c. chickweed pineapple weed .10 13 16 days 19 22 Figure 4 The germination of bent grass in sand as influenced by 1.7$ concentrations of the dried leaf powder-of 3 weeds. 3 3 . T A B L E 3 P e r c e n t a g e g e r m i n a t i o n o f h i g h l a n d b e n t i n f o u r c o n c e n t r a t i o n s o f l e a f e x t r a c t . CONCENTRATION Weed S p e c i e s 2 4 7 14 2 4 % 7 14 2 2 4 •P/o 7 14 2 4 1.2% 7 14 B r o a d l e a v e d p l a n t a i n 0 0 15 25 0 15 20 45 0 30 35 50 15 20 60 70 C a t ' s e a r 0 0 10 30 0 5 30 35 20 30 40 40 25 55 65 65 Common c h i c k w e e d 0 0 0 0 0 0 0 0 0 5 10 20 10 30 60 60 D a n d e l i o n 0 0 0 5 0 15 35 45 20 40 45 45 25 45 65 65 D e a d n e t t l e 0 5 5 15 0 20 25 30 10 35 40 55 15 35 60 60 S t o r k ' s b i l l 0 0 50 55 15 35 65 75 25 40 75 35 25 45 35 95 G r o u n d s e l 0 0 5 5 0 20 25 30 10 35 40 40 15 35 60 60 Hedge M u s t a r d 0 5 5 45 0 15 30 50 0 15 55 60 25 45 55 SO M o u s e e a r c h i c k w e e d 0 15 30 45 0 15 50 50 20 25 50 55 25 45 70 70 N a r r o w l e a v e d p l a n t a i n 0 0 0 5 0 10 30 40 0 20 40 45 10 35 40 50 P i n e a p p l e weed 0 0 0 0 0 0 0 0 0 5 10 10 15 20 50 65 S h e e p s o r r e l 0 0 0 2.5 0 0 5 40 0 15 50 50 5 40 65 35 S h e p h e r d ' s p u r s e 0 10 30 40 0 10 35 50 5 25 45 70 40 45 50 75 Y e l l o w r o c k e t 0 0 10 25 10 30 30 30 20 35 45 50 20 50 60 60 C o n t r o l ( d i s t i l l e d w a t e r ) 10 40 55 55 10 40 55 55 10 40 55 55 10 40 55 55 34. S i m i l a r r e d u c t i o n s and d e l a y s i n g e r m i n a t i o n o c c u r r e d w i t h the o t h e r two s p e c i e s a l t h o u g h e f f e c t s a r e not as marked. The greenhouse bench t r i a l s were d i s a p p o i n t i n g because of the r e l a t i v e l y poor c o m p e t i t i o n o f f e r e d by the g e r m i n a t i n g weed seeds, 5 0 o f w h i c h were p l a c e d i n each square f o o t p l o t . Thus the a n a l y s i s o f v a r i a n c e (Appendix t a b l e 1 1 ) shows no s i g n i f i c a n c e i n d r y w e i g h t y i e l d s as a r e s u l t o f the p r e s e n c e o f weeds a t e i t h e r h a r v e s t . S e e d i n g r a t e s on t h e o t h e r hand were h i g h l y s i g n i f i c a n t a t b o t h h a r v e s t s a l t h o u g h t h e d i f f e r e n c e s appear t o be d e c r e a s i n g as time e l a p s e d . The t i l l e r i n g of t h e more s p a r s e l y seeded g r a s s would undoubtedly be a f a c t o r i n i m p r o v i n g the d r y w e i g h t y i e l d s as time went on. However t h e s e d a t a do reemphasize th e need f o r s e e d i n g r a t e s h i g h enough t o g i v e u n i f o r m e a r l y s t a n d s of g r a s s . Thus h i g h e r r a t e s o f seed a r e needed t h a n would be the case i f a weed-free seed bed were a v a i l a b l e . S i m i l a r l y the presence o f i n h i b i t o r y l e a f m a t e r i a l would a l s o suggest the need f o r h i g h s e e d i n g r a t e s as was i n d i c a t e d i n the p r e v i o u s t r i a l s . C o n t r o l S t u d i e s I n t h e c h e m i c a l c o n t r o l o f l a w n w e e d s i t i s d e s i r -a b l e t o k i l l w e e d s w i t h o u t d o i n g i n j u r y t o t h e g r a s s . To: ; a c h i e v e t h i s r e s u l t i t i s n e c e s s a r y t o h a v e t h e r i g h t c h e m i c a l f o r t h e w e e d ( s ) a n d t h e g r a s s s p e c i e s a n d a p p l y i t a t t h e r i g h t t i m e . L a w n g r a s s e s s h o u l d n o r m a l l y be w e l l e s t a b -l i s h e d b e f o r e s r a y i n g i s d o n e . H o w e v e r , w e e d s a r e m o s t s u s c e p t i b l e w h e n t h e y a r e s m a l l - p r e f e r a b l y i n t h e s e e d l i n g s t a g e . I n p r a c t i c e t h e n i t i s d i f f i c u l t t o a c h i e v e a c o n d i -t i o n when g r a s s i s a t i t s m o s t r e s i s t a n t s t a g e a n d t h e w e e d s a t t h e i r m o s t s u s c e p t i b l e . One i m p o r t a n t i n i t i a l p r o c e d u r e i s t o p r o p e r l y i d e n t i f y t h e w e e d s p e c i e s p r e s e n t . S u s c e p t i -b i l i t y t a b l e s h a v e b e e n e s t a b l i s h e d f o r m o s t c h e m i c a l s i n common u s e a n d t h e p r o b a b i l i t y o f c o n t r o l c a n u s u a l l y be e s t i m a t e d . T h e s e r i e s o f p h o t o g r a p h s i n t h e A p p e n d i x i l l u s -t r a t e s t h e s e e d l i n g a p p e a r a n c e o f 1 3 w e e d s p e c i e s u n t i l t h e y a r e f i v e t o s e v e n w e e k s o f a g e . TABLE 9 Tolerance of four turf grasses to varying rates of NPH/112 (38) (Figures represent percentages of the controls with regrowth figures following the "&" signs) jz/lOOO 3q. f t . Highland t 1" ent 2" Creeping re 1" d fescue 2" Chewings 1" Fescue . 2" Merion bli 1" ie 0.5 90 115 113 105 1.0 92 102 86 94 2.0 68 & 150 150 & 134 93 & 119 85 & 104 4.0 67 & 208 122 & 123 76 & 58 47 & 88 8.0 15 & 52 69 & 60 77 & 115 77 & 109 95 & 71 60 & 104 43 & 67 47 & 100 1 6 . 0 8 & 60 57 & 52 72 & 83 73 & 100 73 & 38 50 & 28 13 & 33 38 & 86 3 7 . The r e s u l t s above i n d i c a t e t h a t c r e e p i n g r e d f e s c u e i s the most t o l e r a n t o f the f o u r s p e c i e s sprayed w i t h N P H / 1 1 2 , showing good response t o t r e a t m e n t e x c e p t when the heavy r a t e was a p p l i e d t o the 1 M growth. High-l a n d bent a p p e a r s t o be t h e most s e n s i t i v e w i t h M e r i o n b l u e s l i g h t l y more t o l e r a n t , and chewings f e s c u e next t o c r e e p i n g r e d f e s c u e i n i t s a b i l i t y t o t o l e r a t e the > c h e m i c a l . Three s p e c i e s showed a b i l i t y t o r e c o v e r f r o m i n i t i a l i n j u r y when sprayed a t the 2 " stage w i t h 8 o z / 1 0 0 0 s q . f t . , t h e e x c e p t i o n b e i n g H i g h l a n d b e n t . From th e d a t a o f T a b l e 1 0 , c r e e p i n g r e d f e s c u e and chewings f e s c u e appear t o t o l e r a t e t h e c h e m i c a l b e t t e r t h a n do H i g h l a n d bentaand M e r i o n b l u e g r a s s a l t h o u g h t h e two l a t t e r g r a s s e s show good r e c o v e r y a f t e r t h e f i r s t c u t t i n g . Under c o n d i t i o n s o f t h i s experiment a l l f o u r showed i n j u r y f r o m w h i c h t h e y d i d not r e c o v e r when t r e a t e d w i t h e i g h t and 1 6 o z . of S u p e r t o x a t t h e one i n c h stage o f g r o w t h . I n t h e second s e r i e s ( 2 " ) l e s s damage was caused i n each s p e c i e s when the g r a s s e s were t r e a t e d w i t h 8 and 1 6 o z . However some i n j u r y f o l l o w e d each t r e a t m e n t and r e g r o w t h g e n e r a l l y showed an i n c r e a s e a t t h e l i g h t e r r a t e . Of the f o u r s p e c i e s t e s t e d c r e e p i n g r e d f e s c u e appeared t o be the most t o l e r a n t and m e r i o n b l u e t h e most s u s c e p t i b l e t o S u p e r t o x . N P H / 1 1 2 and S u p e r t o x are two f o r m u l a t i o n s d e v e l -oped by t h e May and Baker Co. i n E n g l a n d . S u p e r t o x i s a l r e a d y on t h e market i n Great B r i t a i n w h i l e N P H / 1 1 2 i s be-Tolerance of four t u r f grasses to varying rates of Supertox ( 3 $ ) . (Figures represent percentages of the controls, regrowth figures following the "&" signs.) os./lOOO Sq. f t . Highland 1" bent 2 " Creeping re 1" 1 fescue 2 " Chewings 1" fescue 2 " Merion blu 1" e 2 " . 0 , 5 9 3 1 2 0 95 108 1 . 0 8 8 105 8 8 6 3 2 . 0 53 & 2 9 0 1 3 3 & 1 6 2 81 & 98 79 & 1 3 0 . 4 . 0 39 & 1 1 1 0 3 & 1 1 4 7 9 & 8 5 4 2 & 1 2 7 8 . 0 2 3 & 6 9 7 5 & 41 3 6 & 6 3 7 7 & 7 7 59 & 58 7 0 & 59 9 & 2 9 42 & 47 1 6 . 0 7 & 45 6 9 & 4 5 3 1 & 3 2 4 4 & 3 7 4 4 & 47 6 0 & 3 8 4 & 1 3 2 7 & 3 2 i n g t e s t e d b o t h i n E n g l a n d a n d i n C a n a d a . B o t h f o r m u l a -t i o n s c o n t a i n t w o h e r b i c i d e s - S u p e r t o x a 2 : 1 r a t i o o f 2 - ( M C P P ) a n d 2 , 4 - D , a n d N P H / 1 1 2 a 4 : 1 r a t i o . E a c h i s r e c o m m e n d e d f o r u s e a t e i g h t l i q u i d o z / 1 2 0 s q . y d s . T h u s t h e 8 o z . r a t e u s e d i n t h i s t r i a l comes c l o s e t o t h e a m o u n t u s e d i n n o r m a l p r a c t i c e . Y o u n g g r a s s i s much more s e n s i t i v e t h a n o l d e r s t a n d s . T h i s i s b r o u g h t o u t i n t h e d a t a w h i c h show a l a c k o f r e c o v e r y i n t h e more s e n s i t i v e s p e c i e s a t t h e 4 o z . r a t e . A l t h o u g h no s t a t i s t i c a l a n a l y s e s w e r e made i t a p p e a r s u n l i k e l y t h a t s i g n i f i c a n t d i f f e r e n c e s b e t w e e n t h e i n j u r y t o t h e g r a s s e s c a u s e d by t h e t w o c h e m i c a l s w o u l d a p p e a r . P e r h a p s a r e f i n e d t e c h n i q u e w o u l d show d i f f e r e n c e s a t t r i b u t a b l e t o t h e p r o p o r t i o n s o f 2 - ( M C P P ) a n d 2 , 4 - D i n e a c h p r o d u c t b u t t h e v a l u e o f t h e t w o a t t h e r e c o m m e n d e d r a t e s w o u l d seem t o b e l i n k e d more c l o s e l y t o t h e n a t u r e o f t h e w e e d s p e c i e s p r e s e n t a n d t h e i r s u s c e p t i b i l i t y t o e i t h e r 2 - ( M C P P ) o r 2 , 4 - D . I n t h e r e s u l t s w h i c h a r e r e c o r d e d i n t a b l e s 1 1 a n d 1 2 , 2 , 4 - D c a n be c o n s i d e r e d a s t h e s t a n d a r d t r e a t m e n t a g a i n s t w h i c h t h e o t h e r s c a n be m e a s u r e d . When c o n t r o l o f t h e t h r e e c a t e g o r i e s o f w e e d s a n d damage t o t h e t u r f g r a s s a t t h e m a t u r e a n d s e e d l i n g s t a g e s a r e t a k e n i n t o a c c o u n t , i t i s r e m a r k a b l e how f e w o f t h e t r e a t m e n t s w e r e s u p e r i o r t o 2 , 4 - D . O n l y t h r e e c h e m i c a l s , a l l o f w h i c h a r e m i x t u r e s a n d a l l c o n t a i n i n g some 2 , 4 - D , c o u l d be c o n -s i d e r e d a s i m p r o v e m e n t s . T h e s e w e r e S u p e r t o x , N P H / 1 1 2 a n d K i l l e x . A l l t h e o t h e r m a t e r i a l s seem t o h a v e w e a k -40. TABLE 11 Herbicidal effects on weeds and grass in a mature bent-blue grass turf 1962, two months after treatment Rates per acre Percenta Narrow leaved plantain ge of weed c Cat's ear ;ontrol Black medic & clovers Grass injury 2,4-D 16 oz. 60 67 62 8 2,4,5-T 16 oz. 43 67 100 1 2-(MCPP) 16 oz. 100 50 100 15 " 32 oz. 100 0 100 18 Silvex 16 oz. 50 50 100 8 " 32 oz. 50 100 100 18 Killex 1 f l . oz. per 1000 f t . 2 50 50 100 0 Killex 2 f l . oz. : per 1000 ft.2 : 100 100 55 10 Supertox 8 f l . oz.' per 1000 f t . 2 100 : 100 66 0 Supertox 16 f l . oz. per 1000 f t . 2 ' 100 75 83 10 Banvel D 16 oz. 50 100 62 8 Banvel D 32 oz. 67 100 50 12 NPH/112 8 f l . oz. per 1000 f t . 86 75 55 0 NPH/112 16 f l . oz. per 1000 f t . 2 100 75 66 10 Control 0 0 12 0 a . TABLE 12 Weed c o n t r o l and grass i n j u r y r e s u l t i n g from h e r b i c i d a l a p p l i c a t i o n s t o a fescue-bent e s t a b l i s h i n g t u r f 19&3 % of weed c o n t r o l Chemicals & rat e s / a c r e Narrow leaved p l a n t a i n ( a f t e r 3 mos.) C a t 1 s ear ( a f t e r 3 mos.) Black medic # .& cl o v e r s ( a f t e r 1 mo.) Grass i n j u r y ( a f t e r 3 mos,) 1, MCPA - 16 oz. 0 0 8 16 2, 2, 4-D - 16 oz. 40 33 40 6 3. 2,4,5-T - 16 oz. 0 25 62 6 4. 2(MCPP) - 16 oz. 55 0 44 16 5. S i l v e x - 16 oz. 0 0 71 6 6. K i l l e x - 32 oz. 56 33 66 0 7. Banvel D - 32 oz. 40 40 90 16 8. Supertox - 645 f l . oz. 75 75 91 0 9. NPH/112 - 645 f l . oz. 67 0 100 3 10, Banvel D - 16 oz. & 2,4-D - 6 oz. 23 66 100 19 11, Tordon - 8 oz. 2(MCPP) - 16 oz. 55 0 70 13 12. Tordon - 8 oz. 2(MCPP) -.16 oz. Banvel D - 8 oz. 50 0 77 8 13, Tordon - 4 oz. 0 0 41 9 14. Tordon - 8 oz. 23 20 91 17 15. C o n t r o l 0 0 0 0 # Assessed at one month as n a t u r a l senescence and dying has occurred by three months. 4 2 . n e s s e s . F o r i n d i v i d u a l w e e d s , h o w e v e r , a d d i t i o n a l c h e m i c a l s g a v e g o o d c o n t r o l , e . g . 2 - ( M C P P ) w a s v e r y g o o d f o r n a r r o w l e a v e d p l a n t a i n , s i l v e s f o r c a t ' s e a r a n d 2 , 4 , 5 - T , 2 - ( M C P P ) a n d s i l v e s f o r b l a c k m e d i c a n d t h e c l o v e r s . I n g e n e r a l , i n t h e 1962 t r i a l s , t h e h i g h e r r a t e o f t h e c h e m i c a l i n c r e a s e d t h e w e e d c o n t r o l a n d a l s o i n c r e a s e d t h e i n j u r y t o t h e g r a s s . I n t w o c a s e s h o w e v e r 2 - ( M C P P ) a n d S u p e r t o x , i n c r e a s i n g t h e r a t e r e d u c e d t h e c o n t r o l o f c a t ' s e a r . T h i s may h a v e b e e n t h e r e s u l t o f e x p e r i m e n t a l e r r o r b u t i s t h o u g h t t h a t i t i s more l i k e l y t h e r e s u l t o f t h e a p p l i c a t i o n o f a s o l u t i o n w h i c h w a s t o o s t r o n g f o r e f f i c i e n t t r a n s l o c a t i o n t o o c c u r i n t h i s p a r t i c u l a r w e e d . T h u s a n i n i t i a l b u r n w a s o b s e r v e d b u t a f t e r t w o m o n t h s t h e r e s u l t s o f t h e t r e a t m e n t i n d i c a t e d t h a t i n s e v e r a l i n s t a n c e s a n i n s u f f i c i e n t amoun t o f t h e c h e m i c a l h a d become s y s t e m i c w i t h i n t h e p l a n t a n d t h e e x p e c t e d d e a t h o f t h e s e i n d i v i d u a l s h a d n o t d e v e l o p e d . The s l i g h t l y h i g h e r g r a s s i n j u r y a p p a r e n t i n 1963 w h e n e q u i v a l e n t r a t e s o f t h e c h e m i c a l s a r e c o m p a r e d t o t h o s e u s e d i n 1962, i s no d o u b t a n e x p r e s s i o n o f t h e more s e n s i -t i v e c o n d i t i o n o f y o u n g e s t a b l i s h i n g t u r f c o m p a r e d t o a m a t u r e s t a n d . A l s o t h e t r i a l a r e a f o r 1963 i n c l u d e d 30% b e n t g r a s s w h i c h i s more s e n s i t i v e t o h e r b i c i d e s t h a t i s a n n u a l b l u e , K e n t u c k y b l u e a n d c r e e p i n g r e d f e s c u e w h i c h c h a r a c t e r i z e d t h e 1962 t r i a l a r e a . CONCLUSION 43-A study of the weeds common to turf in the Vancouver area confirms the high seed production rates reported in the l i t erature . The largest number of seeds produced in a season was found in corn spurry (25$,706), with the average of 18 species being in excess of 52,800 seeds. The mild climate of the coastal region i s undoubt-edly a factor in determining the number and production periods of weed seeds. It i s believed also that the systematic harvesting of the matured seeds may have caused some plants to produce more seeds than they might other-wise have done. The presence of flowers over a long period of time does not necessarily indicate that mature seed i s being produced during the fru i t ing period. Several species, although exhibiting an extended flowering period during whc which new flowers continued to appear, did not develop ripe seed u n t i l near the end of the season. Those plants which were allowed to set seed under greenhouse conditions reflected the more favourable environment by producing seeds in a much shorter time after flowering. A contributing factor to the re lat ive ly few seeds produced by most species during the early col lection periods was the lower number of seeds developed by each fru i t ing unit . 44 • S t o r k ' s b i l l s h o w e d no s e e d g e r m i n a t i o n t w o m o n t h s a f t e r t h e s e e d w a s h a r v e s t e d w h i l e S h e p h e r d ' s p u r s e h a d 0.6% g e r m i n a t i o n o n l y . O t h e r s p e c i e s g e r m i n a t e d f r o m 4.6% t o 90.6% i n t h e t w o m o n t h p e r i o d . No s p e c i a l t r e a t -ment w a s g i v e n t h e s e s e e d s o t h e r t h a n t o k e e p t h e m i n d r y s t o r a g e . W i t h 14 s p e c i e s i n v o l v e d i n t h i s t e s t one c a n o n l y c o n c l u d e t h a t t h e a b i l i t y t o g e r m i n a t e r e a d i l y i s i n h e r e n t i n m o s t o f t h e s e p l a n t s . E l e v e n w e e d s s p e c i e s a c t u a l l y g e r m i n a t e d w i t h a week o f h a r v e s t . No p a t t e r n w h i c h w o u l d i n d i c a t e a c o r r e l a t i o n b e t w e e n l e a f a r e a a n d r o o t a n d s t e m g r o w t h seemed a p p a r e n t i n t h e s e e d l i n g w e e d s s t u d i e d . I f s u c h a c o r r e l a t i o n e x i s t s i t w o u l d a p p e a r t h a t r e f i n e d i n v e s t i g a t i o n s w o u l d h a v e t o be i n i t i a t e d . The c o m p e t i t i v e e f f e c t o f g r a s s o n t u r f w e e d s a p p e a r s t o b e l e a s t i n s i t u a t i o n s i n v o l v i n g many o f o u r w o r s t w e e d s . C a t ' s e a r , d a n d e l i o n , b r o a d a n d n a r r o w l e a v e d p l a n t a i n showed r e l a t i v e l y s m a l l r e d u c t i o n s i n t o p a n d r o o t d e v e l o p m e n t a n d i n t h e n u m b e r o f s e e d s p r o d u c e d w h e n g r o w i n g i n g r a s s a s c o m p a r e d t o g r o w i n g a l o n e . A n a d d i t i o n a l f a c t o r w h i c h u n d o u b t e d l y p l a y s a p a r t u n d e r scone t u r f t c o n -d i t i o n s i s t h e i n f l u e n c e o f t h e w e e d o n t h e g r a s s . The p r e s e n t s t u d i e s c o n f i r m e d r e p o r t s o n i n h i b i t i o n c a u s e d b y common c h i c k w e e d a n d member s o f t h e p i n e a p p l e w e e d g e n u s . S e v e r a l o t h e r s p e c i e s w e r e s h o w n t o be d e f i n i t e l y i n h i b i t o r y 45. t o g r a s s s e e d g e r m i n a t i o n a l s o . The s u p p r e s s i o n o f g r a s s g r o w t h w h i c h r e s u l t e d f r o m t h e u s e o f w a t e r e x t r a c t s o f l e a f a n d s t e m m a t e r i a l o n f i l t e r p a p e r , a n d f r o m p l a c i n g t h e a c t u a l d r i e d m a t e r i a l i n s a n d w a s s t r i k i n g a n d c o u l d be a f a c t o r o f i m p o r t a n c e i n s e e d i n g p r a c t i c e s . The t r i a l s i n v o l v i n g t h e x p e r i m e n t a l h e r b i c i d e m i x t u r e s NPH/112 a n d S u p e r t o x c o n f i r m e d o b s e r v a t i o n s by-r e s e a r c h w o r k e r s t h a t d i f f e r e n t t u r f g r a s s s p e c i e s vary-i n t h e a m o u n t o f c h e m i c a l t h e y c a n t o l e r a t e . The r e g r o w t h f i g u r e s h o w e v e r s u g g e s t t h a t t h e s e t b a c k i s o f t e n o n l y t e m p o r a r y a n d t h a t t h e w e e d c o n t r o l a c h i e v e d a t t h e e a r l y g r o w t h s t a g e o f t h e g r a s s e s m i g h t more t h a n c o m p e n s a t e f o r t h e i n i t i a l l o s s i n d r y w e i g h t s u f f e r e d b y t h e g r a s s . T h e s e t w o c o m p o u n d s w h i c h a r e m i x t u r e s o f t w o h o r m o n e t y p e h e r b i c i d e s , a n d K i l l e x w h i c h c o n t a i n s t h r e e h e r b i c i d e s , a p p e a r t o h a v e d e f i n i t e a d v a n t a g e s o v e r 2,4-D when one c o n s i d e r s t h e w e e d c o n t r o l a s p e c t s a n d t h e n e e d f o r a m i n i m u m o f g r a s s i n j u r y . T h u s t h e d e v e l o p m e n t o f p r o d u c t s c o n t a i n i n g a m i x t u r e o f h e r b i c i d e s w o u l d seem t o be a t r e n d w h i c h w i l l c o n t i n u e i n t h e f u t u r e . 46. BIBLIOGRAPHY 1. Andus, L. B. 1959* Plant growth substances, Leonard, Hillbooks Ltd. London, Chap. XV: 384-4040. 2 . Brenchley and Warrington 1930. The weed seed population of arable s o i l . I Numerical estimation of viable seeds and observations on t h e i r natural dormancy. Jour. E c o l . 18: 235-272. 3 . Chepil, W. S. 1946. Germination of weed seeds, longevity, p e r i o d i c i t y of germination and v i t a l i t y of seeds i n c u l t i v a t e d s o i l . S c i . Agr. V o l . 26: 239-346. 4 . Cornman, J . and Mower, R. G. 1953. Stubborn lawn weeds defeat,Farm Research 24: 3 , 3 . 5 . Corns, W. G. i 9 6 0 . E f f e c t of compitox on chickweed, Res. Rep. Nat 1 1 . Weed Comm. Wes. Sec. CD.A. Ottawa, Ontario.,- 82-83 PP-6. Crafts, A. S. and W. W, Robbins 1962. Weed control - A textbook .and manual, 3 r d . ed., McGraw H i l l P ublication i n the Agr. S c i . 660 pp. 7. Crocker, W. 1916. Mechanics of dormancy i n seeds. Am. Jour. Bot. ( 3 ) : 99-120. 8. Darrington, H. T. 1922. Dr. Beal's seed experiment i n Michigan. Am. Jour. Bot. 9 : 266-269. 9 . Daubenmire, R. F. 1947. Plant and environment. John Wiley and Sons. New York, Chapman and H a l l Ltd. London Chap. I: 1-2. 10 . E s c r i t t , J . R. 1953* Grass growth stunting with maleic hydrazide, Jour. Sports t u r f . Res. Inst. VIII 29: 269-273. 11 . Eivenari, M. 1949. Germination i n h i b i t o r s . Bot. Rev. 15: 153-194. 12. Ferry, J . F. and H. S. Ward 1959. Fundamentals of plant physiology. The MacMillan Company, New York 283 pp. 13 . Fisher, G. W. 1953• Smuts that p a r a s i t i z e grasses. U. S. D. A. yearbook, Plant Diseases (ed.) A l f r e d Stefferud. 280-284 pp. -47 14. G a l l a g h e r , J . E . a n d C . C . J a c k , 1953. Weed c o n t r o l i n t u r f , P r e c e e d i n g 12th N o r t h E a s t e r n Weed C o n t r o l C o n f e r e n c e 151-153 p p . 15. G a r b , S . 1961. D i f f e r e n t i a l g r o w t h i n h i b i t o r s p r o d u c e d b y p l a n t s . B o t . R e v . 27: 422-443. 16. G i l l , N . T . a n d K . C . V e a r 1953. A g r i c u l t u r a l B o t a n y . G e r a l d D u c k w o r t h a n d C o . L t d . L o n d o n . 367-500 p p . 17. G o e t z e , N . I960. Weed c o n t r o l i n t u r f . O r e g o n Weed C o n t r o l h a n d b o o k , F e d e r a l C o o p e r a t i v e E x t e n s i o n S e r v i c e . O r e g o n S t a t e C o l l e g e , C C o r v a l l i s . 73-76 p p . 13. G r o s s , W . L . 1924. The v i t a l i t y o f b u r i e d s e e d s . J . A g r . R e s . . 349-362. o 19. G u s t a f s s o n , A k e . 1947. A p o m i x i s i n h i g h e r p l a n t s . P a r t I I I B i o t y p e a n d s p e c i e s f o r m a t i o n . L u n d s U n i v . A r s s k r i f t N . F . A v d . 2 . B d 4 3 , N r 12, K u n g e F y s i o g r a f i s k a S a l l s k a p e t s H a n d l i n g e r N . F . B d 53, N r 12, L u n d C . W . K . G l e e r u p . P . 135. 2 0 . H a r p e r , J . L . I960 ( e d . ) . T h e b i o l o g y o f w e e d s - A s y m p o s i u m . o f t h e B r i t i s h E c o l o g i c a l S o c i e t y , O x f o r d , E n g l a n d . 256 p p . 21 . H u g h e s , E . C . I 9 6 0 . H e r b i c i d e s t r i a l s o n t u r f g r a s s e s , S t a n l e y P a r k , V a n c o u v e r , R e s . R e p . N a t * 1 . W e e d C o m m . , W e s . S e c , C D . A . , O t t a w a , O n t a r i o . - P . 33. 2 2 . u 1963. E f f e c t o f h e r b i c i d e s o n l a w n d a i s y ( B e l l i s P e r e n n i s ) i n e s t a b l i s h e d t u r f . R e s . R e p . , N a t 1 ! . Weed C o m m . , W e s . S e c , O t t a w a , C a n a d a . 143-149 p p . 2 3 . 1963. E f f e c t o f h e r b i c i d e s o n s p e e d w e l l ( V e r o n i c a p e r s i c a ) i n t u r f . R e s . R e p . , N a t ' l Weed Comm. W e s . S e c , O t t a w a , C a n a d a . 149-150 p p . 24. 1963. Weed c o n t r o l i n e s t a b l i s h e d l a w n s . R e s . R e p . N a t ' l . Weed C o m m . , W e s . S e c , O t t a w a , C a n a d a . 150 - 151 p p . 25. J a g s c h i t z , J . A . a n d J . F . C o r n m a n . 1955. S t u d i e s o n t h e c o n t r o l o f V e r o n i c a f i l i f o r m i s i n t u r f u s i n g KDCN e n d o t h a l , 24-D a n d 2 4 5 - T , P r o c . 9 t h N o r t h E ' a s t e r n Weed C o n t r o l C o n f . 365 - 369 p p . 2 6 . K l i n g m a n , G . C . 1961. Weed c o n t r o l a s a s c i e n c e , J o h n W i l e y a n d S o n s I n s . New Y o r k . C h a p . I I : 23-44. 48. 27« Kommendahl, Thor., J . B. Kotheimer and J . V. B e r n a d i n i . 1959. The e f f e c t of quackgrass on germination and seedling development of c e r t a i n crop p l a n t s . Weeds 7: 1-12. 28. Korsmo, E. 1930. Unkrauter i n Ackerbau der Neuzeit B e r l i n Translate and e d i t e d by H. W. Wollen Weber.. 580 pp. 29. 1954 Anatomy of weeds. Grondahl & Sons, Oslo. 413 pp. 30. Kummer, A.P. 1951. Weed se e l d i n g s . The U n i v e r s i t y of Chicago. 433 pp. 31. Kutschera L. I960. " W u r z e l a t l a s " M i t t e l e u r o p a i s c h e r Acker-unkrauter and K u l t u r p f l a n z e n . 574 pp. 3 2 . Le Tourneau, Le Duane, G. D. F a i l e s and H. G. Heggeness. 1956. The e f f e c t of aqueous e x t r a c t s of p l a n t s of plan t t i s s u e on germination of seeds and growth of seed-l i n g s . Weeds 4: 363-368. 33« Le Tourneau, Le Duane, H. G. Heggeness. 1957. Germination and growth i n h i b i t o r s i n l e a f l y spurge f o l i a g e and quack-grass r h i z o n e . Weeds 5: 12-19. 34« Mann, H. H. and T. W. Barnes. 1952. The competition between b a r l e y and c e r t a i n weed under c o n t r o l l e d c o n d i t i o n s . V Competition w i t h c l o v e r considered as a weed. Ann. Ap p l . B i o l . 39: 111-119. 35. M a r t i n , P. and B. Rademacher. 1959. S t u d i e s on the mutual i n f l u e n c e s of weeds and crops. The Bi o l o g y of weeds, (ed.) by J . L. Harper, B l a c k w e l l S c i e n t i f i c P u b l i c a t i o n s . Oxford, England.. 256 pp. 36. Muenscher, W. C. 1955. Weeds (2nd ed.) The MacMillan Company, New York. 560 .pp. 37. Ostvald, H. 1948. Toxic exudates from the r o o t s of Agropyron repens. Jour. E c o l . (36): 192-193-38. Renney, A. J . and L. S. Ho. 1962. Tolerance of 4 t u r f grasses to v a r y i n g r a t e s of MPH/112 and Supertox, Res. Rep. N a t ' l . Weed Comm. Wes.. S e c , C.D.A.'jl Ottawa, Canada. 109-110 pp. . 39« Renney, A. J . and W. J . Dent. 1958. Growth i n h i b i t i o n caused by r u s s i a n knapweed (Centaurea repens L.) Res. Rep., . N a t ' l . Weed Comm., Wes. Sec. CD.A. Ottawa, Ontario, p. 122. 49 40. S a l i s b u r y , E. 1952. " W u r z e l a t l a s " Kutschera L. I960. M i t t e -l e u r o p a i s c h e r Ackerunkrauter und K u l t u r p f l a n z e n . 107-109, 250-252, 261-263 pp. 41. Stevens, O.A. 1932. The number and weight of seeds produced by weed. Am. J . Bot. 19: 784-794-42. S w i t z e r , C. M. i 9 6 0 . Weed c o n t r o l i n t u r f by l a t e f a l l t r e a t -ments. Res. Rep. N a t T l Weed Comm. Eas. S e c , Can. Agr. Dept., Ottawa, O n t a r i o , p. 101. 43« Thornton, N. C- 1935. F a c t o r s i n f l u e n c i n g germination and dormancy i n cocklebur seeds. Contribs.Boyce Thompson, I n s t . 7l 477-495. 44. Thurston, J . M. 1959. Dormancy of weed seeds. The biolo g y of weeds (ed.) J . L. Harper, B l a c k w e l l S c i e n t i f i c P u b l i c a t i o n , Oxford, England. 6 9 - 8 1 pp. 45. Toole, E:. H, and E. Brown. 1946. F i n a l r e s u l t s of the Durel buried seed experiment. J . Agr. Res. 72: 2 0 1 - 2 1 0 . 4 6 . Toole, E, H. et a l , 1956. Physiology of seed germination. Ann. Rev. Plant P h y s i o l l 7:• 2 9 9 - 3 2 4 . 47. United State Department of A g r i c u l t u r e 1952. T e s t i n g A g r i c u l -t u r a l and vegetable seeds. Agruculture Handbook. No. 30 Washington, D.C. 273-283 pp. 48. Welbank, P. J . 1959* Toxin production from Agropyron repens. The B i o l o g y of Weeds, (ed.) J . L. Harper. B l a c k w e l l S c i e n t i f i c P u b l i c a t i o n , Oxford,. England. I 5 8 - I 6 4 pp. 49. Weed c o n t r o l i n t u r f 1964. Weed c o n t r o l recommendations f o r Western Canada. N a t ' l . Weed Comm. Wes. S e c Canada Department of A g r i c u l t u r e , Ottawa, 50. A P P E N D I X : Table 1 L i s t of common and botanical name of weed species and t u r f grasses. Common name Botanical name 1. Annual sow t h i s t l e Sonchus oleraceus L. 2. Bent grass, Highland Agrostis tenuis Vasey 3- Black medic Medicago lupulina L. 4. Blue grass, annual 8 Poa annua L. 5. Blue grass, Kentucky- Poa pratensis L. 6. Blue grass, .Merion Poa pratensis L. 7. Cat's ear Hypochaeris radicata L. 8. Chickweed, common S t e l l a r i a media (L^ C y r i l l 9. Chickweed, mouse ear Cerastium vulgatum L. 10. Clovers T r i f o l i u m spp. 11. Cudweed Gnaphalium uliginosum L. 12. Dandelion Taraxacum o f f i c i n a l e L. 13. Dandelion, f a l l Leontodon autumnalis L. 14. Dead nett l e Lamium amplexicaule L. 15. Fescue, red creeping Festuca rubra genuinaZHock. 16. Fescue, chewing Festuca rubra commutata Gaud. 17. Grasses (weed) Gramineae spp. 18. Groundsel Senecio vulgaris L. 19. Knotweed Polygonum aviculare L. 20. Lamb's quarter Chenopodium album L. 51. T a b l e 1 L i s t o f common a n d b o t a n i c a l name cf w e e d s p e c i e s a n d t u r f g r a s s e s , ( c o n t i n u e d ) Common name B o t a n i c a l name 21. M u s t a r d , h e d g e S i s y m b r i u m o f f i c i n a l e ( L . ) S c o p . 2 2 . M u s t a r d , t u m b l i n g S i s y m b r i u m a l t i s s i m u m L . 23. P i n e a p p l e w e e d M a t r i c a r i a m a t r i c a r i o i d e s ( L e s s . ) P o r t e r 24. P l a n t a i n , b r o a d l e a v e d P l a n t ago ma . io r L . 25. P l a n t a i n , n a r r o w l e a v e d P l a n t a g o l a n c e o l a t a L . 26. P u r s l a n e P o r t u l a c a o l e r a c e a L . 27. S h e e p s o r r e l Rumex a c e t o s e l l a L . 2 8 . S h e p h e r d ' s p u r s e C a p s e l l a b u r s a - p a s t o r i s (31.) M e d i c . 2 9 . S m a r t w e e d P o l y g o n u m p e r s i c a r i a L . 3 0 . S p e e d w e l l , c r e e p i n g V e r o n i c a f i l i f o r m i s S m . 3 1 . S p u r r y , c o r n S p e r g u l a a r v e n s i s L . 3 2 . S p u r r y , s a n d S p e r g u l a r i a r u b r a ( L . ) J . 3 3 . S t o r k ' s b i l l ( F i l a r e e ) E r o d i u m c i c u t a r i u m ( L . ) L ' H e r . 34. B i t t e r c r e s s C a r d a m i n e o l i g o s p e r m a N u t t . 3 5 . Y a r r o w A c h i l l e a m i l l e f o l i u m L . APPENDIX Table 2. Leaf area of seedling weeds at three growth stages 52. 4 weeks after emergence '6 weeks after 'emergence T 1 8 weeks after emergence t 1 r 1 Leaf Area X1- '-Leaf Area £ Leaf Leaf No. '• Length Leaf No. ' Length1 _Cm2 1 Gm '• Cm2 • Cm Leaf A r ea X' Leaf No, . Cm2 Leaf Length Cm 1. Stork's b i l l 2.66 0.750 21.90 2.750 47.50 4.625 2. Corn spurry 1.68 1.375 5.92 3.250 24.00 3.250 3. Groundsel 1.10 0.688 15.34 3.125 55.10 4.875 4. Sh ephe rd 1s purse 1.04 0.500 7.10 1.875 57.28 4.625 5. Cat 1s ear 0.72 0.750 3.05 1.815 18 .85 2.875 6. Annual sow th i s t l e 0.72 0.438 3.42 2.500 42.00 3.500 7. Common chickweed 0.60 0.312 5.22 O.625 11.90 . 0.875 8 . Hedge mustard 0.56 O.463 7.84 1.815 79.94 5.125 9 , Yellow rocket 0.40 0.325 2.96 0.875 31.07 3.625 10. Dead nettle 0.40 0.312 7.41 O.625 29.48 0.875 11. Narrow leaved plantain 0.33 1.000 2.96 3.125 12.00 5.000 12. Broad leaved plantain 0.20 0.312 2.55 0.938 7.20 1.625 13. Mouse ear 0.16 0.250 0.84 0.425 .L4.88 1.000 chickweed 53 . APPENDIX Table 3 . Leaf development of 1 3 weed species u n t i l seven weeks a f t e r germination 3 (a) -Weed Leaf number i Leaf l e n g t h t Leaf width Species 1 wk . 3 wks 5 wks 7 1 wks '.wk 3 wks 5 wks 7 wks ' 1 '.wk 3 wks 5 wks 7 wks Stork's b i l l 2 7 1 5 1 9 0 . 8 1 . 8 1 6 1 9 0 , 6 1 . 6 3 . 0 4 . 0 Corn spurry 2 1 2 3 7 1 2 0 1 . 7 4 . 1 7 . 3 9 . 4 0 . 1 0 . 1 0 . 1 0 . 1 Annual sow t h i s t l e 2 6 1 0 0 . 7 1 . 7 3 . 5 1 6 0 . 4 0 . 9 1 . 0 5 . 5 Groundsel 2 5 1 3 3 8 0 . 8 1 . 7 7 . 8 1 5 0 . 3 0 . 7 2 . 2 3 . 9 Mouse ear chickweed 2 4 1 2 48 0 . 4 1 . 0 2 . 6 4 0 . 2 0 . 3 0 . 7 1 . 1 Common chickweed 2 1 0 2 9 3 5 0 . 8 1 . 4 2 . 6 4 . 5 0 . 3 0 . 6 1 . 2 1 . 6 Dead n e t t l e 2 4 1 9 4 4 0 . 5 2 . 0 6 . 5 6 . 1 0 . 5 0 . 9 2 . 1 3 . 0 Yellow rocket 2 5 8 1 3 0 . 6 2 ; 5 5 6 . 4 1 5 * 2 0 . 5 1 . 0 1 . 6 3 . 5 Hedge mustard 2 4 7 1 4 0 . 6 2 , 0 7 . 8 1 8 . 2 0 . 4 1 . 1 3 . 2 7 . 0 Cat's ear 2 4 5 1 3 1 . 4 1 , 7 3 . 4 8 . 5 0 . 5 0 . 9 1 . 3 2 , 8 Shepherd's purse 2 8 1 0 1 6 0 . 7 1 . 8 9 . 0 1 7 . 0 . 3 0 . 7 1 . 6 3 . 6 Broad leaved p l a n t a i n 2 4 5 8 0 . 9 1 . 1 2 . 8 6 . 1 0 . 3 0 . 4 1 . 3 2 . 6 Narrow leaved 2 3 8 8 2 . 6 4 . 4 5 . 5 1 5 . 1 0 . 1 0 . 1 5 0 . 6 2 p l a n t a i n 54. APPENDIX Table 3, Leaf development of 13 weed species u n t i l seven weeks after germination. *f ,_V. , BU. Weed Species 1 wk 3 wks 5 wks 7 wks Odour Stork's b i l l l ight green light green hairy green hairy green yes Corn spurry purple light green green green sticky yes Annual sow th i s t l e brownish green light green hairy green hairy purplish green, hairy no Groundsel brownish green reddish 1. green, hairy reddish green, hairy reddish green sticky yes Mouse ear chickweed light green light green hairy green hairy green hairy no Common chickweed brownish green light green hairy green hairy green no Dead nettle reddish green, hairy reddish hairy green green hairy reddish green yes Yellow rocket brownish green reddish hairy green light green green no Hedge mustard reddish green reddish hairy green purple green hairy purplish green, hairy no Cat's ear light green reddish hairy green green hairy green rough, hairy no Shepherd * s purse light green reddish hairy green light green light green yes Broad leaved plantain purple reddish hairy green green hairy green no Narrow leav$L purple reddish green green green no plantain hairy 55. APPENDIX Table 4. Root development of 13 weed species u n t i l seven weeks af t e r germination. (Averages of f i v e plants i n each case). Species ' 1 'wk i 3 wks 5 wks 7 1 wks 1 i 1 wk 3 wks 5 wks 7 wks (No. x Length) Stork's b i l l 1 16 34 tap root 1 1.5 6.5 8.5 20 289.0 sec. root — Corn spurry 1 9 22 tap root 1 sec. root ~ 2.0 5.2 6.0 17 132.0 Annual sow 1 12 120 f i b . root t h i s t l e sec. root -- 3,3 6.4 7.0 31 840.0 Groundsel 1 17 22 f i b . root 26 3.2 6.0 6.5 37 143.0 sec. root — Mouse ear 1 8 12 tap root 1 1.7 3.3 3.5 15 42.0 chickweed sec. root -— Common 1 11 50 tap root 1 2.1 3.8 6.0 21 300.0 chickweed sec. root — Dead n e t t l e . 1 22 40 tap root 1 2.8 6.7 6.8 22 272.0 sec. root 24 Yellow rocket 1 17 23 tap root 1 2.5 3.9 5.0 26 115.0 sec. root — Hedge mustard ,1 12 40 tap root 1 2.6 4.3 11.0 40 440.0 sec. root — Cat's ear 1 20 25 tap root 1 5.2 6.4 6.5 24 162.5 f i b . root 24 Shepherd's 1 17 18 tap root 1 1.7 4.3 5.5 15.4 99.0 purse sec. root 17 Broadleaved 1 12 20 tap root 1 0.9 4.0 3.1 22 62.0 plantain f i b . root 8 Narrow leaved 1 15 46 tap root 1 5.0 7.9 7.9 27 363.4 plantain f ib, root — # — i n f i n i t e . APPENDIX Table 5. Stem development of 13 weed species -until seven weeks after germination. 5 ( a) 5 (b) Number of stems ' Height of spreading ' Color and stem covering '. stems (rosette) in ». Weed Cms. i Species 1 3 5 •7 ' 1 3 5 7 •' 1 3 5 7 wk wks wks wks '. wk wks wks wks '. wk wks wks wks Stork's b i l l 1 1 1 1 2.5 6.0 28 32 light light green green green green hairy hairy Corn spurry 1 1 1 5 2.0 3.1 9.0 30 greenish purplish green light green purple green Annual sow 1 1 1 1 0.6 2.3 7.2 38 brownish brownish green green th i s t l e green green hairy hairy Groundsel 1 1 1 5 1.6 4.3 14.2 29 brownish brownish reddish purplish purple and purple and green, green green green hairy Mouse ear 1 1 1 7 0.9 1.6 4.0 10 light light green green chickweed green green hairy Common 1 1 1 35 1.0 3.0 8.2 33 brownish brownish green green chickweed green green hairy Deaddnettle 1 1 3. 4 1.9 4.5 10.0 17.5 reddish reddish green green green green hairy Yellow rocket i : 1 1 1 0.6 5.3 7.5 17.5 brownish brownish light reddish green green green green ON Table 5. Stem development of 13 weed species u n t i l seven weeks a f t e r germination. (Continued) Weed Number of stems ' Height of spreading 1 stems ( r o s e t t e ) i n 1 Cms. Color and stem covering Species 1 wk 3 wks 5 wks 7 wks 1 wk 3 wks 5 wks 7 wks ' 1 '. wk 3 wks 5 wks 7 wks Hedge mustard 1. 1 1 1 1.8 2.9 13.1 25 reddish r e d d i s h green p u r p l i s h brown brown hairy- green Cat's ear 1 1 1 1 0.4 2.8 3.8 13 l i g h t l i g h t dark green green green green hairy-Shepherd's 1 1 1 1 1.0 2.4 11.3 30 green green l i g h t l i g h t • purse green green hairy-Broad leaved 1 1 1 1 0.3 1.7 3.5 10.8 green purple green green p l a n t a i n hairy-Narrow leaved 1 1 1 1 0.3 1.3 3.8 13.5 purple purple green r e d d i s h green p l a n t a i n h a i r y APPENDIX Table 6, F l o w e r i n g and seed production periods of 22 t u r f weed species i n the Vancouver area 1962-63. Weed Species Flowering p e r i o d (month ) F r u i t and Seed production p e r i o d (month)  L i f e span Broad leaved p l a n t a i n Cat's ear B l a c k medic Common chickweed Dandelion B i t t e r cress Corn spurry Cudweed F a l l Dandelion Weed grasses Knotweed Lamb's quarter Mouse ear chickweed Narrow leaved p l a n t a i n Pineapple weed Purslane Sheep s o r r e l Shepherd's purse Smart weed Speedwell, creeping Y e l l o w rocket Groundsel June 15 - Aug, June - Aug, May - J u l y Throughout the whole year Aug, - Oct, Feb, - May Apr, - June Sept. - Oct, May - J u l y J u l y - Sept, May - J u l y June - Aug, May - June Apr, - June May - June May - J u l y J u l y - Aug. Mar. - May Mar. - May May - J u l y Apr. - May May - J u l y Feb. - Apr. Aug, - Sept, August June - Sept. June - J u l y Throughout the whole year Mar. - June Mar. - May Apr. - June Sept. - Oct, June - Sept, June - Sept, J u l y - Sept, June - J u l y J u l y - Sept, June - Aug, May - J u l y June - Aug. June - Sept, Aug, - Oct, May - Sept, Mar. - June J u l y - Aug, May - J u l y June - Sept, P e r e n n i a l P e r e n n i a l Summer annual Annual P e r e n n i a l Annual Annual Annual P e r e n n i a l Annual Annual Annual P e r e n n i a l P e r e n n i a l Annual Annual P e r e n n i a l Annual Annual P e r e n n i a l P e r e n n i a l or b i e n n i a l Annual 59. APPENDIX Table 7, Monthly Mean Temperatures and P r e c i p i t a t i o n , U.B.C. M e t e o r o l o g i c a l S t a t i o n I962 and January - June I963. Months Temperature P r e c i p i t a t i o n (inch) Max. mean F° Min. mean F° 1962 January 41.3 33.6 6.75 February 46.2 37.3 2.12 March 45.7 35.5 3.95 A p r i l 54.2 43.2 4.01 May 56.9 45.6 I.65 June 64.4 51.8 0.84 J u l y 67.7 55.6 0.98 August 66.3 55.5 4.29 September 64.0 52.7 2.65 October 56.4 48.1 4.91 November 49.1 41.6 8.64 December 45.1 37.5 9.14 1963 January 37.1 29.0 0.94 February 50.4 40.5 5.87 March 48.1 38.0 3.36 A p r i l 53.0 42.8 2.91 May 63.O 47.9 1.49 June 64.6 52.8 I.69 APPENDIX Table 8. The germination of Highland bent grass and Merion blue grass in areas contaminated by-root exudates of various weeds. Highland Bent grass Merion blue grass Percentag ie Length Percentage Length Cm. Cm. Annual sow thistle 35% 1.2 k0% 0.5 Black medic 55 1.3 25 0.2 Broad leaved plantain 40 0.9 35 0.5 Cat's ear 50 1.1 45 1.0 Common chickweed 51 1.4 5 0.4 Corn spurry 65 2.0 20 0.5 Dead nettle 55 1.2 50 1.0 Filaree 70 1.2 45 1.0 Broundsel 53 2.0 10 0.4 Mouse ear chickweed 51 1.1 30 0.8 Narrow leaved plantain 50 0.8 35 0.3 Sand spurry 40 1.0 20 1.5 Shepherd's purse 53 1.2 35 0.9 Yellow rocket 65 1.5 15 1.0 Control 52.5 0.7 30 0.55 APPENDIX Table 9(a) Germination and shoot l e n g t h of Highland bent grass i n three concentrations of the l e a f e x t r a c t of s i x weeds. Weed 10$(day£ 5% (days) 2.5$ (days) Species 4 8 12 16 20 4 8 .. 12 16 20 4 8 12 16 20 C a t 1 s ear % l e n g t h 0 1.2 0.06 4 0.3 14 0.4 19.2 0.96 2 0.07 10.6 0.3 21.2 0.4 36 0.4 44.6 0.93 9.2 0.1 26 0.26 35 0.26 40.6 0.3 45.2 0.33 Common Chickweed af 1° l e n g t h ' 0 0 0 4 0.06 5.2 0.23 0 2.4 0.1 5.2 0.26 9.2 0.26 23.2 0.33 2,6 0.16 18.6 0.90 30.6 1.6 39.2 1.96 49.2 2.46 Dandelion % l e n g t h 0 0 13.2 0.33 16 0.86 28 2.3 • 0.6 0.03 13.2 0.93 15.2 •1.3 31.2 I . 6 3 47.2 2.36 7.4 0.1 2.4 1.1 35 1.5 38:26 1.93 48 1.93 Groundsel % l e n g t h 0 1.4 0.3 2 0.46 16 0.77 24 2.3 2.6 0.1 7.2 1,16 8 .6 1.7 20.6 1.76 25.2 2.23 11.2 0.1 20.6 1.4 30.6 1.7 38 2.3 54 2.6 Narrow leaved p l a n t a i n 0 ': l e n g t h 0 0 1.32 0.3 3.2 0.36 6.6 1.76 0.66 0,03 3.2 0.4 6 O.60 16 0.7 22.6 1.5 5.2 0.13 22 0,66 22 0.9 31.2 0.9 34 1.46 Pineapple weed % l e n g t h 0 0 0 0.7 0.035 0.7 0.16 0 0 0 1.32 0.1 4.0 0.46 3.2 0.16 6 0.5 12 0.53 22 0.56 37.2 0.73 C o n t r o l % l e n g t h 31.2 0.23 47.2 1.43 50.6 2.26 54 2.33 54.6 2.63 31.2 0.23 47.2 1.43 50.6 2.26 54 2373 54.6 2.63 31.2 0.23 47.2 1.43 50.6 2.26 54 2.37 54.6 2.63 APPENDIX Table 9 (b) A n a l y s i s of •variance of germinating percentage Table 9 (c) Sources df SS MS F F ( t a b l e 1% 5%) Species 6 3,294.9095 549.1516 6.439** 4.82 3.00 Treatments 2 2,423.1171 1,211.5586 14.205** 6.93 3.89 E r r o r 12 1,023.4763 85.2896 T o t a l 20 6,641,5029 A n a l y s i s o f variance of shoot length Sources df SS MS F F (t a b l e 1$ 5%) Species 6 12.228 2.2038 7.230** 4.82 3.00 Treatments 2 0.2934 0.1467 0.4813* 6.93 3.89 E r r o r . 12 3.6571 0,3048 T o t a l 20 17.1733 APPENDIX Table 10 (a) Germination of bent grass in sand as influenced by 1.7% concentrations of the dried leaf powder of three weeds. (October 16 - November 11, 1963) 4 days 7 days 10 days 13 days . 16 days 19 days 22 days Treatments 1 2 3 4 1 2 3 4 1 2 3 4 1 2. 3 4 1 2 3 4 1 2 3 4 1 2 3 4 Grass % 6o 74 52 50 No. 30 37 26 25 68 76 56 50 34 38 28 25 70 78 52 54 35 39 26 27 70 78 52 58 35 39 26 29 72 80 52 54 38 40 26 27 72 80 52 54 36 40 26 27 72 80 52 54 36 40 26 28 Grass & Narrow % Leaved Plantain No, 2 2 0 4 1 1 0 2 12 6 2 18 6 3 1 9 36 14 14 50 18 7 7 25 48 18 14 56 24 9 7 28 70 20 20 60 35 10 10 30 72 22 22 62 36 11 11 31 78 28 34 66 39 14 17 33 Grass & Pineapple Weed % No, 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 1 0 0 0 2 0 0 0 1 0 0 2 2 4 0 1 1 2 0. 12 6 12 10 6 3 6 5 Grass & Common Chickweed at P No. 8 0 6 2 4 0 3 1 12 0 12 6 6 0 6 3 12 4 14 16 6 2 7 8 14 4 14 16 7 2 7 8 18 10 18 20 9 5 9 10 22 12 18 20 11 6 9 10 26 12 20 20 13 6 10 10 APPENDIX Table 10 (b) Analysis of variance of germinating percentage. Source df SS MS F F (table 1% 5%) Treatments 3 2785.33 14.1** 9.78 4.76 Replications 3 654 218.00 1.1 Error 9 190.88 Total 15 10,728 « APPENDIX Table 10 (c) The average of germination r a t e s i n d i f f e r e n t treatments Treatments Days 4 7 10 13 16 19 22 Grass 59 62.5 63.5 64.5 64.5 64.5 64.5 Grass & Narrow 2 9.5 28 .5 34 42.5 44.5 51.5 leaved p l a n t a i n Grass & 0 0 0 0.5 0,5 2 10 Pineapple weed Grass & Common 4 7.5 H . 5 12 16.5 18 19.5 Chickweed APPENDIX Table 11 (a) Greenhouse experiment for competition studies Plan A . B C L7 6 7 18 9 11 8 1 3 15 5 8 12 18 1 .4 11 13 6 12 7 18 17 14 9 16 13 L6 2 15 10 4 5 12 14 13 6 17 2 9 16 7 10 3 14 4 10 15 5 3 1 11 2 8 1, 1.8 gram highland bent grass (4 Ib./lOOO sq. ft.) 2. 0.9 " it It (2 Ib./lOOO sq. ft.) 3. 0.45 " I! II (1 Ib./lOOO sq. ft.) 4. 1.8 •• II II & 50 seeds of groundsel 5. 0.9 " It It & 50 tt it it 6. 0.45 " II II & 50 it it ti 7. 1.8 11 II II & 50 seeds of shepherd's purse 8. 0.9 » 11 II II & 50 tt II ti it 9. 0.45 » 1 1 It II & 50 it It n it 10. 1.8 « >» II II & 50 seeds of common chickweed 11. 0.9 " » II tt & 50 t i II n it 12. 0.45 " ti It II & 50 ti II it ti 13. 1.8 » II tt & 50 seeds of narrow leaved.plantain 14. 0.9 " II II & 50 it II i i it n 15. 0.45 » II tl & 50 it II ti II it 16. 1.8 '• » II II & 50 seeds of stork's b i l l 17. 0.9 " II It & 50 it II it it 18. 0.45 " It II & 50 ti II II II APPENDIX Table 11 ( b ) . A n a l y s i s of v a r i a n c e , competition study - F i r s t Harvest (three weeks a f t e r emergence.) Source df SS MS F V F ( t a b l e 1% 5%) Treatments 2 14.6947 7.3473 8.0753 s* 5.85 3.49 Weed species 5 9.5259 1.9052 2.0940 4.10 2.71 R e p l i c a t i o n s 2 4.2692 2.1346 2.3461 5.85 3.49 T x S 10 19.6542 1.9654 2.1601 3.37 2.35 T x R 4 3.2009 0,8002 0.8795 4.43 2.87 S x R 10 6.9663 O.6966 O.7656 3.37 2.35 E r r o r 20 18.1969 0.9098 T o t a l 53 76.5081 APPENDIX Table 11 (c) A n a l y s i s o f vari a n c e of competition study a f t e r emergence). - Second Harvest ( s i x weeks Source d f SS MS F F ( t a b l e 1% 5%) Treatments 2 26.1411 13.0706 5.86** 5.85 3.49 Weed species 5 16.1527 3.2305 1.448 4.10 2.71 R e p l i c a t i o n s 2 6.8977 3.4489 1.546 5.85 3.49 T x S 10 43.0612 4.3061 1,930 3.37 2.35 T x R 4 9.3012 2,3253 1.042 . 4.43 2.87 S x R 10 25.2779 2.5278 1.133 3.37 2.35 E r r o r 20 44.6165 2.2308 T o t a l 53 171.4483 APPENDIX Table 12„ Chemical names of h e r b i c i d e s Commercial name . Chemical formulae MCPA 2,4-D 2,4,5-T S i l v e x 2(MCPP) Super tox NPH/112 K i l l e x Banvel "D" Tordon Zytron Endothal 4 - Chloro - 2 - methylphenoxyacetic a c i d 2, 4 - Dichlorophenoxyacetic a c i d 2,4, 5 - Trichlorophenoxy a c e t i c a c i d 2 - (2, 4, 5 - Trichlorophenoxy) p r o p i o n i c a c i d 2-Methyl, 4-Chlorophenoxypropionic a c i d Mixture of 2-(MCPP) and 2, 4 - D 2:1 Mixture of 2-(MCPP) and 2} 4 - D 4:1 M i x t u r e of 2-MCPP) 8 o z / g a l l o n , 2,4-D 16 o z / g a l l o n and 2, 4, 5-T 6 o z / g a l l o n Amine s a l t of 2 - methoxy 3, 6, d i c h l o r o b e n z o r i c a c i d 4 Amino - 3, 5, 6 - t r i c h l o r o p i c o l i n i c a c i d 0 - 2 , 4 - D i c h l o r o p h e n y l 0 - methyl i s opropylpho sphoroamidot hioat e disodium 3.6. endoxohexahydrophthalate 71. 74. 76. Mouse Ear Chickweed 

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