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The effect of temperature during fruit development on the quality of green snap beans Dunlop, Clifford Arthur Allan 1968

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THE EFFECT OF TEMPERATURE DURING FRUIT DEVELOPMENT ON THE QUALITY OF GREEN SNAP BEANS by CLIFFORD ARTHUR ALLAN DUNLOP B . S . A . , Un ivers i ty of B r i t i s h Columbia, 1967 A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in the Department of Food Science We accept th is thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA March, 1968 ABSTRACT i The e f fect of temperature and maturity on the q u a l i t y of Tendercrop green snap beans was studied by growing plants in contro l led environment cabinets . Plants were grown in the greenhouse u n t i l 7 days a f ter anthesis at which time o they were removed and transferred to temperatures of 20 C, 25°C, 30°C and 35°C. The beans were harvested at lq., 19, 21;, 29 and 3U- days a f t er anthesis and analyzed for various q u a l i t y f a c t o r s . Growing the f r u i t at a temperature of 35°C resulted in a s i g n i f i c a n t s tunt ing of the size and average weight of the pod. The optimum temperature for maximum y i e l d was found o to be 25 C. Temperature resul ted in a s i g n i f i c a n t increase in l ightness and yellowness and increased s i g n i f i c a n t l y with maturity below 35°C over the period s tudied . Toughness did not change with maturity or temperature between 20°C and 30°C u n t i l 2LL. days a f ter anthes is . Af ter this po int , toughness increased with increas ing temperature. Beans grown at 35°C were s i g n i f i c a n t l y tougher than 20 - 30°C beans and increased in toughness over t h e i r l l i - 2Lj. day maturity p e r i o d . Increased temperature and maturity caused an increase in t o t a l s o l i d s , water insoluble s o l i d s , s tarch , f ibre and o in pect in above 30 C. T o t a l sugars decreased with maturity and increased temperature. T o t a l ash did not change s i g -n i f i c a n t l y with temperature or maturi ty . Pod width and seed length were shown to be accurate indices of matur i ty . T o t a l so l ids appeared to be a good index of edible maturi ty . The need for r e v i s i o n of standards to account for various rates of maturity onset was s tressed . i i 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 o f the r e q u i r e m e n t s f o r an a d v a n c e d d e g r e e a t the U n i v e r s i t y o f B r i t i s h C o l u m b i a , I a g r e e t h a t t h e 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 r e f e r e n c e and S t u d y . I f u r t h e r a g r e e t h a t p e r m i s s i o n f o r e x t e n s i v e c o p y i n g o f t h i s t h e s i s f o r s c h o l a r l y p u r p o s e s may be g r a n t e d by the Head o f my Department o r by h i s r e p r e s e n t a t i v e s . It i s u n d e r s t o o d t h a t c o p y i n g o r p u b l i c a t i o n o f t h i s t h e s i s f o r f i n a n c i a l g a i n s h a l l n o t be a l l o w e d w i t h o u t my w r i t t e n p e r m i s s i o n . D e p a r t m e n t of Food Science The U n i v e r s i t y o f B r i t i s h C o l u m b i a V a n c o u v e r 8, Canada Date March 3. 1968 i i i TABLE OF CONTENTS Page ABSTRACT i LIST OF FIGURES v ACKNOWLEDGEMENTS v i i INTRODUCTION 1 LITERATURE REVIEW 3 1. ) Qual i ty 3 2 . ) Qual i ty Measurement 6 Colour measurement 6 Kinesthet ic measurement 11 Flavour and odour 16 Maturity 17 3 . ) Factors Which Affect Qual i ty 22 Effec t of maturity 22 Effec t of storage 29 Effec t of blanching 31 Effec t of f reez ing and canning 33 Effec t of growing conditions 35 MATERIALS AND METHODS 39 RESULTS AND DISCUSSION If? Experiment I l i7 Experiment II 62 Growth and Y i e l d 62 Colour 70 Texture 75 Composition 79 Maturi ty measurement 92 i v Page SUMMARY OP RESULTS 96 REFERENCES CITED 9 8 APPENDIX IOI4. Table I 105 Table II 107 Table III 115 Table IV 115 LIST OP FIGURES v Figure Page 1. Tissue Development of the Pod 25 2. The Ef fec t of Temperature on T o t a l So l ids 1+9 3 a . The Ef fec t of Temperature on Water Insoluble So l ids 50 3b. The Ef fec t of Temperature on Water Soluble So l ids 51 q.. The Ef fec t of Temperature on Alcohol Insoluble So l ids 53 5 . The Ef fec t of Temperature on T o t a l Sugars 51+ 6. The Ef fec t of Temperature on Ash ' 56 7. The Ef fec t of Temperature on Protein 57 8. The E f f e c t of Temperature on Calsium Pectate 59 9 . The Ef fec t of Temperature on Crude Fibre 60 10. The Ef fec t of Maturi ty and Temperature on Pod Width • 63 11. The E f f e c t of Maturity and Temperature on Pod Length 65 12. The Ef fec t of Maturity and Temperature on Seed Length 67 13. The Ef fec t of Maturi ty and Temperature on Average Weight 69 llx. The E f f e c t of Maturity and Temperature on Lightness 71 15. The Ef fec t of Maturi ty and Temperature on Greenness 72 16. The Ef fec t of Maturi ty and Temperature on Yellowness 7k V I Figure Page 1 7 . The Ef fec t of Maturi ty and Temperature on : Resistance to Shear 77 1 8 . The Ef fec t of Maturi ty and Temperature on Fibre 7Qa. 1 9 . The Ef fec t of Maturi ty and Temperature on T o t a l So l ids 80 2 0 a . The Ef fec t of Maturity and Temperature on Water Insoluble Sol ids 82 2 0 b . The Ef fec t of Maturi ty and Temperature on Water Soluble So l ids 83 2 1 . The Ef fec t of Maturi ty and Temperature on Starch 85 2 2 . The Ef fec t of Maturity and Temperature on T o t a l Sugars 87 2 3 . The Ef fec t of Maturi ty and Temperature on Protein 89 v i i A CKN OWLE DGEMENTS The writer would l i k e to express his appreciation to Dr. D. P. Ormrod who directed this research and who provided encouragement and advice. Thanks are also extended to the members of the research committee for use of f a c i l i t i e s and advice on the preparation of this paper. Dr. J. F. Richards Dr. S. Nakai Dr. C. A. Hornby The writer would also l i k e to acknowledge Mr. J. W. Gates who developed the starch analysis used in this study and who gave valuable assistance in the interpretation of r e s u l t s . Appreciation is expressed to Dr. G. W. Eaton f o r his patience and help concerning the s t a t i s t i c a l analysis of r e s u l t s . 1 INTRODUCTION The snap bean (Phaseolus vulgar is L . ) is an important and widely grown crop with many factors contr ibut ing to i t s wide d i s t r i b u t i o n such as a d a p t a b i l i t y for growth on a wide range of s o i l types. The period from p lant ing to maturity is so short that the crop f i t s e a s i l y into cropping systems and there is a great v a r i e t a l adaptation (Gould, 195lb). The snap bean can be divided into two d i s t i n c t groups, pole and bush beans. Pole beans blossom along the stem, which continues to grow i n d e f i n i t e l y , the ultimate length being dependent upon environment. In bush beans the influorescence is at the top of the plant and blossoming is terminal (Wade, 1937). Snap beans are of two common types: 1) green podded and 2) yellow podded or wax beans. These can be further subdivided into two types: 1) round, in which the pod thickness is not greater than 1 1/2 times t h e i r width and 2) f l a t , in which the thickness is greater than 1 1/2 times the width of the pod. Yellow podded beans lose t h e i r c h l o r o -p h y l l in the very late stages (Gould, 195>lb). Green snap, beans have become an important commodity supplied to the publ ic in fresh , frozen or canned form. The q u a l i t y of the f inished product is dependent upon a number of var iables such as pre-harvest environment, stage of maturity at harvest , processing techniques and storage condit ions . Of a l l of these, pre-harvest environment is the most d i f f i c u l t to contro l and often changes in q u a l i t y may occur due to en-vironmental changes over which man had no c o n t r o l . Therefore, a knowledge of the effect of environment on bean q u a l i t y is 2 e s s e n t i a l i f techniques to maintain or improve q u a l i t y are to be developed. The purpose of this study was to determine the e f fect of a i r temperature on the q u a l i t y of beans grown in contro l led environment cabinets . The changes in the phys ica l q u a l i t y factors such as s i z e , shape, colour and texture as wel l as changes in chemical composition were determined. 3 LITERATURE REVIEW 1.. QUALITY Food q u a l i t y has been defined by Kramer (1951) a s "the sum t o t a l of c h a r a c t e r i s t i c s of a given food item which i n -fluences the a c c e p t a b i l i t y or preference for that food by the consumer". Various aspects of q u a l i t y were grouped according to appearance, k inesthet ic value, f lavour and maturi ty . Appearance referred to the s i z e , shape, pat tern , wholeness, gloss and colour of the food item. Kinesthet ic value re ferred to the mouth f e e l or texture, which included such things as tenderness, chewiness, j u i c i n e s s , g r i t t i n e s s and f ibrousness . Flavour referred to those factors which the consumer evaluated with his sense of taste and smel l . Maturi ty was a lso considered an important q u a l i t y factor be-cause of the re la t i onsh ip of many of the q u a l i t y c h a r a c t e r i s t i c s to the stage of maturi ty . Kramer emphasized the d e s i r a b i l i t y of objective measurement of appearance and kinesthet ic value because of improvements in prec i s ion and dupl icat ion over sub-ject ive eva luat ion . It was decided that a taste panel was the best method of t e s t ing for f lavour because of the l imi ta t ions to objective t e s t ing in this area. Objective t e s t ing of maturity could be used to estimate other q u a l i t y factors because of the re la t ionsh ips which occur. Kramer ( 1965) has also found that hidden c h a r a c t e r i s t i c s which may affect the a c c e p t a b i l i t y of a food item such as n u t r i t i v e value or wholesomeness are not usua l ly of d i rec t importance in market q u a l i t y evaluat ion . Matz (1962) has pointed out the importance of texture, flavour and appearance in q u a l i t y evaluation. He f e l t that to most consumers appearance was most important because v i s u a l perception causes the i n i t i a l awareness of an item and this i n i t i a l perception would probably influence sub-sequent judgement regardings other factors. He f e l t that the r e l a t i v e importance of flavour and texture could not be judged. Factors constituting good q u a l i t y of processing beans have been outlined by Gould (1951+). These included: 1 ) Stringless and low f i b r e content. 2) Long straight pods without constrictions between seeds. 3) A uniform deep green colour (deep yellow in was beans) a f t e r blanching. 1+) White seed. 5) Uniform s e t t i n g and maturation of pods. 6 ) Pods round except for French-cut packs. 7 ) Flesh uniform and preferably the same as the pod colour a f t e r blanching. 8) Flavour and odour t y p i c a l of freshly cooked beans. 9 ) Pods free from sloughing a f t e r processing. 1 0 ) Seed small, completely surrounded by parenchyma a f t e r processing. The attributes of good q u a l i t y were determined and used by the Canadian Department of Agriculture ( 1 9 6 7 ) in order to produce regulations for the grading of frozen and canned snap beans. Their d e f i n i t i o n s of various q u a l i t y grades are as follows: Canned beans "Canada Fancy - is the name for the grade of canned beans that possess s i m i l a r v a r i e t a l c h a r a c t e r i s t i c s ; that possess a very good f lavour t y p i c a l of young tender beans, p r a c t i c a l l y uniform good colour and a good br ine ; that are young and tender and are p r a c t i c a l l y free from units damaged by mechanical or insect i n j u r y , harmless extraneous vegetable matter and other defects . Canada Choice - is the name for the grade of canned beans that possess s i m i l a r v a r i e t a l c h a r a c t e r i s t i c s ; that possess a good f lavour t y p i c a l of f a i r l y young tender beans, a f a i r l y uniform good colour and a f a i r l y good br ine ; that are f a i r l y young and tender and are f a i r l y free from units damaged by mechanical or insect i n j u r y , harmless extraneous vegetable matter and other defects . Canada Standard - is the name for the grade of canned beans that possess s i m i l a r v a r i e t a l c h a r a c t e r i s t i c s ; that possess a normal f lavour for the maturity of beans, a reason-ably uniform good colour and a reasonably good br ine; that are reasonably young and tender and are reasonably free from units damaged by mechanical or insect i n j u r y , harmless extraneous vegetable matter and other defects ." Frozen beans (Green or Wax) "Canada Fancy - is the name for the grade of frozen beans that possess s i m i l a r v a r i e t a l c h a r a c t e r i s t i c s ; that possess a good f lavour t y p i c a l of young tender beans and a p r a c t i c a l l y uniform good colour; that are young and tender and are prac -t i c a l l y free from units damaged by mechanical or insect i n j u r y , 6 harmless extraneous vegetable matter and other defects . Canada Choice - is the name for the grade of frozen beans that possess s i m i l a r v a r i e t a l c h a r a c t e r i s t i c s ; that possess a good f lavour of young tender beans and a f a i r l y uniform good colour; that are f a i r l y young and tender and are f a i r l y free from units damaged by mechanical or insect i n j u r y , harmless extraneous vegetable matter and other defects ." 2 ) QUALITY MEASUREMENT  Colour In the book "Color of Poods" MacKinney and L i t t l e (1962) extensively described the basic colour systems as we l l as the instruments which employ them in colour measurement. The three major systems dealt with were: 1) The CIE Color Space - th is system, developed in 1931 assumes the presence of a "standard observer" for colour s tandardizat ion . This system employs addit ive co lor imetry , in that a s ingle colour is described through the addi t ion of three primaries X, Y and Z. Because s p e c i f i c a t i o n of a colour in terms of these t r i s t imulus values was found to be cumber-some, a s impler method has been developed in which the ent ire luminosity is ascribed to Y ( i . e . l ightness ) and the chroma-t i c i t y is expressed by coordinates x,y and z , where: x = X y = Y x*y+z = 1 X+Y+y X+Y+Z 2) The Munsell Color Space - this system, also developed by addit ive color imetry , describes a colour by means of three coordinates , the hue, value and chroma. The Munsell system involves the systematic sampling of the colour space and may 7 be interpreted in the form of a colour a t l a s . This allows v i s u a l inspect ion of a p a r t i c u l a r colour described by the three coordinates . 3 ) The Lovibond System - The ultimate in an addi t ive system is white. In a subtract ive system colours are sub-tracted from white u n t i l a colour is matched or the ultimate colour of black is reached. The Lovibond system employs the use of r ed , green and yellow f i l t e r s to match and numerical ly speci fy a co lour . Colour measurement in the CIE or Munsell systems may be done with cer ta in addit ive colorimeters or spectrophotometers. A s p e c i a l subtract ive colorimeter has been designed which measures colour in Lovibond notat ions . A tr i s t imulus meter such as the Hunterlab Colour and Colour Difference Meter (CDM) e s s e n t i a l l y adapts the chromatic i ty coordinates of the Munsell system to the a, b, sca le , measured in N . B . S . or Judd u n i t s . A d i rec t reading is poss ib le , in terms of L , a^, b L or R^, a r d » b r d * The units of the L scale have been described by Hunter Associates ( 1 9 6 6 ) for use in measurement of colour and colour d i f f erence . A l l three scales have approximate v i s u a l u n i -formity throughout the colour s o l i d . The R d .(.luminous ref lectance) does not . Tris t imulus ref lectance may also be measured by a t h i r d scale described as measuring in CIE term. Hunter ( 1 9 5 8 ) described the operation of the Hunterlab CDM and the scales the machine employs in colour measurement. L and R d both are a measure of the CIE luminous ref lectance Y. 8 is read as "percent luminous ref lectance" and L is read as "lightness". The r e l a t i o n s h i p between the two i s : L = 1 0 R d ^ Hunter presented the fo l lowing equations for the in terconver-sions of Hunterlab values and CIE values: R^,scale L scale CDM from CIE R d = 1 0 0 Y L = 1 0 0 Y ^ a = 1 7 5 f y (1.02X-Y) a = 175Y~^ (1.02X-Y) b = 7 0 f y (Y-0.81+7Z) b = 7 0 Y " ^ ( Y - 0 . 8 q . 7 Z ) where fy = 0 . 5 1 2 1 + 2 0 Y 1 + 20Y CIE from CDM Y = 0 . 0 1 R d Y = ( 0 . 0 1 L ) 2 X = O.98OI4. (0.01R r t + a \ X = O.98OLL (Y + .01&L] TTFf yj -T737 Z = 1 . 1 8 1 ( 0 . 0 1 - b \ Z = 1 . 1 8 1 (Y - .OlbL) W y j "To—/ MacKinney and L i t t l e ( 1 9 6 2 ) have presented a table in which the CIE values may be determined from Munsell values 0 - 1 0 . Davis and Gould (1955) have developed a method in which Hunterlab readings may be converted to Munsell hue, value and chroma renotat ions , corrected for Munsell value a . This method employed the use of graphs for conversion of a^ and b L to Munsell hue and chroma. The proper choice of the graph was dependent upon the magnitude of the Munsell value, which was determined from the Hunter L value . Kramer ( 1 9 5 D outl ined a number of methods used to determine the colour of a given food item. This included sub-ject ive methods such as colour d i c t i o n a r i e s , Munsell notat ion , the disc colorimeter and objective methods such as color imeters , spectrophotometers and tr i s t imulus ref lectance meters. He 9 pointed out cer ta in l imi ta t ions with measurement of pigment concentration such as the fact that the colour is viewed by the eye may not be c lose ly re la ted to the pigment concen-t r a t i o n . Kramer discussed measurement of colour in terms of value ( l i ghtness ) , hue (dominant wave length) and chroma ( in tens i ty of co lour ) , u t i l i z e d by such tr i s t imulus meters as the Hardy spectrophotometer with t r i s t imulus in tegrator , the Hunterlab Colour and Colour Difference Meter and the Photovolt ref lectometer . Mention was a lso made of the fact that these three d i s t i n c t values could be converted in s ingle values through the use of mult ip le regression equations, charts or nomographs. Many d i f f eren t methods have been used to measure the colour of a sample of green beans. Culpepper ( 1936) in one of the ear ly studies of maturi ty , measured colour' -subject ive ly . The colour was described v e r b a l l y and the samples were ranked in order of preference. Guyer and Kramer ( 1950) u t i l i z e d a panel of s i x members to analyze the q u a l i t y of frozen green beans. Matur i ty , f ibrousness , f lavour and colour were graded on a ten point scale in which 10 indicated the best q u a l i t y and 1 indicated the poorest q u a l i t y . Colour was a lso measured by extract ion of pigments with acetone and determination of t h e i r concentrations with a Beckman spectrophotometer. A three to f ive member taste panel was u t i l i z e d by F i sher and Duyne (1952) to score colour a c c e p t a b i l i t y of green beans, b r o c c o l i and spinach which had been blanched under d i f f erent condi t ions . A f ive point scale was used in which 5 corresponded to very good; L. good; 3 , f a i r ; 2 , poor; and 1, very poor. This method 10 was also used to grade texture , f lavour and abscence of of f f l avour . Objective measurement using the Hunterlab CDM was done by Kattan and Fleming ( 1 9 5 6 ) « Pods were arranged in cross rows in the sample c e l l and measurements were taken on the Rd sca le , with the machine standardized on the pea green -p l a t e . Ross et al_ ( 1 9 5 ° ) u t i l i z e d the spectrophotometrie method of Guyer and Kramer ( 1950) mentioned above as wel l as the Hunterlab CDM. Readings were taken on the Rd scale using a sample which had been ground in a Universal food chopper and spread evenly in a p e t r i plate to a depth:of 3/8 i n . These workers used th is method again (1959) in a study of the "disuniformity" of co lour . Indiv idual beans were a l so measured, by p lac ing them on a p l a s t i c block with a h a l f inch opening. Each bean was s p l i t down the center, and measured for colour on the outside of the pod. Woodroof et al_ (1962) used Hunterlab evaluation as wel l as subjective t e s t ing of fresh and frozen green beans, which had been cooked for 25 minutes. Scoring was done within weights assigned to various q u a l i t y f a c t o r s . Colour was assigned a weight of 3 0 , texture was 30 and f lavour was assigned a weight of h.0. Hunterlab readings were done on beans submersed in . 5 in* of d i s t i l l e d water in a container 1 .5 i n . deep X 3 . 3 i n . square. Readings were taken through a 2 . 2 5 i n . opening, using the Rd sca le . S i s trunk and Fraz i er (1963) u t i l i z e d an eight member panel for t e s t ing cooked canned beans for colour of beans and of l i q u o r , sloughing and 11 general appearance. Deta i l s of the method for r a t i n g samples were not given. The Hunterlab was also used on the canned samples, using the Rd sca le . The Beckman Model B Spectropho-tometer was used to measure the o p t i c a l density of a 1:1 l i q u o r : acetone mixture. Kinesthet ic Measurement Matz (1962) has pointed out the lack of c l a r i t y of the connotation of texture when appl ied to foods. He defined texture as "those perceptions which const i tute the evaluation of a food's phys i ca l c h a r a c t e r i s t i c s by the skin or muscle senses of the buccal cav i ty , excepting the sensations of temperature or p a i n . " The Taste Test ing and Consumer Pre fer -ence Committee of the Inst i tute of Food Technologists (Kramer, 1959) defined texture as "those propert ies of a foodstuff apprehended by the eyes and by the sk in and muscle senses of the mouth, inc lud ing the roughness, smoothness, gra in iness , e tc ." Kramer ( 1 9 5 D l i s t e d chewiness, f ibrousness , succulence and g r i t t i n e s s as the k ines thet ic factors which are important to the objective t e s t ing of vegetable q u a l i t y . Taste panels, consumer preference tests and "expert panel" evaluat ion were discussed by Matz (1962) as a means for tex-ture measurement. The necess i ty of considering the t e s t ing environment inc lud ing such things as i s o l a t i o n , temperature, contro l l ed l i g h t i n g , time of day, number of samples, was s tressed. He a lso stressed the importance of f ibre in veg-etable texture and discussed various means of objective 12 measurement. Matz pointed out the fact that pressure testers incorporat ing a narrow pointed or rounded plunger could not give an accurate measurement of fibrousness because they would tend to spread the f ibres rather than cut them. A discuss ion of the development and use of the shear press was a lso presented. Culpepper ( 1936) measured texture of i n d i v i d u a l fresh snap beans with a pressure tes ter equipped with a . 0 3 2 i n . diameter needle. The tests were made along the sides of the bean midway between the dorsa l and ventra l sutures . The Kramer shear press has been found to be an extremely v e r s a t i l e instrument in r e l a t i o n to i t s t ex tura l measuring propert ies and in r e l a t i o n to i t s use as an ind ica tor of over-a l l q u a l i t y . In studies with peas, Kramer (1953) found the shear press , when modified by e i ther of two types of test c e l l s , was equal in prec i s ion and accuracy to the tenderom-eter , and superior to the texturemeter, the Cefaly instrument and the U.S . raw grade. There was a lso a very good c o r r e l a t i o n to a lcoho l insoluble so l ids ( r = . 82q_ for a l l v a r i e t i e s ) . Rodriguez ejt al_ (1951+) found a high c o r r e l a t i o n between shear press readings and a lcoho l insoluble so l ids of Alaska and Perfect ion peas ( r = . 9 5 1 , . 9 6 5 respect ive ly ) and between the tenderometer and shear press values ( r * . 9 7 3 , . 9 9 8 respec t ive ly ). Kramer ( 1957) b r i e f l y described the operation of the shear press and stated that i t s used included measuring maturity of raw peas, l ima beans and southerm beans, firmness of raw and/or canned apple s l i c e s , beets, spaghett i , chicken, beef and shrimp, fibrousness of asparagus and s t r i n g beans and succulence of sweet corn and apples . Kramer et a l (1959) 13 received good corre la t ions between percent seed and shear press readings of beans, and between shear press readings and percent f i b r e . He used 1 0 0 gram duplicate samples of deseeded pods cut into 2 . 5 i n . lengths. These were l a i d in the sample c e l l perpendicular to the cut t ing blades. A number of d i f f erent sample c e l l s were tested for t h e i r effect iveness by Ang e_t a l ( 1 9 6 2 ) . In studies using canned beans they received widely varying r e s u l t s , regardless of the type of c e l l used ( 1 9 6 3 ) . Using i n d i v i d u a l cans, measured into the c e l l s by means of volume, a poor c o r r e l a t i o n was received in the f i r s t experiment, but a good c o r r e l a t i o n in the second experiment ( r = . 8 7 ) between shear press read-ings and subject ive eva luat ion . The reason for th is was unknown. When samples were composited, weight was used as a c r i t e r i o n of measurement ( l l i 7 grams for the un iversa l c e l l and 2 0 7 grams for the closed sample box). Although resul t s were s t i l l not good, this method did lower the coe f f i c i en t of v a r i a b i l i t y of readings between samples. S i s trunk and Cain ( I 9 6 0 ) measured texture of canned beans o r i g i n a l l y blanched under d i f f erent time-temperature conditions by measuring 150 grams of drained beans into the cup of a standard c e l l and operating the machine at a speed of 5 1/2 using a gauge pressure of approximately 3 0 0 l b s . S i s trunk and F r a z i e r ( 1 9 6 3 ) measured firmness of cooker beans held for d i f f erent periods of time by p lac ing $0 gram duplicate samples in the shear c e l l and using a Kramer shear press modified to contain a 1 0 0 0 l b . pressure r i n g , exc i t er demod-u l a t o r , d i f f e r e n t i a l transformer ind ica tor and a two axis recorder . Ill-Pox and Kramer ( 1 9 6 6 ) used weight as a c r i t e r i o n in studies of grader versus consumer preference in evaluation of bean q u a l i t y . Tests on 100 grams of beans with and without seeds were run in the un iversa l c e l l and in the extrusion c e l l . He found that grading personnel looked at d i f ferent q u a l i t y factors than the consumer. Whereas the graders placed more emphasis on the appearance, the consumer placed more emphasis on the k inesthet ic f ac tor s . They stated that q u a l i t y factors of green beans that contributed to tenderness, appearance and f lavour were c lose ly associated and changed in conjunction with each other as the bean matured. They found that shear press determinations performed on the whole bean corre lated wel l with these associated factors and that the q u a l i t y of the cooked product could be s a t i s f a c t o r i l y predicted by objective t e s t ing of the fresh product.. Fibrousness was measured by Rowe and Bonney ( 1 9 3 6 ) through digest ion with NaOH. This became the USDA o f f i c i a l method. One hundred grams of deseeded pods were cut into 1/2 i n . lengths and pulped in a large mortar. This was transferred to the metal cup of a malted mi lk mixer with 2 0 0 cc of b o i l i n g water and a small piece of p a r a f f i n . The mixture was brought to a b o i l , 25 cc of $0% NaOH was added and boi led for exact ly 5 minutes, then mixed for exact ly 5 minutes. The pulp was f i l t e r e d through a 3 0 mesh monel screen into a Buchner funnel and washed with a 1/1+ i n . stream of b o i l i n g water u n t i l free of a l k a l i n i t y and non fibrous m a t e r i a l . The screen and f ibre were dried for 2 hours at 100°C and weighed 15 Gould (1951) has shown that texturometer readings corre late wel l to f ibre and that th i s machine could be used as a quick method for grading beans as to t h e i r f ibrousness . Guyer and Kramer described the Blendor Method, a modif icat ion of the FDA method described above. One hundred grams of raw, canned or frozen whole green beans were placed in a blender cup with 200 ml . of water and blended for 5 minutes. The sample was poured through a 30 mesh monel screen and washed thoroughly. The f ibrous residue l e f t on the screen was dried in an oven at 100°C for 2 hours, weighed and ca lculated as percent f i b r e . This method was further modified by Wood-roof (1962). He blended 100 grams of deseeded pods for 5 minutes in 200 ml . of water. The pulp was transferred to a 30 mesh monel screen which was 5 1/2 i n . in diameter and 1 1/2 i n . deep. The f ibre was washed with a stream of cold water del ivered through a glass tube 3 i n . long and 1/8 i n . inside diameter, inserted into a rubber tube of l / l | i n . diameter. The glass tube was held approximately 12 i n . above the screen. Af ter washing for 8 minutes the mater ia l was transferred to a tared f i l t e r paper in a Buchner funnel and dried for 2 hours at 1 0 0 ° C . The paper was cooled in a dess icator , weighed and ca lculated as percent f i b r e . Sistrunk (1965) determined f ibre by blending 100 grams of deseeded pods with 200 ml . of water for 5 minutes in a blender at low speed and with the blades reversed on the d u l l s ide . The pulp was washed through a 30 mesh tared monel screen, dried for- 2h. hours at 6 0 ° C , and weighed. The residue was 16 calculated as percent f i b r e . Flavour and Odour Kramer (1951 ) defined f lavour factors as those which the consumer evaluated with his sense of taste and smel l . Even though objective measurement was considered unfeasible due to the phys io log i ca l nature of th is f ac tor , Kramer men-tioned various objective tests which could approximate cer ta in aspects of f l avour . These included sugar determination, s a l t concentrat ion, pH or t o t a l a c i d i t y , and i s o l a t i o n of o f f -f lavour components. Kramer a lso mentioned the use of trained taste panels for evaluation of f lavour and odour. In a d i s -cussion of the factors which produce a fancy pack bean Gould (1950a) stated that f lavour and odour were perhaps the most e lusive factors in qua l i ty evaluation because subjective methods were involved and trained taste panels were requ ired . He f e l t that good f lavour was a product which "excelled in t y p i c a l f lavour and odour, approaching that of the immature fresh bean." Most of the taste panel methods used for evaluation of bean f lavour have already been discussed under the other sections and are not repeated here. These methods included those of Kramer ( 1 9 5 0 ) , F isher and Duyne ( 1 9 5 2 ) , S i s trunk and F r a z i e r ( 1 9 6 3 ) , and Woodroof et a l , ( 1 9 6 2 ) . In addi t ion Gould (1951b) used a panel of 5 judges to rate the f lavour and tenderness of stored canned snap beans. Scores of 1 to 10 were given where a score of 1 indicated o f f - f lavour or toughness and 10 indicated excel lent f lavour or very tender beans. 17 Maturity Maturity has been described as the "stage of development of an organism or that part of an organism that was used as food". (Kramer, 1 9 5 1 ) . Gould ( 1 9 5 0 a , 1 9 5 l b ) has repeatedly stressed the importance of the stage of maturity in the over-a l l q u a l i t y of the f resh , frozen or canned snap bean. He f e l t that maturity was the most important s ingle factor affecting q u a l i t y . Four general methods have been used in measurement of snap bean maturi ty . These included: 1) s i z e , 2 ) time, 3 ) % seed, li) seed length. The Canadian Department of Agr icu l ture (1967) c l a s s i f i e s green and wax beans by means of the pod width. The standards used are: Size of beans (width in inches) Round type of beans (various s ty l e s ) F la t type of beans (various s ty les J No. Optional Word No. Optional Word Less than l l i ^ / 6 l | life/6k to l & V ° h I&V6I4. t o 21/614. 2 l / 6 l i to 2q./6lL 2 l i / 6 l i to 27/6I1 27/6I4. to . . . . des ignation des ignation des ig . des ig . Size 1 small Size 2 small 2 small 2 small 3 medium 3 medium k medium k large 5 large 5 large 6 extra large 6 extra large In a study of the time of development of the f ibrous sheath in the pod wal l Stark and Mahoney (19!i2) u t i l i z e d two methods for grading for maturi ty . Standard sieve sizes recognized by the Bureau of A g r i c u l t u r a l Economics were used, which depended upon the thickness of the pods at the smallest diameter 18 in the center port ion of the pod. The age of the pods was determined by tagging the blossoms at anthes is . Therefore, the second method of maturity measurement used was time. Ross and Brekke (1956) measured maturity by means of size and time. Three s ize groups cons i s t ing of the USDA group s izes 1-3 and size I4. and 5 were used. Maturity by time was reported in terms of an "early", "mid" and "late" p ick ing time. However, the number of days between p ick ing times was not reported. Subjective evaluation was used by Rowe and Bonney (1936) to c l a s s i f y beans into one of three maturity c lasses . The requirements for each class were: Class I - Tender - small or medium sized pods that snapped r e a d i l y when bent. The seeds were underdeveloped in the pod. Class II - F a i r l y tender - large pods that snapped when bent. The seeds were wel l developed but tender. Class III - Mature - large pods, tough, leathery , rubbery or l imp, that would no longer snap when bent. The seeds were general ly wel l developed and s l i g h t l y s h r i v e l l e d . Percentage seeds was a lso studied by these workers as a means of descr ib ing matur i ty . They concluded that standard beans, at optimum q u a l i t y , should not contain any more than 6% seed. 19 V . W o o d r o o f e_t aJL (1962) a l s o g r a d e d b e a n s i n t o m a t u r i t y c l a s s e s b y s u b j e c t i v e e v a l u a t i o n . F i e l d s u b j e c t i v e e v a l u a t i o n was u s e d t o s e p a r a t e pods i n t o "1/h. gr o w n " , "1/2 g r o w n " , o r " f u l l g r o w n " c l a s s e s . W o o d r o o f ert a l p o i n t e d a l i m i t i n g f a c t o r i n t h e u s e o f p e r c e n t s e e d as a means o f c o m p a r i n g m a t u r i t y o f b e a n s grown i n d i f f e r e n t e n v i r o n m e n t s . He showed t h a t c l i m a t e h a d an e f f e c t on t h e p e r c e n t s e e d , c o o l t e m p e r a t u r e and h i g h r a i n f a l l c a u s i n g a r e d u c t i o n . B o a r d and Coote (1959) u s e d t i m e as t h e i r p r i m a r y meas-u r e m e n t o f m a t u r i t y . I n one p r o c e d u r e , p i c k i n g o f a l l beans f r o m one p l o t i n e a c h b l o c k was done e a c h d a y . I n a s e c o n d p r o c e d u r e o n l y t h e l a r g e b e a n s were p i c k e d a t i n t e r v a l s o f 3 , 1+, 5 o r 6 days f o l l o w i n g c o m m e r c i a l p r a c t i c e . E a c h h a r v e s t was f u r t h e r g r a d e d b y means o f s i z e m e a s u r e d a t t h e c e n t e r o f t h e b e a n . The w i d t h l i m i t s u s e d w e r e : No. l - u p ' v t o l h / 6 u . i n . , N o . 2 - l V 6 h - 18/61+ i n . , No. 3-18/61+ - 21/61+ i n . , No.h,- 21/61+ -2I+/61+ i n * a n d No. 5 - g r e a t e r t h a n 21+/6i+-in. Beans h a r v e s t e d b y t h e s e c o n d method were c l a s s i f i e d i n t o t h r e e g r o u p s o n l y : s i z e 3 , s i z e 1+ and s i z e 5« These- w o r k e r s a l s o f o u n d t h a t p e r c e n t s e e d was a f f e c t e d b y s e a s o n , i n c r e a s i n g a t d i f f e r e n t r a t e s f o r c r o p s sown d u r i n g d i f f e r e n t s e a s o n s and a l s o a f f e c t e d b y v a r i e t y . T h i s f u r t h e r i n d i c a t e d t h e l i m i t a t i o n s o f u s i n g p e r c e n t s e e d as a means f o r c o m p a r i n g t h e m a t u r i t y o f g r e e n b e a n s i n d i f f e r e n t e n v i r o n m e n t s . C u l p e p p e r (1936) m e a s u r e d t h e m a t u r i t y o f g r e e n s n a p b e a n s b y t a g g i n g t h e f l o w e r s on t h e d a y t h e y o p e n e d . S a m p l e s 20 were taken at de f in i te time interva ls u n t i l the beans were almost completely mature. Jones and Corner (1968), whild studying the p h y s i o l o g i c a l development of the snap bean pod, used the number of days from flowering as the c r i t e r i a for the stage of maturi ty . They showed that pod development occurred in three stages: I / - pod growth while seeds remain smal l , II - embryo and cotyledons grow r a p i d l y , pod growth decreases, III - pod wal l dries out whild seeds complete t h e i r development. Seed length was found to increase l i n e a r l y with the number of heat units rece ived . These workers suggested the use of the seed: pod r a t i o for pred ic t ion of optimum maturity for harvest . Guyer and Kramer (1950) measured maturity in days from the date of p l a n t i n g . Harvests were made at d i f f erent i n t e r -vals between p l o t s , the ffcst harvest beginning 1+5 days a f t er p lant ing and the others at 1 week, 2 weeks, 10 days or i n t e r -mittent in terva ls a f t er t h i s . Measurement of percent seed was a lso made and these workers concluded that percent seed was the best method of determining optimum market q u a l i t y . They recommended harvest ing at the 8 - 12$ seed stage. Watada and Morris (1967) measured maturity in days, during a study of the growth and r e s p i r a t i o n pattern of the snap bean f r u i t . It was found that the growth rate varied with season, sometimes as much as 2>5%. Because of this they concluded that the chronological age in days a f ter anthesis could not be used for descr ib ing phys io log i ca l changes. This 21 meant that snap beans grown in d i f f erent environments could be at d i f f erent stages of maturity even though t h e i r age was the same. Gould ( 1950a) suggested a q u a l i t y c l a s s i f i c a t i o n of green snap beans on the basis of percent seed. At 8% seed the beans were considered immature. Percent seed and seed length were both found to increase with increas ing sieve s i z e . He a lso found ( 1950c) a c o r r e l a t i o n between percent seed and seed length for frozen ( r = +0.888 ) and for canned ( r = +0.666 ) beans. On the basis of this the q u a l i t y grades became: immature - 9 mm, optimum - 13 mm, and mature — 1? mm seed length. Hibbard and Plynn (191+5) have set up standards by which the seed length may be used to c l a s s i f y green snap beans into maturity c lasses . These standards were: 1. very immature — 7 mm 2 . s l i g h t l y immature - prime market q u a l i t y - 7-10 mm 3 . medium maturity - 10-11+ mm i+. overmature — 11+—18 mm 5- markedly overmature - greater than 18 mm However, they found that summer harvested beans were at a more advanced stage of maturity, than beans of the same seed s ize grown in the f a l l . This indicated that although seed length was a good measure of maturity within a p a r t i c u l a r environment, i t could not be used as a comparison for maturity among beans grown in d i f f erent environments. Parkas ( 1967) found that both percent seed and seed length 22 were h igh ly corre lated with maturi ty . He stated that the seed length w i l l increase at a_rate which is a function of the growing time. He also stated that pod diameter tended to be contro l led by weather, var i e ty and c u l t u r a l pract ices and may increase in e r r a t i c fashion with growing time. This would make pod diameter unsuitable as a comparative technique between environments. Farkas f e l t thatseed length could be used each year in order to determine the grades of crops brought to the processing p lant , rather than the current s i z i n g method. However, he did note that seed length changed between seasons and he stressed the need to revise the s tand-ards each year and between c l imat i c regions . From.the resu l t s of these workers i t can be seen that a l l four methods are affected by environment. Therefore, none of them are absolute for comparison of maturity between d i f f erent environments. 3) FACTORS WHICH AFFECT QUALITY  Ef fec t of Maturity Culpepper (193°) was one of the f i r s t workers to invest igate the ef fect of maturity on q u a l i t y , using the v a r i e t y Burpee S tr ing le s s Green Pod. A subjective evalua-t ion of the cooked product 5 - 1 0 days a f ter anthesis showed a progressive l i ghten ing of the green colour with maturi ty , eventual ly turning greenish brown and then dark brown. Flavour increased to a " r i c h , pleasing" state at 25 days and then decreased. A progressive' increase in toughness with maturity was a lso noted. Culpepper judged the cooked beans to be most 23 palatable at the 20 day stage. The pod was found to increase in length to a maximum at 10 days and to a maximum diameter at 25 -30 days. T o t a l so l ids of the whole bean decreased s l i g h t l y between 5 — 1 ° days and then increased s t e a d i l y . Soluble so l ids decreased in the h u l l and seeds a f t er 15 days while the insoluble so l ids increased s t e a d i l y . It was f e l t that although the increase in insoluble so l ids of the h u l l was due mainly to f ibre accumulation the increase in the whole bean was mainly the e f fect of seed development. The sugar content was always low, increas ing to 20 days and then dropping o f f . There was no change in t i t r a t a b l e a c i d i t y of the h u l l between 15 and 1+0 days, whereas there was a steady decrease in the seed a f ter 15 days. Protein of the whole bean decreased s l i g h t l y between 5 — 1 5 days and then increased. H u l l prote in was low, decreasing a f t er 25 days, whereas the seed prote in s t e a d i l y increased. Resistance to shear increased s t e a d i l y a f ter 10 days. The development of the fibrous sheath in Bount i fu l and Giant S tr ing le s s Green Pod beans was studied by Stark and Mahoney (191+2). They found that the f ibres were located in the inner mesocarp. They or ig inated as a one ce l l ed layer of parenchyma and developed into a layer several c e l l s th i ck which ran at an oblique angle to the pod. The c e l l s remained small u n t i l 20 days a f t er anthesis at which time they thickened by addi t ion of hemice l lu lose . The extent of f ibre development was found to vary with v a r i e t y and to be reduced by cool ra iny f a l l weather compared to hot, dry summer weather. 2 h Stark and Mahoney's descr ipt ion of the f ibrous c e l l s was confirmed by Reeve and Brown ( 1 9 6 8 a ) . In a d d i t i o n , they have studied the development of the other t issues com-posing the bean per icarp (used here to describe a l l the t issues composing the h u l l ) . They found that the basic pattern of t issue development in bean pods is evident several days before f lowering occurs. The outer portions of the per icarp which are we l l developed at opening of the flower consist of an outer epidermis with h a i r - l i k e outgrowths, a one-cel led hypodermal layer immediately below t h i s , and an 8 - 10 ce l l ed young outer parenchyma layer below t h i s . An inner epidermal layer and a one—celled hypodermal layer l ine the pod cav i ty u n t i l just before opening, when they d i f f e r e n t i a t e into the f ibrous sheath and young inner parenchyma l a y e r . A few days a f ter opening, elongation of the f ibre i n i t i a l sheaths is pronounced forming oblique c e l l s at an angle of h $ ° to the pod and about 10 - 12 u wide X 50 T 100 u long. "Transi t ion c e l l s " combining c h a r a c t e r i s t i c s of f ibre i n i t i a l s and parenchymatous c e l l s are present on both sides of the f ibrous sheath. When the pods are about 2 - 5 mm wide, the f ibrous sheath is about 3 or ii c e l l s deep and the inner parenchyma about 10 c e l l s deep. When the pod is about 5 mm wide and 5 cm long, the inner parenchyma is about 30 — LLO c e l l s deep. Growth a f t er th is is due mainly to c e l l e n l a r g -ement. Conducting t issues ar ise from the procambium which is located on the inner port ion of the outer parenchyma c e l l s , during f l o r a l and ear ly p o s t - f l o r a l growth. These changes are shown in Figure 1. FIGURE 1. TISSUE DEVELOPMENT OF THE POD 25 Before Opening outer epiderm hypoderm layer outer parenchyma procambial t issues hypoderm layer inner epiderm Just Before Opening outer epiderm hypoderm layer outer parenchyma i developing vascular bundles young fibrous sheath •j inner parenchyma Pod about 3 mm Wide outer epiderm hypoderm layer outer parenchyma -V- vascular bundles -j- f ibrous sheath , inner parenchyma Further studies by Reeve and Brown (1968b) were made at "edible maturity" or the point where pod diameter was 8 mm. The outer epidermis was found to contain numerous stomata as wel l as a c h a r a c t e r i s t i c a l l y furrowed or ridged c u t i c l e . Although the c e l l walls of the hypodermis were thickened at edible maturity these became great ly thickened at overmature stages. The outer parenchyma contained a wide range of c e l l s izes with not iceably smaller c e l l s just beneath the hypo-dermis and about the vascular bundles. Numerous chloroplasts were located in the middle and innermost c e l l s . These s tarch granules were numerous at edible maturity but disappeared as the pod r ipened. The inner parenchyma c e l l s were thinner walled than the outer parenchyma c e l l s . A few starch granules and some rudimentary chloroplasts were present. Secondary wal l thickening of the s c l e r i d s composing the fibrous sheath was not evident u n t i l the pods were in the l a t e r stages of edible maturi ty . C h a r a c t e r i s t i c wal l thickening was c l e a r l y evident when the pods were overly mature and just beginning to toughen. At maturity the s c l e r i d s were 15 - 30 u in width and 300 - 500 u in length. Tests on s c l e r i d s which had just begun thickening indicated high concentrations of pentosans but only very low concentrations of l i g n i n s . Sc l er ids which form caps about vascular bundles were heavi ly l i g n i f i e d as were secondary wal l thickenings of the xylem elements of the vascular bundles. Pentosans were low in these t i s sues . Hemicelluloses and pectins were found to be h igh ly concentrated in the walls and middle lamellae of the hypodermal layer and c lose ly associated c e l l s . Hibbard and Flynn (191+5) showed that t o t a l ash, phosphorus, calcium, p r o t e i n , n i a c i n , thiamin, ascorbic a c i d , and t o t a l so l ids increase with maturity in the whole bean. Carotene and r i b o f l a v i n were found to decrease with maturi ty . Jones and Corner (1968) found that pod length increased uniformly u n t i l 15 days a f ter anthesis and then varied according to the number of seeds per pod. T o t a l so l ids and a lcoho l insoluble so l ids decreased to 18 - 20 days and then increased. Sugars increased to 20 days and then decreased. In the hu l l s and seeds glucose, fructose and sucrose were the predominant sugars, with stachyose and raff inose present in small quant i t ies Xylose was also found in the h u l l s . Starch was found to decrease in the hu l l s and increase in the seeds with increas ing matur i ty . Guyer and Kramer ( 1950) studied the effects of delaying the harvest past the optimum point of several var i e t i e s of green snap beans. They found percent f ibre increased with maturity and was affected by v a r i e t y and environment. Warm summer weather was found to cause greater production of f ibre than cooler f a l l weather. T o t a l so l ids and ascorbic ac id both increased from the \\% to the 21$ seed stage. Colour was found to decrease in a c c e p t a b i l i t y with increas ing maturi ty . Preference was affected by v a r i e t y and also by season, summer beans being less des irable than f a l l beans. The resu l t s for f lavour a c c e p t a b i l i t y were very contradic tory . One year the 2 1 $ seed stage was rated most f l a v o u r f u l whereas the next year the Q% seed stage was most acceptable. This a l so appl ied to seasonal effects where the f i r s t year the 2 8 spr ing and f a l l crops were considered bet ter than summer and the next year the summer crops were rated h igher . Thereafter , i t was d i f f i c u l t to draw conclusions regarding f lavour alone. Overa l l grade however, which included f i b r e , maturi ty , colour and f lavour decreased as the delay in harvest ing increased. Var ie ty and environment affected th is f a c t o r . The f a l l crop was considered best , followed by the summer and then the spr ing crop. Board and Coote ( 1959) noted a decrease in organoleptic q u a l i t y of Landreth S tr ing le s s bush beans with an increase in matur i ty . The p r i n c i p a l change was due to a de ter iorat ion in texture with the presence of excess seed in mature f r u i t . Fibrousness became noticeable at a very advanced stage of maturity and a lcohol insoluble so l ids increased with matur i ty . An increase in the tough s t r i n g count with increased size was noted by Ross and Brekke (1956) in Blue Lake pole and bush beans. The depth of v i s u a l greenness, measured by the spec tra l absorption of c h l o r o p h y l l , was found to decrease with increased maturi ty . Hunterlab Rd values increased with maturity i n d i c a t i n g a progressive l i ghten ing of co lour . Green-ness, measured on the Hunterlab decreased with increased s i z e . Woodroof et a l (1962) a lso noted th is progressive l i ghten ing of colour as green beans matured to p i ck ing time, accompanied by a decrease in the green and yellow pigments. T o t a l s o l i d s , f ibre and percent seed increased with maturi ty . Percent seed and f ibre were reduced by cool temperatures and high r a i n f a l l . 29 Effec t of Storage An observation that green beans which were packed in ice for 3 or 1+ days tended to become sweeter prompted Flynn et a l (19L.8) to invest igate changes in sugar content during storage. Using the v a r i e t y Tendergreen they followed the reducing sugar and sucrose content over a week at room temp-erature and on cracked i c e . They found that at room temperature sucrose remained unchanged whereas reducing sugars dropped from 1 .92$ to .9% over the 7 day per iod . On cracked i c e , the reducing sugars remained unchanged whereas sucrose rose from .1+0% to . 85$. T o t a l sugars at room temperature changed from 2 .32$ to 1.22$ whereas on cracked ice they changed from 2 .32$ to 2.65%. No mechanism for changes in sugar concentration was proposed and no s t a t i s t i c a l analys is was performed to test the r e s u l t s . S i s trunk (1965) studied the ef fect of storage time and temperature on G a l l a t i n 5 ° and Ear l igreen snap beans. He analyzed samples stored for 1, 3 and 5 days at temperatures of 1.7°C (35 ° F ) , 12.7°C (55 ° P ) and 29.I+°C (85 G F ) . T o t a l sugars, decreased during storage, e s p e c i a l l y at 29 . !+°C. Starch content decreased with storage time and hydrolys i s was marked at 29 . l 4 ° C Cel lulose and hemicel lulose "both decreased in the pods with storage time but increased in the ..seeds. Temper-ature did not markedly af fect the pod ce l lu lose but large increases were evident in the seed stored at 29 .1+°C T o t a l so l ids decreased with time in the pod but increased in the seed~as temperature of storage went up. Protein decreased in the pod but increased in the seed with extended storage 3 0 time or higher storage temperature. Percent f ibre increased with temperature and time of storage. The increase in water soluble pectins was associated with a decrease in calgon soluble pect in (protopectin) with increas ing time in storage. Water soluble pectins increased with temperature in pods and seeds whereas calgon soluble pect in decreased in the ' pods and increased s l i g h t l y in the seeds. Percent seed i n -creased during the storage time and with increased storage temperature. T h i s , along with the changes in prote in which followed Culpepper's descr ipt ion (1936) indicated a con-tinued maturation of the beans during the storage p e r i o d . Watada and Morris (1966a) studied the effects of c h i l l i n g and n o n - c h i l l i n g temperatures on the Tendergreen v a r i e t y of green snap bean. They found that optimum storage was at 5°C whereas de ter iorat ion began a f ter 20 days at 2.5°C and began immediately at .5°C, acce lerat ing at 20 days. At 10°C the symptoms of de ter iora t ion included a s l i g h t l y leathery surface with small and s l i g h t depressions, faded co lour , darkened t i p and calyx and a col lapsed endocarp ( i . e . inner parenchyma). C h i l l i n g symptoms at 2.5°C and .5°C included surface p i t t i n g , diagonal brown streaks , d u l l appearance and b a c t e r i a l breakdown. Some symptoms of both higher and lower temperatures were noted at 5°C. Transfer of low temperature beans to a higher temperature (15°C) caused rapid d e t e r i o r a t i o n . In a second paper (1966b) these workers evaluated 9 c u l t i v a r s of green snap beans for storage l i f e and i n j u r y at 15°C and 5°C At l £ ° C there was a rapid decline in q u a l i t y , then a slowing down accom-31 panied by a decline in r e s p i r a t i o n as the respirable sub-strate was used up. At $ ° C there was slow de ter iorat ion at f i r s t , then more rapid symptoms became evident . Transfer of 5°C stored beans a f t er II4. days to 15°C resul ted in a s t imulat ion of r e s p i r a t i o n and rapid decline in q u a l i t y . There was a marked ef fect of v a r i e t y on storage l i f e at both temperatures used. S i s trunk and Praz i er (1963) studied a d i f ferent kind of storage. Canned Blue Lake pole and Tendercrop bush beans were heated and he l t at 175>°F. These were tested for changes in q u a l i t y at 0, 2 and 1+ hours. They found that colour became l i g h t e r over the l+-hour period and that there was an increase in the yellow : green (bra) r a t i o . Colour changes were markedly affected by matur i ty . Flavour and aroma decreased with extended time. They were not affected over the I4. hours. Size 5 beans were higher in water soluble pectins and sloughed more than size 3, however, and v a r i e t y did have an ef fect upon these f a c t o r s . Ef fect of Blanching A great deal of work concerning the ef fect of blanching on bean q u a l i t y has been done by Van Buren. The ef fect of holding time (I960) was found to depend upon the temperature of b lanching. Above l 8 0 ° F increased time resulted in a decrease in firmness, and an increase in sloughing and s p l i t t i n g . At 170°F however, an increase in firmness and a decrease in sloughing and s p l i t t i n g occurred. It was thought that th is react ion was enzymatieally contro l l ed be-cause a temperature treatment of 190°F or above caused the 32 f i r m i n g a c t i o n t o stop. Presoaking f o r 6 hours i n 2% calcium s o l u t i o n a l s o caused an in c r e a s e i n firmness and a r e d u c t i o n i n s l o u g h i n g and s p l i t t i n g . In another study (Van Buren, 1968a) t h i s c a l c i u m e f f e c t was confirmed and i t was found t h a t the g r e a t e s t response t o calcium occurred before b l a n c h i n g . Van Buren noted t h a t a tex t u r e i n c r e a s e occurred even a f t e r a l l of the c a r b o x y l groups of the i n t e r c e l l u l a r p e c t i c and p e c t i n i c a c i d s had been s a t u r a t e d . Because of t h i s , he f e l t that the f i r m i n g e f f e c t could not be a t t r i b u t e d e n t i r e l y t o the formation of Ca pectate i n the middle l a m e l l a , thereby s t r e n g t h e n i n g c e l l u l a r adhesion. One suggestion was i t h a t other c e l l u l a r t i s s u e s picked up and h e l d c a l c i u m . Calcium pickup was much f a s t e r a f t e r b l a n c h i n g than b e f o r e , presumably due to a lowering of the d i f f u s i o n b a r r i e r as a r e s u l t of b l a n c h i n g . Another e f f e c t of b l a n c h i n g noted by Van Buren ( 1968b) was an in c r e a s e i n a c i d i t y , mainly through the p r o d u c t i o n of p e c t i c a c i d s . T h i s occurred a t b l a n c h i n g c o n d i t i o n s of 1 5 0°P f o r 3 — LL minutes or 1 8 0 ° F f o r 1 minute. Enzyme a c t i o n was once again i n d i c a t e d because the r e a c t i o n could be stopped a t 195 - 2 1 0°P. Presumably, the enzyme i n v o l v e d was p e c t i n methyl e s t e r a s e (PME) d e s c r i b e d by Van Buren et a l (1962) or an enzyme s i m i l a r t o the tomato p e c t i c a c i d deploymerase (PG) d e s c r i b e d by McColloch and Kertesz (191+9). S i s t r u n k and Cain (I960) f o l l o w e d changes i n chemical composition of green snap beans blanched a t d i f f e r e n t tem-p e r a t u r e s . A l c o h o l i n s o l u b l e s o l i d s , r e d u c i n g sugars and water s o l u b l e p e c t i n s were h i g h e s t i n the low temperature 33 blanched ( 130 - 160°P) beans, decreasing with increased temperature. Maximum firmness occurred at 1 6 0 ° P . This was p o s i t i v e l y correlated to the pectate—pectinate concentrat ion. Starch content was highest at 180 - 2 0 0 ° P . The degree of' s loughing and resistance to shear were affected by the temperature of blanch, s ize of beans and by v a r i e t y . Con-s i d e r i n g a l l these factors these workers concluded that optimum blanching conditions were at 170 - l 8 0 ° F for 1 .5 -5 minutes for the Asgrow Regular and the FM-1 pole beans used in the study. In a study of factors which affected the time required to blanch green snap beans at 2 0 0 ° F , Mundt et a l . ( I 9 6 0 ) found that v a r i e t y was the most s i g n i f i c a n t . Size of beans, addi t ion of s a l t s , season and temperature of cool ing water had. l i t t l e or no e f fect on blanching time. Cooling i n a i r fo l lowing blanching reduced the time required to blanch due to longer exposure time of enzymes to heat. Ef fec t of Freezing and Canning Gould ( 1 9 5 l b ) studied a number of d i f f erent factors to see i f they were changed s i g n i f i c a n t l y by canning or--freezing. Fresh and canned beans d i f f e r e d at a l l stages of maturity for a lcoho l soluble s o l i d s , t o t a l s o l i d s , e a s i l y hydrolyzable reserve polysaccharides and in the immature stage for a lcoho l insoluble s o l i d s . A lcoho l insoluble nitrogen and pect in were s i g n i f i c a n t l y , d i f f eren t between samples at the optimum stage. Because canned beans were cons i s tent ly lower, i t was thought that changes were due mainly to leaching into the l i q u o r during the canning process. Fresh and frozen beans d i f fered 3 k only in the immature stage for a lcoho l insoluble so l ids and in the optimum stage for c e l l u l o s e . A l l other com-ponents were non s i g n i f i c a n t i n d i c a t i n g that the fresh and frozen product were nearly i d e n t i c a l in chemical com-p o s i t i o n . Canned and frozen beans d i f f e r e d s i g n i f i c a n t l y at a l l stages of maturity in a lcohol soluble s o l i d s , immature stage in a lcoho l insoluble s o l i d s , t o t a l s o l i d s , e a s i l y hydrolyzable reserve polysaccharides and ash, in the optimum stage for pect in and in the mature stage for c e l l u l o s e . Canned samples were always lower, once again ind ica t ive of leaching during the canning. Ross e_t a_l (1959) studied the degree of uniformity of colour of canned and frozen beans which varied in var ie ty and matur i ty . Increased v a r i a b i l i t y from the mean was i n -dicated by an increase in a "disuniformity" factor which was a c t u a l l y the mean square of the colour values . They found that heat processing caused an increase in the v a r -i a b i l i t y in the l i g h t to dark factor (R d ) whereas freez ing minimized this l ightness v a r i a b i l i t y . They a lso found that l ightness increased in the larger s izes and as p ick ing time approached. Woodroof e_t a l ( 1962) found that green beans frozen quick ly (at - 2 0 ° C unpackaged) contained smaller ice crys ta l s and had a f irmer texture and more a t t r a c t i v e appearance with less leakage a f ter thawing than those frozen slowly in 1 or 2\ l b . packages. Blanched packaged beans retained appearance, aroma, texture , colour and f lavour best at a storage temperature of - 1 5 ° C . Noticeable de ter iorat ion 35 occurred at 12 months although green colour loss occurred, becoming more apparent as storage time increased. Ef f ec t of Growing Conditions As we l l as the work he performed concerning calcium addi t ion during process ing, Van Buren and Peck (1962) a lso studied the effects of calcium concentration in the growth medium. Using Tendercrop bush beans, he found that as the calcium concentration increased, the pods increased in texture and in res istance to sloughing and s p l i t t i n g during process ing. CaSO^ was found to give a greater number of pods/plant and a greater weight/pod per C a C ^ . S o i l moisture has been shown to be a very important fac tor a f f e c t i n g the y i e l d of green snap beans. Binkley (1952) studied the amount of blossom and pod drop occurring in s ix v a r i e t i e s of garden beans. He noticed that plants within a v a r i e t y set s i g n i f i c a n t l y more blossoms than the number of pods harvested from the p lant . The pod and blossom drop var ied widely between plants as we l l as between v a r i e t i e s . The percentage of blossom and pod drop between v a r i e t i e s var ied between 1+11.25$ and 76.21$. Binkley stated that the blossoming and se t t ing period appeared to be the c r i t i c a l period when the bean plant is e s p e c i a l l y sens i t ive to wide var ia t ions in environmental condi t ions . The need for uniform s o i l moisture at this time was indicated by the fact that i r r i g a t i n g dry s o i l increased the blossom and pod drop by 20 - 30$. Kattan and Fleming (1956) subjected the v a r i e t y Wade snap beans to drought conditions at d i f f erent stages of 36 development in order to study the importance of i r r i g a t i o n . They found that i r r i g a t i o n over the period from plant ing to anthesis did not s i g n i f i c a n t l y a l t e r y i e l d , even though moisture stress stunted growth. Water supply during the blossoming and s e t t i n g period was c r i t i c a l , a f f e c t i n g y i e l d through the amount of f l o r a l development and pod set . High moisture stress during the period of pod development was most detrimental to y i e l d , s ize of pods and q u a l i t y , even when preceded by optimal growing condi t ions . Such c o n d i -tions resul ted in lower y i e l d s , high percentage of malformed pods, high percent seed and poor co lour . Consumption and drought i n j u r y increased with the age of the p lan t . Williams (1962) studied the e f fect of water stress on pod set in somewhat more d e t a i l . Water stress before anthesis caused a drop in the degree of f e r t i l i z a t i o n . F l o r a l buds which developed to anthesis produced normal ovules. Stress at anthesis did not af fect the percentage of ovules f e r t i l i z e d . However, water stress during ear ly bloom had long l a s t i n g effects r e s u l t i n g in loss of u n f e r t i l i z e d pods f i r s t , then younger f e r t i l i z e d pods and then older pods. From the resu l t s of these workers i t can be seen that an adequate water supply is required at a l l times, but e s p e c i a l l y during the blossoming, f r u i t set and pod deve l -opment per iods . Production of a water s tress condit ion could af fect re su l t s through i t s a l t e r a t i o n on the y i e l d and q u a l i t y of the f r u i t at harvest . Singh and Mack (1965) found that optimum s o i l temper-ature for the growth of Tendercrop snap beans was between 37 75 and 85°F. The same weights, number of pods and number of flowers were produced by those plants grown under day -night f l u c t u a t i n g temperatures, of 60 - 70°F and 70 - 80°F as those grown at the respective mean temperatures. Growth was bet ter at 55°F than at the f luc tua t ing $0 - 60°F condit ions but poorer at 85°F than at 80 - 90°F condit ions . An ear ly review on the e f fect of a i r temperature on plant growth was by Went (1953). In th is review, Went stated that the optimum temperature for growth of plant parts was f a i r l y h igh , usual ly greater than 25°C. Optimum growth of whole plants was at 31+°C. Respirat ion general ly increased up to 30°C a f ter which i t decreased due to a denaturation of p r o t e i n . Higher sugar contents were a s s -ociated with lower temperatures. Went a lso stated that there was a 1$ reduction in pod set for every degree above 2li°C for peas and beans. Bonner (1957) proposed a theory for the production of chemical defects in plants under conditions of non-optimal temperature. This theory e s s e n t i a l l y stated that climate affected s p e c i f i c biochemical events and non-optimal c o n d i -t ions caused a shortage of one or a few e s s e n t i a l metabol i tes . These shortages of metabolites could be overcome by supplying the substances from an external source. Ketel lapper (1963) tested th is theory by applying l e a f sprays of d i f ferent substances to a number of plants (not inc lud ing Phaseolus) growing under non-optimal conditions caused by temperature v a r i a t i o n s . He found that cer ta in of these sprays did prevent growth reduction under below optimum and above optimum temperatures. IFlhis lent some support to Bonner's theory. 38 More s p e c i f i c a l l y , Mack and Singh (I96I1) found that high temperatures (8I4. - lOl^P) reduced the number of pods/ plant and therefore , the o v e r a l l y i e l d of Tendercrop bush beans. The plants were placed in hotter p l a s t i c cages f ive days a f t er the f i r s t bloom had occurred. I f the f r u i t is removed from the plant before complete maturity is a t ta ined , the plant may set again. The number of times th is w i l l occur is dependent upon temperature, as shown by Ormrod et a l ( 1 9 6 6 ) . Over a 60-day per iod , they found that S tr ing le s s green pod bush beans would under-go two blossoming cycles at 2I4.. 0 / l 5 . 5 ° C (day:night) , three cycles at 2 9 . 5 / 2 1 . 0 ° C and one cycle at 3 5 . 0 / 2 6 . 5 ° C . Beans were misshapen, small had low t u r g i d i t y and lacked f u l l y developed ovules in the 3 5 « 0 / 2 6 . 5 ° C regime and dry maturity was not reached. Dry maturity harvest ing in the f i r s t two temperature regimes resu l ted in senescence with no more f r u i t set . Kaldy (1966) studied the effects of a i r temperature on f ibre development in Tenderlong and Tendercrop snap beans. Temperature was adjusted a f t er f lowering had occurred, to 21 - 2[|°C and 25 - 2 9 ° C . He found that although there were v a r i e t a l differences in amount and length of f i b r e , both v a r i e t i e s increased in content as temperature increased. Tenderlong f ibre consisted mainly of sclerenehyma whereas Tendercrop f ibre consisted of sclerenehyma and collenchyma. He concluded that warm, dry conditions caused an increase in f i b r e . 39 MATERIALS AND METHODS There was a t o t a l of 6 experiments. These were divided in the fol lowing way: Experiment I Temperature was the only var iable and the experiments.were analyzed i n d i v i d -u a l l y . exp. Ia e xp. Ib exp. Ic Experiment II exp. IIa exp. l i b exp. l i e Temperature and maturity were v a r i a b l e s . These were rep l i ca te s in time. The p lant ing and harvest dates for these experiments were: Experiment I - Temperature Date placed Harvest Date of f lowering in chambers Date experiment Ia experiment Ib experiment Ic Aug. 15/67 July 16/67 Aug. 30/67 Aug. 21/67 Sept. 3/67 July 22/67 Aug. 7/67 Sept. 5/67 Sept .22/67 Experiment II - Temperature and maturi ty . Date placed Harvest Date of f lowering in chambers Date experiment I la experiment l i b experiment l i e Experiment I Aug. 2 0 / 6 8 Oct. 9/68 Nov. 2 0 / 6 8 Aug. 27/68 Oct. 16/68 Dec. I1/68 June 3, 8, 13 18, 21+ Oct. 21 ,26 , 31 Nov. 5 , 7 Dec. Ii, 9 , Ik, 19 , 2k. The purpose of the f i r s t experiments was to test the ef fects of temperature on the phys ica l q u a l i t y c h a r a c t e r i s t i c s as wel l as on certa in chemical constituents of green beans. Materia ls The Tendercrop v a r i e t y green snap bush bean was chosen o for th is experiment. Four plants were started in each of 32 one-gallon p l a s t i c pots; then thinned to one plant /pot soon a f ter germination. The plants were grown in a mixture of h a l f s o i l and h a l f peat moss, which had been steam s t e r i l i z e d to destroy weed seeds. Watering was done f r e -quently and the pots were equipped with drain holes so that the s o i l moisture would never exceed f i e l d capaci ty . The plants were grown under greenhouse conditions u n t i l a week a f ter anthes is . At this po int , they were transferred to the environmental growth chambers described by Ormrod ( 1 9 6 2 ) . Temperatures of 20 - 15°C (day:night) , 25 - 2 0 ° C , 30 - 25°C and 35 - 30°C were maintained. Photoperiod was constant for a l l chambers at 16 hours of dayl ight and 8 hours of n ight . The temperature automatical ly dropped to the night temperature when the l i gh t s turned of f . Each chamber had been modified so that i t was a separate unit with two fans on the bottom to provide a i r c i r c u l a t i o n and one fan on top to remove a i r . The high temperature chamber (35 - 30°C) was equipped with a heavy duty heater for be t -t er temperature c o n t r o l . Each chamber contained 8 pots . Methods The plants were grown at these temperatures u n t i l i t was judged that the majori ty of beans had reached the com-m e r c i a l l y des irable #1+ s i z e , (Government of Canada ( I 9 6 7 ) . At th is time, the plants in each chamber were harvested. Two samples were taken from each chamber so as to give some idea of plant to plant v a r i a b i l i t y . The t o t a l weight and t o t a l number of beans were de--termlne'd and then they were hand sorted into #1+ s ize and kl those which were not The percentages of #IL by weight and by numbers were then ca l cu la ted . A l l enzyme a c t i v i t y was stopped by blanching in b o i l i n g water for 3 minutes according to the method of Woodroof ( 1 9 6 2 ) . After blanching the beans were soaked in cold water for 3 minutes. Subsequent analys is included: 1. ) Colour - Each bean was cut into segments I V long and the t o t a l sample was used for colour determination. Colour was measured on the Hunterlab Color and Color Difference Meter using the q." aperture and measuring the L sca l e . The i n s t r u -ment was standardized on the pea green plate (#238h).. 2 . ) Sample preparation - A puree was made by blending the beans with an equal weight of water in a Class ic VIII Oster izer set at "liquefy" for 3 minutes. The weights r e -ported in subsequent analyses are of th is puree and i t should be noted that ca lcu lat ions were done on \ of these reported weights. This was the true wet weight of the samples. 3 . ) pH - The pH was measured d i r e c t l y on the puree using a Bulman Zeromatic pH meter standardized at pH 7 . h.) T o t a l so l ids - The t o t a l so l ids were determined by the method of Ruck ( 1 9 6 3 ) . Eight grams of puree were used. 5. ) Water Insoluble So l ids - A s l i g h t modif icat ion of the method of Ruck (1963) was used. Instead of making the s l u r r y up to 250 ml . i t was made up to 500 ml . before f i l t e r i n g . The f i l t r a t e was saved and used for calcium pectate deter-mination. Twenty grams of puree were used. 6 . ) Percent Water Soluble So l ids - This was done by d i f ference , (Ruck, 1 9 6 3 ) . #W. S. S. = %T. S. - % W. I . S. U2 7. ) Ash - Ten grams of puree were used according to the method of Ruck ( 1 9 6 3 ) . 8 . ) T o t a l Pectin - The Carre and Haynes method (1962) for t o t a l pect in was used on the f i l t r a t e from the water insoluble so l id s determination. 9 . ) Crude Fibre - This was determined according to the Assoc iat ion of O f f i c i a l A g r i c u l t u r a l Chemists (1965) method. The residue from the t o t a l so l ids determination was used as the sample. It was extracted with e thy l ether for ap-proximately 12 hours to remove crude fat before analyses. 1 0 . ) T o t a l Sugars - A modif icat ion of the Lane and Eynon (191+0) copper reduction method was used. The sugar so lut ion was prepared in the normal manner up to the point where the method ca l l ed for invers ion of sucrose by b o i l i n g EOT. Instead, invers ion was caused by leaving the so lut ion 1 overnight a f ter adding 10 ml . of 1:1 H2O : HC1 a c i d . The next day the ac id was neutra l i zed with 5N NaOH, the so lut ion was made up to 100 ml . and t i t r a t e d in the normal way. Twenty grams of puree were used. 1 1 . ) Percent Protein - The percent prote in was deter-mined by MicroKje ldahl (A. 0 . A. @., 1 9 6 5 ) . The factor of 6 . 2 5 was used to convert % N to % p r o t e i n . About 100 mg. of dry sample were used. Experiment II Rather than analyze a s ingle harvest in Experiment II as in Experiment I th is experiment was designed to analyze the green beans over the ent ire maturity range. 1+3 Materia ls Forty pots of the v a r i e t y Tendercrop snap bush beans were grown in the same way as in Experiment I . The pots were rearranged every two days in order to minimize any v a r i a t i o n caused by d i f ferent locat ions on the greenhouse bency. Seven days a f t er anthes is , 10 pots were placed in each growth chamber. The same temperature regimes were employed as in Experiment I . Methods Because of l imi ted m a t e r i a l , only one sample was taken at each harvest . One hundred grams of beans were harvested at 11+, 19, 21+, 29 and 31+ days a f t er anthes is . This exper-iment was repeated three times. The raw mater ia l was measured for t o t a l weight, length of pods, width of pods, seed length. Further analyses included: 1. ) Colour — Each of the beans of the 100 gram sample was cut in h a l f and t h e i r colour was measured on the Hunter-lab Color and Color Difference Meter. Sample presentation was by the method of Woodroof e_t al_ (1962). The L and R d scales were employed, using the 1+" aperture and s tandardiz in on the pea green plate (#2381+). 2. ) Texture - The sample was s p l i t into a 60—gram and a 1+0-gram subsample. The 1+0-gram subsample was placed randomly into a un iversa l c e l l and i t s resistance to shear was measured on the A l i o - Kramer Shear Press . The sett ings employed were: proving r i n g - 2500 l b s . , range - 50%, speed 8 and pressure - 200 l b s . Maximum resistance was determined from the peak of the res istance curve. hh 3 . ) Percent Fibre - This was determined by the Blendor method of Guyer and Kramer ( 1 9 5 1 ) • The residue from the shear press was recovered and used for f ibre determination. Ii. ) Sample preparation - The 60-gram subsample was blanched and used to form a puree in the same way as in Experiment I . After t o t a l so l ids determination, the puree was placed in aluminum trays , frozen and freeze d r i e d . A Thermovac freeze d r i e r (model FDL-10DR) was used with a o pressure of about 2 u and a plate temperature of J±0 — 50 F . Time of drying was approximately 12 hours. Af ter drying the residue was ground with a mortar and pestle and stored in a i r - t i g h t j a r s . In order to minimize v a r i a t i o n due to lab technique subsequent analys is was not performed u n t i l a l l of the samples from the experiment had been c o l l e c t e d . 5 . ) T o t a l so l ids - Two-gram duplicate samples were used to determine t o t a l so l ids by the method of Ruck ( 1 9 6 3 ) . 6 . ) Water Insoluble So l ids - Because of the d i f f i c u l t y encountered in f i l t e r i n g the s l u r r y in the f i r s t experiment, Ruck's method was modif ied. Duplicate 1-gram samples were weighed into 250 ml . beakers and about 200 ml . of water were added. This was bo i l ed gently for one hour, during which time the water evaporated to less than 100 ml . The water and insoluble so l ids were transferred completely to 100 ml . volumetrics , made up to volume and then transferred to 250 ml . centrifuge b o t t l e s . Centr i fugat ion was carr ied out for 10 minutes in an Internat ional IEE Centrifuge (size 2 ) . Each sample was then e a s i l y suct ion f i l t e r e d through weighed and dried #ii Whatman f i l t e r paper. The residue was washed l i g h t l y and the f i l t r a t e was saved for pect in determination. After removing the f i l t r a t e , the insoluble so l ids were thoroughly washed with d i s t i l l e d water, dr ied at 105>°C and weighed. $W. I . S. = 100 x wt. paper + wt. i n s o l . s o l . - wt. paper Ingram 7. ) Water Soluble Sol ids — This was again determined by d i f f erence . $W. S. S. = 100$ - $W. I . S. 8. ) Ash - About .3 grams of sample was weighed into tared and weighed crucibles and ashed for 12 hours at 550°C in a muffle furnace. 9. ) T o t a l Pectin - The 100 ml . so lut ions from the water insoluble so l ids determination were used for calcium pectate determination bythe Carre and Haynes method (1962). 1 0 . ) T o t a l Sugars - The same procedure was used a s - i n Experiment L . I t was found that as the maturity increased, the weight of sample had to be increased from 1.5 grams up to 3 grams in order to obtain readings with the 100 ml . s o l u t i o n . 11.) Prote in - The same method as experiment I was employed. 12.) Starch - A modif icat ion by Gates (1969) of the method by Pucher e_t a_l (191+8) was used for starch determin-a t i o n . About 100 mg. of sample were weighed accurate ly into 100 x 13 mm. test tubes. The samples were rehydrated in h. ml . of d i s t i l l e d water and the starch was ge la t in ized by heating in a b o i l i n g water bath for 1$ minutes. The tubes were then cooled below 20°C in crushed ice to prevent any hydrolys i s of the s tarch due to the pH drop and heat r i se u.5a caused by addition of acid. A f t e r standing at room tem-perature the samples were centrifuged in a P h i l l i p s Drucher Model L - 7 0 8 Centrifuge and the supernatant was poured into a 50 ml. volumetric f l a s k . Four ml. of water were added to the residue, the tubes were cooled and 3 ml. of 70$ perchloric acid were added. After 20 minutes, the contents of the tubes were transferred to the appropriate volumetric f l a s k which was made up to volume and then f i l t e r e d through lilH Whatman f i l t e r paper. A standard curve was prepared of the concentration of p u r i f i e d potato starch and the 0 . D. on reaction with iodine solution. This was used to determine starch concentrations of the samples. Five ml. of the starch solution were mixed with 50 ml. of 1:1 B^O:iodine solution and the 0 . D. determined on a Beckman Model C colorimeter, using a $0% transmission neutral density f i l t e r . The composition of the stock iodine solution was: 11 g. I 2 crystals + 2L g. KI made up to 500 mis (Sandstedt, 1 9 3 9 ) . S t a t i s t i c a l Analysis Experiment I_ - The experimental design for this f i r s t major experiment was that of a Complete Randomized Design. The material was grown under equal conditions and then allocated to four chambers. Replications within each experiment under this section were supplied by taking two samples from each chamber. Single factor analysis of variance was employed for each experiment to test the significance of r e s u l t s . Duncan's New Multiple Range Test was employed on the means of the replicates to determine where s i g n i f i c a n t differences occurred. Ii6 S t a t i s t i c a l Analysis cont 'd . Experiment I I - This was designed as a S p l i t P l o t . Because three r e p l i c a t i o n s in time and k temperatures were used, there were twelve b locks . Within each block a number of harvests were taken. The beans reached maturity faster as the temperature was r a i s e d . Because of t h i s , there was not the same number of harvests within each temperature. At 35>°C f u l l maturity was reached by 21+ days. At 30°C f u l l maturity was reached by 3k days but there was i n s u f f i c i e n t sample to al low for any analys is other than these on the raw beans. At 25°C maturity occurred at 3k days with s u f f i c i e n t sample for a l l analyses . Although complete maturity had not occurred at 3k days for samples grown at 20°C no more harvests were done a f ter th is time. Because of these varying end po ints , three separate analyses of variance were performed. The f i r s t included a l l four temperatures for the f i r s t three harvests . The second analys is included 20°C, 25°C and 30°C values for k harvests and the la s t analysis included the f i r s t two tem-peratures for a l l f ive harvests . In analyses where resu l t s for 30°C had been obtained for 5 harvests , the analys is of variance was performed for 20°C, 25 C and 30°C for 5 harvests . In this way, a l l values composing the maturity curves of the beans grown at each temperature were compared. 1+7 RESULTS AND DISCUSSION EXPERIMENT I The major purpose of Experiment I was to determine which resu l t s appeared to be affected by temperature and would warrant further inves t igat ion during the l i f e of the f r u i t . Single Factor Analys is of Variance was used to determine whether the values received for each analys is d i f fered s i g -n i f i c a n t l y . Duncan's New Mul t ip l e Range Test was employed to determine where any s i g n i f i c a n t differences had occurred. Although i t was not r e a l i z e d at the time of Experiment I , the values for experiments a, b and c could not be used as rep l i ca te s in the Analys is of Variance program.. The date of harvest was chosen v i s u a l l y and in doing so the samples in experiments a, b and c d i f f ered chrono log ica l ly in t h e i r stage of matur i ty . Experiment a was harvested 20 days a f t er anthesis , experiment b at 23 days and experiment c at 21+ days a f t er anthes is . I t was f e l t that i f these were combined the natura l changes due to increas ing maturity would be confused with those of temperature. Therefore, each experiment was analyzed separately and conclusions were drawn from a comparison of t h e i r r e s u l t s . The resu l t s from Duncan's New Mul t ip le Range Test are pr inted in the f igures for each a n a l y s i s . T o t a l Sol ids When the s t a t i s t i c a l analys is of the three experiments was compared, the resu l t s did not co inc ide . In experiment l a , the t o t a l so l ids for temperatures 20°C and 25>°C were not s i g n i f i c a n t l y d i f f e r e n t . This means that s i g n i f i c a n t differences occurred between 20 - 25°C, 30°C and 35°C. In ii8 experiment Ib, t o t a l so l ids d i f fered s i g n i f i c a n t l y between the ranges of 20 - 25°C and 30 - 3 5 ° C . In experiment Ic, the converse of experimentIa occurred and s igni f icance occurred between t o t a l so l ids of beans grown at 2 0 ° C , 25°C and 30 - 35°C. In Figure 2 , i t can be seen that t o t a l so l ids for experiment Ia and Ib increased only moderately when compared to the rapid increase in t o t a l so l ids of experiment I c . It can be concluded, however, that increases in temperature did cause an increase in t o t a l so l ids of the snap bean. T o t a l so l ids determination was, therefore, c a r r i e d on to the maturity study of Experiment I I . Water Insoluble So l ids The analys is of resu l t s for experiments Ia and Ib showed consistent trends. These both indicated a high l e v e l of s ign i f i cance between insoluble so l ids in beans grown at 2 0 ° C , 25°C and 30 - 3 5 ° C . Experiment Ic indicated s i g n i f -icant differences among a l l four growing temperatures. Temperature was shown to have a marked ef fect on the water insoluble so l ids component of the green bean composition. Increasing temperature caused an increase in the percent water insoluble s o l i d s , as can be seen in Figure 3 a . On reference on Figure 3 b , however, i t can be seen that water soluble so l ids (calculated by dif ference) remain r e l a t i v e l y constant. A l s o , the curves for water insoluble so l ids are remarkably s i m i l a r to those for t o t a l so l ids of the same samples. This s i m i l a r i t y is to be an ind ica t ion that the major increase in t o t a l so l ids is due to-an increase in some or a l l of the components of the water insoluble so l ids with matur i ty . Culpepper ( 1 9 3 ° ) a t t r ibuted this mainly to 1+9 FIGURE 2 . THE EFFECT OF TEMPERATURE ON TOTAL SOLIDS 21+r 22U 20 3 18 hi o co < EH O EH 16 12 10 20 25 CENTIGRADE 30 35 Duncan's New Mul t ip le Range Test exp. Ia 20 25 30 35 '** #* ** 30 ** * 25 N.S. exp. Ib 20 25 30 •jO ** ** 25 'N.S. N.S exp. Ic 20 25 30 35 ** ** N.s 25 * * S ign i f i cant to the 5% l e v e l . * # S ign i f i cant to the 1% l e v e l . Duncan's New Mult ip le Range Test exp. Ia exp. Ib exp. Ic 20 25 30 20 25 30 20 25 30 35 * * * * N . S . 35 * * * * N . S . 35 30 30 30 25 ** 25 ** 25 51 FIGURE 3b. THE EFFECT OF TEMPERATURE ON WATER SOLUBLE SOLIDS lOf -J 1 1 i _ 20 25 30 35 ° CENTIGRADE DuncanTs New Mul t ip le Range Test exp. Ia exp. Ib exp. Ic 20 ^ 30 2 0 2 5 3 0 2 0 2 5 3 O 35 35 35 30 N. s. 30 N. s. 30 N. s. 25 25 25 52 Alcohol Insoluble Sol ids Alcohol insoluble so l ids determination was used in Ex-periment I as an estimation of the s tarch content. This procedure was replaced in Experiment II with a s tarch a n a l y s i s . In experiment l a , a lcohol insoluble so l ids did not d i f f e r s i g n i f i c a n t l y between 20 and 25°C but s i g n i f i c a n t differences occurred between 20 - 2 5 ° , 30°C and 35°C. In experiment l b , s i g n i f i c a n t differences occurred in a lcoho l insoluble so l ids between 20°C, 25°C and 30 - 3 5 ° C In experiment Ic , a l coho l insoluble so l ids d i f f ered s i g n i f i c a n t l y between a l l growing temperatures. The pattern of the a lcoho l insoluble so l ids curves in Figure 1+ is s i m i l a r to that cf t o t a l so l ids and a temperature increase has resul ted in an increase of a lcoho l insoluble s o l i d s . T o t a l Sugars Sugar analys is was done for experiments l a and Ic only, but the resu l t s for these experiments indicated a s i g n i f i c a n t difference in sugar content between the ranges of 20 - 25^C and 30 - 3 5 ° C Sugar content did not change s i g n i f i c a n t l y within these ranges. Figure 5 shows that increased temperature has resul ted in a drop in sugar content of the whole bean. This drop in sugar content was in con-junct ion with the increase in a lcohol insoluble so l ids and may be ind ica t ive of a temperature ef fect on maturi ty . Temperature increase may be hastening the onset of maturity with a resul tant fas ter increase in s tarch content ( indicated by a lcohol insoluble s o l i d s ) and a net decrease in the ava i lab le energy source, the free sugars. The increased 53 FIGURE hJ THE EFFECT OF TEMPERATURE ON ALCOHOL INSOLUBLE SOLIDS I 6 r 12 10 8 6 k 2 C O P M O C O CQ E> o C O fe H o o o Ic l a lb 20 25 ° CENTIGRADE L_ 30 i _ .35 Duncan's New Mul t ip le Range Test exp. Ia 20 25 30 35 ** 30 ** 25 N.S. exp. Ib 20 25 30 35 ** 30 ** 25 * ** N.S. exp. Ic 20 25 30 35 ** •jo ** ** 25 * FIGURE 5. THE EFFECT OF TEMPERATURE ON TOTAL SUGARS 20 25 30 ° CENTIGRADE 35 Duncan's New Mul t ip le Range Test exp. -Via 20 25 30 35 * * 35 30 * 30 25 N.S . 25 exp. Ib 20 . 25 3£ Analysis not done exp. Ic 20 25 30 35 * * N.S, 30 * * 25 N.S . 55 Ash The resu l t s for experiment la showed no s igni f icance in d i f ference , but analys is of variance resu l t s of experiments lb and Ic had consistent d i f ferences . There was a s i g n i f i c a n t difference in ash between beans grown in the range of 20 -25°C and 30 - 35°C. It can be seen in Figure 6 that increas ing temperature has caused an increase in ash content. It was not cer ta in whether the non s i g n i f i c a n t resu l t s for experiment La were due to the younger chronological age of the sample. This uncertainty led to a study of the changes in ash content over the maturity cycle at these temperatures in Experiment I I . Protein The resu l t s for prote in determination were v a r i a b l e s . In experiment l a , there were no s i g n i f i c a n t differences in prote in content at the four temperatures. In experiment lb prote in content was I.'sign i f i c a n t l y d i f f erent at 20°C versus the other temperatures. In experiment Ic , however, s i g n i f i -cant differences in temperature were noted for 20 - 25°C; 30°C and 35°C. It can be seen in Figure 7 that prote in in Experiment l a rose s l i g h t l y with increased temperature even though differences were non s i g n i f i c a n t , a lso experiment lb showed a trend opposite to that i n experiment Ic . Whereas prote in in experiment Ic decreased at f i r s t , there was an increase in experiment lb which rap id ly reached the maximum value at 30°C and then decreased. Experiment Ic prote in increased a f t er 25°C to reachaa maximum value at 35°C. This lack of consistency did not allow def in i te conclusions about the effect of temperature on prote in content. Protein was a lso determined in Experiment I I . 56 FIGURE 6. THE EFFECT OF TEMPERATURE ON ASH Duncan's New Mul t ip le Range Test exp. Ia exp. Ib exp. Ic 2 0 2 5 3 0 20. 25 30 2 0 2 5 3 0 35 35 * * * N . s . 35 * * N . S 30 N . S . 30 ** ** 30 * * 25 25 N . S . 25 N . S . FIGURE 7. THE EFFECT OF TEMPERATURE ON PROTEIN 57 Duncan's New Mul t ip le Range Test exp. Ia 20 25 30 35 30 N. S. 25 exp. Ib 20 25 30 35 * N.S. N.S. 30 * N.S. 25 * exp. Ic 20 25 3£ 25 N.S. 58 Pectin The resu l t s for pect in were also confusing because they not consistent among experiments l a , Ib and Ic . In e x p e r i -ment Ia , a high l e v e l of s ign i f i cance occurred for a l l growing temperatures but in experiment Ib, the differences were non s i g n i f i c a n t . In experiment Ic , only pect in values o from beans grown at 35 C d i f fered s i g n i f i c a n t l y and pect in values from 20°C, 25°C and 30°C did not d i f f e r s i g n i f i c a n t l y . Figure 8 i l l u s t r a t e s th is confusion. Experiment Ia and the non s i g n i f i c a n t experiment Ib tend to follow the same pattern with the maximum value at 30°C. Experiment Ic , o however, drops s l i g h t l y at 30 C and then r i ses r a p i d l y . This is the complete opposite of the other two experiments. Because of the confusion of these resul t s no conclusions could be made about pect in at th is time. Because there did appear to be some response this analys is was carr ied on to Experiment I I . pH The pH values of the puree were not analyzed or graphed because the pH of the puree samples never varied from the s ingle value of 6.1. It was obvious that temperature had no ef fect on pH and so this port ion of the experiment was discont inued. Crude Fibre Crude Fibre analys is was not performed on experiment Ia . The analys is of variance for experiments Ib and Ic showed no s i g n i f i c a n t d i f f erence . Figure 9 shows that the crude f ibre content did not change much over the temperature 59 FIGURE 8. THE EFFECT OF TEMPERATURE ON CALCIUM PECTATE 20 35 ** ** 30 ** * 25 •** Duncan's New Multiple Range Teat exp. Ia exp. Ib exp. I 30 20 25 30 20 25 ** 35 35 * ** 30 N. S. 30 N.S. N.S 25 25 N.S. 60 FIGURE 9. THE EFFECT OF TEMPERATURE ON CRUDE.FIBRE Duncan's New M u l t i p l e Range Test exp. Ia exp. Ib exp. Ic 2 0 2 5 3 0 2 0 2 5 3 0 2 0 2 5 3'5 35 35 Analys is not 30 30 N - S. 30 N - S. done 25 25 25 61 range. Experiment lb showed a s l i g h t decrease a f t er 2 5 ° C o whereas experiment Ic showed a decrease a f t er 2 5 C and then a s l i g h t r i s e a f t er 3 0 ° C . These non s i g n i f i c a n t differences warranted d iscont inuing crude f ibre determination. Colour The resu l t s for Hunterlab Color determinations were extremely poor and of no value in determining the effects of temperature on the colour of the green beans. Results for experiments l a and lb did not coincide and were gross ly d i f f erent for l ightness (L) , greenness (a), a/b r a t i o and L / a r a t i o . Results from experiment Ic showed no s i g n i f i -cant d i f f erences . These poor resu l t s were probably due to the method of presentation of sample. It was thought that two items were not adequately c o n t r o l l e d . F i r s t , no contro l of sample weight was exerc ised , probably r e s u l t i n g in varying densit ies of samples. Because the Hunterlab r e l i e s upon the amount of l i g h t re f l ec ted back to the photo sens i t ive c e l l s , th is varying density could cause gross differences in the read-ings which could not be v a l i d l y compared. The second item: was presenting a blanched sample to the machine, because blanching resulted in a deepening of the green colour and poss ib ly cancel led out many of the effects that growing conditions had imparted. Results could not be v a l i d l y a t -tr ibuted to temperature because of this influence of blanching. In Experiment II this method of presentation was changed so as to give a v a l i d appra i sa l of co lour . One hundred gram samples were used which were not blanched. These were placed in a tray and water was added to a depth of V , (Woodroof, 1 9 6 2 ) . 62 EXPERIMENT II The major purpose of Experiment II was to determine the ef fects of temperature through the ent ire l i f e span of the f r u i t . Growth and Y i e l d Most of the work done on growth and y i e l d has been concerned with the ef fect of temperature on blossom and pod drop. The conclusions were that high temperature during anthesis and/or pod set reduced lower y i e l d because of low f r u i t set or blossom and pod drop. In this study, the temperature was changed s u f f i c i e n t l y late to prevent these phenomena from occurring and the ef fect of temperature on the development of the f r u i t i t s e l f was s tudied. Any effects on the f r u i t and therefore on the f i n a l y i e l d would be expressed through changes in the pod width, pod length, seed length and average weight. Pod Width Pod width was found to increase s i g n i f i c a n t l y with maturity (Figure 1 0 ) . It can be seen in Figure 10 that there is considerable in terac t ion between the maturity curves of the 2 0 ° C , 25°C and 30°C grown beans. The 3 0 °C beans began to decrease in width a f t er 21± days, but the 25°C beans con-tinued a steady increase to 29 days when maximum width ap-pears to have been a t ta ined . The 20°C beans maintained a steady increase in pod width and by 3k days they had shown no signs of reaching a maximum or decreasing. These resul t s are ind ica t ive of varying rates of maturity onset. The beans grown at higher temperatures appear to have reached a cer ta in 63 FIGURE 10. EFFECT OF MATURITY AND TEMPERATURE ON POD WIDTH • 5r . 2 • — 1 • ' lb" 19 2k 29 3k DAYS AFTER ANTHESIS Analysis of Variance ^•Time *"* Temperature * Time x Temperature N.S. ©Time ** Temperature 'N.S.Time x Temperature ** £ Calculated for l i temperatures up to 2I4. days. © C a l c u l a t e d for 3 temperatures up to 3k days. 6[+ stage of maturity within a shorter time than beans grown at a lower temperature. The decrease in pod width a f t er th is point is thought to be due to a reduction in thickness of the pod wal l associated with the onset of senescence of the pod, as the seed approaches complete maturi ty . The most s t r i k i n g e f fect of temperature was the s i g n i -f i cant reduction in pod width of those beans grown at 35>°C. In this case, the high temperature had caused a stunting of the pod development such that the width of the pods over the whole maturity range, was less than that of the lowest growing temperature 20°C. This reduction in diameter could very wel l r e s u l t in a decrease of f i n a l y i e l d of the crop. Pod Length Culpepper (1936) stated that maximum pod length occurred 10 days a f t er anthes is . Jones and Corner (1968) found that maximum length was attained 15 days a f ter anthes is . No matter which value is considered, the ac tua l pod length increase could not be followed in th i s experiment. What could be determined was whether any temperature would extend this period of increase or whether a temperature change, beginning 7 days a f t er anthesis would have a net effect on the pod length. Prom Figure 11, i t can be seen that there was a s i g n i f i -cant e f fect of temperature and maturity on pod length. The range of 20 - 25°C has a lso extended the period of length increase reported by the above workers so that at these lower temperatures maximum length occurred at 21+ days. Greater pod lengths were attained at 3 ° ° C by the time of the f i r s t harvest . This remained constant u n t i l 21+ days when the length 65 Analys is of Variance ^TimeNS Temperature * ©Time *•• Temperature * Time x Temperature NS Time x Temperature NS ^Calcu la ted for li temperatures up to 2k. days. © C a l c u l a t e d for 3 temperatures up to 3k days. 66 began to decrease, once again probably as an ef fect of pod senescence. High temperature ( 3 5 ° C ) has once again caused a s tunt in of the s ize of pods so that values were lower than for any of the other temperatures. These resu l t s indicate that at temperatures above 25°C the pod length was stunted and that th i s condit ion was started some time before 11+ days a f ter anthes i s . Seed Length Measurement of seed length showed the r e l a t i v e s izes of the seeds in the beans grown at the four temperatures. Seed length was found to increase s i g n i f i c a n t l y with tem-perature to 3 ° ° C and to increase s i g n i f i c a n t l y with maturity Figure 12 shows that seed length increased with temperature up to 21+ days but that 30°C rather than 3 5 ° C was the optimum temperature for large seed lengths. Once again 3 5 ° C had a s tunt ing e f f e c t . In this case, rather than causing a reduction below the values of the other temperatures, seed length was reduced u n t i l i t was just below the values for 30°C beans. Maximum seed length occurred at 29 days for 30°C beans and maximum length appears to have occurred for 25°C beans at 31+ days. Once again the 20°C beans have exhibi ted a steady increase in seed length u n t i l 31+ days and there is no i n d i c a t i o n that a maximum length had been reached at th is po in t . Average Weight Whereas the other measurements described the s ize of 67 i FIGURE 12. EFFECT OF MATURITY AND TEMPERATURE ON SEED LENGTH —I 1 1 1 i -111. 19 21+ 29 3 1 + DAYS AFTER ANTHESIS Analys is of Variance •fcTime '** Temperature** Time x Temperature NS © T i m e ** ; Temperature* Time x Temperature NS f ^Calcu la ted for 1+ temperatures up to 21+ days. © C a l c u l a t e d for 3 temperatures up to 31+ days. 68 bean th is factor measured the y i e l d of whole beans in terms of weight. The average weight was found to be affected by both temperature and maturi ty . As can be seen in Figure 1 3 , the optimum temperature was 25°C u n t i l 29 days. At the higher temperatures of 30°C and 3 5 ° C there was a large o reduction in y i e l d . The 20 C beans although low for the major part of the time"studied increased s t ead i ly and at 29 days these pods became the heaviest . o It can be concluded that 35 C is too high a temperature for good bean development because there is a reduction in the o v e r a l l s ize and also average weight of the pods. A l -though the pod width and seed length of 30°C beans are high for part of the maturation stage, the reduction in s ize expressed by pod length and reduction in average weight i n -dictate that th is temperature is a lso too high for good development and maximum y i e l d . Considering pod width, pod length and average weight over the time s tudied, the resu l t s o indicate that 25 C is the optimum growing temperature. I f th is study had been carr i ed pas the 31+ day per iod , i t would be expected that the 20°C beans would become greater than the other three temperatures for seed length, pod width and average weight because of the steady increase these curves showed. Loewenberg ( 1965) has found that f i n a l s ize is not so much re lated to the rate of growth as to the dur-at ion of growth and so this large f i n a l s ize of the slower growing 20°C beans would be expected. However, at 3k- days these beans were past the point of edible maturity , as i n -dicated by the large seed length. Since y i e l d is important only in terms of edible beans i t is concluded that 25°C i s the best temperature for obtaining the good q u a l i t y high y i e l d . 69 FIGURE 13. EFFECT OF MATURITY AND TEMPERATURE ON AVERAGE WEIGHT — I 1 1 I L Ik 19 21+ 29 3 k DAYS AFTER ANTHESIS Analys is of Variance ^.Time-** Temperature** Time x Temperature NS ©Time ** Temperature ** Time x Temperature ** ^•Calculated for l i temperatures up to 2q. days. © C a l c u l a t e d for 3 temperatures up to 3 k days. 70 Colour Colour was measured on the Hunterlab Color and Color Difference Meter and each of the three parameters, l i g h t -ness, greenness and yellowness were analyzed separate ly . Lightness - The l ightness did not change s i g n i f i c a n t l y for the f i r s t 21+ days a f ter anthesis , but a f t er this time a rapid increase in l ightness occurred for beans grown at 30°C and a s l i g h t increase in beans grown at 25 and 20°C (Figure 11+). Temperature did not af fect l ightness very much over the 20 - 25°C range, but a large increase in l ightness occurred at temperatures of 30°C and again at 35°C. The 35°0 beans appeared to have reached a maximum l ightness at 19 days and then decreased. This case is thought to be due to a change in the i n t e g r a l nature of the green colour of the bean. Culpepper (1936) noted that a l i ghten ing occurred with increas ing maturity followed by a change to a greenish brown colour and f i n a l l y a brown co lour . I f the beans at 35°C had reached this stage a f t er 19 days, the new colour could have caused a net decrease arlt l i gh tnes s . This stage was not reached in beans grown at 30°C or lower over the period s tudied . Greenness - This did not change s i g n i f i c a n t l y with maturity for a l l four temperatures over the ent ire period studied (Figure 15)« Temperature did not cause any s i f -n i f i c a n t differences in greenness from 20 - 30°C but at 35°C there was a s i g n i f i c a n t increase . Woodroof (1962) noted a decrease in the greenryellow pigments as the bean grew af ter normal p i ck ing time. In the present experiments, at 35°C a decrease in greenness occurred a f ter 19 days and a It FIGURE l l i . EFFECT OF MATURITY AND TEMPERATURE ON LIGHTNESS 111 19 2li 29 3k DAYS AFTER ANTHESIS Analys is of Variance ^Time NS Temperature-** Time x Temperature NS © T i m e / * * Temperature ** Time x Temperature NS ^Calcu la ted for li temperatures up td 2LL days. © C a l c u l a t e d for 3 temperatures up to 3k days. 7 2 FIGURE 15. EFFECT OF MATURITY AND TEMPERATURE ON GREENNESS 1 2 r ca CO CO w W es 1 1 . 1 0 35°C " 3 0 ° C 25°C 2 0 ° C .« Ik 1 9 2LL 2 9 31*. DAYS AFTER ANTHESIS Analys is of Variance ^ TimeNS Temperature ** Time x Temperature NS © T i m e N S Temperature NS.Time x Temperature ** £ Calculated for LL temperatures up to 2 L L days. © C a l c u l a t e d for 3 temperatures up to 31+ days. 73 o decrease at 30 C occurred a f ter 2 9 days. This is an i n -d ica t ion that at 35°C the beans quick ly entered a stage of overmaturity not attained by 3 0 ° C beans u n t i l 29 days. The 20° and 2 5 ° C beans did not decrease as did those at higher temperatures, but the 2 5 ° C beans showed a rapid r i s e in greenness at 29 days. Because th is occurred just before the decrease in greenness in 3 0 ° C beans i t may be an i n d i c a t i o n that these beans are about to enter this stage of overmaturity a l s o . Because the f i n a l harvest occurred at 3k days this condit ion could not be determined. As o with l i ghtness , the 20 C beans were increas ing slowly with no signs of any abrupt changes occurr ing . Yellowness - The curves in Figure 16 were very s i m i l a r to the curves for greenness. Over the f i r s t three harvests there was no s i g n i f i c a n t change with maturity but a change in yellowness did occur a f ter this po int . S i g n i f i c a n t increases in yellowness were apparently a temperature e f f ec t . At 35°C the yellowness decreased a f ter 19 days s i m i l a r to the changes in greenness. Yellowness began to increase in the 3 0 ° C beans at 2LL days but instead of dropping off this yellowness continued increas ing to the 3k day po int . There was no d i s t i n c t separation of yellowness in beans grown at 25 C or 20 C over the lq. to 3 k day per iod . This indicated that the beans at these lower temperatures had not reached the stage of maturity which was attained by beans at 3 0 ° C . Guyersand Kramer (1950) noted a decrease in a c c e p t a b i l i t y for colour as beans matured past the edible stage. This decrease in a c c e p t a b i l i t y a lso occurred for beans grown in 71* FIGURE 16. EFFECT OF MATURITY AND TEMPERATURE ON YELLOWNESS 19 h 18 17 •° 16 CO CO w o I 11+ 13 12 2 0 ° C ^ 11+ 19 21+ 2 9 31+ DAYS AFTER ANTHESIS Analysis of Variance •fcTimeNS Temperature ** Time x Temperature NS ©Time #* Temperature ** Time x Temperature NS £ Calculated for 1+ temperatures up to 21+ days. © C a l c u l a t e d for 3 temperatures up to 31+ days. 75 the hot summer, compared to those grown in the r e l a t i v e l y cool f a l l . Greenness was shown to not be changed s i g n i f i c a n t l y with increased maturity (except of course, in very late stages when green colour was destroyed), but l ightness and ye l low-ness were. Because of this colour preference appears to depend upon the degree of l ightness and yellowness rather than on the ac tua l amount of green co lour . Changes in e i ther of these two factors would change the nature of the green colour perceived by the consumer. By using these two factors as c r i t e r i o n for preference the optimum temperature for good colour can be determined. Because of the high degree of l ightness and yellowness, o the 35 C beans were less acceptable at any time than those grown at lower temperatures. Changes in greenness and yellowness indicate that the green colour was being los t and the pods were turning to the greenish brown colour noted by Culpepper (1936). Beans grown at 30°C are unae*-ceptable compared to those produced at lower temperatures because of the increased l ightness as wel l as the increas ing yellowrgreen r a t i o a f ter 29 days. The s i m i l a r i t y of the curves for a l l three factors of the 20°C and 25°C beans, leads to the conclusion that these beans rate the same for colour preference. When green snap beans are grown above 25°C changes may occur which are large enough to s i g n i f i c a n t l y a l t e r the colour to the point of unacceptab i l i ty . Texture Culpepper (1936) noted an increase in toughness of green beans with increas ing maturi ty . Using a needle point 76 type of texturometer, he found that resistance to shear i n -creased s t ead i ly a f ter 10 days. Board and Coote (1959) stated that the decrease in organoleptic a c c e p t a b i l i t y with increas ing maturity was due to a de ter iorat ion of texture due to the presence of excess seed in the mature f r u i t . Resistance to shear was found to be affected s i g n i f i -cant ly by temperature and maturi ty . Figure 17 shows that the ef fect of 35°C was very s t r i k i n g . Resistance to shear was higher than at any of the lower temperatures at lq. days and increased r a p i d l y over the remainder of the mat-u r i t y per iod . High temperatures are undesirable in this respect because of the s i g n i f i c a n t toughening they have on the f r u i t . There was no noticeable increase in resistance to shear u n t i l the 2 k t h day at any of the lower temperatures. At th is point an increase in toughness of the 30°C beans had occurred, which rose r a p i d l y to avery h igh , undesirable value by the 29th day. At 29 days a separation of shear o .o values between 20 C and 25 C beans had occurred and by 31+ days the 25°C beans were not iceably tougher. The 20°C beans f luctuated over the whole maturity range but there was no noticeable increase in toughness at the 31+th day. The curves show that for the f i r s t 2LL days, toughness is not important as a q u a l i t y factor as long as no high temperatures have occurred during the period of bean dev-elopment . Fibre Fibre changed s i g n i f i c a n t l y with maturity at a l l four temperatures but there was no s i g n i f i c a n t difference in 77 FIGURE 17. EFFECT OF MATURITY AND TEMPERATURE ON RESISTANCE TO SHEAR o < E H CO M CO 1200 1100 1000 900 800 700 600 500 20°C 11* 19 21+ 29 31+ DAYS AFTER ANTHESIS A n a l y s i s o f V a r i a n c e ii. Time * T e m p e r a t u r e ** Time x T e m p e r a t u r e NS €> Time ** T e m p e r a t u r e ** Time x T e m p e r a t u r e ** \ Time ** T e m p e r a t u r e ** Time x T e m p e r a t u r e * ^ C a l c u l a t e d f o r I4. t e m p e r a t u r e s up t o 2h_ d a y s . ©Calculated f o r 3 t e m p e r a t u r e s up t o 29 d a y s . • ^ C a l c u l a t e d f o r 2 t e m p e r a t u r e s up t o 31+ d a y s . 78 f ibre between the 20 and 25°C beans. Figure 18 shows that o the f ibre increase at 35 C was steady and that this curve was very s i m i l a r to that for resistance to shear for 35°C. o At 30 C a s l i g h t increase occurred u n t i l 21+ days, a f ter which time the increase was much higher . This increase occurred at the same point where resistance to shear began to r i s e r a p i d l y , i n d i c a t i n g that f ibre had an e f fect upon the increas ing toughness. Fibre increased s t ead i ly in 25^0 and 20 G C beans with time. In this case however, the increase in f ibre does not match the corresponding resistance to shear curves. Even though this steady increase in f ibre occurred over the 11+ - 31+ day period no increase in toughness occurred for 25°C beans u n t i l a f ter 21+ days and the 20°C beans did not increase not iceably in toughness. This indicates that f ibre alone- is not responsible for the increase in toughness but that other components must a lso be involved. Board and Coote (1959) stated that f ibre increased not iceably in the l a t e r stages of maturi ty . At this point f ibre would probably be the most important factor responsible for increas ing toughness. This advanced stage probably occurred with the higher temperatures and this may explain the s i m i l a r i t y be-tween f ibre increase and shear. However, i f th is stage had not been attained at the lower temperatures then f ibre would not have been as important in causing toughness and the curves would not necessar i ly match. Therefore , although ;there is an increase in fibre, at a l l temperatures, f ibre is more im-portant as a q u a l i t y factor for beans grown at higher tem-peratures because there's an e a r l i e r increase in toughness than for beans grown at temperatures of 20 - 2 5 ° C 78a FIGURE 18. EFFECT OF MATURITY AND TEMPERATURE ON FIBRE K CQ M fx, 3 -I L L 1 9 2 L L 2 9 3U, DAYS AFTER ANTHESIS Analys is of Variance ^Time * Temperature ** Time x Temperature NS eTime ** Temperature * Time x Temperature NS \ Time ** Temperature NS .Time x Temperature NS ? Calculated for LL temperatures up to 2LL days. © C a l c u l a t e d for 3 temperatures up to 29 days. + Calculated for 2 temperatures up to 31+ days. 79 Qual i ty preference with respect to texture is the same as that determined for co lour . Beans grown at 20 - 25°C are most des irable with a decreasing preference for 30°C beans and then 35°C beans. Compos i t i o n  T o t a l So l ids Culpepper ( 1 9 3 6 ) , Guyer and Kramer ( 1950) and Board and Coote (1959) a l l noted an increase in t o t a l so l ids with matur i ty . In this experiment t o t a l so l ids were found to increase with maturity and with temperature. At the l a s t harvest , 25°C and 30°C beans both attained a higher percentage of t o t a l so l ids than in 35°C beans (Figure 19). The longer duration of growth at both these temperatures allowed th i s increased percentage. At 2 0 ° C , however, the t o t a l so l ids remained low over the ent ire 314-day per iod . From a n u t r i t i o n a l standpoint, i t appears that beans grown at a higher temperature are more desirable because they supply a greater amount of so l ids at any one time than the lower temperature beans do. However, the resu l t s discussed previous ly indicated that temperature causes an increase in the rate of onset of maturi ty . In p r a c t i c e , beans are harvested at edible maturity because they are most des irable at th is stage. I f 35°C beans were harvested at 11+ days they would con-ta in very close to the same percentage t o t a l so l ids as 30°C beans at 19 days, 25°C beans at 21+ days and 20°C beans at 31+ days. I f 35°C beans were harvested at 19 days they would contain close to the same percentage of t o t a l so l ids as 80 FIGURE 1 9 , EFFECT OF MATURITY AND TEMPERATURE ON TOTAL SOLIDS 2tV EH 5r » T : I . 1 — 1 ». Ik 19 2k 29 3k DAYS AFTER ANTHESIS Analys is of Variance % Time ** Temperature ** Time x Temperature NS © T i m e ** Temperature NS Time x Temperature NS ^ C a l c u l a t e d for li temperatures up to 21i days. © C a l c u l a t e d for 3 temperatures up to 3k days. 81 30°C beans at 2LL days, 25°C beans at 29 days and 20°C beans at 3k days. Because there is no accurate method to index maturity as ye t , the same stages of maturity for each tem-perature could not bet/determined in th is study. However, the above data do give some ind ica t ion of what may occur i f these stages of maturity could be accurate ly determined and t o t a l so l ids values compared. Water Insoluble So l ids The water insoluble so l ids content was shown to i n -crease s i g n i f i c a n t l y with maturity and to increase s i g n i f i -cant ly with temperatures above 2 £ ° C . The water insoluble so l ids were ca lculated on a dry weight basis as were a l l the analyses which fo l low. It was intended to determine what changes were taking place within the t o t a l so l ids of the beans. A l s o , i t was d i f f i c u l t to store a puree without r i s k of contamination by micro-organisms or to prevent any changes in chemical composition. Figure 20a shows the changes in water insoluble so l ids with time and temperature. Figure 20b gives an ind ica t ion of the changes of water soluble s o l i d s , which is the inverse of the water insoluble so l ids curve. As the t o t a l so l ids had increased with time and temper-ature , so did the water insoluble s o l i d s . Water insoluble so l ids for 20°C beans remained r e l a t i v e l y low u n t i l 29 days a f t er which there was a rapid increase . Above this temperature the rates of increase were more uniform and were about equal . Culpepper (1936) a lso noted this increase in water insoluble soluble so l ids with maturi ty . He stated that the increase 82 FIGURE 20a. EFFECT OF MATURITY AND TEMPERATURE ON WATER INSOLUBLE SOLIDS 1 ' 1 i ; i L_I lk 19 2k 29 3k DAYS AFTER ANTHESIS Analysis of Variance •** Time** Temperature ** Time x Temperature ** © Time** Temperature *.* Time x Temperature ** f Time**. Temperature NS- . Time x Temperature * ? Calculated for k temperatures up to 21+ days. © C a l c u l a t e d for 3 temperatures up to 29 days. j-Calculated for 2 temperatures up to 3k days. FIGURE 20b. EFFECT OF MATURITY AND TEMPERATURE ON WATER SOLUBLE SOLIDS « • i i , 11+ 19 21+ 29 3k DAYS AFTER ANTHESIS Analysis of Variance £ T i m e ** Temperature * Time x Temperature *'* © T i m e * * Temperature * Time x Temperature** f-Time ** Temperature NS . Time x Temperature * ^ C a l c u l a t e d for k temperatures up to 21+ days. © C a l c u l a t e d for 3 temperatures up to 29 days. •J-Calculated for 2 temperatures up to 3k days. 8k in the h u l l was due to increas ing f ibre whereas the increase in the whole bean was mainly due to seed development. Fibre has been shown to increase in the same pattern as the water insoluble so l ids and since s tarch is the major component of the seed, i t would be expected that an increase in starch would a lso occur. Since water insoluble so l ids was a general analys is incorporat ing many d i f ferent components, other more s p e c i f i c analyses were performed. Starch An increase in s tarch in the seed and a decrease in the f r u i t with time has been noted by Board and Coote ( 1 9 5 9 ) . This study has shown that s tarch of the whole bean increased s i g n i f i c a n t l y with temperature and maturi ty . Experiment II showed that the increase in seed starch is high enough to override the decrease in the h u l l . Figure 21 shows that between 25 and 35°C s tarch content rose r a p i d l y and s t e a d i l y whereas at 20°C there was only a s l i g h t increase u n t i l 2LL days. Af ter th is point s tarch rose r a p i d l y . This increase is thought to be due to a delay in the onset of maturity at the lower temperature. Beans at 30°C rose s t ead i ly in s tarch content but unl ike the trends shown with other analyses i t did not reach or approach a maximum before the 25°C beans. The 25°C beans rose s t e a d i l y and began to reach a maximum at about 2Li days. Although th is had not occurred by 3k days, the rapid rate of increase had d e f i n i t e l y f a l l e n o f f . There is no apparent explanation for such r e s u l t s . At both 3Q°C and 35°C there was no maximum starch by f i n a l harvest . Poss ib ly this s i tua t ion is due to a d i rec t e f fect of temperature on the s tarch synthesis mechanism. 85 FIGURE 21. EFFECT OF MATURITY AND TEMPERATURE ON STARCH — i i > i i 11+ '19. • 21+ 29 . 3U, DAYS AFTER ANTHESIS Analys is of Variance > tTime ** Temperature ** Time x Temperature NS © T i m e ** Temperature * Time x Temperature NS \ Time *# Temperature * Time x Temperature NS £ Calculated for li temperatures up to 2li days. © C a l c u l a t e d for 3 temperatures up to 29 days. {-Calculated for 2 temperatures up to 2>h days. 8 6 T o t a l Sugars Culpepper (1936) noted that sugars increased u n t i l 20 days and then dropped of f s t e a d i l y . S i g n i f i c a n t decreases were obtained for sugar with both maturity and temperature from 25 - 3 5 ° C Plynn e_t al_ ( 19h5) found that storage of green beans increased the sugar content at low temperatures. This i n -crease in sugars with lower temperature can also be seen in Figure 22 for the development per iod . However, despite the s i m i l a r i t y , the reasons for the two phenomena may be quite d i f f e r e n t . Flynn did not state whether the beans had been stored in the dark or in the l i g h t . In any case, sugar production was probably due to the act ion of alpha amylase. Although the optimum temperature for alpha amylase a c t i v i t y is about iiO°C, in many plants such as potatoes at lower temperatures s i g n i f i c a n t l y greater amounts of alpha amylase are produced. Then there is a net increase of s tarch breakdown and higher sugar content. In the developing bean the problem is compounded with maturity changes. Since temperature increases the rate of maturity and since sugars decrease with maturi ty , at any one point the high temperature beans would l i k e l y be lower in sugars than beans grown at lower temperatures. This is thought to be the case in the present study but i t cannot be absolute ly proven. Once again, what is required is a good index of maturity which would allow one to obtain beans at the same stage but grown at d i f ferent temperatures. I f 87 FIGURE 2 2 . EFFECT OF MATURITY AND TEMPERATURE ON TOTAL SUGARS DAYS AFTER ANTHESIS Analys is of Variance 3 : Time** Temperature ** Time x Temperature NS © T i m e # # Temperature ** Time x Temperature NS ••V T i m e T e m p e r a t u r e \NS. Time x Temperature NS ^Calcu la ted for 1+ temperatures up to 21+ days. © C a l c u l a t e d for 3 temperatures up to 29 days. "^Calculated for 2 temperatures up to 31+ days. 88 s i g n i f i c a n t differences were then found i t would be due to this alpha amylase a c t i v i t y . Sugar decrease with maturity probably occurs as a resu l t of increasing starch formation. Although the increase u n t i l 20 days before dropping noted by Culpepper (1936) did not occur here, a certain increase should be expected due to photosynthesis in the developing pod. When the seed begins to develop, sugar decreases because there is an increased demand on the pod sugar for raw materials for starch synthesis. This change becomes even more s i g n i f i c a n t when the pod begins to senesce because then the photosynthetic apparatus cannot supply enough sugar to keep the concentration up to the previous amount. Hydrolysis of pod starch probably helps to supply sugars to the seed but the deman is high enough that a net decrease in sugar occurs. Protein The results for protein showed no s i g n i f i c a n t differences for both temperature and maturity at 35°C. The maturity curves in Figure 23 show that a d e f i n i t e pattern occurs at 20°C, 30°C and 35°C, but there is con-fusion when the 25°C curve is included. Protein at 25°C rose to a maximum at 21i days and then decreased rapidly un-t i l 29 days. This phenomena is thought to be due to the difference between the r e l a t i v e increases of t o t a l solids and protein. In order to understand what may have occurred i t must be remembered that the values reported indicate changes of protein concentration within the t o t a l solids of the bean. In order to increase using this context, the rate of protein 89 FIGURE 2 3 . EFFECT OF MATURITY AND TEMPERATURE ON PROTEIN i t 19 2h~ 29 3k DAYS AFTER ANTHESIS Analys is of Variance Time *~ Temperature NS' Time x Temperature NS © TimeNS Temperature NS Time x Temperature NS fTimeNS Temperature NS Time x Temperature NS % Calculated for 1+ temperatures up to 21+ days. © C a l c u l a t e d for 3 temperatures up to 29 days. •1-Calculated for 2 temperatures up to 3k days. 90 production would have to increase faster than any increase in.:the rate of t o t a l so l ids product ion. If the rate of production did not increase, the absolute amount of prote in would not change but the increased amount of other com-ponents would tend to d i lu te this p r o t e i n . As a r e s u l t , the percentage of prote in in the dry matter would decrease. The rate of prote in increase was s u f f i c i e n t l y high compared to t o t a l so l ids increase to keep the percent prote in high in 35°C and 30°C beans over t h e i r ent ire maturity c y c l e . Protein increase at 25>°C was a lso high u n t i l 21+ days. Between 21+ and 29 days there was a 21$ increase in t o t a l so l ids at 25°C but prote in increase must have been so low as to allow this t o t a l so l ids increase to d i lu te i t , r e s u l t i n g in a lower percentage of prote in in the dry matter. Af ter 29 days there was a 20$ increase in t o t a l s o l i d s . Because percent prote in did not decrease there must have been an increase in the rate of prote in production af ter 29 days which allowed prote in to remain at about the same concentra-t ion as before. o At 20 C prote in remained quite low over the f i r s t 21+ days, as did t o t a l s o l i d s . However, prote in production must have started to increase a f ter that time because the percent prote in increased even though t o t a l so l ids also increased. Prote in , as a component of t o t a l so l ids did not change s i g n i f i c a n t l y with maturity or with temperature over 20 -30°C. These resul t s might have changed r a d i c a l l y i f the t o t a l prote in had been p lo t t ed . However, due to a lack of a standard base, th is cannot be done in this study. 91 Pectin This was non-s ign i f i cant both with temperature and with maturi ty . It was mentioned that the decrease of s tarch in the h u l l may have been re la ted to seed starch increase by act ing as a p a r t i a l source for sugars. Results by S i s trunk (1969) indicate that th is does not happen with the pec t ins . He r e -ported that calgon soluble pect in and protopect in increased in the pods with maturity but water soluble pectins do not change s i g n i f i c a n t l y . Calgon soluble and water soluble pectins decrease in the seed. Since these were calculated on a dry weight b a s i s , the same s i t u a t i o n as for prote in may have occurred. The decrease of pectins in the seed may have been due to the r e l a t i v e rate of increase of other components, mainly s tarch . In any case, there was not a high increase in seed pect in content. Seed pect in decrease would compete with the pod pect in increase in this case and when t o t a l pect in was considered, this competition may have caused the net changes with maturity to vary non s i g n i f i c a n t l y . More information could have been gained in the study i f water so luble , calgon soluble and protopectin had been determined separately rather than as t o t a l p e c t i n . Ash Ash did not vary s i g n i f i c a n t l y with temperature or with matur i ty . The percent ash showed a considerable amount of v a r i a t i o n with maturity and temperature over the whole 3k-day period and no def in i te patterns could be found. Thus, i t must be concluded that neither temperature nor maturity have a d e f i n i t e , s i g n i f i c a n t e f fect on the ash content. 92 M a t u r i t y Measurement The need f o r a good m a t u r i t y measuring technique has been expressed e a r l i e r . Many of the r e s u l t s obtained i n t h i s study have i n d i c a t e d that the e f f e c t of temperature had was an i n c r e a s e i n the rate of m a t u r i t y onset. When beans are harvested at d e f i n i t e time i n t e r v a l s as i n t h i s study, many of the d i f f e r e n t values obtained i n the analyses were probably due to d i f f e r e n t stages of m a t u r i t y . In order t o determine the e f f e c t of temperature only, i t would be nec-e s s a r y t o p i c k beans of equal m a t u r i t y but grown at d i f f e r e n t temperatures. M a t u r i t y , i n the sense i t i s used i n t h i s d i s c u s s i o n r e f e r s to the stage of development at which a l l f a c t o r s present i n the bean are optimal f o r consumption, i . e . e d i b l e m a t u r i t y . At present, standards are set f o r pod width and #1+ beans are considered t o be optimum. However, i f s i g n i f -i c a n t changes i n growing temperature occur between seasons, the optimum standard may no longer apply, because a much more advanced u n d e s i r a b l e stage of m a t u r i t y may have occurred by the time the beans have reached the #1+ stage. In order to determine the p o i n t s of e d i b l e m a t u r i t y , d i f f e r e n t f a c t o r s would have t o be c o r r e l a t e d with the ob-s e r v a t i o n s of a t a s t e p a n e l . Because of the need f o r such an index, i t was not p o s s i b l e w i t h i n t h i s study. However, from f o r e g o i n g observations i t was judged t h a t 35°C beans were c l o s e s t to e d i b l e m a t u r i t y by 19 days, 30°c beans at 21+ days, 25°C beans at 29 days and 20°C beans at 29 days. o o Maximum m a t u r i t y was a t t a i n e d by the 35 C beans and 30 C beans w i t h i n the 11+ — 31+ day p e r i o d of t h i s study but maximum 93 o o maturity was not attained by 25 C beans and 20 C beans. Beans grown at 25°C were, however, thought to be v i s i b l y o more mature at anyone time than 20 C beans. A maturity index may or may not vary with temperature. If th is index does not, i t s r a t e 0 o f change would remain the same regardless of temperature and determination of standards would be r e l a t i v e l y easy. In this case d i f f erent points alon g the l ine would be found and assessed as the standard for beans grown in a p a r t i c u l a r kind of environment. I f the index used does change with temperature, i t would be preferable that the rate of change in this index would be the same as that for matur i ty . In th i s case, the same value would suf f ice as a standard for beans grown at d i f f erent temperatures. Pod width does not change appreciably with temperatures up to 30°C and therefore , i t is a reasonably good index of maturi ty . Figure 10-shows that at 34- days the pod width has dropped considerably but from a commercial standpoint th is is unimportant because 30°C beans were past the stage of edible maturity at this t ime. What is required is a rev i s ion of pod width standards when the growing temperature changes considerably . Lower pod widths would be required when temperatures go up. When width was corre lated with edible maturity th is r e v i s i o n would be comparatively easy. Because of the stunt ing of growth at 3 5 G C a more dras t i c decrease in pod width standards would be requ ired . I f edible maturity of 35°C beans was found to occur on 19 days, no dras t i c r e -v i s i o n would be required but a s i g n i f i c a n t decrease in standards would probably be required i f edible maturity occurred before 9k th is time. Seed Length: Hibbard and Flynn ( 19k5) found that summer and f a l l beans of the same seed size d i f fered in maturi ty . Although seed length was found to vary with temperature i t is obvious from Figure lz-that this v a r i a t i o n is mainly due to the lower values at 20°C and that values for the 25 - 35°C beans were very c lose . I f one standard was set up to indicate optimum maturi ty , i t would be i n e f f e c t i v e . For example, i f the o standard indicated optimum maturity for 25 C beans the 30 C beans and 35°C beans would be overmature by the time t h e i r seeds had atta ined this length. Because of the slow rate o of increase ©f seed length at 20 C, these beans could also be overmature, although not to the same extent as the higher temperatures. Once again, c o r r e l a t i o n of seed length to taste panel evaluation of d i f f erent temperature beans i s required . Since temperature hastens maturity a lower value would be required by higher temperature beans than beans grown at lower tem-o peratures . One exception is the beans grown at 20 C. Because seed length increase is so slow, a lower value would probably occur at edible maturity than 25°C beans. This standard should not be used u n t i l these corre la t ions have been es tab l i shed . Farkas (1967) has a lso stressed th is need for rev i s ions of seed length standards between c l imat ic reg ions . T o t a l So l ids T o t a l so l ids may be another good c r i t e r i o n for maturi ty . Apparently , edible maturity for 35>°C beans occurred at 19 95 days, 30°C at. 21+ days and 25°C at 29 days and 20°C at 29 days. The respective percent t o t a l so l ids values are: 35°C - 1 3 . 3 6 3 $ , 30°C - 1 3 . 8 7 0 $ , 25°C - l l+.770$ and 20°C - 1 1 . 9 8 2 $ . Over the range of 25 - 35°C the t o t a l so l ids values were very c lose . I f these observations on edible maturity were confirmed by further study, t o t a l so l ids could be valuable as an index of maturi ty . Once again, this appears to be useless at 20°C unless a reduction in the standard for low temperature beans was made. Therefore , there are three possible methods by which edible maturity or o v e r a l l maturity may be determined. Be-cause of the fact that temperature hastens maturi ty , there cannot be one set value for any except perhaps for t o t a l s o l i d s . Revision of standards is possible only a f t er exten-sive taste panel t e s t ing defined the stages of maturity at d i f f erent temperatures. 96 SUMMARY OF RESULTS Y i e l d , in terms of s ize and average weight, was s i g -n i f i c a n t l y reduced at temperature of 33>°C. The optimum temperature for y i e lds was 25°C. Lightness and yellowness increased with increased temperature above 25°C. Lightness and yellowness increased with maturity except at 35°C where i t was thought a complete colour change resul ted in decreased l ightness and yellowness values . Greenness did not change s i g n i f i c a n t l y with temperature or maturi ty . Beans grown at 35°C were tougher over the 11+ - 21+ day period than beans grown at 20 - 30°C. . Toughness i n -creased markedly over this per iod . Beans grown at 20 - 30°C did not d i f f e r s i g n i f i c a n t l y in texture due to temperature or maturity u n t i l a f ter 21+ days. At th is point increased toughness occurred with maturity and temperature above 20°C. Fibre content increased with temperature and maturity but was not s o l e l y responsible for the toughness of beans. T o t a l s o l i d s , s tarch , water insoluble so l ids and prote in above 30° increased with maturity and temperature. Tota l sugars decreased with temperature and maturi ty . Calcium pectate and t o t a l ash did not change s i g n i f i c a n t l y with temperature or maturi ty . Pod width and seed length appear to be reasonably good measures of maturi ty . Due to d i f f erent rates of maturity onset with temperature changes, a rev i s ion of standards is required to show a consistent standard of q u a l i t y . 97 T o t a l so l ids appears to be a reasonably good measure of edible matur i ty . The ef fect of increased temperature on q u a l i t y appears to be through hastening the onset of maturi ty . REFERENCES CITED 98 1. Ang, J . K . , Hartman, J . D. and Isenberg, F . 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IOLL A P P E N D I X EXPERIMENT I DATA TABLE I Temperature Experiment l a 1*1 1*2 Experiment lb Experiment Ic Ic^ Ic2 TOTAL SOLIDS 2 0 - l 5 ° C 2 5 - 2 0 3 0 - 2 5 3 5 - 3 0 9.798 10 . 1 5 0 13.060 13.908 10.121+ 10.891+ 11 .923 1 3 . 9 1 1 9 . 1 6 1 9 . 1 7 5 10.713 10.1*1+7 8.889 9.1+17 10.338 10.395 12.1+06 1 5 . 8 6 3 2 0 . 3 6 1 2 3 . 7 1 8 11*. 306 17.1+18 2 1 . 6 6 5 2 3 . 6 3 0 WATER INSOLUBLE SOLIDS 2 0-1-5° C 2 5 - 2 0 3 0 - 2 5 3 5 - 3 0 2 . 6 9 9 3 . 1 5 1 5 . 2 1 1 6.1*19 2 . 7 9 9 3.121* l * .578 5 . 7 5 2 3 . 2 6 8 1*.211 1*.613 2 . 3 0 7 3.288 1*.11*1* 1*.217 5.1*61* 7 . 3 0 0 11.1*70 11*. 21+1 6.11*3 8 .135 1 2 . 5 6 1 1 3 . 7 5 9 WATER SOLUBLE SOLIDS 2 0 - 1 5 ° C 2 5 - 2 0 3 0 - 2 5 3 5 - 3 0 7.099 6.999 7.839 7.1*89 7.321* 7 . 7 6 5 7 . 3 5 1 8.159 6.61+0 6.1+11 6 . 5 0 2 5.831* 6 . 5 8 2 6 .133 6.191* 6 . 1 7 8 6 . 7 6 6 8 .563 8 . 8 9 1 9.1*77 8.163 1 1 . 2 8 3 9.101* 9 . 8 7 1 ALCOHOL INSOLUBLE SOLIDS 2 0 - l 5 ° C 2 5 - 2 0 3 0 - 2 5 3 5 - 3 0 5 . 1 6 6 5.681* 7 . 9 9 2 8 . 7 3 1 5 . 5 2 1 6 . 0 1 0 7 . 3 1 6 8.62I4. I*. 331* 5 . 2 6 1 6.I4.20 6 . 5 6 7 ft. 578 1*.892 6.1+61* 6.692 7.811* 9 . 6 6 9 11*.236 16.91*1 8.599 10.799 11*.319 16.931 H O VA "emperature Experiment Ia Experiment Ib Experiment Ic l a . I b 2 I c i I c 2 TOTAL SUGARS 20-l5°C 2 . 0 2 3 2 . 1 2LL i . 7 k 5 1 . 6 8 8 25-20 2 . 0 L L 8 2 . 1 6 9 1 .739 1 . 8 3 5 30-25 1 .763 I.6I4.8 i . 5 k 3 1 .376 3 5 - 3 0 I . L L 8 5 1.1+75 - 1 .871 1 . 8 6 0 ASH 20-15 0c .579 .616 . 6 5 5 . 6 k 2 . 7 0 3 .821 25-20 .719 .577 . 7 0 k . 6 8 k . 8 3 2 .879 30-25 .762 .662 . 771 . 8 2 7 1 . 2 0 2 1 .259 3 5 - 3 0 . 7 5 0 .762 .772 . 7 7 5 i . 5 3 k 1 . 188 PROTEIN 20-l5°C 1 3 . 6 3 5 1 6 . 1 0 6 i k . 9 2 5 i k . 9 7 5 1 3 . 8 6 3 1 3 . 6 1 6 25-20 15.316 l k . 1+78 l 8.5kl 2 1 . 5 7 2 1 3 . 6 6 3 l k . 2 5 3 30-25 1 6 . 5 0 3 15 .038 2 2 . 8 5 7 20.k25 1 6 . 3 7 k I 5 . 8 k 7 3 5 - 3 0 15 .350 15.769 2 0 . 0 6 9 2 0 . 9 3 1 I6 . k 3 8 16 .713 TOTAL PECTIN 20-l5°C . 2 0 0 .199 . 8 1 0 . 8 6 5 1 .187 L 5 0 5 25-20 . .253 . 2 k 8 1 . 120 . 8 3 0 1 . 0 6 1 l.lj.87 30-25 . 2LL3 . 2 3 7 1.025 . 8 0 5 i.55k 1 .816 3 5 - 3 0 .153 • lk5 • 5k5 . 6 0 5 2 . 3 9 6 2 . 2 8 3 CRUDE FIBRE 20-l5°C 8 . 2 9 7 9 . 5 3 2 8 . 3 1 0 9 . 0 6 5 25-20 8.767 8 . k 8 7 9 . 1 k 8 9 . 1 6 2 30-25 9 . 5 9 6 9 . 2 9 2 8 . 2 0 1 9 . 1 k 9 3 5 - 3 0 9 . 3 6 0 9 . L 8 1 8 . k 3 9 8.ki>7 o EXPERIMENT II DATA TABLE II Temperature Experiment POD WIDTH l i t 2 0 - l 5 ° C 2 5 - 2 0 3 0 - 2 5 3 5 - 3 0 POD LENGTH 2 0 - l 5 ° C 2 5 - 2 0 3 0 - 2 5 3 5 - 3 0 SEED LENGTH H a l i b l i e H a l i b H e H a l i b H e H a l i b H e Ha . l i b H e H a l i b l i e H a l i b H e H a l i b H e . 2 6 5 .312 . 3 2 2 . 3 0 5 . 3 9 8 . 3 9 7 . 3 2 1 . I I I I L .U22 . 2 9 5 . 3 2 8 .197 l i . 190 3.821 LL .385 It. 730 5 . 0 L 6 k . 2 8 5 LL .560 k . k 8 6 U-.352 Li .200 3 . 8 l i 0 2 . 1 8 3 Days Af ter Anthesis 19 2g 29 . 3 9 6 . k 2 5 . . k 7 0 . 3 2 0 . k 0 0 .375 • k29 . 3 9 k -k37 . 3 8 5 . k k 3 . k 7 0 . 3 9 5 . k 3 0 .1430 , k 2 5 -k56 .509 . k 0 3 . k 2 3 .k lO . k 2 0 .kkO . 3 8 0 .k/33 . k 2 5 . k 2 2 . 3 7 8 .382 . 3 7 0 . 3 0 0 . 3 6 1 . 3 8 7 14..750 5 . 2 1 0 5 . 5 1 0 3 . 9 0 0 Li .k70 k-770 5 . 2 5 0 6 . 5 5 6 k . 2 3 5 5 . 2 2 0 5 . 3 2 0 k . 8 k 0 k . 1 0 0 k . 1 3 0 k . 0 5 0 5 . 1 2 5 7 . 8 6 1 k - 2 9 k k . 7 8 0 k -790 k - 8 0 0 3 . 6 8 0 3 . 7 1 0 3 . 2 0 0 k . 6 6 6 k . k l 6 3.24.6I k . 5 k 0 3 . 8 3 0 3 . 1 7 0 2 . 5 6 0 k . 0 0 0 3 . 9 1 3 Ik • k99 . k 2 0 • k9k • k57 • k75 • k60 . 3 5 6 . 3 9 3 • k 2 k 5 . 0 9 0 3.990 k-395 k.890 k . 1 0 0 k . 0 0 9 3 . 7 3 0 2.680 3 . 0 5 0 2 0 - 1 5 ° C H a k.koo 6 . 3 3 0 1 0 . 1 3 0 13.3kO 1 5 . 2 0 0 Temperature Experiment 25-20 30-25 35-30 AVERAGE WEIGHT l i b l i e I l a l i b l i e I l a l i b l i e I la l i b l i e 2 0 - l 5 ° C 25-20 30-25 35-30 LIGHTNESS 2 0 - l 5 ° C 25-20 30-25 H a l i b l i e I la l i b l i e I l a l i b l i e I la l i b l i e I la l i b l i e I l a l i b l i e I la l i b l i e 5.833 ft.700 5.630 7 .905 6.000 6.600 10.1*73 11.733 7.000 9.190 10.071* 3.726 5.053 1*.207 5.388 5.722 5.323 5.118 1*.51*5 5.791* 1*.1*68 1.1*81 2.183 28 29 27 31 30 29 .300 .600 .800 .1*00 .900 .000 32.500 31*.100 31*.700 i i l*.58o 6.000 9.380 7.310 10.333 10.1*14.0 10.1*1*0 8.000 9.370 11.21*0 8.1*00 6.1*87 3.61*1* 7.112 7.120 6.1*37 7 .531 6.731 5.321 5.800 I*. 972 2 .772 1*.128 30.200 26 .100 28.900 30.000 26 .510 31.100 33.1*00 30.900 32.100 Days Af ter Anthesis =|j. 6.210 7.882 11.800 10.270 12.500 13.600 11.1*70 13.850 10.1*50 11.570 11*. 700 8.591* 3.31*6 6.556 8.1*11 1*.801* 7.861 6.363 5.005 6.1*53 2,578 2.938 3.738 30.600 27.690 28.1*00 29.800 29.250 27.800 33.1*00 31*. 71*0 29.300 29 9.650 9.636 15.650 11*. 170 15.535 11*. 080 15.090 15.250 8.770 6.338 5.988 7.51*7 6.875 6.258 i*.51*8 3.710 3.969 32 .300 29.300 27.200 31.600 29.200 27.800 39.600 36.600 32.600 Ik 10.790 11*. 11*2 17.200 11*. 1*60 15.529 13.700 11*.L*21* 11*. 800 8.352 9.1*88 6.1*80 6.036 6.181 5.606 1.901 1.695 3.393 31.500 31.200 29.100 36.800 29 .700 30.1*00 1*1.900 39.385 35.600 t—1 o CO Temperature Experiment 3 5 - 3 0 GREENNESS 2 0 - 1 5 ° C 2 5 - 2 0 3 0 - 2 5 3 5 - 3 0 YELLOWNESS 2 0 - 1 5 ° C 2 5 - 2 0 3 0 - 2 5 3 5 - 3 0 I la l i b l i e I l a l i b l i e I la l i b l i e I la l i b l i e I la l i b l i e I la l i b l i e I la l i b l i e I la l i b l i e I la l i b l i e RESISTANCE TO SHEAR 2 0 - l 5 ° C I la l i b 36 .600 3 8 . 6 0 0 3 U - 7 0 0 9 . 2 0 0 9 . 7 0 0 9 . 3 0 0 1 0 . 7 0 0 1 0 . 5 0 0 9 . 5 0 0 1 0 . 7 0 0 9 .800 1 0 . 9 0 0 1 1 . 3 0 0 1 1 . 0 0 0 1 0 . 5 0 0 1 2 . 3 0 0 1 2 . 9 0 0 1 2 . 7 0 0 l f t .200 13 .600 1 2 . 9 0 0 l f t .300 1 3 . 5 0 0 l f t .900 I6.I4.OO 15-ftOO l f t .900 5 3 7 . 5 0 0 537.50O Days Af ter Anthesis 19 I S - 3 9 . 1 0 0 3 6 . 9 0 0 3ft .500 3 3 . 0 0 0 3 7 . 1 0 0 32 .800 9 . 9 0 0 1 0 . 7 0 0 8 . 5 3 0 9. f t80 1 0 . 0 0 0 : 9 . 8 0 0 1 0 . 3 0 0 1 0 . 5 0 0 9.280 1 0 . 0 6 0 1 0 . 7 0 0 9 . 8 0 0 1 0 . 3 0 0 1 0 . 7 0 0 1 0 . 0 0 0 1 0 . 2 5 0 1 0 . 2 0 0 9 .800 1 0 . 8 0 0 1 0 . 2 0 0 1 0 . 6 0 0 9 . 9 0 0 1 1 . 0 0 0 1 0 . 9 0 0 29 l i t 1 3 . 2 0 0 1 1 . 0 2 0 1 2 . 9 0 0 1 3 . 5 0 0 1 1 . 3 3 0 1 3 . 2 0 0 13.800 1 5 . 0 2 0 1 3 . 5 0 0 16.800 1 5 . 0 0 0 1 6 . 2 0 0 7 2 5 . 0 0 0 5 6 2 . 5 0 0 l f t .200 12.I4.6O 1 2 . 7 0 0 1 3 . 3 0 0 1 3 . 1 9 0 1 2 . 3 0 0 l ft .600 l f t .280 1 2 . 9 0 0 1 5 . 2 0 0 l f t .100 l f t .900 6 2 5 . 0 0 0 5 3 7 . 5 0 0 1 0 . 6 0 0 1 0 . 5 0 0 1 0 . 0 0 0 1 0 . 0 0 0 1 0 . 1 0 0 9 . 3 0 0 1 0 . 9 0 0 1 0 . 9 0 0 1 1 . 3 0 0 1 5 . 2 0 0 1 3 . 2 0 0 1 2 . 0 0 0 1 3 . 5 0 0 1 3 . 1 0 0 1 1 . 6 0 0 1 6 . 7 0 0 1 5 . 7 0 0 l f t .200 1 0 . 7 0 0 10.100 11.000 11.000 10.200 10.600 7.800 8.587 10.100-l f t .600 1 3 . 7 0 0 1 3 . 7 0 0 1 5 . ft00 1 3 . ftOO 12.900 1 7 . 0 0 0 1 6 . ft57 I5.ft00 O 6 8 7 . 5 0 0 5 7 5 . 0 0 0 6 0 0 . 0 0 0 5 3 7 . 5 0 0 Days Af ter Anthesis Temperature Experiment Ik 19 '4k 29 3]fc H e 550.000 612.500 500.000 537.500 6 0 0 . 0 0 0 25-20 H a 612.500 6 2 5 . 0 0 0 575.000 7 5 0 . 0 0 0 887.500 l i b 5 7 5 . 0 0 0 600.000 5 7 5 . 0 0 0 6 5 0 . 0 0 0 662.500 H e 550.000 687.500 500.000 6 5 0 . 0 0 0 7 2 5 . 0 0 0 30-25 H a 500.000 6 5 0 . 0 0 0 712.500 1 0 0 0 . 0 0 0 l i b 5 6 3 . 0 0 0 575 .000 832.500 887.500 H e 600.000 :612.500 500.000 987.500 3 5 - 3 0 H a 6 5 6 . 3 0 0 793.800 1000.boo l i b 7 8 0 . 0 0 0 800.000 1 0 0 0 . 0 0 0 H e 6 0 0 . 0 0 0 1137.500 937.500 FIBRE 2 0-l5 ° C H a . 6 9 7 1.150 1 .269 2 . 0 0 0 3 . 2 2 5 l i b . 9 7 0 .883 1 .027 1 .170 1.522 l i e . 9 7 8 1.1178 1 . 0 2 2 1.081+ 1 . 5 3 8 25-20 H a . 8 7 0 1 .079 I.4.4-6 1 . 7 0 0 2.005 l i b 1.193 1 .069 1 .503 1 .951 2 . 2 8 1 lie . 9 6 2 1 .721 1.591+ 2 . 0 0 0 2.1+32 30-25 H a .761+ 1.169 I .64.6 1 . 9 0 0 l i b 1 . 5 8 0 1 .336 2 . 3 0 7 3.152 lie 1 .135 2 . 3 6 5 1.36k 2 . 8 1 5 3 5 - 3 0 H a .933 1.4-91 3.091+ -l i b 2 . 1 8 6 1 .733 2 . 0 0 0 H e 1 . 5 3 8 2.96L. 2.62k TOTAL SOLIDS 2 0-l5 ° C H a 8 . 1 2 0 8.500 1 0 . 3 9 0 15.190 15.1+50 l i b 8 . 6 5 0 9 . 3 2 0 8 .767 10.255 1 1 . 6 5 0 H e 8 . 3 9 0 9.1+20 9.21i0 10.500 1 2 . 2 0 2 25-20 H a 8 . 1 7 0 9 . 5 7 0 1 2 . 6 7 0 16.1+10 19.1+1+0 l i b 10.515 1 0 . 1 2 0 11.1+77 1 3 . 9 0 0 15.320 H e 9.1+50 12.1i30 11.550 lk.. 000 1 8 . 1 9 0 30-25 H a 8 . 3 2 0 9 . 7 2 0 1 2 . 7 5 0 16.520 11+.220 l i b 1 2 . 1 3 5 1 2 . 0 9 0 l6.k/30 2 0 . 7 3 0 21.1+4-5 H e 1 0 . 2 1 0 1 3 . 9 1 0 12.1+30 1 6 . 0 0 0 22.91+3 Temperature Experiment 3 5 - 3 0 Ha li b He WATER INSOLUBLE SOLIDS 2 0 - l 5°C 2 5 - 2 0 3 0 - 2 5 3 5 - 3 0 Ha li b He Ha lib He Ha lib He Ha li b He WATER SOLUBLE SOLIDS 2 0 - l 5°C 2 5 - 2 0 3 0 - 2 5 3 5 - 3 0 Ha li b He Ha l i b He Ha li b He Ha li b He Ik 1 0 . 2 8 0 lk. 1.88 1 3 . 1 6 0 37.620 3 3 . k 8 6 k 0 . 3 k 0 3 6 . 0 5 0 2 8 . 8 9 0 31.1+90 3 9 . 5 1 0 3 1 . 3 2 3 3 5 . 5 9 5 3 5 . 9 7 0 3 2 . 7 2 0 3 7 . 9 8 0 62.380 66 . 5 1 k 59.660 63 . 9 5 0 71.110 68 .510 60 . L 9 0 68.677 6k . k 0 5 6k.030 67.280 62.020 Days After Anthesis 19 1 1 . 0 3 0 1 2 . 7 1 0 l k . 0 6 0 1 7 . 2 2 2 1 5 . 0 0 0 l k . 3 3 0 3 k - 3 6 0 36.OOO 3 0 . 6 9 9 3 3 . 5 5 7 3 k - 8 8 6 3 k - 1 5 0 3 3 . 3 5 0 ko .000 3 1 . 3 3 3 3 2 . 5 9 9 3 5 . 1 2 5 3 9 . 8 5 0 3 9 . k 6 0 5 k - 8 5 0 3 0 . 9 1 3 3 5 . 3 2 0 k 8 . 0 9 5 1+8.01+5 ko .3ko k 0 . 6 k 0 5 3 . 6 9 0 ^2.$20 5 5 . 9 7 0 29 3Jt 65.64O 6 9 . 3 0 1 6 5 . n k 6 6 . 6 5 0 6 8 . 7 6 7 6 k . 8 7 5 6O .5I1O 6 9 . 0 8 7 5 1 . 9 0 5 59.660 5 9 . 3 6 0 k 7 . k 8 0 61+. 000 6 6 . k k 3 6 5 . 8 5 0 6 0 . 0 0 0 6 7 . 1 k l 6 0 . 1 5 0 k 5 . i 5 o 66.680 5 1 . 9 5 5 k 7 . k 3 0 k 6 . 3 1 0 kk . 0 3 0 3 k . k 0 0 3 1 . 9 3 2 3 5 . 8 5 5 k 7 . 8 7 0 3 6 . 3 5 9 k 9 . 8 l 5 5 9 . 7 0 0 5 0 . 6 9 7 60.0LL5 6 5 . 6 0 0 68.068 6 k - l k 5 5 2 . 1 3 0 6 3 . 6 k l 5 0 . 1 0 5 k 0 . 3 0 0 k 9 . 0 8 3 3 9 . 9 5 5 k 7 . 3 9 0 5 7 . i k 6 5 9 . 0 6 5 62 .960 kk -123 5 6 . 3 6 0 5 2 . 6 1 0 k 2 . 8 5 k kO.935 37.0kO 5 5 . 8 7 7 k3.6k0 H I—1 1 Temperature Experiment STARCH 2 0 - 1 5 ° C 2 5 - 2 0 3 0 - 2 5 3 5 - 3 0 TOTAL SUGARS 2 0 - l 5 ° C 2 5 - 2 0 3 0 - 2 5 3 5 - 3 0 PROTEIN 2 0 - l 5 ° C I l a l i b l i e I la l i b l i e I la l i b l i e I la l i b l i e I la l i b l i e I la l i b l i e I la l i b l i e I la l i b l i e I la 1ft 2 . 7 2 1 5 . 9 3 7 3 . 5 0 0 3 . 5 3 5 1 2 . 7 6 9 5 . 6 5 2 1 . 7 8 8 2 0 . 6 1 8 79 . 8 3 6 ft.8ft3 21.ft.59 1 7 . 2 7 1 2 9 . 0 2 0 3 0 . 8 9 0 2ft .057 28 . 0 6 0 2 3 . 0 7 0 2f t .7 f t l 2 7 . 0 2 0 2 6 . 5 6 2 2 1 . 2 L 5 2 5 . 0 7 3 2 1 . 3 9 6 lft .113 15 .906 Days Af ter Anthesis 19 1 £ 3 . 1 0 8 6 . 1 1 8 1 1 . 5 0 5 2 . 2 8 2 I5.5ftft 2 5 . 2 7 3 3 . 3 2 3 2 1 . 1 6 8 29 . 5 8 5 2 . 7 0 2 2 6 . 8 9 2 2 5 . 1 6 7 2 9 . 2 3 8 3 0 . 3 1 7 2 2 . 8 1 3 28 . 6 3 7 2ft .855 1 2 . 5 3 7 27.7ftft 1 6 . 2 7 8 7 . 3 1 9 2 f t . O i l 1 6 . 2 7 8 5 . 8 7 1 l f t .656 3 . 8 0 5 8 . 6 0 9 lft. 836 2 8 . 5 7 1 2ft .553 3 2 . 5 2 0 2 1 . 5 9 3 3 2 . 7 1 0 3ft.ft82 31.70ft 3 1 . 3 6 3 36.5ft9 2 5 . 1 9 8 2 9 . 8 3 0 18.21ft 20.I4.96 10.2ft0 1 7 . 6 0 6 9 . 8 8 7 8.612 1 3 . 2 9 9 8.69ft 5 . 2 5 3 13.ft72 29 3 1 . 6 9 0 23.76ft 1 6 . 7 9 0 3 5 . 3 5 0 2 9 . 6 7 7 3 6 . 6 1 9 ftO.750 ft3.ft38 ft0.68ft 2 0 . 0 0 0 2 1 . 7 7 9 1 1 . 1 6 5 1 2 . 8 7 1 11 .762 7 . 2 0 3 5 . 8 8 8 8.ft58 ft.933 3 k 3 1 . 1 6 6 ft2.505 ft2.853 3 6 . 8 9 2 3 1 . 5 6 0 fto.5fto 1 0 . 1 7 6 lft.062 ft.323 5 . 6 5 6 1 0 . 2 3 2 6.602 lft.68ft 15 .631 Temperature Experiment 25-20 30-25 35-30 l i b H e H a l i b H e H a l i b H e H a l i b H e CALCIUM PECTATE 20-l5°C 25-20 30-25 35-30 ASH 20-l5°C 25-20 30-25 H a l i b H e H a l i b H e H a l i b H e H a l i b H e H a l i b H e H a l i b H e H a l i b Ik 17 .269 17.181 ILL . 100 Ik .100 15.556 l k . 563 16.1L0+ 1 7 . k l 9 15.282 20.625 17.513 k.715 9.297 7.855 7.185 9.337 10.110 8.110 7.800 9.770 9.885 9.897 12.6k0 k.556 6 .862 k-k77 k .358 5.k91 3.579 k .380 k.862 Days After Anthesis 19 25 19.563 l k - 7 k 3 13.185 17.79k l k . 5 8 8 15.950 18.038 16.750 17 .266 22.319 19.638 6.980 9.583 9.165 10.315 9.030 11.160 9.130 9.293 7 . k 8 0 16.958 10.033 11.865 k . 6 0 1 6.723 3.668 k-059 $.$33 k . 7 8 i k-k58 5.033 20 .600 I3.k50 17.072 23.325 17.788 19 .662 15.763 19 .600 16.89k 21.656 21.175 10.010 6.253 10.315 9.908 7.857 12.610 17.898 9.390 7.705 13 .k28 9.503 8.225 k .058 6 .088 3.036 k.163 6.229 k .078 5.03k 5.799 29 16.756 I6.6kk I6 . k l 3 15.350 17.531 17.319 19.7kk I8.k38 13.000 7.887 7.750 9.000 7.523 7.135 l k . 0 0 0 8.736 8.k90 3.839 5.650 k-550 k .032 5.332 k-535 k . 8 5 i 5.925 3A I 8 . 8 k k 19.29k 17.678 l k . 1 1 3 17.756 15.275 7.750 9.785 7.915 7.973 9.k30 3 . 808 6.731 k .568 k.023 6.7k6 k-k5o Temperature Experiment 3 5 - 3 0 H e H a l i b H e Ik It. 196 k . k l k k . 9 1 5 k . 6 6 5 Days Af ter Anthesis 19 7 g k . 0 5 7 k . 2 5 6 k.-6k7 k .292 6 . 6 3 2 5 . 7 9 0 k . 7 3 8 k . 3 8 8 29 k-829 TABLE III EXAMPLE: ANALYSIS OF VARIANCE KEYOUT  FOUR TEMPERATURES COMPARED EXPERIMENT I Source Of Temp 3 E r r o r ft T o t a l 7 TABLE IV EXAMPLE: ANALYSIS OF VARIANCE KEYOUT  TWO TEMPERATURES COMPARED  FIVE HARVESTS EXPERIMENT II Source o_i Run 2 Temp 1 RxT(A) 2 Harv k H-T k E r r o r 16 T o t a l 29 

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