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UBC Theses and Dissertations

Factors affecting growth and fruiting of Phaseolus vulgaris L. Stobbe, Elmer Henry 1965

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FACTORS AFFECTING GROWTH AND FRUITING- OF PHASEOLUS VULGARIS L. by ELMER HENRY STOBBE B. S. A., The University of British Columbia, 196l A THESIS SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE IN AGRICULTURE in the Division of Plant Science We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA Ap r i l , I 9 6 5 I n 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 t h e 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 t h e U n i v e r s i t y o f • B r i t i s h C o l u m b i a , 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 study., 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 t h e Head o f my D e p a r t m e n t o r by h i s r e p r e s e n t a t i v e s . I t 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 i v i s i o n o f Brt+ i M i I. I I I H M i, I»P P l a n t S c i e n c e 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, C a n a d a D a t e A p r i l 30, i i A b s t r a c t E x p e r i m e n t s were c o n d u c t e d i n c o n t r o l l e d - e n v i r o n m e n t c a b i n e t s t o show t h e e f f e c t o f t e m p e r a t u r e a n d l i g h t i n t e n s i t y on t h e growth and f r u i t i n g o f snap beans. L e a f w e i g h t s v a r i e d i n v e r s e l y w i t h t h e t e m p e r a t u r e , b u t stem w e i g h t s a n d numbers o f nodes were n o t g r e a t l y a f f e c t e d by day t e m p e r a t u r e i n t h e ra n g e o f 7 5 ° t o 95°F. B l o s s o m i n g a n d pod s e t were s i m i l a r a t day t e m p e r a t u r e s o f 7 5 ° and 85°F b u t were r e d u c e d a t 9 5 ^ • When day t e m p e r a t u r e was 95°F, a 6o°F n i g h t t e m p e r a t u r e r e s u l t e d i n i n c r e a s e d b l o s s o m i n g and pod s e t compared t o 80°F. When pods were h a r v e s t e d a t m a r k e t a b l e m a t u r i t y , b l o s s o m i n g i n bush beans was c y c l i c . P l a n t s grown a t a l i g h t i n t e n s i t y o f 1 9 0 0 f o o t - c a n d l e s had a l o w e r f r e s h a nd d r y w e i g h t o f l e a v e s , stems, a n d pods, and f e w e r blossoms and pods s e t t h a n p l a n t s grown a t 2 7 0 0 and kOOO f o o t -c a n d l e s • F i e l d e x p e r i m e n t s showed t h a t p l a n t i n g d a t e s a f t e r May 2 9 r e d u c e d t h e y i e l d o f pods i n p o l e beans. N i t r o g e n l e v e l a n d row d i r e c t i o n d i d not a f f e c t y i e l d o f pods i n p o l e beans. Number o f pods p e r p l a n t i n p o l e beans i n c r e a s e d d i r e c t l y w i t h t h e row s p a c i n g . C h e m i c a l s p r a y s a t b l o s s o m i n g c a u s e d no i n c r e a s e i n y i e l d o f pods i n p o l e b e a n s , and o n l y a s l i g h t i n c r e a s e i n t h e y i e l d o f pods i n bush beans. D i f f e r e n c e s i n y i e l d s o f pods between v a r i e t i e s o f bush beans were due d i f f e r e n c e s i n t h e number o f pods p e r p l a n t . ACKNOWLEDGMEMTS I w o u l d l i k e t o t h a n k Dr. D.P. Ormrod, A s s o c i a t e P r o f e s s o r , D i v i s i o n o f P l a n t S c i e n c e , U n i v e r s i t y o f B r i t i s h C o l u m b i a , under whose s u p e r v i s i o n t h i s p r o j e c t was u n d e r t a k e n . Not o n l y d i d he p r o v i d e t e c h n i c a l a d v i c e b u t a l s o p r o v i d e d wholesome s u r r o u n d i n g s t o cond u c t r e s e a r c h . F o r t e c h n i c a l a s s i s t a n c e beyond t h e c a l l o f d u t y i n t h e p r e p a r a t i o n o f t h i s t h e s i s I w o u l d l i k e t o t h a n k : -Mr. E a r l J e n s t e d Mr. J o h n Y o r s t o n M r s . Maxine Wiebe Thanks a r e a l s o a c c o r d e d t o my t h e s i s committee:-Dr. V.C. B r i n k , ' D i v i s i o n o f P l a n t S c i e n c e Dr. A . J . Renney, D i v i s i o n o f P l a n t S c i e n c e Dr. C.A. Hornby, D i v i s i o n o f P l a n t S c i e n c e Dr. D.J. Wort, Department o f B i o l o g y and B o t a n y My s p e c i a l t h a n k s a r e e x t e n d e d by my w i f e Wilma whose encouragement and h e l p was g r a t e f u l l y a p p r e c i a t e d . iv TABLE OF CONTENTS INTRODUCTION 1 LITERATURE REVIEW 2 MATERIALS AND METHODS lk I. Controlled-Environment Studies XU A. Temperature Effects on Growth and Fruiting.. lh Experiment 1. Effects of Variable Day and Constant Night 15 Temperature. Experiment 2. Effects of Variable Day and Variable Night 15 Temperature. Experiment 3. Effects of Constant Day and Variable Night 16 Temperature. Experiment h. Repetition of Experiment 3. l6 Experiment 5. Effects of Variable Day and Constant Night Temperature. 16 B. Light Intensity Effects on Growth and Fruiting 16 Experiment 6. 16 Observations of Low Temperature Effects 17 II. F i e l d Studies •. 17 A. Pole Bean Experiments" at the University of British Columbia 18 Experiment 7. Effect of Planting Date on the Fruiting 18 Response; Experiment 8. Effect of Nitrogen Level on the Fruiting 19 Response. Experiment 9* Effect of Row Spacing on the Fruiting 19 Response. Experiment 10. Effect of Row Direction on the Fruiting 19 Response. Experiment 11. Effect of Chemical Sprays on the Fruiting 19 Response. B. Bush Bean- Experiments at the University of British Columbia ....... 19 Experiment 12. Effect of Chemical Sprays on the Fruiting 19 Response. Experiment 13. Effect of Variety on the Fruiting Response. 20 C. Pole Bean Experiment at Agassiz 20 Experiment 1*J. Effect of Chemical Sprays on the Fruiting 20 Response. V D. Bush Bean Experiment at Agassiz 20 Experiment 15.' Effect of Chemical Sprays on the Fruiting • 20 Response. RESULTS • 21 I. Controlled-Environment Studies , 21 II. F i e l d Studies 33 DISCUSSION ^6 I. Controlled-Environment Studies U6 II. F i e l d Studies 51 SUMMARY AND CONCLUSIONS ..... 56" LITERATURE CITED 58 v i L I S T OF TABLES T a b l e 1. E f f e c t o f 90/60, 80/60, 70/60°F d a y / n i g h t t e m p e r a t u r e s on 22 growth and f r u i t i n g o f S t r i n g l e s s G r e e n P o d bush beans i n E x p e r i m e n t 1. T a b l e . 2. E f f e c t o f 95/80, 85/70, 75/6"0°F d a y / n i g h t t e m p e r a t u r e s .on 23 growth a n d f r u i t i n g o f S t r i n g l e s s Green P o d bush beans i n E x p e r i m e n t 2. . . . . . . . . . . T a b l e 3. E f f e c t o f 95/80, 95/70, 95/6o°F d a y / n i g h t t e m p e r a t u r e s on 31 growth and f r u i t i n g o f S t r i n g l e s s G r e e n P o d bush beans i n E x p e r i m e n t 3- ..Marketable m a t u r i t y s i n g l e h a r v e s t . T a b l e T a b l e T a b l e k. E f f e c t of 95/80, 95/70, 95/60°? d a y / n i g h t t e m p e r a t u r e s on 32 t h e f r u i t i n g o f S t r i n g l e s s Green P o d bush beans i n E x p e r i m e n t h. F i r s t 15 days o f b l o s s o m i n g . 5. E f f e c t of 95/6O, 85/60, J5/60°F d a y / n i g h t t e m p e r a t u r e s on 32 f r u i t i n g o f S t r i n g l e s s Green P o d bush "beans i n E x p e r i m e n t 5. F i r s t 15 days o f b l o s s o m i n g . 6. E f f e c t o f l i g h t i n t e n s i t y on t h e growth a n d f r u i t i n g o f 3^  S t r i n g l e s s G r e e n Pod bush beans w i t h 80/70 F d a y / n i g h t t e m p e r a t u r e i n E x p e r i m e n t 6. M a r k e t a b l e m a t u r i t y h a r v e s t . T a b l e 7. E f f e c t o f p l a n t i n g d a t e on t h e f r u i t i n g o f B l u e L a k e FM1 35 p o l e beans a t t h e U n i v e r s i t y of B r i t i s h C o l umbia i n E x p e r i m e n t 7-Ta"ble 8. E f f e c t of n i t r o g e n on t h e f r u i t i n g r e s p o n s e o f B l u e Lake 35 FM1 p o l e beans a t t h e U n i v e r s i t y of B r i t i s h C o l umbia i n E x p e r i m e n t 8. T a b l e 9. E f f e c t of row s p a c i n g on t h e f r u i t i n g r e s p o n s e o f B l u e 36 Lake FM1 p o l e b.eans a t t h e U n i v e r s i t y o f B r i t i s h C o l umbia i n E x p e r i m e n t 9-T a b l e 10. E f f e c t o f row d i r e c t i o n on t h e f r u i t i n g r e s p o n s e o f B l u e 36 L a k e FM1 p o l e beans a t t h e U n i v e r s i t y of B r i t i s h C o l umbia i n E x p e r i m e n t 10. T a b l e 11. E f f e c t o f c h e m i c a l s p r a y s on t h e f r u i t i n g r e s p o n s e of B l u e 37 L a k e FM1 p o l e beans a t t h e U n i v e r s i t y of B r i t i s h Columbia i n E x p e r i m e n t 11. T a b l e 12. E f f e c t o f c h e m i c a l s p r a y s on t h e f r u i t i n g r e s p o n s e of 39 S t r i n g l e s s Green P o d "bush beans a t t h e U n i v e r s i t y of B r i t i s h C o l umbia i n E x p e r i m e n t 12. T a b l e 13. E f f e c t o f c h e m i c a l s p r a y s on t h e f r u i t i n g r e s p o n s e o f ^0 T e n d e r c r o p bush beans a t t h e U n i v e r s i t y o f B r i t i s h C o l u mbia i n E x p e r i m e n t 12. v i i Table lh . E f f e c t of chemical sprays on the f r u i t i n g response of Bush III Blue Lake Asgrow #27^  bush beans at the University of B r i t i s h Columbia i n Experiment 12. Table 15- E f f e c t of v a r i e t y on the f r u i t i n g response of bush "beans i n It2 Experiment 13-Table 16. E f f e c t of chemical sprays on the f r u i t i n g response of Blue hh Lake FM1 pole beans at Agassiz i n Experiment l i t . Table 17. E f f e c t of chemical sprays on the f r u i t i n g response of It5 Tendercrop bush beans at Agassiz i n Experiment 15-v i i i L I S T OF FIGURES F i g u r e 1 . E f f e c t o f 9 5 / 8 0°F d a y / n i g h t t e m p e r a t u r e s on t h e b l o s s o m i n g 26 p a t t e r n o f S t r i n g l e s s G r e e n P o d b u s h beans. Wo mature pods had d e v e l o p e d . F i g u r e 2 . E f f e c t o f 85/70°F d a y / n i g h t t e m p e r a t u r e s on t h e b l o s s o m i n g 2 7 p a t t e r n o f S t r i n g l e s s Green Pod bush beans when pods were h a r v e s t e d a t m a r k e t a b l e m a t u r i t y . F i g u r e 3 - E f f e c t o f 8 5 / ? 0 O F d a y / n i g h t t e m p e r a t u r e s on t h e b l o s s o m i n g 2 8 p a t t e r n o f S t r i n g l e s s G r e e n P o d bush beans when pods were h a r v e s t e d a t d r y m a t u r i t y . F i g u r e k. E f f e c t o f 7 5 / 6 0°F d a y / n i g h t t e m p e r a t u r e s on t h e b l o s s o m i n g 2 9 p a t t e r n o f S t r i n g l e s s G r e e n P o d bush beans when pods were h a r v e s t e d a t m a r k e t a b l e m a t u r i t y . F i g u r e 5 - E f f e c t o f 7 5 / 6 0°F d a y / n i g h t t e m p e r a t u r e s on t h e b l o s s o m i n g 3 0 p a t t e r n o f S t r i n g l e s s Green Pod bush beans when pods were h a r v e s t e d a t d r y m a t u r i t y . IMTBpDUCTION Y i e l d i n beans i s l a r g e l y dependent on t h e s e t of pods a n d low s e t o f pods i s c l o s e l y a s s o c i a t e d w i t h b l o s s o m d r o p . I n v e s t i g a t o r s have f r e q u e n t l y a t t r i b u t e d b l o s s o m d r o p i n beans t o h i g h t e m p e r a t u r e s , low r e -l a t i v e h u m i d i t y a n d low a v a i l a b l e s o i l m o i s t u r e ( D a v i s , 19^5; Lambeth, 1950; W i l l i a m s , 1962). O t h e r c a u s a l f a c t o r s m e n t i o n e d a r e s i z e o f p l a n t ( C o r d n e r , 1933), l i g h t i n t e n s i t y ( i n o u e a n d S u z u k i , 1956), s o i l f e r t i l i t y ( W o l f , 19^2; Lambeth, 1950), a n d i n s e c t s ( B a k e r , e t a l . , 19^6; F i s h e r , e t a l . , 19^6). I t has been r e p o r t e d t h a t "blossom d r o p c o u l d be r e d u c e d by t h e a p p l i c a t i o n o f growth r e g u l a t o r s (Murneek, e t a l . , l$kk; F i s h e r , e t a l . , 19^6) and i r r i g a t i o n (Bahn, 1955; W i l l i a m s , I962) d u r i n g t h e b l o s s o m i n g p e r i o d s . Snap beans, P h a s e o l u s v u l g a r i s L., a r e d i s t i n c t l y d i v i d e d i n t o two g r o u p s , p o l e a n d bush beans. P o l e beans b l o s s o m a l o n g t h e stem, w h i c h c o n t i n u e s t o grow i n d e f i n i t e l y , i t s u l t i m a t e l e n g t h d e p e n d i n g on e n v i r o n -m e n t a l c o n d i t i o n s . I n bush beans t h e i n f l o r e s c e n c e i s a t t h e t i p o f t h e p l a n t , a n d b l o s s o m i n g i s t e r m i n a l (Wade, 1937)- Most v a r i e t i e s o f t h e s p e c i e s P h a s e o l u s v u l g a r i s L. a r e day n e u t r a l ( A l l a r d a nd Zaumeyer, I9M). S i n c e p o l l i n a t i o n i n t h e bean o c c u r s b e f o r e t h e b l o s s o m opens ( i n o u e a n d S h i b u y a , 195^), beans a r e a h i g h l y s e l f p o l l i n a t e d c r o p a n d c o n s i d e r e d c l e i s t o g a m o u s . The o b j e c t i v e s o f t h i s s t u d y were t o i n v e s t i g a t e i n c o n t r o l l e d -e n v i r o n m e n t c a b i n e t s , t h e e f f e c t o f t e m p e r a t u r e a n d l i g h t i n t e n s i t y on t h e g r o w t h and f r u i t i n g r e s p o n s e o f bush beans and i n f i e l d e x p e r i m e n t s t o i n v e s t i g a t e t h e e f f e c t o f p l a n t i n g d a t e , n i t r o g e n f e r t i l i t y , row s p a c i n g , row d i r e c t i o n a nd c h e m i c a l s p r a y s on t h e f r u i t i n g r e s p o n s e o f bush and p o l e b e ans. - 2 -LITERATURE! REVIEW I n f i e l d e x p e r i m e n t s w i t h w h i t e pea beans, D a v i s (19^5) s t u d i e d t h e e f f e c t o f maximum t e m p e r a t u r e , minimum r e l a t i v e h u m i d i t y , s o i l m o i s t u r e , l e a f a r e a a n d f e r t i l i z e r on t h e s e t o f pods. Maximum t e m p e r a t u r e i n f l u e n c e d t h e s e t o f pods more t h a n any o t h e r f a c t o r s t u d i e d . Minimum r e l a t i v e h u m i d i t y a n d s o i l m o i s t u r e e x e r t e d o n l y a m i n o r i n f l u e n c e on t h e s e t o f pods. L e a f a r e a a n d f e r t i l i z e r l e v e l s d i d n o t i n f l u e n c e t h e s e t o f pods. A s i g n i f i c a n t r e l a t i o n between p e r c e n t p o d s e t a n d t h e mean d a i l y t e m p e r a t u r e was f o u n d f o r snap beans by Lambeth (1950). When t h e mean t e m p e r a t u r e f o r t h e 2*i-bour p e r i o d a f t e r a n t h e s i s was above 78°F, t h e pod s e t was m a t e r i a l l y r e d u c e d . L i m a beans showed a s i m i l a r r e s p o n s e a l t h o u g h t h e c o r r e l a t i o n was n o t as h i g h s i n c e t h e l i m a bean was a b l e t o s e t pods s a t i s f a c t o r i l y a t c o n s i d e r a b l y h i g h e r t e m p e r a t u r e s t h a n d i d t h e snap bean. Low n i g h t t e m p e r a t u r e s d e c r e a s e d t h e number o f blossoms and d e l a y e d t h e o n s e t o f b l o s s o m i n g ( V i g l i e r c h i o a n d Went, 1957)- Low day t e m p e r a t u r e s d e l a y e d t h e o n s e t o f b l o s s o m i n g b u t i n c r e a s e d t h e number of b l o s s o m s . Low n i g h t t e m p e r a t u r e (15°C) was f a v o u r a b l e t o f l o w e r f o r m a t i o n b u t not t o node f o r m a t i o n i n beans (Watanabe, 1953 ( a ) ) . I n l i m a beans t h e w e i g h t o f pods p r o d u c e d was m a r k e d l y a f f e c t e d by n i g h t t e m p e r a t u r e s b o t h b e f o r e a n d a f t e r a n t h e s i s ( f i a p p a p o r t a n d C a r o l u s , 1956). C o n t r o l l e d t e m p e r a t u r e e x p e r i m e n t s i n d i c a t e d t h a t t h e minimum n i g h t t e m p e r a t u r e was an i m p o r t a n t c o n s i d e r a t i o n , as was t h e maximum day tempera-t u r e (Lambeth, 1950). I n g e n e r a l , bean p l a n t s showed g r e a t e r stem growth a t h i g h e r tempera-t u r e s ( V i g l i e r c h i o and Went, 1957). P l a n t s grown a t c o o l t e m p e r a t u r e s (17° day / l 2°C n i g h t ) m a n i f e s t e d s t u n t i n g , t h i c k stems, s h o r t i n t e r n o d e s , and - 3 -s m a l l d a r k l e a v e s . The p l a n t s e v e n t u a l l y y e l l o w e d a n d d i e d w i t h o u t f l o w e r i n g . P l a n t s grown a t warm t e m p e r a t u r e s (30° day/2^°C n i g h t ) grew r a p i d l y , d e v e l o p e d l o n g i n t e r n o d e s , t h i n stems and s m a l l p a l e l e a v e s . These f r a i l s p i n d l y p l a n t s d i d not f l o w e r . W i t h c o n s t a n t t e m p e r a t u r e t r e a t m e n t t h e growth o f bea n p l a n t s , i n a l l a s p e c t s measured, i n c r e a s e d as t h e t e m p e r a t u r e i n c r e a s e d up t o 25°C (and f o r some a t t r i b u t e s , up t o 30°C) ( D a l e , 196^). Growth was not alw a y s p r o p o r -t i o n a l t o t h e mean t e m p e r a t u r e , b u t growth under c o n s t a n t c o n d i t i o n s , was s u p e r i o r t o t h a t under a l t e r n a t i n g t e m p e r a t u r e s , h a v i n g t h e same mean t e m p e r a t u r e . T h e r m o p e r i o d i s m as p r o p o s e d by Went (19^) w o u l d p r e d i c t t h e r e v e r s e . Use o f p l a s t i c cages t o r a i s e t h e g r o w i n g t e m p e r a t u r e s o f bush beans f o r a f i v e - d a y p e r i o d a f t e r f i r s t b loom r e d u c e d y i e l d s f r o m 22 p e r c e n t t o 67 p e r c e n t i n s i x p l a n t i n g s (Mack and S i n g h , 196^). A v e r a g e maximum tempera-t u r e s under t h e p e r f o r a t e d p o l y e t h y l e n e p l a s t i c cages r a n g e d f r o m 8^° t o 101°F f o r t h e s i x p l a n t i n g s w h i l e maximum t e m p e r a t u r e s f o r c o n t r o l s w i t h no p l a s t i c cages a v e r a g e d 7^° t o 82°F. Soybeans grown i n c o n t r o l l e d e n v ironment c a b i n e t s showed t h a t h i g h t e m p e r a t u r e s a n d l o n g p h o t o p e r i o d s r e s u l t i n I n c r e a s e d b l o s s o m and young pod d r o p (Van S c h a i k a n d P r o b s t , 1958). No mature pods were p r o d u c e d w i t h a t e m p e r a t u r e o f 60°F r e g a r d l e s s o f t h e d a y l e n g t h i n s e v e r a l v a r i e t i e s o f soybeans. S h e d d i n g o f blossoms was n o t c a u s e d by a l a c k o f v i a b l e p o l l e n . A d v e r s e e f f e c t o f u n f a v o u r a b l e t e m p e r a t u r e on p l a n t growth were p a r t l y o r c o m p l e t e l y p r e v e n t e d by a p p l y i n g e s s e n t i a l m e t a b o l i t e s t o p l a n t s ( K e t e l l a p p e r , I963). The n a t u r e o f t h e e f f e c t i v e m e t a b o l i t e s depended on t h e s p e c i e s a n d on t h e t e m p e r a t u r e . V i t a m i n C s t i m u l a t e d t h e growth o f b r o a d beans grown a t 30° day and 23°C n i g h t t e m p e r a t u r e . The e f f e c t o f - Il -h i g h temperature on peas growing i n a r t i f i c i a l l i g h t was c o u n t e r a c t e d by s u c r o s e , a v i t a m i n B mix ture o r r i b o s i d e m i x t u r e , depending on the seed source and temperature c o n d i t i o n s . Under c o n d i t i o n s of h i g h r e s p i r a t i o n , h i g h tempera tures , and l i m i t e d p h o t o s y n t h e s i s under low l i g h t i n t e n s i t y , sucrose sprays on tomatoes gave the g r e a t e s t dry mat ter i n c r e a s e ( B e r r i e , i960). A t low temperatures and h i g h r a t e s of p h o t o s y n t h e s i s the e f f e c t s of sucrose sprays were n e g l i g i b l e . An i n c r e a s e i n s o i l temperature f r o m 5^°F t o 78°F was r e l a t e d t o increases i n dry weight of beans f rom 60 t o 850 percent (Mack, et a l . , .196^) . A s i m i l a r r e l a t i o n s h i p of phosphorus content of p l a n t s was f o u n d . A p p l i -c a t i o n s of h i g h r a t e s of phosphorus f e r t i l i z e r d i d not compensate f o r t h e i n h i b i t o r y e f f e c t of the lowest s o i l temperature (5^°F) on the growth of beans. Beans grown under greenhouse c o n d i t i o n s w i t h f o u r mois ture l e v e l s were found t o have s i g n i f i c a n t l y d i f f e r e n t y i e l d responses (Burman and Bohmont, 1961). The h i g h e r m o i s t u r e l e v e l s produced a g r e a t e r weight of beans , number of beans per p o t , and number of pods per p l a n t . The h i g h e s t m o i s t u r e l e v e l ( i r r i g a t i o n a t 0-5 atmospheres) had a maximum growth r a t e n e a r l y t h r e e t imes as great as the lowest m o i s t u r e l e v e l ( i r r i g a t i o n a t I4 a tmospheres) . Supplementary i r r i g a t i o n of o n l y 0.5 acre i n c h a t the onset of f l o w e r i n g and 2.0 acre inches s p l i t between a p p l i c a t i o n s a t the onset of f l o w e r i n g and d u r i n g f r u i t development i n beans i n c r e a s e d y i e l d s up t o 5ln7 and 79 percent r e s p e c t i v e l y , and gave more seeds per pod compared w i t h the c o n t r o l s (Gabelman and W i l l i a m s , I962). Most of the seeds which developed on m o i s t u r e - d e f i c i e n t p l a n t s were nearest t h e s t i g m a t i c end of the o v a r y . Pods se t l a t e i n the season had fewer seeds t h a n those se t e a r l i e r , r e g a r d l e s s of i r r i g a t i o n t r e a t m e n t . - 5 -I n l i m a b e a n s , a s i n g l e i r r i g a t i o n a t b l o o m c a u s e d no s i g n i f i c a n t y i e l d i n c r e a s e ( R a h n , 1 9 5 5 ) . When t h e w e a t h e r was h o t a n d t h e r e l a t i v e h u m i d i t y low a t t h e p o d s e t p e r i o d , a n i r r i g a t i o n a p p e a r e d t o h a v e some v a l u e . W i t h i n e x p e r i m e n t a l l i m i t s , w a t e r r e l a t i o n s o f t h e s o i l - p l a n t c o m p l e x were c o n s i d e r e d t o h a v e a g r e a t e r e f f e c t o n p o d s e t t h a n h i g h t e m p e r a t u r e ( L a m b e t h , 1 9 5 0 ) • I n a l l c a s e s , s a t i s f a c t o r y p o d s e t was d e p e n d e n t u p o n ' m a i n t e n a n c e o f a f a v o u r a b l e m o i s t u r e s u p p l y a t t h e s t i g m a t i c s u r f a c e . S e v e r e w i l t i n g b e t w e e n t h e t i m e o f a n t h e s i s a n d f e r t i l i z a t i o n i n beans d i d n o t e f f e c t t h e p e r c e n t a g e o f o v u l e s f e r t i l i z e d a l t h o u g h p r o l o n g e d m o i s t u r e s t r e s s p r i o r t o a n t h e s i s e f f e c t e d a s l i g h t d e c r e a s e i n f e r t i l i z a t i o n ( W i l l i a m s , 1 9 6 2 ) . D r o u g h t i n f l u e n c e d f r u i t i n g b e h a v i o r a l m o s t e x c l u s i v e l y t h r o u g h i t s e f f e c t o n p r o c e s s e s o t h e r t h a n f e r t i l i z a t i o n ; s h o r t p e r i o d s o f m o i s t u r e s t r e s s , e s p e c i a l l y d u r i n g e a r l y b l o o m , i n d u c e d l o n g l a s t i n g c h a n g e s i n s u b s e q u e n t f r u i t i n g b e h a v i o r . The g e n e r a l p a t t e r n o f a b s c i s s i o n f o u n d was a s f o l l o w s : u n f e r t i l i z e d pods f e l l f i r s t , f o l l o w e d b y t h e l a s t s e t pods o n t h e p l a n t , f o l l o w e d b y a t h i n n i n g p r o c e s s on e a c h i n f l o r e s c e n c e , t h e y o u n g e r pods f a l l i n g f i r s t . T h r e e s t a g e s o f f l o w e r a b s c i s s i o n were r e c o g n i z e d i n t h e r u n n e r b e a n ( i w a m i , 1 9 5 1 ) ; a n e a r l y s t a g e , a t t r i b u t e d t o c o m p e t i t i o n o f n u t r i e n t s b e t w e e n t h e f l o w e r s a n d t h e d e v e l o p i n g p l a n t ; a m i d d l e s t a g e , a t t r i b u t e d t o c o m p e t i t i o n f o r n u t r i e n t s b e t w e e n f l o w e r s ; a n d a l a t e s t a g e , a s s o c i a t e d w i t h t h e d e c l i n e o f t h e p l a n t . F l o r a l a b s c i s s i o n d u r i n g t h e i n i t i a l s t a g e s o f f l o w e r i n g i n l i m a b e a n s was l a r g e l y i n d e p e n d e n t o f t h e l e a f a r e a , a n d g e n e r a l l y o c c u r r e d w i t h i n ^ 8 h o u r s f o l l o w i n g t h e h o o d e d b u d s t a g e i n c a s e o f u n f e r t i l i z e d f l o w e r s ( L a m b e t h , 1 9 5 0 ) . A minimum o f one o v u l e p e r p o d h a d t o b e f e r t i l i z e d a n d s t a r t d e v e l o p m e n t t o p r e v e n t a b s c i s s i o n . I n l i m a b e a n s , t h e pods a t t h e b a s e o f t h e r a c e m e s r e d u c e d p o d s e t toward the apical end (Cordner, 1933). Apical pod set could be increased by basal defloration. Early blossoming racemes were more f r u i t f u l than later blossoming ones, which stresses the importance of early pod set. Fruit setting followed u n t i l "capacity set" was obtained; the remaining reproductive structures, were disposed of by abscission. Failure to obtain a capacity set with large-seeded lima beans was most frequently due to lack of f e r t i l i z a t i o n of the egg cells (Lambeth, 1950)' The expression of climatic and edaphic factors on pod set was primarily through pollen tube growth and f e r t i l i z a t i o n . Pod set and yield were considered to be nottnecessarily comparable since blossom, bud, and pod abscission may occur later i n the blossoming period as a result of the competition for essential metabolites (Lambeth, 1950). If the capacity set was obtained during the f i r s t two weeks after blossoming, the yi e l d was considered to be dependent primarily on the "active" leaf area and light conditions. In beans, yield was not correlated with the number of blossom per plant (Binkley, 1932). There was also a negative correlation between the percent blossom and pod drop and yi e l d per plant. Domestic marketability harvest curves suggested that f r u i t production may be cyclic in pole beans (Viglierchio and Went, 1957)' The frequency of the cycle appeared to increase as the night temperature increased. In three bean varieties there was a highly significant correlation between increasing age and decreasing percent set of pods (Smith and Pryor, I962). There was also a highly significant correlation between increasing temperature and decreasing pod set, Tin two of the varieties used. After the plants began to set f r u i t , there was a steady decrease in the percentage of blossoms that set f r u i t , u n t i l the setting capacity was reached (Schrader, 19^3)-S i d e d r e s s i n g s o f n i t r o g e n f e r t i l i z e r s a p p l i e d t o beans i n c r e a s e d t h e p e r c e n t a g e pod s e t , however, a d d i t i o n a l n i t r o g e n a p p l i e d d u r i n g b l o s s o m i n g d e c r e a s e d pod s e t , w h i c h emphasized t h e i m p o r t a n c e of t i m e l y a p p l i c a t i o n i n f e r t i l i z e r p r a c t i c e (Lambeth, 1950). I n l i m a beans p l a n t s w i t h good pod s e t had s u b s t a n t i a l l y h i g h e r c o n c e n t r a t i o n s o f n i t r a t e n i t r o g e n , p o t a s s i u m , a v a i l a b l e c a l c i u m and magnesium, b u t l e s s phosphate i n t h e stems t h a n p l a n t s w i t h p o o r pod s e t ( W o l f , 19^2). The c o n c e n t r a t i o n s o f n i t r a t e a n d a v a i l a b l e c a l c i u m were c l o s e l y a s s o c i a t e d w i t h pod s e t . When t h e c o n c e n t r a t i o n of n i t r a t e and a v a i l a b l e c a l c i u m i n t h e stem was above 2250 a n d 9000 ppm, r e s p e c t i v e l y , t h e p l a n t had a good s e t o f pods a n d when t h e c o n c e n t r a t i o n was b e l o w 1250 a n d 6000 ppm, r e s p e c t i v e l y , t h e p l a n t had a p o o r s e t o f pods. A r e d u c t i o n i n l i g h t i n t e n s i t y l o w e r e d t h e a s s i m i l a t i o n a b i l i t y i n snap bean p l a n t s ( I n o u e a n d S u z u k i , 1956). A t l e s s t h a n 30 p e r c e n t n a t u r a l l i g h t (no l i g h t i n t e n s i t i e s were g i v e n by t h e a u t h o r s ) growth was m a r k e d l y c h e c k e d . As t h e l i g h t i n t e n s i t y was r e d u c e d t h e number o f l a t e n t f l o w e r b u d s i n c r e a s e d a n d t h e number o f blossoms d e c r e a s e d . S e v e r e r e s t r i c t i o n s o f l i g h t i n t e n s i t y r e s u l t e d i n t h e i n c r e a s e of f l o w e r bud d r o p and t h e r e d u c t i o n o f b l o s s o m number. P o d number was r e d u c e d t o h a l f t h a t i n t h e c o n t r o l p l o t , The r e d u c t i o n i n l i g h t i n t e n s i t y had a l m o s t no e f f e c t on p o l l e n g e r m i n a t i o n . When l i g h t i n t e n s i t y was r e d u c e d by s h a d i n g w i t h c h e e s e c l o t h w i t h o u t m a r k e d l y a f f e c t i n g t h e t e m p e r a t u r e (20°F), tomatoes d o u b l e d t h e i r growth an d f r u i t i n g r e s p o n s e ( J o h n s o n and H a l l , 1955)' F a c t o r s o t h e r t h a n low c a r b o h y d r a t e c o n t e n t l i m i t e d f r u i t i n g i n tomatoes under c o n d i t i o n s o f h i g h t e m p e r a t u r e a n d l i g h t i n t e n s i t y . Reduced pod s e t was n o t die t o t h e i n a b i l i t y o f c o n d u c t i v e t i s s u e t o t r a n s l o c a t e c a r b o h y d r a t e s . Net u p t a k e of c a r b o n d i o x i d e i n bean p l a n t s a t l i g h t i n t e n s i t i e s above t h e c o m p e n s a t i o n p o i n t was n o t m a r k e d l y i n f l u e n c e d by t e m p e r a t u r e (Ormrod, 196^). Net l o s s e s o f r e s p i r a t o r y c a r b o n d i o x i d e a t t h e l o w e r l i g h t i n t e n s i t i e s and i n d a r k n e s s were m a r k e d l y a f f e c t e d by t e m p e r a t u r e w i t h u n i f o r m l y i n c r e a s i n g l o s s e s o f c a r b o n d i o x i d e w i t h i n c r e a s i n g t e m p e r a t u r e . Bean p i s t i l s became r e c e p t i v e t h r e e days b e f o r e a n t h e s i s , a n d t h e p e r c e n t a g e f r u i t s e t i n c r e a s e d u n t i l t h e day b e f o r e a n t h e s i s ( i n o u e and S u z u k i , 1959)* I f t h e s t y l e was c u t one hour a f t e r p o l l i n a t i o n , t h e f r u i t s e t was low ( a p p r o x i m a t e l y 20 p e r c e n t ) , b u t i n c r e a s e d w i t h d e l a y e d t i m e o f c u t t i n g a n d was low a t h i g h t e m p e r a t u r e s . P o t t e d p l a n t s p l a c e d under c o n s t a n t t e m p e r a t u r e s f o r f o u r hours a f t e r p o l l i n a t i o n * had no pods a t 10° a n d lt5°C, a few pods between 30° a n d i40°C, an d a good pod s e t between t 15° a n d 2 5 ° C P o t t e d p l a n t s p l a c e d under c o n s t a n t t e m p e r a t u r e s f o u r hours 1 b e f o r e p o l l i n a t i o n had no pods a t 10° a n d k5°C b u t i n t h e 15° t o kO°C r a n g e , t h e r e were no s i g n i f i c a n t d i f f e r e n c e s between t e m p e r a t u r e s . Beans f l o w e r e d n o r m a l l y f r o m m i d n i g h t t o s u n r i s e (Watanabe, 1953 C D ) ) -Day a n d n i g h t t e m p e r a t u r e a f f e c t e d f l o w e r i n g , pod s e t b e i n g d e c r e a s e d by h i g h e v e n i n g t e m p e r a t u r e s . P o l l e n a c t i v i t y was h i g h e s t a t a n t h e s i s a n d 10 hours b e f o r e i t . P o l l e n g e r m i n a t i o n and p o l l e n t u b e growth were f a v o u r e d by damp c o n d i t i o n s a n d moderate t e m p e r a t u r e s , t h e optimum b e i n g 9h t o 100 p e r c e n t r e l a t i v e h u m i d i t y a n d 20 t o 25°C. G e r m i n a t i o n o f bean p o l l e n was r e c o g n i z a b l e t h e a f t e r n o o n b e f o r e f l o w e r i n g , b u t t h e p e r c e n t a g e g e r m i n a t i o n i n c r e a s e d t o w a r d t h e t i m e o f a n t h e r - d e h i s c e n c e ( a n t h e s i s o c c u r r e d m a i n l y between 5:00 and 7*00 a.m. ( i n o u e , 1 9 5 5 ) ) , a n d t h e n d e c r e a s e d r a p i d l y a n d t h e p o l l e n g r a i n s a l m o s t l o s t t h e i r v i t a l i t y 5-6 hours a f t e r a n t h e s i s ( i n o u e and. S h i b u y a , 195*0-The optimum i n v i t r o t e m p e r a t u r e f o r p o l l e n g e r m i n a t i o n was 20° t o 25°C and t h e optimum r e l a t i v e h u m i d i t y 80 p e r c e n t . Waen bean p l a n t s were - 9 -treated with temperatures between 25° to 30°C, the germinability was greatly reduced, compared to the optimum temperature. The optimum i n vivo temperature f o r pollen germination was 15°C and the c r i t i c a l temperature 30°C (Ahmadi, 1956). At 32.2°C blossoms dropped from intact plants, but not at 21.1°C. Anatomical studies showed that abscissed flowers were not f e r t i l i z e d . Blossom abscission of the dry beans under adverse conditions was probably due to the i n a b i l i t y of the pollen grains to germinate. Long-sustained high temperature (30°C) and high night temperature before pollen mother c e l l reduction d i v i s i o n i n beans resulted i n abnormal flowers, most of which had abortive pollen (Watanabe, 1953 (a)). Proper germination of the pollen grain was dependent upon a r e l a t i v e l y high sugar concentration (10 percent or more), boron (which may reach as much as one percent of the t o t a l ash content of the stigmatic exudate), gi b b e r e l l i n s , and others as yet, i l l - d e f i n e d factors (Nitsch, 1962). In tomatoes, two responses correlated with higher temperature were associated with parthenocarpy (Johnson and H a l l , 195*0- The f i r s t was a tendency f o r many v a r i e t i e s to exhibit style exsertion and the second involved a loss of pollen v i a b i l i t y at temperatures above 90°F. Thus, i f either condition was present, f e r t i l i z a t i o n was either reduced or did not occur., and any f r u i t s that developed were p a r t i a l l y or en t i r e l y seedless. Pollen grains contain auxins (Leopold, 1955)- When p o l l i n a t i o n occurs, there i s a great increase i n auxin content i n the ovaries. Without p o l l i n a -t i o n such an increase i s e n t i r e l y lacking. The increase i n auxin l e v e l i-n ' t'ta'-e. ovary at the time of pollinated f r u i t - s e t i s too great to be accounted f o r simply on the basis of the auxin supplied by the pollen i t s e l f . Evidence indicates that the enzymatic production of auxin i s - 10 -a c t i v a t e d by p o l l i n a t i o n , p o s s i b l y by i n c r e a s e d a v a i l a b i l i t y o f some p r e c u r s o r o f a u x i n . As much as one hun d r e d t i m e s more a u x i n i s f o r m e d i n t h e o v a r y t h a n i s p r e s e n t e d t o t h e o v a r y by t h e p o l l e n . T h i s new s u p p l y of a u x i n i n t h e o v a r y s t i m u l a t e s o v e r a l l p l a n t g r o w t h . N a t u r a l p a r t h e n o c a r p y t a k e s p l a c e i n o v a r i e s w h i c h have n a t u r a l l y h i g h a u x i n c o n t e n t s . F l o w e r o v a r i e s c a n o f t e n be a r t i f i c i a l l y i n d u c e d t o s e t p a r t h e n o c a r p i c f r u i t by t h e a p p l i c a t i o n o f a u x i n s . F r u i t - s e t r e q u i r e s more t h a n a u x i n a l o n e ( L e o p o l d a n d S c o t t , 1 9 5 2 ) . There i s a r e q u i r e m e n t f o r o r g a n i c n u t r i e n t s o r s u b s t r a t e s f o r g r o w t h . When a l l mature l e a v e s o f tomato p l a n t s were removed f r o m t h e p l a n t t h e r e was no f e r t i l i z e d o r p a r t h e n o c a r p i c f r u i t - s e t . As t h e number of mature l e a v e s i n c r e a s e d , t h e r e was a q u a n t i t a t i v e i n c r e a s e i n f r u i t - s e t . A r t i f i c i a l l y -i n d u c e d p a r t h e n o c a r p i c f r u i t had a l o w e r l e a f r e q u i r e m e n t t h a n f r u i t - s e t by p o l l i n a t i o n . When 0.ft p e r c e n t i n d o l e b u t y r i c a c i d was a p p l i e d t o open blossoms o f For d h o o k bush l i m a beans t h e r e was a s i g n i f i c a n t d e c r e a s e i n pod s e t ( S c h r a d e r , 1 9 ^ 3 ) -The a p p l i c a t i o n o f Parmone as a d u s t c o n t a i n i n g n a p h t h a l e n e a c e t i c a c i d (NAA) t o bush beans i n t h r e e a p p l i c a t i o n s a t one-week i n t e r v a l s d u r i n g t h e b l o s s o m i n g p e r i o d s i g n i f i c a n t l y r e d u c e d t h e number o f pods s e t (H a r d e r i b u r g , 19^ 1 I t ) . I n beans t h e g r e a t e s t i n c r e a s e i n y i e l d (59 t o 72 p e r c e n t ) was o b t a i n e d f r o m NAA a n d b e t a - n a p h t h o x y a c e t i c a c i d s p r a y s under h i g h tempera-t u r e , a f a i r i n c r e a s e (6 t o 19 p e r c e n t ) when t h e w e a t h e r was m o d e r a t e l y warm, a n d a d e c r e a s e under c o o l t e m p e r a t u r e s (Murneek, e t a l . , l y k k ) . The i n c r e a s e i n y i e l d under h i g h t e m p e r a t u r e s was due t o i n c r e a s e i n pod s e t a n d s i z e . - 11 -Wax beans w i t h two a p p l i c a t i o n s o f d u s t s a t b l o s s o m i n g , c o n t a i n i n g N M a t kO and 80 ppm gave a 2k a n d 12 p e r c e n t y i e l d i n c r e a s e , r e s p e c t i v e l y ( F i s h e r , e t a l . , lykG). A d e c r e a s e i n y i e l d was n o t e d w i t h d u s t s a t 160 ppm. The i n c r e a s e i n y i e l d was due t o a g r e a t e r number o f s m a l l pods r a t h e r t h a n l a r g e r pods. When low c o n c e n t r a t i o n s o f 2, k, 5 - t r i c h l o r o p h e n o x y a c e t i c a c i d were a p p l i e d t o l i m a beans a t b l o s s o m i n g , a l m o s t a l l t h e i r b l o ssoms d r o p p e d and t h e p l a n t c e a s e d t o grow v e g e t a t i v e l y f o r a p e r i o d o f 20 t o 30 days ( M a r t h and Wester, 195^)• A f t e r t h e p l a n t s resumed growth t h e y d e v e l o p e d more a x i l l a r y b r a n c h e s t h a n c o n t r o l s a n d were v e r y bushy i n a p p e a r a n c e . Pods on t h e s p r a y e d p l a n t s m a t u r e d l a t e a n d when no f r o s t i n t e r f e r e d , t h e s p r a y e d p l a n t s p r o d u c e d 18 t o 35 p e r c e n t more f r e s h m a r k e t a b l e pods t h a n d i d t h e c o n t r o l s . U n t r e a t e d p l a n t s on w h i c h e a r l y b l ossoms had been removed by hand p r o d u c e d 33 p e r c e n t more pods t h a n t h e c o n t r o l s , b u t t h e p l a n t s them-s e l v e s were no l a r g e r t h a n t h e c o n t r o l s . When 10 t o 20 ppm o f 2,k-diehlorophenoxyacet'i'c" a c i d (2 ,^-D) was a p p l i e d t o two-week o l d bean s e e d l i n g s o r 10 ppm o f 2>^-D t o fo u r - w e e k o l d s e e d l i n g s , t h e i n i t i a l e f f e c t was t o s t o p a l l f u r t h e r development f o r 10 t o lk days (Wedding, e t a l . , I 9 5 6 ) . When t h e p l a n t resumed n o r m a l g r o w t h , t h e new l e a v e s were t w i s t e d a n d o t h e r w i s e deformed showing t y p i c a l 2,k-D i n d u c e d e f f e c t s . The p l a n t s d e v e l o p e d more s l o w l y a n d u s u a l l y had a bushy, s t u n t e d a p p e a r a n c e . The appe a r a n c e o f blossoms was d e l a y e d on t h e t r e a t e d p l a n t s b u t u l t i m a t e l y d e v e l o p e d i n g r e a t e r abundance t h a n on u n t r e a t e d p l a n t s , p o s s i b l y due t o i n c r e a s e d b r a n c h i n g . The t r e a t e d p l a n t s a l s o p r o d u c e d a l a r g e r s e t o f pods. L a t e r treatment's- a n d h i g h e r c o n c e n t r a t i o n s t e n d e d t o f u r t h e r d e l a y b o t h f l o r a l i n i t i a t i o n a n d m a t u r i t y o f t h e f r u i t . A l p h a -o r t h o - c h l o r o p h e n o x y p r o p i o n i c a c i d a n d N-metaTtolylphthalamic a c i d o f f e r e d p r o m i s e i n p r e v e n t i n g f r u i t d r o p i n beans when a p p l i e d o v e r t h e b l o s s o m s . - 12 -Growth i n h i b i t i o n o f bean p l a n t s c a u s e d by 2,b-D c a n be r e d u c e d by u s i n g i r o n i n t h e c h e l a t e d f o r m as f e r r i c - e t h l y l e n e d i a m i n e t e t r a a c e t a t e (FeEDTA) w i t h t h e 2,k-V (Wort, 1962). When f i e l d beans were s p r a y e d lk days a f t e r emergence w i t h h i g h c o n c e n t r a t i o n s o f 2,k-D (100 ppm) t o g e t h e r w i t h FeSOl* (300 ppm'Fe), t h e r e were no i n h i b i t o r y e f f e c t s on p l a n t g r o w t h , number o f pods s e t p e r p l a n t , s e e d s i z e , y i e l d o f d r y beans a n d d r y m a t t e r y i e l d 93 days a f t e r t r e a t m e n t ( M i l l e r , e t a l . , 1962). D e l a y e d m a t u r a t i o n was o b s e r v e d a t 2,k-B l e v e l s g r e a t e r t h a n 5 VVm> a n d w i t h added Fe t h e d e l a y was p r o l o n g e d f u r t h e r . I n a l l c a s e s where 100 ppm 2,^-D a l o n g a d v e r s e l y a f f e c t e d v e g e t a t i v e a n d r e p r o d u c t i v e development o f be a n s , t h e f o l i a r a p p l i c a t i o n o f FeSOlj e i t h e r overcame t h e i n h i b i t o r y e f f e c t s . A s i g n i f i c a n t r e d u c t i o n i n bush bean y i e l d o c c u r r e d f o l l o w i n g a p p l i c a t i o n o f a f o l i a r s p r a y c o m b i n i n g 1 ppm 2,I»-D a n d 100 ppm m a l e i c h y d r a z i d e (Mack, 1963)- Tre a t m e n t s o f 1 ppm 2,k-D a l o n e o r i n c o m b i n a t i o n w i t h an i r o n c h e l a t e , p r o d u c e d no s i g n i f i c a n t d i f f e r e n c e s i n y i e l d when compared t o a c o n t r o l . F o l i a r s p r a y s were a p p l i e d t o p l a n t s when t h e p r i m a r y l e a f was o n e - h a l f t o t h r e e - f o u r t h s expanded i n s i z e . I n tomatoes t h e a b s c i s s i o n o f n o r m a l f l o w e r s o c c u r r e d a t t i m e when t h e v e g e t a t i v e g r o w t h was a t a h i g h l e v e l , . ( J o h n s o n , 1956). A h i g h l e v e l o f a u x i n e x i s t e d a n d i n moving t o t h e a b s c i s s i o n zone o f f s e t t h e e f f e c t o f t h e a u x i n moving f r o m t h e f e r t i l i z e d f l o w e r . The f l o w e r t h e n f a l l s , a c c o r d i n g t o t h e a u x i n g r a d i e n t t h e o r y p r o p o s e d by A d d i c o t t , e t a l . , (1955). A t a low c o n c e n t r a t i o n o f 2,k-V ( l ppm) a p p l i e d d i s t a l l y t o t h e a b s c i s s i o n zone g e n e r a l l y p r e v e n t e d a b s c i s s i o n i n e x c i s e d f l o w e r s ( J o h n s o n , 1956), whereas t h e same c o n c e n t r a t i o n a p p l i e d p r o x i m a l t o t h e zone i n d u c e d a b s c i s s i o n . However, a t a h i g h e r c o n c e n t r a t i o n (10 ppm), a p p l i c a t i o n s on e i t h e r s i d e o f t h e zone t e n d e d t o p r e v e n t a b s c i s s i o n . - 13 -Work w i t h bean l e a f e x p l a n t s showed t h a t t h e r e was a two-phase a c t i o n o f a u x i n s on a b s c i s s i o n ( B r i g g s a n d L e o p o l d , 1958). The p r i m a r y a c t i o n o f a u x i n s was d i r e c t l y on t h e a b s c i s s i o n zone a n d was o f t h e two-phase t y p e w i t h low c o n c e n t r a t i o n s a c c e l e r a t i n g a n d h i g h c o n c e n t r a t i o n s i n h i b i t i n g a b s c i s s i o n . The d i f f e r e n c e s between p r o x i m a l and d i s t a l a p p l i c a t i o n s o f a u x i n s c o u l d be e x p l a i n e d on t h e b a s i s o f d i f f e r e n c e s i n t r a n s p o r t , w i t h o u t t h e n e c e s s i t y o f an a u x i n g r a d i e n t i n v o l v e m e n t . Lygus bugs, by " t o x i c " f e e d i n g , c a u s e d a s h e d d i n g o f blossoms a n d young pods up t o two i n c h e s l o n g i n l i m a beans ( B a k e r , e t a l , , 191*6). The young pod commonly t u r n e d y e l l o w , w i t h e r e d a n d dropped, t h e s e were r e f e r r e d t o by growers as " b u c k s k i n s " a n d a t t r i b u t e d t o h i g h t e m p e r a t u r e . V a r i o u s i n s e c t s , e s p e c i a l l y Lygus bugs, i n d u c e d bud, b l o s s o m , and s m a l l pod d r o p , a n d d i s t o r t e d a n d d w a r f e d t h e s m a l l l e a f l e t s o f bean p l a n t s ( F i s h e r , e t a l . , 191*6). Some o f t h e l o s s was p r e v e n t e d by d u s t i n g w i t h NAA a p p l i e d a t b l o s s o m i n g . The optimum p l o t s i z e s f o r t o t a l y i e l d , number o f pods a n d e a r l i n e s s i n l i m a beans were f o u n d t o be 15-0, 26.2 a n d 2k.k s q u a r e f e e t r e s p e c t i v e l y , when rows were p l a n t e d t h r e e f e e t a p a r t ( H o l l e a n d P e i r c e , i960). S i n g l e o r d o u b l e row p l o t s gave a p p r o x i m a t e l y e q u a l e f f i c i e n c y f o r number o f pods and e a r l i n e s s . A s i n g l e row p l o t was r e q u i r e d t o s a t i s f y t h e optimum p l o t requirement f o r t o t a l y i e l d . E a r l i n e s s d a t a showed low c o e f f i c i e n t o f v a r i a b i l i t y i n a l l c o m b i n a t i o n s o f p l o t a n d b l o c k d i m e n s i o n s . D a t a s u g g e s t e d t h a t no r e p l i c a t i o n was r e q u i r e d t o measure e a r l i n e s s . E x t e n s i v e r e p l i c a t i o n was r e q u i r e d f o r e f f e c t i v e e v a l u a t i o n o f t o t a l y i e l d a n d number o f pods. - Ill -MATERIALS AND METHODS Two t y p e s o f e x p e r i m e n t s were c o n d u c t e d , c o n t r o l l e d - e n v i r o n m e n t s t u d i e s a n d f i e l d e x p e r i m e n t s . I . C o n t r o l l e d - E n v i r o n m e n t S t u d i e s . A. Temperature E f f e c t s on Growth a n d F r u i t i n g . The p r e s e n t e x p e r i m e n t s o f t e m p e r a t u r e e f f e c t s on t h e g r o w t h and f l o w e r i n g b e h a v i o r o f beans were c o n d u c t e d i n c o n t r o l l e d - e n v i r o n m e n t growth c a b i n e t s (Ormrod, 1962). Day a n d n i g h t t e m p e r a t u r e s were con-t r o l l e d t o 2°F, u s i n g s e p a r a t e t h e r m o s t a t s . L i g h t was s u p p l i e d by s t a n d a r d b i p i n f l u o r e s c e n t t u b e s (2/3 S y l v a n i a L i f e l i n e c o o l w h i t e r e -f l e c t o r a n d l / 3 S y l v a n i a G r o - L u x ) w i t h a l i g h t i n t e n s i t y o f a p p r o x i m a t e l y 2000 f o o t - c a n d l e s ( r e a d w i t h a Weston Model 756 i l l u m i n a t i o n m e t e r w i t h o u t c o s i n e f i l t e r ) a t a d i s t a n c e e q u i v a l e n t t o h a l f t h e d i s t a n c e between t h e t o p o f t h e p l a n t a n d s o i l s u r f a c e . The p h o t o p e r i o d was 16 h o u r s . There was no h u m i d i t y c o n t r o l . O n e - g a l l o n p l a s t i c p o t s w i t h d r a i n h o l e s were f i l l e d w i t h a f e r t i l e s o i l . A t h r e e - f o u r t h s i n c h l a y e r o f p e a t moss was p l a c e d on t h e s o i l t o r e d u c e w a t e r l o s s due t o e v a p o r a t i o n . A t h r e e - f o u r t h s i n c h l a y e r of g r a v e l o r s a n d was p l a c e d a t t h e b o t t o m o f each p o t t o f a c i l i t a t e sub-I r r i g a t i o n . I n t h e f i r s t e x p e r i m e n t e i g h t S t r i n g l e s s Green P o d bush bean seeds were sown i n each pot a n d s e e d l i n g s were t h i n n e d l a t e r t o f o u r u n i f o r m p l a n t s . I n t h e o t h e r e x p e r i m e n t s f o u r seeds were sown i n each p o t and s e e d l i n g s were l a t e r t h i n n e d t o one p l a n t . Temperature t r e a t m e n t s were imposed f r o m s e e d i n g . The p o t s were randomly p l a c e d on aluminum pans i n t h e c o n t r o l l e d -- 15 -environment growth cabinets. The plants were watered from the top or by sub-irrigation. The position of the plants was frequently moved to minimize accumulated micro-climate effects due to location in the cabinet. When blossoming commenced, in a l l experiments but the f i r s t , each blossom was labelled to show date of blossoming. There was no fixed time for harvest, since the effect of temperature on blossom drop was considered more important for the purposes of this study than the effect of temperature on the yie l d of pods, leaves and stems. For s t a t i s t i c a l comparisons, pots were used as experimental units. For a l l experiments there were eight pots per treatment, except Experiment 3 , which had four pots per treatment. The experiments conducted were as follows:-Experiment 1. Effects of Variable Day and Constant Night Temperature. a) 90° day and 6o°F night. b) 80° day and 6o°F night. c) 70° day and 6o°F night. This experiment was conducted to determine an effective tempera-ture range for blossom drop studies. The pods were harvested at optimum marketable maturity, that is when 15 percent of pods were more than 27/6*4 inch diameter at the thickest portion of the pod. The average of the four plants was used in a l l comparisons between treatments. Experiment 2. Effects of Variable Day and Variable Night Temperature. a) 95° day and 80°F night. b) 85° day and 70°F night. c) 75° day and 60°F night. When the pods reached marketable maturity {21-2k/6k inch), the - 16 -pods on o n e - h a l f o f t h e e i g h t p l a n t s i n each t e m p e r a t u r e r e g i m e were p i c k e d . The pods on t h e o t h e r f o u r p l a n t s were a l l o w e d t o r i p e n . E x p e r i m e n t 3- E f f e c t s of C o n s t a n t Day an d V a r i a b l e N i g h t Temperature. a ) 95° day a n d 8o°F n i g h t . b) 95° day a n d 70°F n i g h t . c ) 95° day a n d 60°F n i g h t . T h i s e x p e r i m e n t was r e p e a t e d t o p r o v i d e a d d i t i o n a l i n f o r m a t i o n on b l o s s o m a n d young pod d r o p . E x p e r i m e n t *t. R e p e t i t i o n o f E x p e r i m e n t 3-T h i s e x p e r i m e n t was t e r m i n a t e d when c o m p l e t e o b s e r v a t i o n s o f b l o s s o m a n d young pod drop f o r t h e f i r s t 15 days o f b l o s s o m i n g were made. E x p e r i m e n t 5. E f f e c t s o f V a r i a b l e Day and Co n s t a n t N i g h t Temperature. a ) 95° day an d 60°F n i g h t . b.) 85° day andt6o°F n i g h t . c ) 75° day and 6o°F n i g h t . T h i s e x p e r i m e n t was t e r m i n a t e d when co m p l e t e o b s e r v a t i o n s o f b l o s s o m a n d young pod drop f o r t h e f i r s t 15 days o f b l o s s o m i n g w.ere made. B. L i g h t I n t e n s i t y E f f e c t s on Growth and F r u i t i n g . E x p e r i m e n t 6. The e x p e r i m e n t was c o n d u c t e d i n a P e r c i v a l c o n t r o l l e d - e n v i r o n -ment c a b i n e t . Three l i g h t i n t e n s i t i e s were used: 1*000, 2700, 1900 f o o t - c a n d l e s a t p l a n t l e v e l . The l i g h t s u s e d were v e r y h i g h o u t p u t c o o l w h i t e f l u o r e s c e n t t u b e s . The t e m p e r a t u r e was 80°F day a n d 70°F n i g h t , w i t h a l6-hour p h o t o p e r i o d . The p l a n t s y w e r e p r e p a r e d as i n t h e t e m p e r a t u r e s t u d y e x p e r i m e n t s , w i t h one p l a n t p e r p o t a n d f o u r p o t s - 17 -p e r t r e a t m e n t . Each b l o s s o m was i n d i v i d u a l l y l a b e l l e d t o show d a t e o f b l o s s o m i n g . The p l a n t s were h a r v e s t e d when t h e pods r e a c h e d optimum m a r k e t a b l e m a t u r i t y . O b s e r v a t i o n s o f Low. Temperature E f f e c t s . O b s e r v a t i o n s were made o f p l a n t s grown i n P e r c i v a l c o n t r o l l e d -e n v i ronment c a b i n e t s w i t h day t e m p e r a t u r e s o f 55° o r k^°F, a n d n i g h t t e m p e r a t u r e o f iiO°F. The l i g h t i n t e n s i t y was a p p r o x i m a t e l y 1100 f o o t -c a n d l e s a t p l a n t l e v e l . The p h o t o p e r i o d was 16 h o u r s . I I . F i e l d S t u d i e s . G e n e r a l P r o c e d u r e s . F i e l d e x p e r i m e n t s were c o n d u c t e d a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , V a n c o u v e r , B.C. ( A l d e r w o o d sandy loam) and a t t h e Canada Department o f A g r i c u l t u r e E x p e r i m e n t a l Farm a t A g a s s i z , B.C. (Monroe s i l t loam) t o compare l o c a t i o n e f f e c t s on t h e f r u i t i n g r e s p o n s e i n beans. B o t h p o l e and bush beans were u s e d i n t h e s e e x p e r i m e n t s . A l l e x p e r i m e n t s w i t h p o l e beans used t h e v a r i e t y B l u e L a k e FM1. S i x v a r i e t i e s o f bush beans were s t u d i e d ; S t r i n g l e s s Green Pod, Tender-c r o p ( A s g r o w ) , T e n d e r c r o p ( B u c k e r f i e l d ' s ) , Bush B l u e Lake (Asgrow #27*0> Bush B l u e Lake ,0SU 9^9-186^-2, Bush B l u e Lake BLS (Seed R e s e a r c h S p e c i a l i s t s ) a n d Asgrow. E a r l y Wax. Ex c e p t f o r t h e row s p a c i n g s t u d i e s , a l l p o l e beans were p l a n t e d i n rows f i v e f e e t a p a r t . The s e e d was sown f o u r t o f i v e seeds p e r f o o t . I n bush b e a n s , t h e rows were p l a n t e d t h r e e f e e t a p a r t w i t h n i n e seeds p e r f o o t . A t A g a s s i z , a l l t h e rows were p l a n t e d n o r t h a n d s o u t h . A t t h e U n i v e r s i t y o f B r i t i s h Columbia e x c e p t f o r t h e row d i r e c t i o n e x p e r i m e n t s , t h e rows were p l a n t e d e a s t - n o r t h - e a s t t o w e s t - s o u t h - w e s t . r- 18 . E x c e p t f o r t h e n i t r o g e n e x p e r i m e n t , a l l beans r e c e i v e d 500 pounds o f 6-27-25 f e r t i l i z e r p e r a c r e a t s e e d i n g . The f e r t i l i z e r was banded l | i n c h e s t o t h e s i d e a nd L| i n c h e s below t h e s e e d . I n a l l p l o t s , e x c e p t t h e p l a n t i n g d a t e e x p e r i m e n t , weeds were c o n t r o l l e d by t h e a p p l i c a t i o n o f "Premerge" (Dow C h e m i c a l Co.) a t t h e r a t e o f 3.6 pounds p e r a c r e i n 30 g a l l o n s o f w a t e r , a t t h e " h y p o c o t y l hook" s t a g e . A d d i t i o n a l weed c o n t r o l was done by one machine c u l t i v a t i o n a n d hand h o e i n g . I n t h e p l a n t i n g d a t e e x p e r i m e n t , a l l weeds were c o n -t r o l l e d by machine c u l t i v a t i o n a n d hand h o e i n g . The p o l e beans were s t a k e d . I n a l l p o l e bean e x p e r i m e n t s , t h e e x p e r i m e n t a l u n i t s were t e n f e e t by f i v e f e e t , e x c e p t i n t h e row s p a c i n g s t u d i e s , a n d i n a l l bush bean e x p e r i m e n t s , 10 f e e t by t h r e e f e e t . There were f i v e r e p l i c a t e s p e r t r e a t m e n t i n a l l f i e l d e x p e r i m e n t s . I n a l l e x p e r i m e n t s , e x c e p t E x p e r i m e n t 7, a r a n d o m i z e d c o m p l e t e b l o c k d e s i g n was used . A t h a r v e s t , t h e c e n t r e s i x f e e t o f row (30 s q u a r e f e e t p l o t ) i n p o l e b e a n s , a n d t h e c e n t r e e i g h t f e e t of row (2*1 s q u a r e f e e t p l o t ) i n t h e bush beans were h a r v e s t e d f r o m each e x p e r i m e n t a l u n i t . D a t a were c o l l e c t e d on number a n d f r e s h w e i g h t o f pods when pods were a p p r o x i m a t e l y 2l/6k-27/6k i n c h i n d i a m e t e r a t t h e t h i c k e s t p o r t i o n o f t h e pod, f o r a l l p o l e bean e x p e r i m e n t s . Bush beans were h a r v e s t e d when a p p r o x i m a t e l y 15 p e r c e n t o f t h e pods were more t h a n 27/6*4 i n c h i n d i a m e t e r a t t h e t h i c k e s t p o r t i o n o f t h e pod. A. P o l e Bean E x p e r i m e n t s a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , E x p e r i m e n t 7. E f f e c t o f P l a n t i n g Date on t h e F r u i t i n g Response. F i v e d i f f e r e n t p l a n t i n g d a t e s - w e r e s t u d i e d ; May 1, 15, 29, June 12 a n d 26. A L a t i n s q u a r e e x p e r i m e n t a l d e s i g n was used. - 19 -E x p e r i m e n t 8. E f f e c t o f N i t r o g e n L e v e l on t h e F r u i t i n g Response. T h r e e l e v e l s o f n i t r o g e n were s u p p l i e d : 0, 30 a n d 60 pounds p e r a c r e o f a v a i l a b l e n i t r o g e n as ammonium n i t r a t e . One hun d r e d e i g h t y f i v e pounds p e r a c r e o f a v a i l a b l e phosphorus as su p e r p h o s p h a t e and 175 pounds p e r a c r e o f a v a i l a b l e p o t a s s i u m as KCL were a p p l i e d t o a l l e x p e r i m e n t a l u n i t s . B l o s s o m d r o p c o u n t s were made each week by g a t h e r i n g a b s c i s s e d blossoms and young pods. E x p e r i m e n t 9- E f f e c t o f Row S p a c i n g on t h e F r u i t i n g Response. Three row s p a c i n g s were s t u d i e d ; two f e e t , f o u r f e e t and e i g h t f e e t . E x p e r i m e n t 10. E f f e c t o f Row D i r e c t i o n on t h e F r u i t i n g Response. The row d i r e c t i o n e x p e r i m e n t was s e t up i n two d i r e c t i o n s ; w i t h t h e p r e v a i l i n g w i n d s , e a s t - n o r t h - e a s t , w e st-south-west, a n d a t r i g h t a n g l e t o t h e p r e v a i l i n g w i n d s , n o r t h - n o r t h - w e s t t o s o u t h - s o u t h - e a s t . E x p e r i m e n t 11. E f f e c t o f C h e m i c a l S p r a y s on t h e F r u i t i n g Response. N i n e t r e a t m e n t s and one c o n t r o l were used; I n d o l e a c e t i c a c i d ( I A A) a t 10 a n d 100 ppm, NAA a t 10 and 100 ppm, s u c r o s e a t 1 and 20$, 2,k-D a t 1 a n d 10 ppm a n d 2,*)-D a t 10 ppm w i t h FeEDTA a t 5 ppm. The 100 mg. NAA and 10 mg. 2,^-D were f i r s t d i s s o l v e d i n 30 and 5 m l . o f e t h a n o l r e s p e c t i v e l y , b e f o r e b e i n g d i l u t e d i n a 1000 m l . o f d i s t i l l e d w a t e r . A " s p r e a d e r " was u s e d w i t h a l l s p r a y s . B l o s s o m d r o p c o u n t s were made each week. B. Bush Bean E x p e r i m e n t s a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a . E x p e r i m e n t 12. E f f e c t o f C h e m i c a l Sprays on t h e F r u i t i n g Response. T h r e e v a r i e t i e s of bush beans were used; S t r i n g l e s s G r e e n P od, T e n d e r c r o p and Bush B l u e Lake Asgrow #2lM. The t r e a t m e n t s were t h e same as f o r t h e p o l e beans a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a . - 20 -B l o s s o m d r o p c o u n t s were made each week f o r t h e c e n t r e two f e e t i n each p l o t , A t h a r v e s t , o n l y t h e f r e s h w e i g h t o f pods was r e c o r d e d . E x p e r i m e n t 13. E f f e c t o f V a r i e t y on t h e F r u i t i n g Response. The v a r i e t i e s , Bush B l u e L a k e OSU 9U9-I86I4-2, Bush B l u e Lake Asgrow #27** > Bush B l u e L a k e BLS (S e e d R e s e a r c h S p e c i a l i s t s ) , S t r i n g l e s s G r e e n Pod, T e n d e r c r o p ( B u c k e r f i e l d ' s ) , T e n d e r c r o p (Asgrow) a n d Asgrow E a r l y Wax were used. A t w o - f o o t row s e c t i o n i n t h e c e n t r e o f each p l o t was u s e d t o d e t e r m i n e t h e b l o s s o m d r o p . The number ( g r a d e d t o s i z e v i s u a l l y ) a n d f r e s h w e i g h t o f pods a n d t h e number o f p l a n t s were d e t e r m i n e d f r o m t h e c e n t r e e i g h t f e e t o f each p l o t . C. P o l e Bean E x p e r i m e n t a t A g a s s i z . E x p e r i m e n t 1*4. E f f e c t o f C h e m i c a l S p r a y s on t h e F r u i t i n g Response. Seven t r e a t m e n t s a n d one c o n t r o l were used; IAA a t 10 and 100 ppm, HAA a t 10 a n d 100 ppm, s u c r o s e 1$ s o l u t i o n , a n d 2,*4-D a t 1 a n d 10 ppm. B l o s s o m d r o p was c o u n t e d each week. D. Bush Bean E x p e r i m e n t a t A g a s s i z . E x p e r i m e n t 15. E f f e c t o f C h e m i c a l S p r a y s on t h e F r u i t i n g Response. T e n d e r c r o p beans were u s e d , a n d t h e s p r a y s were t h e same as on t h e p o l e beans a t A g a s s i z . B l o s s o m d r o p ( w e e k l y c o u n t s ) a n d number o f pods were d e t e r m i n e d f o r t h e c e n t r e two f e e t o f row i n each p l o t . F r e s h w e i g h t s o f pods were d e t e r m i n e d a t h a r v e s t . Data o b t a i n e d i n a l l e x p e r i m e n t s was s t a t i s t i c a l l y e v a l u a t e d u s i n g a n a l y s i s o f v a r i a n c e methods f o l l o w e d by Duncan's m u l t i p l e range t e s t s . Most o f t h e s t a t i s t i c a l a n a l y s e s were c a r r i e d o ut u s i n g t h e I.B.M. 70*40 computer (U.B.C. Computing C e n t r e ) . I n t h e p r e s e n t a t i o n o f r e s u l t s a nd i n d i s c u s s i o n o n l y t h o s e d i f f e r e n c e s w h i c h were s i g n i f i c a n t a t t h e 5 p e r c e n t l e v e l were c o n -s i d e r e d t o be m e a n i n g f u l a n d w o r t h y o f comment. - 21 -RESULTS I . C o n t r o l l e d - E n v i r o n m e n t S t u d i e s . I n E x p e r i m e n t 1 t h e l e a f w e i g h t was i n v e r s e l y r e l a t e d t o t h e t e m p e r a t u r e ( T a b l e l ) . As t h e t e m p e r a t u r e i n c r e a s e d f r o m 70/60°F t o 8o/60°F t o 90/6o°F, t h e f r e s h a nd d r y w e i g h t o f t h e l e a v e s d e c r e a s e d . There was no d i f f e r e n c e i n r e s p o n s e between t h e f r e s h a n d d r y w e i g h t of t h e stems. The h e i g h t o f t h e p l a n t s was g r e a t e r a t $o/60°F t h a n a t t h e o t h e r two t e m p e r a t u r e s . A t t h e h i g h e s t t e m p e r a t u r e t h e p l a n t s were t a l l e r t h a n a t l o w e r t e m p e r a t u r e s . T h e r e was no d i f f e r e n c e i n node number between t h e l o w e r t e m p e r a t u r e s b u t a t 90/60°F t h e r e were f e w e r nodes. There was no d i f f e r e n c e i n pod number and w e i g h t between t h e two l o w e r t e m p e r a t u r e s , b u t a t 90/6o°F t h e r e were f e w e r pods and t h e pod w e i g h t was l e s s . I n E x p e r i m e n t 2, when t h e pods were h a r v e s t e d a t m a r k e t a b l e m a t u r i t y ( f i n a l h a r v e s t was t h r e e months a f t e r p l a n t i n g ) , t h e l e a f w e i g h t was i n v e r s e l y r e l a t e d t o t h e t e m p e r a t u r e ( T a b l e 2). As t h e t e m p e r a t u r e i n c r e a s e d f r o m 75/60°F t o 85/70°F t o 95/80°F, t h e f r e s h a n d d r y w e i g h t o f l e a v e s d e c r e a s e d . A t t h e h i g h e r t e m p e r a t u r e , 95/80°F t h e r e was l e s s f r e s h a n d d r y st e m w e i g h t t h a n a t l o w e r t e m p e r a t u r e s . The h e i g h t of t h e p l a n t s grown a t 95/80°F was l e s s t h a n a t l o w e r t e m p e r a t u r e s b u t t h e number o f nodes was u n a f f e c t e d . The pod w e i g h t was s i m i l a r a t t h e two l o w e r t e m p e r a t u r e s b u t a t t h e h i g h t e m p e r a t u r e pod w e i g h t was l e s s t h a n a t l o w e r t e m p e r a t u r e s , T h e r e were more blossoms a t 85/70°F t h a n a t 75/60°F b u t a t 95/80°F t h e r e was a d e c r e a s e i n number o f blossoms compared t o l o w e r t e m p e r a t u r e s . T a b l e 1. E f f e c t o f 90/60, 80/60, a n d 70/60°F d a y / n i g h t t e m p e r a t u r e s on growth and f r u i t i n g o f S t r i n g l e s s Green P o d bush beans i n Experiment 1. Pod Weight L e a f Weight Stem Weight H e i g h t Nodes F r e s h Dry Pods (number) Temperature F r e s h Dry F r e s h Dry T o t a l (number) M a r k e t a b l e T o t a l T o t a l M a r k e t a b l e T o t a l (gm. (gm.) (gm.) (gm-) ( i n . ) (gm.) (gm.) (gm.) 90/60 11.3c* 1.35c 9.2a 1.50a 16.1) a 8.3b 7.7b 8.6b 0.96b 3-Ob 5.3b 80/60 13-*Jb 1.63b 9.0a 1.52a II4 . l b 9-3a 18. Oa 19.2a 1.92a 5.3a 8.0a 70/60 15.8a 1.93a 9.2a 1.80a 13.8b 9.1a 21.1a 21.5a 2.07a 6.0a 7.6a * means f o l l o w e d by t h e same l e t t e r a r e not s i g n i f i c a n t l y d i f f e r e n t a t t h e 5$ l e v e l ( Duncans m u l t i p l e range t e s t ). T a b l e 2. E f f e c t o f 95/80, 85/70, 75/60°F d a y / n i g h t t e m p e r a t u r e s a n d h a r v e s t t i m e on growth and f r u i t i n g o f S t r i n g l e s s Green P o d b u s h beans i n E x p e r i m e n t 2. Temp. L e a f Weight Stem Weight H e i g h t Nodes Pods Weight Blossoms °F F r e s h Dry F r e s h . Dry T o t a l (number ) F r e s h Dry T o t a l M a r k e t a b l e (gm.) (gm.) (gm-) (gm.) ( i n . ) (gm.) (gm.) (number) M a t u r i t y 95/80 H a r v e s t 26.6c k .kOa l a . 6 b 8.3lib 13 .5b 11.2a 1.0b O .Ub 25.0c 85/70 9k . l b ll.lkb 65.8a 16.22a 19.8a 10 . 8 a 111 .6a 10.1»5a 102 . 5 a 75/60 125.5a 17.06a 65.1a 16.77a 17 .9a 9.8a 129.3a 11 .07a 67.8b Dry M a t u r i t y 95/80 H a r v e s t 5l.ka 6 Me. l j l . 8 a 6.1)0a 13-Ob 11.0a 0.11b 2k .0b 85/70 22 .6b 2.90b 2k .ko 14.57b 18.6a 10.2ab 13.58a lj2 . 8 a 75/60 50.6a 5-kla 32 .6b 5-53ab 20.1a 9-2b II4 -90a l42-2a F i r s t 15 Days of B l o s s o m i n g Temperature °F 95/80 85/70 75/60 Blossoms T o t a l (number) lk .6b kS. 8a 1)3-9a Pods Set (number) 0.1b l6.1)a 17.0a Blossoms Dropped (number) 111. 5b 30.lia 26.9a Blossoms Dropped (*•) 99.5a 65.1b 6l.kb Set [number] 2.2b 52.8a kl. 8a Blossoms Dropped )(number) 22.8b l49.8a 27.0b 2.0b 22.0a - 21) -The number o f pods s e t was r e d u c e d a t t e m p e r a t u r e s above 85/TO°F. There was no d i f f e r e n c e between t h e number o f blossoms t h a t d r o p p e d a t 95/80°F a n d 75/60°F b u t t h e r e were more blossoms a t 85/70°F. I n E x p e r i m e n t 2 when t h e pods were h a r v e s t e d a t d r y m a t u r i t y ( h a r v e s t e d two months a f t e r p l a n t i n g ) t h e r e was no d i f f e r e n c e i n f r e s h a n d d r y w e i g h t o f l e a v e s between 95/80°F a n d 75/60°F b u t a t &5/lO°F t h e f r e s h a n d d r y w e i g h t o f t h e l e a v e s was l e s s t h a n a t t h e o t h e r t e m p e r a t u r e s . The f r e s h w e i g h t s o f stems i n a l l t r e a t m e n t s were d i f f e r e n t , w i t h t h e h i g h e s t t e m p e r a t u r e g i v i n g t h e g r e a t e s t w e i g h t , f o l l o w e d by 75/60°F and t h e l o w e s t w e i g h t a t 85/70°F. There was no d i f f e r e n c e i n d r y w e i g h t o f stems between 95/80°F a n d 75/60°F, a n d no d i f f e r e n c e between Q^/lO°F a n d 75/6o°F, b u t a t 95/80°F stems were h e a v i e r t h a n a t 8^/l0°f. The h e i g h t o f t h e p l a n t s grown a t 95/80°F was l e s s t h a n a t l o w e r tempera-t u r e s . T h e r e was no d i f f e r e n c e i n t h e number o f nodes between 95/80°F a n d 75/60°F b u t p l a n t s grown a t 95/80°F had more nodes t h a n p l a n t s grown a t 75/60°F. There were no d i f f e r e n c e s i n pod d r y w e i g h t , t o t a l b lossoms a n d pods s e t between t h e l o w e r two t e m p e r a t u r e s , b u t a t 95/8o°F t h e r e were f e w e r pods s e t t h a n a t t h e l o w e r t e m p e r a t u r e s . There were no d i f f e r e n c e s i n number o f blossoms t h a t d r o p p e d a t a l l t h r e e tempera-t u r e s . When t h e f i r s t 15 days o f b l o s s o m i n g a t a l l t e m p e r a t u r e s were compared t h e r e were no d i f f e r e n c e s i n t o t a l b l o s s o m s , pods s e t , blossoms d r o p p e d a n d p e r c e n t a g e blossoms d r o p p e d between 85/70°F a n d 75/60°F, b u t t h e s e two t e m p e r a t u r e r e g i m e s had g r e a t e r numbers o f blossoms a n d more pods s e t t h a n a t 95/80°F. When p l a n t were h a r v e s t e d a t m a r k e t a b l e m a t u r i t y , t h e b l o s s o m i n g p a t t e r n was f o u n d t o be c y c l i c ( F i g . 1, 2, and h). The f i r s t c y c l e had - 2 5 -the greatest number of flowers, but subsequent cycles had a greater percentage of pod set. The plants remained vigorous, and at 8 5 / 7 0°F and 7 5 / 6 0°F plants showed increased growth (Table 2 ) . When plants were harvested at dry maturity only one blossoming occurred followed by senescence of the entire plant (Fig. 3 and 5 ) . In Experiment 3 there were no differences between 9 5 / 8 0°F and 9 5 / 6 0°F or between 9 5 / 8 0°F and 9 5 / 9 0°F i n fresh weight of leaves but 9 5 / 6 0°F plants had more leaf fresh weight than plants grown at 9 5 / 7 0°F (Table 3 ) . Plants grown at 9 5 / 8 0°F and 9 5 / 7 0°F had the same dry weight of leaves but plants grown at 9 5 / 8 0°F had a higher dry weight of leaves. Plants grown at a l l temperatures had si m i l a r fresh and dry weight of stems. The height of the plant varied inversely with the night temperature, with the plants grown with cooler nights being t a l l e r than those grown at the high night temperature. There were sim i l a r numbers of nodes per plant at a l l temperatures. The lowest night temperature resulted i n a higher y i e l d of pods (fresh and dry) than the higher night temperatures. The highest night temperatures resulted i n a reduced number of blossoms, pods set and number of blossoms dropped per plant compared to lower night temperatures. Results of Experiment ^ were very s i m i l a r to those of Experiment 3 f o r which the same temperatures were used except that at the higher night temperatures no pods set (Table k shows blossoming data only). There was a decrease i n percent blossoms dropped at the lower night temperatures. In Experiment 5 plants at 9 5 / 6 0°F, 8 5 / 6 0°F and 7 5 / 6 0°F had s i m i l a r numbers of pods but there was a reduction of pods set at the 9 5 / 6 0°F temperature (Table 5 ) . The number of blossoms that dropped and the percent blossoms dropped was highest at the highest day temperature. - 26 -10 w 2 O in in o PODSET C BLOSSOM DROP OD 2 4 Z 19 < !> DC ' UJ 3 N i l J k . 1 12 18 24 30 36 42 48 DAYS AFTER FIRST BLOSSOMING 54 60 Figure 1. Effect of 95/80 F day/night temperatures on the blossoming pattern of Stringless Green Pod bush beans. No mature pods had developed. - 27 -10 s £ 8 en O -i OD 6 -DC LU CD z PODSET C BLOSSOM DROP J . J l i d 12 18 24 30 36 42 48 54 DAYS A F T E R FIRST BLOSSOMING 60 F i g u r e 2 . E f f e c t o f 85/70°F d a y / n i g h t t e m p e r a t u r e s on t h e b l o s s o m i n g p a t t e r n o f S t r i n g l e s s G reen P o d bush beans when pods were h a r -v e s t e d a t m a r k e t a b l e m a t u r i t y . - 28 -10 i -2 O </) CO o u- 6 CE Ui ffi S , Z o Ul 1 PODSET C BLOSSOM DROP 6 12 18 24 30 DAYS AFTER FIRST BLOSSOMING 36 F i g u r e 3. E f f e c t o f 85/70 F d a y / n i g h t t e m p e r a t u r e s on t h e b l o s s o m i n g p a t t e r n o f S t r i n g l e s s G r e e n P o d b u s h beans when pods were h a r -v e s t e d a t d r y m a t u r i t y . - 29 -10 s o co CO Q PODSET BLOSSOM DROP UJ CO s Z 2 2 i JL 12 18 24 30 36 42 48 DAYS AFTER FIRST BLOSSOMING 54 60 F i g u r e I4. E f f e c t o f 75/60 F d a y / n i g h t t e m p e r a t u r e s on t h e b l o s s o m i n g p a t t e r n o f S t r i n g l e s s G reen P o d bush beans when pods were h a r v e s t e d a t m a r k e t a b l e m a t u r i t y . - 30 -io i -o to 8 in o _i CD 6 -ui CD CO < ui c > < PODSET BLOSSOM DROP 1 6 12 18 24 30 DAYS AFTER FIRST BLOSSOMING 36 Figure 5. Effect of 75/60°F day/night temperatures on the blossoming pattern of Stringless Green Pod "bush beans when pods were harvested at dry maturity. T a b l e 3. E f f e c t o f 95/80, 95/70$ 95/60°F d a y / n i g h t t e m p e r a t u r e s on t h e growth a n d f r u i t i n g o f S t r i n g l e s s Green P o d bush beans i n Experiment 3« M a r k e t a b l e m a t u r i t y s i n g l e h a r v e s t . Temperatures L e a f Weight Stem Weight H e i g h t Op F r e s h Dry F r e s h Dry T o t a l (gm.) (gm.) (gm.) (gm.) ( i n . ) 95/80 55.8ab 6.55b 31.8a 5-8i*a 12.8b 95/70 51.6b 6.55b 32.8a 6.k0a lit.8 a 95/60 6k.k* 8.37a 29.8a 6 . l 6 a i M a Nodes Pods Weight Blossoms Pods Set Blossoms number) F r e s h Dry T o t a l (number) Dropped (gm.) (gm.) (number) (number) 8.5a Q.l lb 0.06b 13.8b 1.0b 12.8b 9.0a 2.2b 0.32b 36.5a It.8a 31.8a 8.8a 8.8a 0.96a I f l . O a 11. Oa 30. Oa - 32 -T a b l e k. E f f e c t o f 95/80, 95/70, 95/60°F d a y / n i g h t t e m p e r a t u r e s on f r u i t i n g o f S t r i n g l e s s G r e e n P o d bush beans i n E x p e r i m e n t k . F i r s t 15 days o f b l o s s o m i n g . Temperatures O p Blossoms T o t a l (number) P o d S e t (number) Blossoms Dropped (number) Blossoms Dropped ( p e r c e n t ) 95/80 13.8b 0.0b 13 .8b 100.Oa 95/70 2k .6a OCOb 2k.6a 100.0a 95/60 31.0a 1 .5a 29-5a 95.l4b T a b l e 5. E f f e c t o f 95/60, 85/60, 75/60°F d a y / n i g h t t e m p e r a t u r e s on f r u i t i n g o f S t r i n g l e s s Green P o d bush beans i n E x p e r i m e n t 5? F i r s t 15 days of b l o s s o m i n g . Temperatures °F Blossoms T o t a l (number) Pods S e t (number) Blossoms Dropped (number) Blossoms Dropped ( p e r c e n t ) 95/60 26.5a 0.2b 26.3a 99-2a 85/6O 26.8a 13.0a 13.8b 149. Ob 75/60 29.0a 15.2a 13.8b l46.9b - 33 -I n E x p e r i m e n t 6 f r e s h a n d d r y l e a f w e i g h t , f r e s h stem w e i g h t , f r e s h a n d d r y pod w e i g h t , t o t a l blossoms a n d b l o s s o m d r o p were a l l s i m i l a r a t t h e U000 a n d 2700 f o o t - c a n d l e s l i g h t i n t e n s i t i e s , b u t were r e d u c e d a t t h e 1900 f o o t - c a n d l e s l i g h t i n t e n s i t y ( T a b l e 6 ) . Dry stem w e i g h t v a r i e d d i r e c t l y w i t h t h e l i g h t i n t e n s i t y . H e i g h t a n d number o f nodes were not a f f e c t e d by l i g h t i n t e n s i t y . P l a n t s grown a t *4000 a n d 2700 f o o t - c a n d l e s had more pods s e t t h a n t h o s e g r o w i n g a t t h e l o w e r l i g h t i n t e n s i t y . P l a n t s grown a t r e s u l t e d i n s t u n t e d g r o w t h . The number o f nodes a n d t h e t o t a l h e i g h t were l o w e r t h a n a l l o t h e r t e m p e r a t u r e r e g i m e s . A few b l o s s o m s f o r m e d , b ut none s e t pods. Seeds p l a n t e d a t k^/M0°'F d i d n o t g e r m i n a t e . I I . F i e l d S t u d i e s . I n E x p e r i m e n t 7, t h e number a n d w e i g h t o f pods were s i m i l a r f o r t h e f i r s t t h r e e p l a n t i n g d a t e s ( T a b l e 7 ) ' Number o f pods a n d y i e l d s were l o w e r a t t h e l a s t two p l a n t i n g d a t e s compared t o e a r l i e r p l a n t i n g d a t e s . I n E x p e r i m e n t 8, t h e l e v e l o f n i t r o g e n f e r t i l i t y h ad no e f f e c t on t h e number a n d w e i g h t of pods?; number of blossoms d r o p p e d o r t h e number of p l a n t s p e r p l o t ( T a b l e 8). I n E x p e r i m e n t 9, t h e number a n d w e i g h t o f pods v a r i e d d i r e c t l y w i t h t h e row s p a c i n g ( T a b l e 9 ) . The w i d e r t h e rows a p a r t , t h e g r e a t e r t h e y i e l d p e r u n i t l e n g t h o f row. However, i f t h e d a t a were a d j u s t e d f o r a r e a , t h e n a r r o w e r row s p a c i n g s gave t h e g r e a t e s t y i e l d . The number of p l a n t s p e r p l o t was s i m i l a r a t a l l row s p a c i n g s . I n E x p e r i m e n t 10, row d i r e c t i o n had no e f f e c t on t h e number a n d w e i g h t o f pods, o r t h e number of blossoms t h a t d ropped ( T a b l e 10). I n E x p e r i m e n t 11, p l a n t s s p r a y e d w i t h IAA (100 ppm), s u c r o s e (20$) an d t h e c o n t r o l had s i m i l a r numbers o f pods ( T a b l e 11). O n l y 2,*!-D T a b l e 6. E f f e c t o f l i g h t i n t e n s i t y on t h e growth and f r u i t i n g o f S t r i n g l e s s Green P o d bush beans w i t h 8o/70°F d a y / n i g h t t e m p e r a t u r e i n Experiment 6. M a r k e t a b l e m a t u r i t y s i n g l e h a r v e s t . L i g h t I n t e n s i t y ( f t . - c a ) L e a f F r e s h (gm.) Weight Dry (gm.) Stem Weight F r e s h Dry (gm.) (gm.) H e i g h t T o t a l ( i n . ) Nodes (number Pods Weight F r e s h Dry (gm.) (gm.) Blossoms T o t a l (number) Pods Set (number) Blossoms Dropped (number) 1)000 73-3a 9.08a 53.8a 10.53a 18.6a 8.0a 98.0a 10.5lta 95.0a 32.8a 62.2a 2700 67.9a 7-36a 1*5-8a 7.10b 20.8a 7.5a 86.6a 8.19a 73-Oa 21.5ab 51.5a 1900 1*8.lib l|.61fb 25.6b 3.98b 18.5a 8.0a 1)2.8b 3.97b 35.8b 13.2b 22.5b - 35 -T a b l e 7 • E f f e c t o f p l a n t i n g d a t e on t h e f r u i t i n g o f B l u e Lake F M 1 p o l e beans a t t h e U n i v e r s i t y o f B.C. i n E x p e r i m e n t 7-Pods Number Pods Weight May 1 9 7 ^ 5171a May 15 996a 5052a May 29 1123a 5521a June 12 7*» 3b 3 2 8 l b June 26 336c 121*rc T a b l e 8 . E f f e c t o f n i t r o g e n on t h e f r u i t i n g r e s p o n s e o f B l u e L a k e FML p o l e beans a t t h e U n i v e r s i t y o f B.C.. i n E x p e r i m e n t 8 . N i t r o g e n Pods T o t a l Pods Weight Blossoms Dropped P l a n t s S u p p l i e d (number) (gm-) (number) (number) 0 pounds 10*t5.0a 5339a *46.8a 2 0 . 0 a 30 pounds 1 0 1 3 . 6 a 5169a 3 7 - 8 a 1 9 - 8 a 6 0 pounds 99I4 . 6 a 512^a 1)0.6a 1 9 . 6 a - 36 -T a b l e 9. E f f e c t o f row s p a c i n g on t h e f r u i t i n g r e s p o n s e o f B l u e Lake FM1 p o l e beans a t t h e U n i v e r s i t y o f B.C. i n E x p e r i m e n t 9-Row Spac i n g Pods Number A d j u s t e d T o t a l f o r a r e a Pods Weight (gm.) A d j u s t e d T o t a l f o r a r e a P l a n t s Number 2 F o o t Ittty.2c 1936.8a 2930c 11600a it Foot. 775-8b 1551.6b ltl53b 8307b 8 F o o t 972. it a 972-it c 5230a 5230c 23-8a 23.6a 22.6a T a b l e 10. E f f e c t o f row d i r e c t i o n on t h e f r u i t i n g r e s p o n s e o f B l u e Lake FM1 p o l e beans a t t h e U n i v e r s i t y o f B.C. i n E x p e r i m e n t 10. E a s t - n o r t h - e a s t t o w e s t - s o u t h - w e s t N o r t h - n o r t h - w e s t t o s o u t h - s o u t h - e a s t Pods T o t a l (number) 805.6a 79k.8a Pods Weight Blossoms Dropped (gm.) (number) 5205a 5109a 53-Oa 51.6a - 37 -T a b l e 11. E f f e c t o f c h e m i c a l s p r a y s on t h e f r u i t i n g r e s p o n s e o f B l u e L a k e FM1 p o l e beans a t t h e U n i v e r s i t y o f B.C. i n E x p e r i m e n t 11. C h e m i c a l Sprays Pods Pods Weight Blossoms Dropped (number) (gnu) (number) I A A . - 10 ppm 1032.6d 5 3 5 3 d 92.8de - 100 ppm 1056.Ocd 5538bc 1*4 8.8b N A A . - 10 ppm 928.2e 5071e 129-Obc - 100 ppm ii75-8g 26l*7h 23k.k& S u c r o s e - 1 $ 1035.6d 5257<le 109-8cd - 20 j> 1112.lib 5712b 108.6cd 2,1)-D - 1 ppm 1190.0a 5707b 135.l4bc - 10 ppm 78I.kf I)821f 73-2e 2,k-D - 10 ppm & FeEDTA 5 ppm 771.2f k$lkg 78.6e C o n t r o l IO85.Obc 596 5a 132.Obc - 38 -s p r a y e d a t 1 ppm i n c r e a s e d t h e number o f pods, A l l o t h e r c h e m i c a l s p r a y s c a u s e d r e d u c t i o n s incumbers o f pods. A l l t r e a t m e n t s r e d u c e d pod w e i g h t compared t o t h e c o n t r o l . The h i g h e r c o n c e n t r a t i o n s o f 2,k-D and NAA g r e a t l y r e d u c e d t h e y i e l d . IAA (10 ppm) and 2,b-B (10 ppm a n d 10 ppm w i t h FeEDTA 5 PPm) s p r a y e d p l a n t s showed r e d u c e d b l o s s o m d r o p . O n l y NAA (100 ppm) showed an i n c r e a s e d b l o s s o m d r o p . B l o s s o m d r o p i n o t h e r t r e a t m e n t s was s i m i l a r t o t h e c o n t r o l . I n E x p e r i m e n t 12, p l a n t s s p r a y e d w i t h IAA (10 ppm) s u c r o s e (20$) a n d t h e c o n t r o l had s i m i l a r w e i g h t s o f pods f o r t h e v a r i e t y S t r i n g l e s s G r e e n P o d ( T a b l e 12). Only NAA (100 ppm) r e d u c e d t h e y i e l d . O t h e r s p r a y s r e s u l t e d i n i n c r e a s e d w e i g h t o f pods compared t o t h e c o n t r o l . The number o f blossoms t h a t d r o p p e d i n a l l t r e a t m e n t s were s i m i l a r . I n T e n d e r c r o p bush beans IAA (10 a n d 100 ppm) and s u c r o s e ( l a n d 20$) t r e a t e d p l a n t s had s i m i l a r f r e s h w e i g h t s o f pods compared t o t h e c o n t r o l ( T a b l e 13). NAA (.10 a n d 100 ppm), 2,*4-D (10 ppm and 10 ppm w i t h FeEDTA 5 ppm) r e s u l t e d i n i n c r e a s e d y i e l d s compared t o t h e c o n t r o l s . O n l y 2,^-D ( l ppm) r e d u c e d t h e y i e l d o f b e a n s . The number o f blossoms t h a t d r o p p e d was s i m i l a r f o r a l l t r e a t m e n t s , e x c e p t NAA (100 ppm) w h i c h r e s u l t e d i n i n c r e a s e d b l o s s o m d r o p . I n Bush B l u e L a k e Asgrow #27^, IAA ( l O ppm) a n d NAA ( l O ppm) had s i m i l a r f r e s h w e i g h t s o f pods compared t o t h e c o n t r o l ( T a b l e ). A l l o t h e r t r e a t m e n t s r e d u c e d t h e y i e l d o f beans. The number o f blossoms d r o p p e d were s i m i l a r f o r a l l t r e a t m e n t s . I n E x p e r i m e n t 13, Bush B l u e L a k e OSU 9^ 9-196^ -2 a n d Asgrow E a r l y Wax p r o d u c e d t h e h i g h e s t t o t a l a n d m a r k e t a b l e (medium s i z e ) number o f pods ( T a b l e 15). A l l o t h e r v a r i e t i e s had a l o w e r number o f pods ( t o t a l a n d m a r k e t a b l e ) w i t h Bush B l u e L a k e BLS t h e l o w e s t . S t r i n g l e s s G r e e n - 39 -T a b l e 12. E f f e c t o f c h e m i c a l s p r a y s on t h e f r u i t i n g r e s p o n s e o f S t r i n g l e s s G r e e n P od bush beans a t t h e U n i v e r s i t y o f B.C. i n E x p e r i m e n t 12. C h e m i c a l S p r a y s Pods Weight Blossoms Dropped (gm.) (number) IAA - 10 ppm 1280de 3-0a - 100 ppm 1377b 3-0a K M - 10 ppm 1376b 2.8a - 100 ppm 1095f 2.6a S u c r o s e - 1 $ 1320cd 1.6a - 20 <f> 1251e 2.6a 2,1»-D- - 1 ppm 1362bc 2.8a - 10 ppm 1586a 1.2a 2,1»-D- - 10 ppm & FeEDTA 5 ppm 1 5 ^a 2.6a C o n t r o l 1257e 3-8a - ho -T a b l e 13. E f f e c t o f c h e m i c a l s p r a y s on t h e f r u i t i n g r e s p o n s e o f T e n d e r c r o p bush beans a t t h e U n i v e r s i t y o f B.C. i n Ex p e r i m e n t 12. C h e m i c a l S p r a y s Pods Weight (gm.) Blossoms Dropped (number) IA4 - 10 ppm 1032cd 5-6ab - 100 ppm 1118b 3.8b MA - 10 ppm 1208a *t.8ab - 100 ppm 1196a 7-*ta S u c r o s e - 1 $ l l l * t be 2,8b - 20 $ 1089bc 5-*»ab 2,*t-D 1 ppm 992d 5.0ab - 10 ppm . 1267a 3.8b 2,h-B - 10 ppm & FeEDTA 5 ppm 1228a 5-2ab C o n t r o l 111*1 be 3.0b -1*1 -T a b l e 1*4. E f f e c t o f c h e m i c a l s p r a y s on t h e f r u i t i n g r e s p o n s e o f Bush B l u e L a k e Asgrow #27*4 bush beans a t t h e U n i v e r s i t y o f B.C. i n E x p e r i m e n t 12. C h e m i c a l S p r a y s Pods Weight Blossoms Dropped (gm.) (number) IAA - 10 ppm 2262bc 6.2a - 100 ppm 2l80cd 3.8a NAA - 10 ppm 2367a - 100 ppm l837f 2.8a S u c r o s e - 1 $ 1902f 7.2a - 20 <f> 20l8e 6.2a 2,k-3- - 1 ppm l879f 3.6a - 10 ppm 2112d 3-l»a 2^-D - 10 ppm & FeEDTA 5 ppm 2ll4 3d. 3.8a C o n t r o l 2313ab l».6a T a b l e 15. E f f e c t o f v a r i e t y on t h e f r u i t i n g r e s p o n s e o f bush beans i n E x p e r i m e n t 13. Bush B l u e Lake S t r i n g l e s s T e n d e r c r o p Asgrow OSU 9^9- Asgrow G r e e n B u c k e r - Asgrow E a r l y 18614-2 #27t< BLS P o d f i e l d ' s Wax Pods (number) - T o t a l 62k.2a 393.6b 271.0c 336.6bc 358.Obc 389.6b 568.l»a - S m a l l * 203.8ab 109.l4C 86.2c 91.0c 109.2c l l j l . l l b c 251.6a - Medium 319-6a 197.6b 115.2c 230.1tb 195.8b 179.8b 316.Ija - L a r g e 100.8a 86.6a 69.6b 15.2c 53.2b 67.6b 0.14C Pods Weight - T o t a l 3053.0a 2308,0b 130l).0f I 5 8 5 .Od ll ) 8 6 . 0 e l l460 .0e 1718.Oc (gm.) - S m a l l 275•Oab 155-Oc 105.0c 115-Oc II47.OC 191.Obc 318.Oa - Medium 1723.0a 1207.0d 556.Of 1333-Oc 915.Oe 738.Oef lit 0 0 . Ob - L a r g e 952.0a 8914.0b 613.OC 136.Of k32.0e 531.Od 3-0g Pods P e r c e n t - S m a l l 32-5ab 27.7b 31-5ab 27.5b 30.2ab 36.1(ab 1)0.9a - Medium 51-2bc 50.1bc l42.5c 67.8a 5l).3bc 146.1c 59.Oab - L a r g e 16.3b 22.2a 26.0a li .6c 15. lib 17-5ab 0 . 2 d Blossoms Dropped (number) 7.8a 2.2c 2.2c 3-2bc 2.2c 5-2b 5.0b P l a n t s (number) 1)9.8ab 3k. 3c 37-ka 56.0a l)2.l4bc kl.Oab 51.2ab Pods p e r P l a n t 12.6a 9-7bc 7-3de 6.0e 8.1»cd 8.3cd 10.9ab * S m a l l - up t o 2l/6k i n c h i n d i a m e t e r a t t h e t h i c k e s t p o r t i o n o f t h e pod. Medium - 2l/6k-2l/6k i n c h in.'diameter a t t h e t h i c k e s t p o r t i o n o f t h e pod. La r g e - 2l/6k i n c h e s and up i n d i a m e t e r a t t h e t h i c k e s t p o r t i o n o f t h e pod. - 1*3 -P o d had a g r e a t e r p e r c e n t a g e o f pods i n t h e m a r k e t a b l e " range t h a n a l l v a r i e t i e s e x c e p t Asgrow E a r l y Wax. A l l o t h e r v a r i e t i e s were s i m i l a r a n d l o w e r . Bush B l u e L a k e OSU 9*49-186*4-2 had t h e h i g h e s t t o t a l w e i g h t o f pods f o l l o w e d by Bush B l u e L a k e Asgrow #27*1, Asgrow E a r l y Wax, S t r i n g l e s s G r e e n P o d , T e n d e r c r o p a n d Bush B l u e L ake BLS i n o r d e r o f d e c r e a s i n g y i e l d . Bush B l u e L ake OSU 9*49-186*4-2 a l s o had t h e h i g h e s t m a r k e t a b l e y i e l d o f pods f o l l o w e d by Asgrow E a r l y Wax, S t r i n g l e s s Green Pod, Bush B l u e L ake Asgrow #27*4, T e n d e r c r o p a n d Bush B l u e Lake BLS. A l t h o u g h d i f f e r e n c e s were shown between v a r i e t i e s , b l o s s o m d r o p was c o n s i d e r e d t o be t o o low t o e f f e c t y i e l d . S t r i n g l e s s Green P o d , Asgrow E a r l y Wax, Bush B l u e L ake 9 ^ 9 - 1 8 6 ^ - 2 a n d T e n d e r c r o p had a s i m i l a r number o f p l a n t s p e r p l o t ; Bush B l u e Lake Asgrow #27*4 and BLS were l o w e r . Bush B l u e L ake OSU 9 U 9 - I 8 6 U - 2 had a h i g h e r number o f pods p e r p l a n t t h a n a l l v a r i e t i e s e x c e p t Asgrow E a r l y Wax. The l o w e s t number o f pods were Bush B l u e Lake BLS a n d S t r i n g l e s s G r e e n P od. I n E x p e r i m e n t 1*4, p l a n t s s p r a y e d w i t h IAA ( 1 0 ppm), s u c r o s e (l$>) and t h e c o n t r o l h ad a s i m i l a r number of pods ( T a b l e 1 6 ) . A l l o t h e r t r e a t m e n t s had a l o w e r number o f pods w i t h a s e v e r e r e d u c t i o n i n pod number c a u s e d by 2,*4-D ( 1 0 ppm) a n d NAA ( 1 0 0 ppm) s p r a y s . Only s u c r o s e ( 1 $ ) had a f r e s h w e i g h t y i e l d s i m i l a r t o t h e c o n t r o l . A l l o t h e r t r e a t m e n t s had l o w e r pod w e i g h t w i t h t h e h i g h e r c o n c e n t r a t i o n o f t h e s p r a y s . I n E x p e r i m e n t 1 5 , t h e r e were no c h e m i c a l s p r a y e f f e c t s on number a n d w e i g h t o f pods a n d t h e number o f blossoms d r o p p e d i n T e n d e r c r o p b u s h beans a t A g a s s i z ( T a b l e 1 7 ) . - kk -T a b l e 16. E f f e c t o f c h e m i c a l s p r a y s on t h e f r u i t i n g r e s p o n s e o f B l u e L a k e FM1 p o l e beans a t A g a s s i z i n E x p e r i m e n t 1*4. C h e m i c a l S p r a y s Pods (number) P o d Weight (gm.) Blossoms Dropped (number) IAA - 10 ppm 726.2abc 3688b 6l .8bc -lOOOppm 596.Od 298*4 d 7k .Obc HAA - 10 ppm 621.8cd 3370c 82.2b - 100 ppm 2*41.8f ll»l»2e 20*4.8a S u c r o s e - 1 $ 789-lfab *4 031a 76.6bc 2,14-D - 1 ppm 709.2bcd 3702b 59.2c - 10 ppm lt82.0e 29l8d 69-2bc C o n t r o l 828.0a 14200a 82.6b - k5 -T a b l e 17. E f f e c t o f c h e m i c a l s p r a y s on t h e f r u i t i n g r e s p o n s e o f T e n d e r c r o p bush beans a t A g a s s i z i n E x p e r i m e n t 15• C h e m i c a l S p r a y s I A A - 10 ppm - 100 ppm H A A - 10 ppm - 100 ppm S u c r o s e - 1 $ 2,k-V - 1 ppm - 10 ppm C o n t r o l Pods (number) 227.2a 269.6a 259.^a 231.8a 226.2a 302.0a 237-8a 2i)i).8a Pods Weight (gm-) 16714 a l661)a 117l» a 1732a 1728a 1757a 1856a 1672a Blossoms Dropped (number) 7.6a 6.l4a 6.6a 9-2a 5.6a 6.8a 5.6a l).6a - k6 -DISCUSSION I . C o n t r o l l e d - E n v i r o n m e n t S t u d i e s . I n a l l c o n t r o l l e d - e n v i r o n m e n t e x p e r i m e n t s , h i g h day o r n i g h t t e m p e r a t u r e d e c r e a s e d l e a f w e i g h t s , w h i l e t h e stem w e i g h t s a t a l l t e m p e r a t u r e s were r e l a t i v e l y s i m i l a r . A t a l l t e m p e r a t u r e s t h e number o f nodes was s i m i l a r . H e i g h t o f t h e p l a n t s i n c r e a s e d w i t h i n c r e a s i n g day t e m p e r a t u r e s t o 90°F b u t a t 95°F t h e h e i g h t was r e d u c e d . When t h e day t e m p e r a t u r e was 95°F, c o o l n i g h t t e m p e r a t u r e s o f 70°F o r l e s s r e s u l t e d i n i n c r e a s e d p l a n t h e i g h t compared t o t h e 80°F n i g h t . A c o m p a r i s o n o f number of nodes a n d t o t a l h e i g h t i n d i c a t e d t h a t a t h i g h t e m p e r a t u r e s t h e i n t e r n o d e l e n g t h was s h o r t e r t h a n a t c o o l t e m p e r a t u r e s . P l a n t s grown a t h i g h t e m p e r a t u r e s had more a x i l l a r y b r a n c h i n g r e s u l t i n g i n s i m i l a r stem d r y w e i g h t s f o r a l l t r e a t m e n t s . The d e c r e a s e d h e i g h t o f p l a n t s grown a t h i g h t e m p e r a t u r e s m i g h t be a s s o c i a t e d w i t h t h e d e s t r u c t i o n of a u x i n o r s u p p r e s s i o n o f a u x i n f o r m a t i o n a t h i g h tempera-t u r e s . T h i s a u x i n e f f e c t has been s u g g e s t e d by L e o p o l d ( 1 9 5 5 ) - He r e p o r t e d work w i t h r i c e s e e d l i n g s e x p o s e d t o warm t e m p e r a t u r e s ( 2 6 ° C o r 7 9 ° F ) . These s e e d l i n g s had a much l o w e r a u x i n c o n t e n t compared t o t h o s e e x p o s e d t o c o o l t e m p e r a t u r e s . The s h o r t e r stems a n d g r e a t e r a x i l l a r y b r a n c h i n g a t t h e h i g h e r t e m p e r a t u r e s c o u l d a l s o be a s s o c i a t e d w i t h low a u x i n p r o d u c t i o n i n t h e a p i c a l m e r i s t e m . I n e x p e r i m e n t s c o n d u c t e d i n t h e c o n t r o l l e d - e n v i r o n m e n t c a b i n e t s , b l o s s o m i n g o c c u r r e d a t a l l t e m p e r a t u r e r e g i m e s s t u d i e d . Blossoms on p l a n t s g r o w i n g a t 95/80°F and 9 5 / 7 0 ° ? a n d a t 55Ao°F t e m p e r a t u r e s d i d n o t s e t pods. The p l a n t s grown a t 95/80°F a n d low 55/*)0°F t e m p e r a t u r e s were s t u n t e d , a n d had s m a l l d a r k l e a v e s . The l e a v e s r e m a i n e d d a r k g r e e n f o r t h e d u r a t i o n o f t h e e x p e r i m e n t s , ( 8 9 a n d 1 3 3 days f o r 95/80°F a n d - kl -55/^0°F) a l t h o u g h some o f t h e o l d e r l e a v e s had dropped. These f i n d i n g s were not i n c o m p l e t e agreement w i t h work done by V i g l i e r c h i o a n d Went ( 1 9 5 7 ) , who work w i t h K e n t u c k y Wonder p o l e beans. They f o u n d t h a t h i g h day a n d n i g h t t e m p e r a t u r e s (30/2*t°C o r 8 6 / 7 5°F) w i t h an e i g h t - h o u r day u s i n g n a t u r a l d a y l i g h t r e s u l t e d i n p l a n t s w i t h v e r y l o n g i n t e r n o d e s , t h i n stems a n d s m a l l p a l e l e a v e s . These p l a n t s d i d n o t bloom. P l a n t s grown a t low day a n d n i g h t t e m p e r a t u r e s (l7/20°C o r 6 2 . 5 / 5 3 . 5 ° F a n d 2 3 / 6°C o r 7 3 - 5 A 3 ° F ) w i t h a n e i g h t - h o u r day u s i n g n a t u r a l d a y l i g h t showed s t u n t i n g , t h i c k s t e m s , s h o r t i n t e r n o d e s a n d s m a l l d a r k l e a v e s . The p l a n t s e v e n t u a l l y y e l l o w e d a n d d i e d w i t h o u t f l o w e r i n g . Comparing V i g l i e r c h i o a n d Went's ( 1 9 5 7 ) e x p e r i m e n t s w i t h p r e s e n t e x p e r i m e n t s w o u l d i n d i c a t e t h a t t h e r e was a d a y l e n g t h o r v a r i e t a l d i f f e r e n c e i n r e s p o n s e o f bean p l a n t s t o low a n d h i g h t e m p e r a t u r e s . Many w o r k e r s ( D a v i s , 19**5; Lambeth, 1950; Iwami, 1951; v a n S e h a i k an d P r o b s t , I958; S m i t h a n d P r i o r , 1 0 6 2 ; Mack a n d S i n g h , l$6k) have i n d i c a t e d t h a t h i g h t e m p e r a t u r e s c a u s e d blossoms t o d r o p i n beans. Lambeth (1950), Watanabe ( 1 9 5 3 ( b ) ) , Inoue a n d S h i b u y a ( 1 9 5 *0 and Ahmadi ( 1 9 5 6 ) showed t h a t f a i l u r e t o s e t pods a t h i g h e r t e m p e r a t u r e s was a s s o c i a t e d w i t h t h e i n a b i l i t y o f t h e p o l l e n t o g e r m i n a t e . The r e s u l t s o f t h e p r e s e n t e x p e r i m e n t s a g r e e d w i t h t h e s e f i n d i n g s r e p o r t e d i n t h e l i t e r a t u r e . H i g h day t e m p e r a t u r e s ( 9 0 a n d 9 5°F) s e v e r e l y r e d u c e d pod s e t . When t h e t e m p e r a t u r e was h e l d a t 9 5°F, p l a n t s w i t h t h e l o w e r n i g h t temperatures.(6o°F) s e t a few pods, b u t t h e s e pods h a d o n l y one o r two s e e d s . H i g h n i g h t t e m p e r a t u r e s r e s u l t e d i n 100 p e r c e n t b l o s s o m an d immature pod d r o p . P o d s e t c o u l d t a k e p l a c e a t l o w e r n i g h t t e m p e r a -t u r e s t h a n 7 0°F s i n c e Inoue a n d S h i b u y a ( 1 9 5 *0 f o u n d t h a t bean p o l l e n g e r m i n a t i o n was r e c o g n i z a b l e t h e a f t e r n o o n b e f o r e b l o s s o m i n g , a n d t h e - l»8 -p e r c e n t a g e g e r m i n a t i o n i n c r e a s e d t o w a r d t h e t i m e o f b l o s s o m i n g ( m a i n l y between 5:00 a n d 7:00 a.m. ( i n o u e , 1955))- The t e m p e r a t u r e s a f t e r p o l l i n a t i o n were more c r i t i c a l t h a n t h e t e m p e r a t u r e b e f o r e p o l l i n a t i o n ( i n o u e a n d S u z u k i , 1959)- The r e s u l t s o f t h e p r e s e n t e x p e r i m e n t s on t h e e f f e c t o f n i g h t t e m p e r a t u r e were i n agreement w i t h s t u d i e s on l i m a beans r e p o r t e d by Lambeth (1950) a n d Rappaport a n d C a r o l u s (1956). A l t h o u g h D a l e (196*1) f o u n d t h a t g r o w t h under c o n s t a n t c o n d i t i o n s was s u p e r i o r t o t h a t under a l t e r n a t i n g c o n d i t i o n s , t h e p r e s e n t e x p e r i m e n t s showed t h a t t h e b l o s s o m i n g number, under h i g h day t e m p e r a t u r e c o n d i t i o n s (95°F), was i n c r e a s e d a s t h e n i g h t t e m p e r a t u r e was r e d u c e d . These f i n d i n g s a r e i n agreement w i t h s t u d i e s r e p o r t e d by Watanabe (1953(6)). . o . P l a n t s grown a t h i g h day t e m p e r a t u r e s (95 P ) p r o d u c e d pods a t a l l n i g h t t e m p e r a t u r e s , b u t o n l y a t a n i g h t t e m p e r a t u r e o f 60°F d i d any o f t h e pods r e a c h m a r k e t a b l e s i z e . E x a m i n a t i o n o f t h e immature pods showed t h a t none o f t h e o v u l e s h a d d e v e l o p e d . The f r u i t was t h e r e f o r e p a r t h e n o c a r p i c . J o h n s o n and H a l l (195*0, s i m i l a r l y f o u n d t h a t h i g h t e m p e r a t u r e was a s s o c i a t e d w i t h p a r t h e n o c a r p y i n t o m a t o e s . The immature bean pods i n t h e p r e s e n t e x p e r i m e n t s d i d n o t d e v e l o p n o r m a l l y and dr o p p e d a f t e r s e v e r a l weeks. Ahmadi (1956) f o u n d t h a t young pods t h a t had d r o p p e d were n o t f e r t i l i z e d a n d Lambeth (1950) showed t h a t a t l e a s t one o v u l e p e r pod had t o be f e r t i l i z e d t o s t a r t pod development and t o p r e v e n t a b s c i s s i o n . S i n c e t h e immature, u n f e r t i l i z e d pods r e m a i n a t t a c h e d t o t h e p l a n t f o r a l o n g p e r i o d o f t i m e , s e v e r a l weeks must e l a p s e b e f o r e t r u e pod s e t c a n be d e t e r m i n e d . There was no r e l a t i o n between t h e number of blossoms t h a t f o r m e d a n d t h e number o f pods t h a t s e t , w h i c h a g r e e d w i t h s t u d i e s by B i n k l e y (1932). Even a t t e m p e r a t u r e s l o w enough t o e n s u r e optimum c o n d i t i o n s - 1*9 -f o r p o l l i n a t i o n , n o t a l l b l o s s o m f o r m e d s e t pods. P o d s e t a t l o w e r t e m p e r a t u r e s o c c u r r e d a c c o r d i n g t o t h e " c a p a c i t y s e t " c o n c e p t f i r s t e x p l a i n e d by Co r d n e r (1933)' S i n c e t h e p l a n t s a t 85°F a n d 75°F day t e m p e r a t u r e s had a s i m i l a r p l a n t s i z e , t h e y w o u l d be e x p e c t e d t o have a s i m i l a r pod s e t . The number a n d f r e s h and d r y w e i g h t o f pods was s i m i l a r f o r p l a n t s grown a t 85°F a n d 75°F day t e m p e r a t u r e s . P o d s e t and b l o s s o m d r o p o c c u r r e d t h r o u g h o u t t h e b l o s s o m i n g p e r i o d , a l t h o u g h t h e l a s t blossoms f o r m e d f a i l e d t o s e t f r u i t . The b l o s s o m drop p a t t e r n was i n agreement w i t h Iwami (1951), S c h r a d e r (19^3), a n d Lambeth (1950) who f o u n d t h a t once c a p a c i t y s e t was a t t a i n e d t h e p e r c e n t a g e o f blossoms t h a t s e t was r e d u c e d . Bush beans were f o u n d t o have a c y c l i c p a t t e r n o f b l o s s o m i n g i f t h e pods were h a r v e s t e d a t m a r k e t a b l e m a t u r i t y . The o n l y p r e v i o u s r e f e r e n c e t o c y c l i c b l o s s o m i n g i n beans was t h a t o f V i g l i e r c h i o a n d Went (1957) who worked w i t h K e n t u c k y Wonder p o l e b e a n s . When pods were h a r v e s t e d a t m a r k e t a b l e m a t u r i t y , t h e p l a n t s r e m a i n e d v e g e t a t i v e , a n d showed renewed growth a c t i v i t y a t day t e m p e r a t u r e s o f 85°F o r l e s s . The l e a f w e i g h t i n c r e a s e d a n d t h e p l a n t s r e m a i n e d v i g o r o u s . The stem d r y w e i g h t o f p l a n t s when beans were h a r v e s t e d a t d r y m a t u r i t y two months a f t e r p l a n t i n g were U.5T a n d 5-53 grams f o r p l a n t s grown a t 85 0 a n d 75°F r e s p e c t i v e l y . These p l a n t s were s e n e s c i n g . When t h e pods were h a r v e s t e d a t m a r k e t a b l e m a t u r i t y t h e stem d r y w e i g h t s t h r e e months a f t e r p l a n t i n g were 16.22 a n d 16-77 grams f o r p l a n t s grown a t 85 0 a n d 75°F r e s p e c t i v e l y . The h e i g h t o f t h e p l a n t and t h e number o f nodes were s i m i l a r f o r b o t h t r e a t m e n t s . When f e r t i l i z a t i o n o c c u r s , t h e r e i s a g r e a t i n c r e a s e o f a u x i n i n t h e p l a n t ( L e o p o l d , 1955). T h i s new s u p p l y o f a u x i n moving i n t o t h e - 50 -p l a n t s t i m u l a t e s o v e r a l l p l a n t g r o w t h . No c o n c l u s i o n s r e l a t i v e t o t h e f r u i t i n g e f f e c t on p l a n t g r o w t h h a b i t c o u l d be drawn f r o m p l a n t s h e l d a t 95/80°F i n t h e p r e s e n t e x p e r i m e n t s because m a r k e t a b l e pods were n o t p r o d u c e d a t t h i s t e m p e r a t u r e . The l o n g e r t h e p l a n t s were h e l d a t t h e h i g h t e m p e r a t u r e t h e l o w e r t h e l e a f w e i g h t , b u t t h e stem w e i g h t , t o t a l h e i g h t , a n d t h e number o f nodes d i d not change a f t e r two months. The f a c t t h a t t h e r e was no i n c r e a s e i n growth w i t h t i m e o f p l a n t s h e l d a t 95/80°F w i t h no pod s e t , w o u l d i n d i c a t e t h a t t h e l a c k o f a u x i n s u p p l i e d by d e v e l o p i n g embryos r e s u l t e d i n l a c k o f v e g e t a t i v e growth compared t o p l a n t s t h a t had pods. From t h e p r e s e n t e x p e r i m e n t s i t w o u l d a p p e a r t h a t t h e c y c l i c b l o s s o m -i n g p a t t e r n was r e l a t e d t o t h e c a p a c i t y s e t c o n c e p t o f Cordner (1933) a t day t e m p e r a t u r e o f 85°F and l e s s . The f i r s t c y c l e , w h i c h l a s t e d o n l y 15 d a y s , h a d t h e g r e a t e s t number o f b l o s s o m s . Even th o u g h t h e f i r s t c y c l e o f blo s s o m s was t h e g r e a t e s t , subsequent c y c l e s had a h i g h e r p e r c e n t a g e o f pods s e t . The b l o s s o m i n g c y c l e o f p l a n t s grown a t 85/70°F was s h o r t e r t h a n t h a t o f p l a n t s grown a t 75/6o°F. 'There were f e w e r days f r o m b l o s s o m i n g t o h a r v e s t i n p l a n t s grown a t 85/70°F t h a n a t 75/60°F. P l a n t s grown a t 85/70°F d u r i n g a two-month b l o s s o m i n g p e r i o d p r o -d u ced more blossoms t h a n p l a n t s grown a t 75/60°F. P o d s e t a n d f r e s h and d r y w e i g h t o f pods was s i m i l a r . E q u a l y i e l d s between t h e two tem-p e r a t u r e r e g i m e s s u p p o r t s t h e c a p a c i t y s e t c o n c e p t , s i n c e t h e p l a n t s grown a t 85/70°? were no l a r g e r t h a n p l a n t s grown a t 75/60°F. B l o s s o m drop d u r i n g t h e f i r s t 15 days o f b l o s s o m i n g ( f i r s t c y c l e ) c o u l d f o l l o w t h e t h e o r y p r o p o s e d by Iwami (1951); an e a r l y s t a g e o f b l o s s o m d r o p , a t t r i b u t e d t o c o m p e t i t i o n f o r n u t r i e n t s between t h e - 51 -f l o w e r s a n d t h e d e v e l o p i n g p l a n t ; a m i d d l e s t a g e , a t t r i b u t e d t o com-p e t i t i o n f o r n u t r i e n t s between f l o w e r s ; a n d a l a t e s t a g e , a s s o c i a t e d w i t h t h e d e c l i n e o f t h e p l a n t . Lambeth (1950) f o u n d t h a t i f c a p a c i t y s e t was o b t a i n e d d u r i n g t h e f i r s t two weeks a f t e r b l o o m i n g , t h e y i e l d was dependent p r i m a r i l y on t h e " a c t i v e " l e a f a r e a a nd l i g h t c o n d i t i o n s . I n t h e s e c o n d and t h i r d c y c l e o f b l o s s o m i n g t h e p l a n t s h ad f e w e r blossoms and were more v i g o r o u s , a n d c o u l d t h e r e f o r e s e t a g r e a t e r p e r c e n t a g e o f pods. The h i g h p e r c e n t a g e o f pod s e t i n t h e l a s t c y c l e , e s p e c i a l l y a t 85/70OF, was not i n d i c a t i v e o f t h e a c t u a l y i e l d s . Many o f t h e pods r e m a i n e d s m a l l , n o t r e a c h i n g m a r k e t a b l e s i z e i n t h e t i m e n o r m a l l y r e q u i r e d by o t h e r pods g r o w i n g a t t h e same t e m p e r a t u r e . I t c o u l d be p o s s i b l e t h a t t h e n a t u r a l a u x i n l e v e l i n t h e p l a n t was s u f f i c i e n t l y h i g h t o p r e v e n t t h e a b s c i s s i o n o f t h e young pods, even i f t h e y were n o t f e r t i l i z e d . The e x t e n t o f f e r t i l i z a t i o n o f blossoms was not n o t e d i n t h e p r e s e n t e x p e r i m e n t s . Low l i g h t i n t e n s i t y c a u s e d a r e d u c t i o n i n p l a n t g r o w t h a n d number o f b l o s s o m s . The p l a n t s grown a t low l i g h t i n t e n s i t i e s h ad a l o w e r l e a f w e i g h t t h a n p l a n t s grown a t h i g h l i g h t i n t e n s i t i e s , a n d t h e y i e l d of pods was s i m i l a r l y r e d u c e d . P l a n t s grown a t low l i g h t i n t e n s i t i e s h ad a low pod s e t c a p a c i t y . These f i n d i n g s were i n agreement w i t h s t u d i e s r e p o r t e d by Inoue and S u z u k i (1956). I I . F i e l d S t u d i e s . P l a n t s s t a r t e d a t p l a n t i n g d a t e s t o May 29, 196*1 had s i m i l a r numbers and w e i g h t s o f pods. P l a n t s s t a r t e d a t l a t e r p l a n t i n g d a t e s showed r e d u c e d numbers a n d w e i g h t s o f pods. S o i l t e m p e r a t u r e s r e m a i n e d low u n t i l t h e end o f May, t h e n i n c r e a s e d a n d r e m a i n e d c o n s t a n t f o r t h e - 52 -r e m a i n d e r o f t h e summer a t t h e U n i v e r s i t y o f B r i t i s h C o l u mbia. The J u n e p l a n t i n g s d i d not have a l o n g enough g r o w i n g s e a s o n t o p r o d u c e maximum y i e l d s . The n i t r o g e n l e v e l o f t h e s o i l a t t h e U n i v e r s i t y o f B r i t i s h C o l umbia was s u f f i c i e n t l y h i g h f o r v i g o r o u s bean growth b e c a u s e a d d i t i o n a l n i t r o g e n f e r t i l i z e r gave no i n c r e a s e i n g r o w t h . The f i e l d had been h e a v i l y manured i n t h e f a l l o f 1963-The row s p a c i n g e x p e r i m e n t s were c o n d u c t e d t o d e t e r m i n e t h e e f f e c t o f a i r d r a i n a g e a n d r e l a t e d h u m i d i t y as i t i n f l u e n c e d bean d i s e a s e s and t h e e f f e c t o f p l a n t t o p l a n t c o m p e t i t i o n f o r l i g h t and s o i l n u t r i e n t s on t h e number o f pods i n beans. The t w o - f o o t row s p a c i n g s were t o o c l o s e t o a l l o w a c c u r a t e b l o s s o m d r o p c o u n t s . As t h e row s p a c i n g i n c r e a s e d , t h e number an d w e i g h t o f pods p e r p l a n t i n c r e a s e d . When t h e number an d w e i g h t o f pods were a d j u s t e d f o r a r e a , t h e narrow row s p a c i n g s o u t -y i e l d e d t h e w i d e row s p a c i n g s . Comparisons "between t h e e i g h t - f o o t row s p a c i n g a n d a d j a c e n t f i v e - f o o t row s p a c i n g showed s i m i l a r r e s u l t s f o r number a n d y i e l d o f pods p e r f o o t o f row. These r e s u l t s i n d i c a t e d t h a t t h e r e was no e f f e c t i v e i n c r e a s e i n pods s e t i n row s p a c i n g s g r e a t e r t h a n f i v e f e e t . Even t h o u g h y i e l d s p e r a c r e were i n c r e a s e d a t narrow row s p a c i n g s (11.6, 8.3 and 5.2 t o n p e r a c r e f o r two, f o u r a n d e i g h t - f o o t row s p a c i n g s r e s p e c t i v e l y ) , i i r c o m m e r c i a l f i e l d s o f p o l e beans t h e rows a r e p l a n t e d f i v e t o s i x f e e t a p a r t t o i n c r e a s e a i r d r a i n a g e a n d t h u s d e c r e a s e t h e i n c i d e n c e o f d i s e a s e s , and t o f a c i l i t a t e h a v e s t i n g . The row d i r e c t i o n e x p e r i m e n t was c o n d u c t e d t o d e t e r m i n e t h e e f f e c t o f a i r d r a i n a g e and r e l a t e d h u m i d i t y on t h e number o f pods s e t a n d b l o ssoms d r o p p e d . Rows p l a n t e d w i t h t h e p r e v a i l i n g w i n d s h o u l d have b e t t e r a i r d r a i n a g e t h u s r e d u c e t h e i n c i d e n c e o f B o t r y t i s and S c l e r c t j l n i a . - 53 -There were no d i f f e r e n c e s i n number and w e i g h t o f pods and b l o s s o m d r o p p e d between t h e two row d i r e c t i o n s . Bean d i s e a s e s were not a p r o b l e m a t t h e U n i v e r s i t y o f B r i t i s h C o l umbia i n t h e summer o f 1961) . A u x i n s a n d s u c r o s e s p r a y s were a p p l i e d t o r e d u c e b l o s s o m d r o p a n d t h u s i n c r e a s e y i e l d s . Ahmadi (1956) u s i n g a u x i n s p r a y s a t b l o s s o m i n g of d r y beans f o u n d t h a t t h e r e was an i n c r e a s e i n t h e number o f pods b u t n o t i n t h e number o f s e e d s . A u x i n a p p l i c a t i o n s d e v e l o p e d some p a r t h e n o c a r -p i c f r u i t . B e r r i e (i960) f o u n d t h a t t h e s u p p l e m e n t a r y s u c r o s e s p r a y s g r e a t l y i n c r e a s e d d r y w e i g h t i n tomatoes i f c o n d i t i o n s f o r r e s p i r a t i o n were h i g h a n d p h o t o s y n t h e s i s l o w . The p r e s e n t e x p e r i m e n t s showed t h a t u n l e s s b l o s s o m d r o p was e x c e s s i v e l y h i g h , t h e r e was no r e l a t i o n : b e t w e e n b l o s s o m d r o p a n d y i e l d , w h i c h a g r e e s w i t h f i n d i n g s by B i n k l e y (1932). I n B l u e Lake FM1 p o l e beans none o f t h e s p r a y s i n c r e a s e d t h e y i e l d o f beans. O n l y IAA a t 100 ppm, NAA a t 10 a n d 100 ppm a n d 2,1)-D a t 10 ppm w i t h o r w i t h o u t FeEDTA r e d u c e d y i e l d s . These f i n d i n g s were i n agreement w i t h Murneek, e t a l . , (I9M) who f o u n d t h a t a u x i n d e c r e a s e d t h e y i e l d o f pods o f p l a n t s g r o w i n g a t c o o l t e m p e r a t u r e s . Bush beans were l e s s a f f e c t e d by h i g h c o n c e n t r a t i o n s o f a u x i n s t h a n p o l e b e a n s . Only NAA a t 100 ppm i n S t r i n g l e s s G r e e n P o d "bush beans showed a r e d u c t i o n i n y i e l d . I n c r e a s e s i n b e a n y i e l d s a f t e r u s i n g a u x i n amd- s u c r o s e s p r a y s were n o t e d i n S t r i n g l e s s Green P o d and T e n d e r c r o p b u s h beans a t t h e U n i v e r s i t y o f B r i t i s h C o l u m b i a , b u t i n no c a s e were t h e s e i n c r e a s e s g r e a t e r t h a n 13 p e r c e n t o v e r t h e c o n t r o l . Murneek, e t a l . , (191)!)) f o u n d t h a t a u x i n s p r a y s d e c r e a s e d t h e y i e l d o f pods on S t r i n g l e s s Green P o d p l a n t s g r o w i n g a t c o o l t e m p e r a t u r e s . Temperature r e c o r d s f o r t h e summer o f I96I) show t h a t t h e maximum a i r t e m p e r a t u r e - 5«< -a t t h e U n i v e r s i t y o f B r i t i s h C o l umbia was 79°F a n d t h a t o n l y f o r one day. C o n t r o l l e d - e n v i r o n m e n t s t u d i e s showed t h a t t e m p e r a t u r e s o f above 85°F were r e q u i r e d t o cause b l o s s o m d r o p . Bush B l u e Lake OSU 9^9-l86l)-2 was t h e h i g h e s t y i e l d i n g bush v a r i e t y t e s t e d . T h e r e was n o t s u f f i c i e n t b l o s s o m d r o p i n any v a r i e t y t o show v a r i e t a l d i f f e r e n c e s . The number o f pods p e r p l o t was not r e l a t e d t o t h e number o f p l a n t s p e r p l o t . There were v a r i e t a l d i f f e r e n c e s i n t h e number o f pods p e r p l a n t . H i g h y i e l d i n g v a r i e t i e s h ad t h e g r e a t e s t number o f pods p e r p l a n t . F u r t h e r work on t h e e f f e c t o f t e m p e r a t u r e on growth a n d f r u i t i n g r e s p o n s e s h o u l d i n c l u d e s t u d i e s on IAA. c o n t e n t i n t h e p l a n t , a x i l l a r y b r a n c h i n g , t o t a l d r y m a t t e r p r o d u c t i o n o f t h e p l a n t ( i n c l u d i n g f a l l e n l e a v e s ) , p e r c e n t a g e m o i s t u r e i n t h e p l a n t , p o l l e n g e r m i n a t i o n , embryo sac development and d e v e l o p i n g s e e d s , number o f seeds p e r pod, p o s i t i o n of s e e d i n t h e pod, development o f f l o w e r p r i m o r d i a , a n d t h e e f f e c t o f c o n s t a n t d a y / n i g h t t e m p e r a t u r e on pod s e t ( e s p e c i a l l y 85°F). A d d i t i o n a l work s h o u l d be c o n d u c t e d t o d e t e r m i n e t h e e f f e c t o f f r u i t i n g a n d h a r v e s t i n g on t h e c y c l i c p a t t e r n o f b l o s s o m i n g i n b e a n s , a n d t h e e f f e c t o f c y c l i c b l o s s o m i n g on t h e IAA c o n t e n t a n d CO2 upt a k e i n t h e p l a n t , a n d t o d e t e r m i n e w h e t h e r c y c l i c b l o s s o m i n g i s a v a r i e t a l r e s p o n s e . A d d i t i o n a l s t u d i e s w i t h c h e m i c a l s p r a y s s h o u l d i n c l u d e t h e e f f e c t o f c h e m i c a l s p r a y s on t h e f r u i t i n g r e s p o n s e when w e a t h e r c o n d i t i o n s a r e a d v e r s e t o pod s e t ( i n t h e f i e - l d a n d i n c o n t r o l l e d - e n v i r o n m e n t c a b i n e t s ) , e f f e c t o f h i g h r a t e s o f FeEDTA t o r e d u c e growth i n h i b i t i o n c a u s e d by 2,l4-D a t b l o s s o m i n g , and t h e e f f e c t o f a u x i n s p r a y s on t h e f r u i t i n g r e s p o n s e when a p p l i e d t o young p l a n t s . - 55 -There appeared to be a difference i n number of pods on the sunny and shady side of the row. Studies should be conducted to determine the effect of row di r e c t i o n on the number of pods on either side of the row. - 56 -SUMMARY AMD CONCLUSIONS I n c o n t r o l l e d - e n v i r o n m e n t s t u d i e s u s i n g S t r i n g l e s s Green P o d bush b e a n s , h i g h t e m p e r a t u r e was f o u n d t o be t h e most c r i t i c a l f a c t o r a f f e c t i n g pod s e t i n be a n s . When day t e m p e r a t u r e s were h i g h , l ow n i g h t t e m p e r a t u r e i n c r e a s e d b l o s s o m i n g and pod s e t . As t h e day o r n i g h t t e m p e r a t u r e i n c r e a s e d , f r e s h a n d d r y w e i g h t s o f t h e l e a v e s d e c r e a s e d . B l o s s o m drop o c c u r r e d a t a l l t e m p e r a t u r e s a n d pod s e t a t t e m p e r a t u r e s o f 85°F a n d below was c o n s i d e r e d t o o c c u r a c c o r d i n g t o t h e c a p a c i t y s e t c o n c e p t . B l o s s o m i n g o c c u r r e d a t a l l t e m p e r a t u r e regimes s t u d i e d . When pods were h a r v e s t e d a t m a r k e t a b l e m a t u r i t y , t h e b l o s s o m i n g p a t t e r n i n bush beans was f o u n d t o be c y c l i c . P l a n t s grown a t Q^/"]0°W d a y / n i g h t t e m p e r a t u r e s had a s h o r t e r c y c l e t h a n p l a n t s grown a t 75/60°F. The c y c l i c b l o s s o m i n g p a t t e r n was c o n s i d e r e d t o be a s s o c i a t e d w i t h t h e c a p a c i t y s e t c o n c e p t . P l a n t s h a r v e s t e d a t m a r k e t a b l e m a t u r i t y were more v i g o r o u s and r e s u l t e d i n h i g h e r f r e s h a n d d r y w e i g h t s o f l e a v e s and stems a n d more blossoms a n d pods t h a n p l a n t s h a r v e s t e d a t d r y m a t u r i t y . P l a n t s grown a t a l i g h t i n t e n s i t y o f 1900 f o o t - c a n d l e s had r e d u c e d l e a f a n d stem w e i g h t s , number o f blossoms a n d number a n d w e i g h t o f pods compared t o p l a n t s grown a t 2700 and ^ 000 f o o t - c a n d l e s . F i e l d s t u d i e s showed t h a t p l a n t i n g d a t e s a f t e r May 29 had r e d u c e d number a n d w e i g h t o f pods i n p o l e beans a t t h e U n i v e r s i t y o f B. C. The n i t r o g e n l e v e l i n t h e s o i l a t t h e U n i v e r s i t y o f B. C. was h i g h a n d added i n c r e m e n t s o f n i t r o g e n c a u s e d no s i g n i f i c a n t r e s p o n s e i n t h e y i e l d o f pods i n p o l e beans. As t h e row s p a c i n g s i n c r e a s e d , up t o f i v e f e e t , t h e number and w e i g h t o f pods i n c r e a s e d p e r p l a n t i n p o l e beans. Row d i r e c t i o n had l i t t l e e f f e c t j o n t h e f r u i t i n g r e s p o n s e o f p o l e beans. - 57 -Use o f c h e m i c a l spays c a u s e d no i n c r e a s e i n y i e l d o f pods i n p o l e beans a n d o n l y s l i g h t i n c r e a s e s i n y i e l d o f pods i n bush beans. Of t h e v a r i e t i e s t e s t e d , Bush B l u e L ake OSU 9^9-186^-2 h a d t h e h i g h e s t number and w e i g h t o f pods. Y i e l d o f pods was r e l a t e d t o t h e number o f pods p e r p l a n t . - 58 -LITERATURE CITED A d d i c o t t , F.T., R.S. L y n c h , and H.R. Ca r n s . 1955- A u x i n g r a d i e n t t h e o r y o f a b s c i s s i o n r e g u l a t i o n . S c i e n c e 121: 6*4*4-6*45. Ahmadi, A.A. 1956. B l o s s o m d r o p i n d r y be a n s . ( P h a s e o l u s v u l g a r i s , L. v a r . Red K i d n e y ) PhD T h e s i s , C o r n e l l U n i v e r s i t y . A l l a r d , H.A. an d W.J. Zaumeyer. 19*4*4. Responses o f beans ( P h a s e o l u s ) a n d o t h e r legumes t o l e n g t h o f day. U.S.D.A. Tech. B u i . 867. B a k e r , K.F., W.C. Snyder a n d A.H. H o l l a n d . 19*16. Lygus bug i n j u r y o f l i m a beans i n C a l i f o r n i a . P h y t o p a t h . 36: *493-503. B e r r i e , A.M.M. i960. The e f f e c t o f s u c r o s e s p r a y s on t h e growth o f tomato. P h y s i o l . P l a n t . 13: 9-I9. B i n k l e y , A.M. 1932. The amount o f b l o s s o m a n d pod dr o p i n s i x v a r i e t i e s o f ga r d e n beans. P r o c . Amer. Soc. H o r t . S c i . 29:. U89-U92. B r i g g s , R.H. and A.C. L e o p o l d . 1958. The 2-phase a c t i o n of a u x i n on a b s c i s s i o n . Amer. J . B o t . »»5: 5^7-551. Burman, R.D. a n d D.W. Bohmont. .1961. E v a l u a t i n g t h e growth r a t e o f G r e a t N o r t h e r n beans as i n f l u e n c e d by s o i l m o i s t u r e l e v e l under greenhouse c o n d i t i o n s . A g r o n . J . 53: 3^-3l)5. C o r d n e r , H.B. 1933. E x t e r n a l a n d i n t e r n a l f a c t o r s a f f e c t i n g b l o s s o m d r o p and s e t o f pods i n l i m a beans. P r o c . Amer. Soc. H o r t . S c i . 30: 571-576. D a l e , J . E . 196*4. Some e f f e c t s o f a l t e r n a t i n g t e m p e r a t u r e on t h e growth o f F r e n c h bean p l a n t s . Ann. B o t . 28: 127-135-D a v i s , J . F . 19*45. The e f f e c t o f some environment f a c t o r s on t h e s e t o f pods a n d y i e l d o f w h i t e pea beans. J . A g r i . Res. 70: 237-2*4 9. F i s h e r , E.H., A . J . R i k e r , and T.C. A l l e n . 19*46. Bud, b l o s s o m , a n d pod dr o p o f c a n n i n g s t r i n g beans r e d u c e d by p l a n t hormone.s. P h y t o p a t h . 36: 50*4-523. - 59 -Gabelman, W.H. a n d D.D.F. W i l l i a m s . 1 9 6 2 . Water r e l a t i o n s h i p s a f f e c t i n g pod s e t o f g r e e n beans. P r o c . P l a n t S c i . Symp. Ca m p b e l l Soup Co., pages 25-35• Hardenburg, E.V. 191*1). E f f e c t o f hormone d u s t on p o d - s e t and y i e l d i n beans. P r o c . Amer. Soc. H o r t . S c i . 1)5: 3 6 7 - 3 7 Q . H o l l e , M., and L.C. P e i r c e . i 9 6 0 . P l o t t e c h n i q u e f o r f i e l d e v a l u a t i o n o f e a r l i n e s s , pod number, and t o t a l y i e l d i n t h e l i m a bean. P r o c . Amer. Soc. H o r t . S c i . 7 6 : 1)03-1)08. I n o u e , Y. 1 9 5 5 . S t u d i e s on t h e r e p r o d u c t i v e p h y s i o l o g y o f common beans, P h a s e o l u s v u l g a r i s L. I V . Some r e l a t i o n s "between f l o w e r bud d i f f e r e n t i a t i o n , f l o w e r i n g and f r u i t i n g i n common beans. J . H o r t . A s s . J a p a n . 2k: 5 6 - 5 8 . ( E n g l i s h summary). I n o u e , Y. a n d M. S h i b u y a . 195k . S t u d i e s on t h e r e p r o d u c t i v e p h y s i o l o g y o f common beans. P h a s e o l u s v u l g a r i s L. I I . On f e r t i l i t y o f p o l l e n . J . H o r t . A s s . J a p a n . 2 3 ; 7 1 - 7 8 . I n o u e , Y., a n d Y. S u z u k i . I 9 6 5 . S t u d i e s on t h e r e p r o d u c t i v e p h y s i o l o g y o f common be a n s , P h a s e o l u s  . v u l g a r i s . V I . The e f f e c t o f l i g h t i n t e n s i t y on t h e r e p r o d u c t i o n o f common beans. J . H o r t . A s s . J a p a n . 2 5 : 1 5 2 - 1 5 6 . I n o u e , Y., a n d Y. S u z u k i . 1 9 5 9 . S t u d i e s on t h e r e p r o d u c t i v e p h y s i o l o g y o f common be a n s , P h a s e o l u s  v u l g a r i s L. V I I . The e f f e c t o f t e m p e r a t u r e o f t h e f u n c t i o n o f p o l l e n and p i s t i l J . Hort. A s s . J a p a n . 2 8 : 1 9 - 2 2 . Iwami, N. 1 9 5 1 . E c o l o g i c a l s t u d i e s on t h e common beans. I I . On f l o w e r d r o p . I . J . H o r t . A s s . J a p a n . 2 0 : 5 3 - 5 7 - ( H o r t . A b s t r . 23:7kk). J o h n s o n , S.P. 1 9 5 6 , I n f l u e n c e o f growth r e g u l a t o r s on s e t t i n g o f tomato f r u i t s : A c o n c e p t . P r o c . Amer. Soc. H o r t . S c i . 6 7 : 3 6 5 - 3 6 8 . J o h n s o n , S.P., and W.C. H a l l . I95I4. P a r t h e n o c a r p y i n t h e t o m a t o . P r o c . Amer. Soc. Hort. S c i . 6 3 : 3 2 9 - 3 3 2 . J o h n s o n , S.P., a n d W.C. H a l l . 1955- F u r t h e r s t u d i e s on v e g e t a t i v e and f r u i t i n g r e s p o n s e s o f tomatoes t o h i g h t e m p e r a t u r e a n d l i g h t i n t e n s i t y . B o t . Gaz. 117: 1 0 0 - 1 1 3 . K e t e l l a p p e r , H.J. 1 9 6 3 . T e m p e r a t u r e - i n d u c e d c h e m i c a l d e f e c t s i n h i g h e r p l a n t s . P l a n t P h y s i o l . 3 8 : 1 7 5 - 1 7 9 -- 6o -Lambeth, V.N. 1950. Some f a c t o r s i n f l u e n c i n g pod s e t a n d y i e l d o f t h e l i m a bean. U n i v . Mo. A g r i . Exp. Sta., Res. B u i . k66: 1-60. L e o p o l d , A.C. 1955. A u x i n s a n d P l a n t Growth. U n i v . o f C a l i f . P r e s s , B e r k e l e y a n d Los A n g e l e s . L e o p o l d , A.C. and F . I . S c o t t . 1952. P h y s i o l o g i c a l f a c t o r s i n tomato f r u i t - s e t . Amer. J . B o t . 39s 310-317. Mack, H.J. 1963. 2,*l-D c a n r e d u c e bush bean y i e l d . Ore. Veg. D i g e s t 12 ( l ) : 1. Mack, H.J., S.C. Fa n g , a n d S.B. A p p l e , J r . 196*1. E f f e c t s o f s o i l t e m p e r a t u r e a n d phosphorus f e r t i l i z a t i o n on snap beans a n d peas. P r o c . Amer. Soc. H o r t . S c i . 8*1: 332-338. Mack, H.J., a n d J.N. S i n g h . 196*). H i g h t e m p e r a t u r e s r e d u c e bean y i e l d . Ore. Veg. D i g e s t 13 ( l ) : 1-3-M a r t h , P.C., and R. E. W e s t e r . 195^. E f f e c t o f 2 , * l , 5 - t r i c h l o r o p h e n o x y a c e t i c a c i d on f l o w e r i n g a n d v e g e t a t i v e growth o f For d h o o k 2*12 bush l i m a beans. P r o c . Amer. Soc. H o r t . S c i . 63: 325-328. M i l l e r , M.D., D.S. M i k k e l s e n , a n d R.C. H u f f a k e r . 1962. E f f e c t s o f s t i m u l a t o r y a nd i n h i b i t o r y l e v e l s o f 2,*f-D a n d i r o n on growth a n d y i e l d o f f i e l d b eans. Crop S c i . 2: 11*1-116. Murneek, A.E., S.H. W i t t w e r , and D.D. H e m p h i l l . 19*i*t. "Hormone" s p r a y s f o r snap beans. P r o c . Amer. Soc. H o r t . S c i . kk: *)28-*i32. N i t s c h , J . P . I962. B a s i c p h y s i o l o g i c a l p r o c e s s e s a f f e c t i n g f r u i t d evelopment. P r o c . P l a n t S c i . Symp. Cam p b e l l Soup Co., pages 5-23-Ormrod, D.P. 1962. Note on i n e x p e n s i v e m u l t i p l e p l a n t growth c a b i n e t s . Can. J . P l a n t S c i . *12: 7^2-7*i5-Ormrod, D.P. 196*i. Net c a r b o n d i o x i d e exchange r a t e s i n P h a s e o l u s v u l g a r i s L. as a f f e c t e d by t e m p e r a t u r e , l i g h t , i n t e n s i t y , l e a f a r e a i n d e x , a nd age o f p l a n t . Can. J . B o t . *i2: 393-lt01. Rahn, E.M. 1955- The e f f e c t o f c e r t a i n c u l t u r a l a nd growth r e g u l a t o r t r e a t m e n t s on p o d - s e t a n d y i e l d o f l i m a beans. P r o c . Amer. Soc. H o r t . S c i . 66: 298-307. - 61 -R a p p a p o r t , L., and R.L. C a r o l u s . 1956. E f f e c t o f n i g h t t e m p e r a t u r e a t d i f f e r e n t s t a g e s o f development on r e p r o d u c t i o n i n t h e l i m a bean. P r o c . Amer. Soc. H o r t . S c i . 67: 1*21-1* 2 8 . S c h r a d e r , O.L. 19l*3. E s t u d o de a l g u n s f a t o r e s que i n f l u e n c i a m na producao dos f e i j o e s de l i m a da v a r i e d a d a F o r d h o o k . ( A s t u d y o f c e r t a i n f a c t o r s a f f e c t i n g t h e y i e l d o f Fordhook bush l i m a ibeans. ) B o l . M i n i s t . A g r i . R i o de J . 32 ( l ) : 1-52. ( H o r t . A b s t r . 16: 350) S m i t h , F.L., and R.H. P r y o r . , I962. E f f e c t s o f maximum t e m p e r a t u r e a n d age on f l o w e r i n g and s e e d p r o d u c t i o n o f t h r e e bean v a r i e t i e s . H i l g a r d i a 33: 669-688. Van S c h a i k , P.H,, a n d A.H. P r o b s t . I958. E f f e c t o f some e n v i r o n m e n t a l f a c t o r s on f l o w e r p r o d u c t i o n a n d r e p r o d u c t i v e e f f i c i e n c y i n soybeans. A g r o n . J . 50? 192-197-V i g l i e r c h i o , D.R., a n d F.W. Went. 1 1957. P l a n t growth under c o n t r o l l e d c o n d i t i o n s I X . Growth and f r u i t i n g o f K e n t u c k y Wonder bean ( P h a s e o l u s v u l g a r i s L.) Amer. J . B o t . 1*1*: 1*1*9-1*53-Wade, B.L. 1937. B r e e d i n g and improvement o f peas and be a n s , i n U.S.D.A. Yearbook o f A g r i . 1937- U.S. Gov't P r i n t . O f f . Watanabe, H. 1953(a). S t u d i e s on t h e u n f r u i t f u l n e s s o f beans. I I . I n f l u e n c e o f t e m p e r a t u r e on f l o w e r b u d d i f f e r e n t i a t i o n a nd b l o o m i n g . J . H o r t . A s s . J a p a n , 22: 100-106. ( H o r t . A b s t r . 2k: 1*63.) Watanabe, H. i 1953(b). S t u d i e s on t h e u n f r u i t f u l n e s s o f beans. I I I . I n f l u e n c e o f t e m p e r a t u r e on b l o o m i n g , and o f t e m p e r a t u r e and t h e r e l a t i v e h u m i d i t y on t h e p o l l e n a c t i v i t y o f beans. J . H o r t . A s s . J a p a n , 22: 172-176. ( H o r t . A b s t r . 2l*: 2686.) Wedding, R.T., J.B. K e n d r i c k , J r . , W.S. S t e w a r t , a n d B . J . H a l l . 1956. Growth r e g u l a t o r s on b e a n s , C a l i f . A g r i . 10 ( A p r i l ) : k. Went, F.W. 19l*l*. P l a n t growth under c o n t r o l l e d c o n d i t i o n s . I I . T h e r m o p e r i o d i c i t y i n . g r o w t h and f r u i t i n g o f t h e tomato. Amer. J . B o t . 31: 135-150. W i l l i a m s , D.D.F. I962. I n f l u e n c e o o f s o i l m o i s t u r e l e v e l on f l o w e r a b s c i s s i o n , o v u l e a b o r t i o n and s e e d development i n t h e snap bean ( P h a s e o l u s • v u l g a r i s L . ) . D i s s . A b s t r . 22: 2933-- 62 -W o l f , B. 19*4 2. C h e m i c a l f a c t o r s i n f l u e n c i n g t h e s e t of Henderson bush l i m a b eans. J . Amer. Soc. A g r o n . 3^ - 6*16-650. Wort, D.J. 1962. The a p p l i c a t i o n o f s u b l e t h a l c o n c e n t r a t i o n s of 2,14^ -D, and i n c o m b i n a t i o n w i t h m i n e r a l n u t r i e n t s . W o r l d Rev. P e s t C o n t r o l , 1 (*f): 2-15. 

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