Hormone Effects on Tomato Fruit Set and Development

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P U R D U E U N IV E R SIT Y

THIS IS TO CERTIFY THAT THE THESIS PREPARED UNDER MY SUPERVISION

by

Clyde C. Singletary

e n t i t l e d ___________ Hormone

Effects on Tomato Fruit Set

and Development

COMPLIES WITH THE UNIVERSITY REGULATIONS ON GRADUATION THESES

AND IS APPROVED BY ME AS FULFILLING THIS PART OF THE REQUIREMENTS

FOR THE DEGREE OF

Doctor of Philosophy

P

H

June 9

19

r o fe sso r in

ead

of

S

Charge

chool or

of

T h e s is

Departm ent

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TO THE LIBRARIAN: THIS THESIS IS NOT TO BE REGARDED AS CONFIDENTIAL.

p k o it e s s o r

GKAD. SCHOOL FORM O—3 .4 0 — 1M

m

charge

HORMONE EFFECTS ON TOMATO FRUIT SET AND DEVELOPMENT A T h e sis S u b m itte d t o t h e F a c u l t y of P u rd u e U n i v e r s i t y

by C lyde C e c i l S i n g l e t a r y In P a r t i a l F u lf illm e n t o f th e R e q u ir e m e n ts f o r th e D eg ree of D o c to r o f P h i l o s o p h y J u n e , 1950

ProQuest Number: 27714113

All rights reserved INFORMATION TO ALL USERS The q u a lity of this re p ro d u c tio n is d e p e n d e n t u p o n the q u a lity of the co p y su b m itte d . In the unlikely e v e n t that the a u th o r did not send a c o m p le te m a n u scrip t and there are missing p a g e s, these will be n o te d . Also, if m a te ria l had to be re m o v e d , a n o te will in d ic a te the d e le tio n .

uest P roQ uest 27714113 Published by ProQuest LLC (2019). C o p y rig h t of the Dissertation is held by the A uthor. All rights reserved. This work is p ro te cte d a g a in s t u n a u th o rize d co p yin g under Title 17, United States C o d e M icroform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 48106 - 1346

ACKNOWLEDGEMENTS

The a u t h o r w i s h e s t o a c k n o w le d g e t h e g u i d a n c e , h e l p f u l c r i t i c i s m and i n t e r e s t g i v e n b y D r. G. F . W arren d u r i n g th e c o u r s e of th is in v e stig a tio n .

He w is h e s t o t h a n k

D r . N. K, E l l i s , D r. A. C. L e o p o ld , D r. E* O* S t e v e n s o n , D r. G. A. G r i e s and D r. E l i z a b e t h L. Maokay, members o f t h e t h e s i s c o m m i t t e e , and a l s o Mr. ST. H. K l e i n f o r t h e i r h e l p f u l a ssista n c e .

T A B UK O F C O H T M T S

P ag e ABSTRACT INTRODUCTION

..........................................................................................

REVIEW OF LITERATURE

...........................................................

N a t u r a l F a c t o r s A f f e c t i n g Tomato F r u i t S e t E f f e c t o f Hormones on Tomato F r u i t S e t

1 5 3

.......................

6

Hormone E f f e c t s on P o l l e n G e m i n a t i o n a n d Tube Growth .................................

12

R e l a t i o n s h i p o f A u x in t o Tomato F r u i t D evelopm ent ........................................................

13

GENERAL MATERIALS AND METHODS FIELD STUDIES

......................................

15

...................... .. I ..................... . .................................. 18

E x p e rim e n t Number 1 . E f f e c t o f Hormone S p r a y s on a C an n in g Tomato V a r i e t y i n 1948

18

E x p e rim e n t Number 2 . E a r l y M a rk e t T e s t W ith Hormone T r e a t m e n t s i n C o m b in a tio n W ith a F u n g i c i d e i n 1949 » . ............

21

E x p e rim e n t Number 3 . E a r l y M a rk e t Hormone T e s t in N o rth e rn In d ia n a . 1949• ... ............................ 31 E x p e rim e n t Number 4 . Hormone S p ra y s on C a n n e ry T o m ato es. 1 9 4 9 .......................................................................... 32 E x p e rim e n t Number 5 . C o m p a ra tiv e E f f e c t o f t w o Hormone P r e p a r a t i o n s on a P o s i t i o n a l S t e r i l e M u ta n t. 1 9 4 9 ............................................................................. 40 GREENHOUSE STUDIES

.........................................................

E x p e r im e n t Number 1 . C o m p a ra tiv e E f f e c t o f F o u r Hormone P r e p a r a t i o n s . 1 9 4 8 ............................. 43 E x p e rim e n t Number 2 . R e l a t i o n o f a F r u i t s e t t i n g Hormone S p r a y t o T e m p e r a tu r e and S o i l M o istu re ........................................................................ .....

43

P age E x p e r im e n t Mimber 5 . Hand P o l l i n a t e d and Hormone S e t P r u i t a Compared i n H a te o t Growth .............» . ................ » .......................

48

E x p e r im e n t Humber 4 . E f f e c t o f a Hormone .......................... S p r a y on B i f f e r o n t F lo w e r S t a g e s

55

LABORATORY 8T0DIBS

........................................................................... 59

E x p e r im e n t Number 1 . E f f e c t o f a Hormone on Tomato P o l l e n G e r m in a tio n a n d Tube G row th in V itro . ...........

59

E x p e rim e n t Number 2 . The C o m p a ra tiv e A uxin C o n c e n t r a t i o n a t D i f f e r e n t S t a g e s of D ev elo p m en t o f Hormone and N a t u r a l l y - s e t F ru its. ............ ............................ » ...............60 DISCUSSION OF RESULTS

...........

SUMMARY AND CONCLUSIONS APPENDIX A. TABLES APPENDIX B. FIGURES LITERATURE CITED

-.............. 68 ................................. .......................

......................................

75 76 78

.......... * ......................*............................ 80

abstract

F i e l d e x p e r i m e n t s w ere c o n d u c te d to d e t e r m i n e t h e e f f e c t o f £ - c h l o r o p h e n o x y a c e t i c a c i d a t 30 ppm (PCA) and B - n a p h t h o x y a e e t i c a c i d a t 50 ppm ( BNOA) on t h e y i e l d o f e a r l y m a r k e t and c a n n e r y t o m a t o e s .

G re e n h o u s e and l a b o r a ­

t o r y t e s t s w ere made t o s t u d y t h e e f f e c t o f t h e s e h orm on es on f r u i t and p o l l e n t u b e g r o w th . S u b s t a n t i a l i n c r e a s e s i n e a r l y y i e l d o f t o m a t o e s w ere o b t a i n e d fro m w hole p l a n t a p p l i c a t i o n s o f PCA and BNOA t o R u t g e r s , V a l i a n t and E a r l i a n a X V a l i a n t t i e s grown f o r t h e e a r l y m a rk e t i n 1 9 4 9 .

h y b rid ) v a r i e ­ The seme i n c r e a s e s

w ere i n d i c a t e d when t h e horm ones w ere com bined w i t h a f u n g i ­ c id e ( P a r z a te ).

T h e re was no e f f e c t on t o t a l y i e l d .

L arge i n c r e a s e s i n e a r l y y i e l d w ere o b t a i n e d i n an e a r l y m a rk e t e x p e r i m e n t i n n o r t h e r n I n d i a n a i n 1949 when PCA was a p p l i e d a s a c l u s t e r s p r a y t o i S a r l i a n a , E a r l i a n a X P r i t c l a a r d (F^ h y b r i d ) , R u t g e r s , Z1 and S o u th la n d to m a to v a rie tie s .

A g a in , t h e r e was no e f f e c t on t o t a l y i e l d *

T h e re was no d i f f e r e n c e i n y i e l d o f R u t g e r s t o m a to e s when t h e s e horm ones w ere a p p l i e d a s a c l u s t e r s p r a y i n a l a t e c a n n in g e x p e r i m e n t i n 1 9 4 8 .

Some s e e d l e s s f r u i t s r e ­

s u l t e d fro m t h e hormone t r e a t m e n t s .

A d e c r e a s e i n y i e l d was

r e c o r d e d fro m w h o l e - p l a n t s p r a y s o f t h e horm ones i n a l a t e c a n n in g e x p e r i m e n t w i t h R u t g e r s , R u t g e r s X P r i t c h a r d , and In d ia n a B a ltim o re v a r i e t i e s i n 1949. t r a t i o n s caused s e v e re f o lia g e i n j u r y ,

T hese horm one c o n c e n ­ e s p e c i a l l y PCA.

A l a r g e num ber o f f r u i t s w ere h a r v e s t e d when w h o le p l a n t a p p l i c a t i o n s of PGA a n d BNOA w ere made on a p o s i t i o n a l - s t e r i l e m u ta n t o f t h e J o h n B aer to m a t o v a r i e t y i n a f i e l d ex p e rim e n t i n 1949. fro m t h e u n t r e a t e d p l a n t s .

No f r u i t s w e re h a r v e s t e d

A l l f r u i t s h a r v e s t e d w ere

s e e d le s s . Many to m a to f r u i t s w e re s e t on R u t g e r s to m a to p l a n t s w i t h f l o w e r s p r a y s o f PCA u n d e r t e m p e r a t u r e s ab o v e 9 0 ° F . i n t h e g r e e n h o u s e a s c o n t r a s t e d t o few f r u i t s s e t on t h e c o n tro l p la n ts . T h ere was no d i f f e r e n c e i n num ber and s i z e o f f r u i t s f o r t h e f i r s t tw o c l u s t e r s b e tw e e n f l o w e r s o f R u t g e r s to m a to e s s p r a y e d w i t h PCA i n b u d , h a l f - b l o o m o r f u l l bloom s t a g e s o r n a t u r a l l y - s e t f r u i t s .

C o n sid e rin g th e

tim e o f hormone a p p l i c a t i o n , t h e e a r l i e s t m a t u r i n g f r u i t s r e s u l t e d fro m t h e hormone t r e a t m e n t i n t h e h a l f - b l o o m sta g e . P r a c t i c a l l y a l l horm o n e-set f r u i t s

in th e g reen h o u se

w ere s e e d l e s s , y e t p o l l i n a t i o n was f a c i l i t a t e d as in th e n a t u r a l l y - s e t f r u i t s in a l l c a se s.

t h e same

t h a t c o n t a i n e d many s e e d s

Tomato p o l l e n g e r m i n a t i o n o r t u b e g ro w th

was n o t a f f e c t e d by 30 ppm o f PCA i n a s y n t h e t i c medium o f 3 p e r c e n t a g a r , 10 p e r c e n t s u c r o s e an d 100 ppm o f a u to ly z e d y e a s t.

The e f f e c t o f hormone on m ale g am ete

f o r m a t i o n o r o v u l e a b o r t i o n w h ic h may h av e c a u s e d t h e h i g h p e r c e n t a g e s e e d l e s s f r u i t s was n o t s t u d i e d .

Yh© a u x i n c o n c e n t r a t i on a s d e t e r m i n e d i n t h e Avena t e s t was g r e a t e r f o r p l a c e n t a l t i s s u e t h a n f l e s h t i s s u e fro m f r u i t s f i v e , t w e n t y - f i v e and f o r t y - n i n e d a y s a f t e r tim e o f s e t .

N a t u r a l l y - s e t f r u i t s c o n t a i n e d m ore a u x i n

i n b o t h p l a c e n t a l and f l e s h t i s s u e t h a n d i d h o r m o n e - s e t f r u i t s e x c e p t i n t h e f i v e - d a y - o l d f r u i t s i n w h ic h c a s e b o t h w ere a b o u t e q u a l .

The horm one and ne t u r a l l y - s e t

f r u i t s w e re fo u n d t o grow a t a p p r o x i m a t e l y t h e same r a t e . T h e re fo re , n a t u r a l l y - o c c u r r i n g a u x in d id n o t a p p e a r to be t h e f a c t o r r e s p o n s i b l e f o r t h e g ro w th o f t h e horm one f r u i t s s i n c e n a t u r a l l y - s e t f r u i t s c o n t a i n e d a much l a r g e r amount o f a u x i n t h a n d i d h o r m o n e - s e t f r u i t s .

HORMONE EFFECTS ON TOMATO FRUIT SET AND DEVELOPMENT INTRODUCTION The to m a to i Lyo op a r a l e on. e s c u l a n t u m MILL* i s a n im p o rta n t h o r t i c u l t u r a l crop i n I n d ia n a .

D u r in g t h e

to m a to g ro w in g s e a s o n i n t h i s s t a t e th e t e m p e r a t u r e may r a n g e fro m belo w 60°F* i n t h e s p r i n g t o ab o v e 9 0 ° F . d u r i n g t h e summer.

T hese t e m p e r a t u r e c o n d i t i o n s h av e

b e e n shown t o r e d u c e th e f r u i t s e t o f to m a to f l o w e r s , th e re b y re d u c in g th e y i e l d of f r u i t .

M ethods f o r i n ­

c r e a s i n g t h e f r u i t s e t u n d e r t h e s e c o n d i t i o n s w ou ld h a v e econom ic i m p o r t a n c e . The p u r p o s e o f t h i s i n v e s t i g a t i o n was t o d e t e r m i n e t h e e f f e c t i v e n e s s o f horm one s p r a y s i n i n c r e a s i n g t h e s e t o f to m a to e s u n d e r p o o r f r u i t - s e t t i n g c o n d i t i o n s .

E x p e ri­

m ents w ere c o n d u c te d w i t h c e r t a i n o f t h e s e s p r a y s t o overcom e p o o r s e t i n t h e to m a to u n d e r f i e l d c o n d i t i o n s when t h e n a t u r a l s e t was e x p e c t e d to be lo w .

Due t o t h e

f a c t t h a t hormone a p p l i c a t i o n s to i n d i v i d u a l f l o w e r s w ould be i m p r a c t i c a l f o r l a r g e to m a to p r o d u c e r s , and ev e n w h o l e - p l a n t s p r a y a p p l i c a t i o n s w ould r e q u i r e a d d i t i o n a l s p r a y i n g e q u ip m e n t and i n c r e a s e t h e l a b o r c o s t i n to m a to p r o d u c t i o n , t h e p o s s i b i l i t y o f c o m b in in g th e horm one t r e a t ­ m e n ts w i t h f u n g i c i d a l s p r a y s f o r l a r g e - s c a l e a p p l i c a t i o n s a s a n a l l - p l a n t c o v e r a g e t r e a t m e n t was i n v e s t i g a t e d .

a Tomato f l o w e r s on i n d i v i d u a l c l u s t e r s may r a n g e fro m bud s t a g e , t o . a n ttie & is s t a g e •

W h o l e - p la n t hormone s p r a y s

w ould a f f e c t f l o w e r s o f a l l s t a g e s •

T h is e f f e c t o f h o r ­

mone s p r a y s on f l o w e r s o f d i f f e r e n t s t a g e s was i n v e s t i g a t e d . A s t u d y was a l s o made o f f r u i t s e t u n d e r c o n t r o l l e d greenhouse c o n d itio n s to d e te rm in e i f a r e l a t i o n s h i p e x i s t e d b e tw e e n hormone t r e a t m e n t s and h i g h t e m p e r a t u r e s . S e e d le s s f r u i t s o f te n o c c u r f o llo w in g th e a p p l i c a t i o n o f hormone s p r a y s to t o m a to f l o w e r s ev e n when p o l l i n a t i o n has o cc u rred .

The e f f e c t o f t h e s e hormone s p r a y s on p o l l e n

g e r m i n a t i o n and t u b e g ro w th was s t u d i e d t o d e t e r m i n e t h e r e l a t i o n s h i p o f t h e s e f a c t o r s to t h e p r o d u c t i o n o f s e e d l e s s fru its. Avena t e s t s w ere c o n d u c te d w i t h f r u i t e x t r a c t s o f d i f f e r e n t a g e s fro m b o t h n a t u r a l and hormone s e t f r u i t s i n o r d e r t o d e t e r m i n e i f a n y r e l a t i o n s h i p e x i s t e d b e tw e e n a u x i n c o n c e n t r a t i o n and d i f f e r e n c e s i n g ro w th p a t t e r n s o f t h e two t y p e s o f f r u i t s .

S uch a r e l a t i o n s h i p w ould be a n

a d d i t i o n to f u n d a m e n ta l k now ledge o f t h e r o l e o f p l a n t g ro w th s u b s t a n c e s .

3

fie v ie w o f 14 t w e t u r e N a iju ra l g a e t o r s A f f e c t i n g Tomato g r u i t S e t I n 1 9 1 8 , K ra u s and K r a y b i l l (1 6 ) d e m o n s t r a t e d t h a t to m a to p l a n t s w i t h o u t a b a l a n c e d r a t i o o f c a r b o h y d r a t e s and n i t r o g e n w ere u n f r u i t f u l .

P l a n t s w i t h low c a r b o ­

h y d r a t e a n d h i g h n i t r o g e n w e re h i g h l y v e g e t a t i v e b u t u n fru itfu l.

Those p l a n t s w h ic h w ere r i c h i n c a r b o h y d r a t e s

b u t low i n n i t r o g e n w ere weak v e g e t a t i v e l y an d u n f r u i t f u l . P l a n t s made n o rm a l v e g e t a t i v e g ro w th an d w ere f r u i t f u l o n l y when m o d e ra te n i t r o g e n was p r e s e n t and s u f f i c i e n t c a rb o h y d ra te s y n th e s is e x i s t e d ,

l a c k o f f r u i t d e v e lo p m e n t

was n o t due a l o n e t o p o l l i n a t i o n o r f e r t i l i z a t i o n ,

sin c e

f l o w e r s so o n a b s e i s s e d a f t e r p o l l i n a t i o n o r re m a in e d a t t a c h e d f o r s e v e r a l d a y s w i t h o u t d e v e lo p m e n t o f t h e f r u i t . They r e p o r t e d t h a t i n s t a n c e s o f s t e r i l i t y may b e th e r e s u l t o f p h y s i o l o g i c a l i n o o m p a t a b i l i t y due t o a s t a t e o r c o n d i t i o n of n u t r i t i o n in th e p la n t i t s e l f . A c c o r d in g t o H o w i e t t (11) a l o n g p i s t i l i n r e l a t i o n t o t h e s ta m e n s o f t h e to m ato f l o w e r was p ro d u c e d when p l a n t s w ere g ro w in g d u r i n g a p e r i o d o f r e l a t i v e l y s h o r t d a y l e n g t h * u n d e r l i g h t o f lo w i n t e n s i t y an d w i t h a n ©Dundance o f n itro g e n .

The s h o r t p i s t i l i n r e l a t i o n t o t h e s ta m e n s*

w h ich was n e c e s s a r y f o r n o rm a l s e l f p o l l i n a t i o n , was pro*» duoed when t h e d a y s w ere l o n g , t h e l i g h t o f h i g h i n t e n s i t y and th e s u p p l y o f r e a d i l y a v a i l a b l e n i t r o g e n o n l y m o d e r a t e .

4

He s t a t e d t h a t a l o n g p i s t i l i n r e l a t i o n t o t h e s ta m e n le n g th i s a s s o c ia te d w ith , i f n o t caused by, c a rb o h y d ra te d e fic ie n c y . H e w le t t (1 0 ) a l s o gave e v i d e n c e t h a t c a r b o h y d r a t e d e f i c i e n c y i n t h e to m a to r e s u l t e d i n s u p p r e s s i o n o f t h e m ale o r g a n s , m i c r o s p o r e d e g e n e r a t i o n and s t e r i l i t y . M itro g e n d e f i c i e n c y a f f e c t e d t h e d e v e lo p m e n t o f t h e m a le g a m e to p h y te v e r y l i t t l e

i n d i c a t i n g t h a t n i t r o g e n and

c a r b o h y d r a t e s had d i f f e r e n t e f f e c t s on m i c r o s p o r e s and p o lle n g r a in s . W ittw e r (5 1 ) h a s shown t h a t to m a to e s a r e u n f r u i t f u l when grown d u r i n g s h o r t p h o t o p e r i o d s , o r i n s e a s o n s o r a r e a s h a v i n g lo w l i g h t i n t e n s i t i e s w h ic h f a v o r p i s t i l e lo n g a tio n o r in v ia b le p o lle n .

A ls o W i t t w e r , S t a l l w o r t h

and H o w ell (52 ) and w ent and u o s p e r (50 ) o b s e r v e d t h a t a v a r i e t y was e a r l y due t o i t s a b i l i t y t o s e t f r u i t s a t a lo w e r n i g h t t e m p e r a t u r e t h a n a n o t h e r v a r i e t y ,

x h ey showed

t h a t t h e tim e i n t e r v a l s fro m s e e d i n g t o an t h e s i s v a r i e d o n l y © few d a y s ev en when e a r l y , m id s e a s o n and l a t e v a r i e ­ t i e s w ere co m p ared .

*£his was t r u e a l s o of t h e tim e fro m

f r u i t s e t t i n g to r i p e n i n g ,

irhey s t a t e d , h o w e v e r, t h a t t h e

d a t e when t h e f i r s t f r u i t w i l l s e t on d i f f e r e n t v a r i e t i e s may v a r y c o n s i d e r a b l y . A c c o r d in g to «Judkins ( 1 5 ) , to m a to p o l l e n e x h i b i t e d a p r o g r e s s i v e l y lo w e r v i a b i l i t y on d ay s o f low l i g h t i n t e n ^ s i t y and d u r i n g s h o r t d ay s o f f a l l and w i n t e r .

R ate o f

5

p o l l e n t u b eo t& rotigh t h e s t y l o d e c re a s e d , d u r i n g i n t e n s i f y t o d s h o r t d ay s*

A p p r o x i m a t e l y 38 p e r

o f p o l l e n t u b e s had e x te n d e d t h r o u g h t h e s t y l e i n ►four h o u r s , w h e re a s 70 p e r c e n t had grow n t h e comd e p th i n se v e n ty -tw o h o u rs .

F r u i t s s t a r t e d t o make

a p p r e c i a b l e g ro w th a b o u t t h r e e o r f o u r d a y s a f t e r p o llin a * » tio a *

R ip en in g o f f r u i t o c c u rre d i n ab o u t f i f t y - t h r e e d a y s . S m ith (87) fo u n d t h a t t h e optim um 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 and. t u b e g ro w th was a ro u n d 7 5 ° F .

The

g e r m i n a t i o n and tu b e g ro w th d e c r e a s e d a p p r e c i a b l y when e x ­ p o se d t o t e m p e r a t u r e s o f 6 0 ° and 8 5° F .

The p o l l e n g e r m in a ­

t i o n p e r c e n t a g e a t 1 0 0 ° F . was a l m o s t z e r o .

W ith few

e x c e p t i o n s , f o r t y - e i g h t h o u r s o r l o n g e r were r e q u i r e d f o r e x t e n s i o n o f t h e p o l l e n t u b e th r o u g h t h e s t y l e t o t h e o v a r y . F lo w e r a b s c i s s i o n o c c u r r e d a t a much m ore r a p i d r a t e a t t h e h i g h t e m p e r a t u r e s t h a n a t 753 F* to m ato f l o w e r s f a i l e d t o s e t f r u i t when grown u n d e r t e m p e r a t u r e s w h ic h e x c e e d e d 9 0 ° F . a c c o r d i n g t o M u l l i s o n and M i l l i s o n ( 1 9 ) .

The c o n d i t i o n o f p i s t i l g ro w th beyond

t h e p o l l e n t u b e s was e x h i b i t e d by f l o w e r s u n d e r t h e h i g h te m p e ra tu re s. Went and G o sp er (3 0 ) o b s e r v e d t h a t optimum t e m p e r a t u r e s f o r to m a to f r u i t s e t i n t h e e a r l y s p r i n g f o r m ost v a r i e t i e s was fro m 5 9 °Z . t o 68°3?.

T e m p e r a tu r e s below 5 5 ° F . g av e a

v e r y p o o r s e t o f f r u i t , e v e n on an e a r l y v a r i e t y s u c h a s , w l± h no f r u i t i n g a t a l l on l a t e r t y p e s .

6

W r& e e k (SO) r e p o r t e d t h a t f r a i t i n g o f t o m a t o e s and Stem e l o n g a t i o n w ere n e g a t i v e l y c o r r e l a t e d ,

A p ro g re ssiv e

d e c r e a s e i n s te m e l o n g a t i o n o c c u r r e d w i t h i n c r e a s e s i n fru itin g #

E r u i t p r o d u c t i o n h ad a s t r i k i n g r e t a r d a t i o n on

growth# C a r o l u s (3 ) r e p o r t e d t h a t s l i g h t d e f i c i e n c y o r e x c e s s o f p o t a s s i u m i n tom ato p l a n t s c a u s e d a c o n d i t i o n o f p h y s i o ­ l o g i c a l u n b a l a n c e t h a t r e s u l t e d i n d e c r e a s e d g r o w th and reduced y i e l d s .

The q u a l i t y o f f r u i t was a l s o im p a ire d *

D eath r e s u l t e d fro m h e a v y - f r u i t e d , p o t a s s i u m - d e f i c i e n t p la n ts. N i g h t i n g a l e , S c h e r m e rh o rn and R o b b in s (2 3 ) fo u n d t h a t p o t a s s i u m d e f i c i e n c y u p s e t t h e n i t r o g e n and c a r b o h y d r a t e r e l a t i o n s h i p i n t h e to m a to p l a n t .

C arb o h y d rate s y n t h e s i s

was r e d u c e d by p o t a s s i u m d e f i c i e n c y g i v i n g weak v e g e t a t i v e and h i g h l y u n f r u i t f u l p l a n t s , E f f e c t o f Hormones on Tomato F r u i t S e t P a r t h e n o c a r p i e f r u i t s w e re f i r s t p r o d u c e d b y t r e a t i n g to m ato f l o w e r s w i t h hormone s u b s t a n c e s by G u s t a f s o n (4 ) i n 19 36,

He s t a t e d t h a t c e r t a i n g r o w t h - p r o m o ti n g s u b s t a n c e s

Such a s i n d o l e b u t y r i c , i n d o l e p r o p i o n i c , i n d o l e a c e t i e , an d p h e n y l a o e t i e a c i d s when a p p l i e d t o c u t s t y l e s o f t e n c a u s e d t h e o v a r y t o grow f o r some l e n g th o f t i m e . w i t h o u t s e e d s w ere p r o d u c e d i n t h e t o m a t o .

M a tu re f r u i t s The s u b s t a n c e s

c a u s i n g a f l o w e r to d e v e lo p i n t o a f r u i t seem ed t o be

7

r e l a t e d t o t h e a u x i& s ♦

G u s t a f s o n (7 ) fo u n d t h a t

t h e p e r c e n t a g e o f f r u i t - s e t t i n g i n t h e to m a to w i t h c h e m i­ c a l t r e a t m e n t s was p r o b a b l y a s g r e a t a s w i t h p o l l i n a t i o n ; h o w e v e r, p a r t h e n o c a r p i e f r u i t s w ere d e f i n i t e l y s m a l l e r t h a n se e d e d f r u i t s . G u s t a f s o n (8 ) fo u n d i n a l a t e r e x p e r i m e n t , h o w e v e r, t h a t s e e d l e s s f r u i t s p ro d u c e d w i t h a horm one s p r a y w ere l a r g e r t h a n s e e d e d f r u i t s p ro d u c e d by p o l l i n a t i o n .

He

f u r t h e r showed t h a t s e t t i n g was som ewhat g r e a t e r t h a n w i t h p o llin a tio n *

He r e p o r t e d t h a t when B - n a p h t h o x y a o e t l c a c i d

was a p p l i e d b elow t h e f l o w e r o n ly s e e d e d f r u i t s w ere p r o ­ duced. Zimmerman (5 3 ) r e p o r t e d a g r e a t l i s t o f c h e m ic a l s p r a y s t h a t w ere e f f e c t i v e i n i n c r e a s i n g to m a to f r u i t s e t .

T h e se

s u b s t a n c e s c l o s e l y r e s e m b le d t h e c h e m i c a l s t r u c t u r e o f a u x in s. G u s t a f s o n (5 ) r e p o r t e d t h a t e x t r a c t s o f p o l l e n fro m s e v e r a l ty p e s o f p l a n t s p ro d u ced s e e d le s s f r u i t s i n e g g p la n t, p e p p e r , s q u a s h , an d c u c u m b e r. P - c h l o r o p h e n o x y a c e t i c a c i d g av e fro m 50 t o 75 p e r c e n t i n c r e a s e i n t h e y i e l d o f f a l l - g r o w n g r e e n h o u s e to m a to e s i n e x p e r i m e n ts c o n d u c te d by Murneek ( S 2 ) .

A w h o le -p la n t sp ray

was m ore e f f e c t i v e when a p p l i e d o n c e e a c h week t h a n a c l u s ­ t e r s p ra y *

He s t a t e d ;

"E v id e n tly th e s e su b sta n c e s e x e rt

t h e i r c a t a l y t i c p o t e n c y n o t o n l y d i r e c t l y on t h e f l o w e r s b u t a l s o i n d i r e c t l y t h r o u g h t h e f o l i a g e and p o s s i b l y t h e

8

à w tre lo p in g f r u i t * w

B o r i n g e l o u d y w e a t h e r many p u f f y f r u i t s

r e s u l t e d fro m t h e j ^ e à l o r o p h e n o x y s e e t i c a c i d s p r a y .

U nder

t h e s e e e m d it i e n s , B - n a p h t h o x y a e e t i c a c id gave h i g h e r q u a l i t y f r u its hut npt as g re a t a y ie ld . m irm eek, W ittw e r and H e m p h ill (3 1 ) r e p o r t e d t h a t i n ­ c r e a s e s i n t o t a l y i e l d and f r u i t s i z e w ere o b t a i n e d w i t h f l o w e r s p r a y s o f B - n a p h t h o x y a c e t i o and £ - c h l o r o p h e n o x y a e e t i c a c id s a t v a ry in g c o n c e n tr a tio n s .

I n c r e a s e s r a n g i n g fro m

3 7 .5 t o 7 1 .5 p e r c e n t f o r t o t a l y i e l d and - 2 . 2 t o 8 . 2 p e r c e n t i n a v e r a g e f r u i t s i z e w ere o b t a i n e d d e p e n d in g on c o n ­ c e n t r a t i o n o f t h e c h e m i c a l s p r a y s and to m a to v a r i e t y t r e a t e d . They fo u n d t h a t t h e g r e a t e s t r e s p o n s e s o c c u r r e d d u r i n g c l o u d y o r s h o r t d a y s when t h e r e was l e s s n a t u r a l f r u i t s e ttin g *

G r e a t e r u n i f o r m i t y i n f r u i t w e ig h t and s i z e i n

a d d i t i o n t o an i n c r e a s e i n f r u i t w e ig h t and s i z e g e n e r a l l y r e s u l t e d fro m f r u i t s e t w i t h horm one s p r a y s .

F l o w e r s , ev en

th o u g h n o t t h e same ag e when s p r a y e d w ith a h o rm o n e, s e t and m a tu re d f r u i t a t a b o u t t h e same r a t e . They s t a t e d t h a t t h e new er c h lo r o p h e n o x y compounds t e n d t o s t i m u l a t e o u t e r d e v e lo p m e n t o f t h e p e r i c a r p g i v i n g p u f f y fru its.

They fo u n d t h a t t h e more s e e d s t h a t Were p r e s e n t

t h e b e t t e r t h e d e v e lo p m e n t of p l a c e n t a l t i s s u e an d t h e more s o lid th e f r u i t . I n e x p e r i m e n t s c o n d u c te d by H o w le tt ( 1 3 ) ,

in d o le b u ty ric

a c i d was fo u n d e f f e c t i v e i n i n c r e a s i n g f r u i t s e t a n d d e v e l ­ opment u n d e r g r e e n h o u s e c o n d i t i o n s d u r i n g t h e e a r l y s p r i n g

9

môBtsàs *

fo u n d t h a t t h e e x t e n t o f i n c r e a s e d e p e n d e d u po n

t h e am ount o f f e r t i l i s a t i o n and e m b ry o n ic d e v e lo p m e n t o ç e m r r in g p r e v i o u s l y o r s i m u l t a n e o u s l y # B o b e r t s and a t r u c k m e y e r (26} r e p o r t e d t h a t horm one s p r a y s h av e c o n s i s t e n t l y f a i l e d t o a i d i n th e s e t t i n g o f tomat© f r u i t s w h ic h n o r m a l l y a b s c i s s and d ro p fro m n u t r i ­ t i o n a l causes*

Old b lo s s o m s w ere in d u c e d t o s e t f r u i t

w h ich made i t p o s s i b l e

to d e la y sp ra y in g u n t i l s e v e ra l

b lo sso m s c o u ld be s e t a t one tim e g i v i n g a v e r y u n i f o r m s i z e o f f r u i t ; a l s o * o n l y one s p r a y i n g p e r c l u s t e r was needed*

I n c a s e some b lo s so m s d i d n o t b e g i n t o d e v e lo p

i n t o f r u i t s , r e s p r a y i n g them a f t e r s e v e r a l d a y s s t i l l p r o ­ duced f r u i t * They s t a t e d t h a t f r u i t s d e v e lo p e d fro m f l o w e r s s p r a y e d i n t h e bud s t a g e w ere c o n s i s t e n t l y s m a l l e r t h a n f l o w e r s s p r a y e d when i n f u l l bloo m .

T h e ir d a ta in d ic a te d t h a t

b lo sso m s i n t h e e a r l y bud s t a g e w h ic h h av e b e e n s e t w i t h c h e m ic a l horm ones d e v e lo p e d i n t o s e e d e d f r u i t s i f p o l l i n a ­ te d l a t e r a t th e fu ll- b lo s s o m s ta g e . m eyer a l s o s t a t e d :

R o b e r t s and S t r u c k -

"When f u l l s e t s on a l l c l u s t e r s a r e

s e c u r e d fro m hormone t r e a t m e n t s i t

i s i m p o r t a n t t o ch a n g e

t h e c u l t u r a l p r a c t i c e s t o m eet th e n u t r i t i o n a l r e q u i r e m e n t s of th e p la n t#

Ho p r e c a u t i o n i s n e c e s s a r y t o a p p r e c i a b l y

p r e v e n t th e p l a n t s fro m b eco m in g o v e r v e g e t a t i v e , " H e m p h ill (9 ) a p p l i e d a 10 ppm c o n c e n t r a t i o n s p r a y o f j a - e h l o r o p h e n o x y a e e t i c a c i d to to m a to f l o w e r s a t bud s t a g e s

10

BiFtewBSs IrSeg®* t o w fle w e r B la ste r*

is f S s fS e r a n t h e s i s , and to th e e n t i r e

E â s d a t a i m d â a a t e â t h a t ti m e o f horm one

S lSS f- a p B l i a a t i O B was im g e rta m t s i n c e i n j u r y was n o t e d on f l o w e r s when t h e h o r s e n e s p r a y was a p p l i e d e i g h t d a y s h e fe re e a th e s is *

A g r e a t e r i n c r e a s e i n num ber o f f r u i t s

was o b t a i n e d when t h e horm one was a p p l i e d f o u r d ay s a f t e r a n th e sis sta g e . W ittw e r (3 1 ) r e p o r t e d t h a t a horm one s o l u t i o n c o n t a i n ­ i n g 10 ppm o f £ v ç h l o r e p h e n o x y a e e t i c a c i d an d 40 ppm o f B -n a p h th o x y a c e t i c a c i d gave i n c r e a s e s i n y i e l d o f g r e e n h o u s e to m ato es.

L a r g e r i n c r e a s e s i n y i e l d w ere o b s e r v e d i n t h e

s p r i n g c r o p t h a n i n t h e f a l l grown t o m a t o e s ,

D iffe re n tia l

v a r i e t a l r e s p o n s e s w ere fo u n d t o e x i s t d u r i n g b o t h s p r i n g and f a l l s e a s o n s *

A c c o r d in g t o W ittw e r, t h e s i g n i f i c a n c e

o f s e a s o n and o f v a r i e t a l r e s p o n s e s was d i r e c t l y c o r r e l a t e d w i t h t h e c h a n g in g d a y - t o - d a y p a t t e r n o f s o l a r r a d i a t i o n * W n llis o n and M u l l i s o n (1 9 ) f o u n d t h a t to m a to f l o w e r s s e t f r u i t when s p r a y e d w i t h s o l u t i o n s o f j^ - c h lo r o p h e n o x y a e e t i e o r B -n a p h th o x y a c e tie a c id s u n d e r h ig h te m p e r a tu r e s when n o r m a l l y t h e f l o w e r s would a b s c i s s .

No c o r r e l a t i o n

e x i s t e d b e tw e e n hormone s p r a y s and i n c i d e n c e o f b lo s s o m -e n d re t*

J ? - e h l o r o p h e n o x y a e e t ie a c i d b r o u g h t a b o u t b e t t e r f r u i t

s e t and f r u i t d e v e lo p m e n t th a n o t h e r g ro w th r e g u l a t o r s em p lo y ed .

D é te rm in a t e - t y p e v a r i e t i e s w ere s u p e r i o r t o t h e

in d e te r m in a te - ty p e f o r f r u i t p r o d u c tio n d u rin g h o t, t r o p i c a l se a so n s w h eth e r t r e a t e d o r u n t r e a t e d .

11

CS§) r ^ o r t e d

th a t th e t o t a l

y i e l i ®f t e s » t o f r m i t s waa i n e r e a s e â h y s p r a y i n g to m a to S S ê S e ss o f t h e V a l i a n t v a r i e t y m i t h B - n a p h t h o x y a o e t i e a c i d , i© p p s t o - e h l o r o p h e n o x y p r o p i o n i c a c id * 50 ppm; jD -e h lo r o p h e s o x y a e e ti® a c i d , S5 ppm; and 2 , 4 , 5 - tr i c h l o r o p h e n o x y - * â e ê t i è a c i d , 10 ppm, u n d e r g r e e n h o u s e c o n d i t i o n s .

S p ra y in g

t h e f l e w e r s one© mhen h a l f t h e f l o w e r s w e re o p en and s e c o n d à when a l l t h e f l o w e r s had o p ened r e s u l t e d i n a g r e a t e r s e t Of f r u i t s t h e n was o b t a i n e d fro m t h e u n t r e a t e d p l a n t s . lEometee© fro m t r e a t e d p l a n t s w ere more u n i f o r m , r i c h e r i n c o l o r and l a r g e r i n s i z e t h a n t h e c h e c k e x c e p t f o r a n o c c a s i o n a l m is s h a p e n f r u i t , some w i t h u n f i l l e d l o c u l e s o r g re e n is h p u lp c o lo r . I n c o n t r a s t , H o w l e t t (1 4 ) i n h i s l a t e r e x p e r i m e n t s r e p o r t e d t h a t t r e a t m e n t of g r e e n h o u s e to m ato f l o w e r s w i t h hormone s p r a y s was d i s c o n t i n u e d i n Ohio and t h a t t h e E x p e r i ­ m ent S t a t i o n was n o t m aking f u r t h e r re c o m m e n d a tio n s b e c a u s e o f t h e n a t u r e of t h e f r u i t s p r o d u c e d .

He d e m o n s t r a t e d t h a t

p r e m a tu r e s o f t e n i n g and breakdo w n o f horm one t r e a t e d f r u i t s o c c u r r e d much i n e x c e s s o f n a t u r a l l y - s e t f r u i t s . f r u i t s a lso

T re a te d

c o n t a i n e d a much g r e e n e r p u l p t h a n u n t r e a t e d

fru its. W ittw e r , S t a l l w o r t h , a n d H ow ell (3 2 ) r e p o r t e d t h a t l a r g e i n c r e a s e s i n y i e l d of e a r l y m a r k e t , o u t d o o r to m a to e s w ere p r o d u c e d w i t h hormone c l u s t e r s p r a y s o f

jd- c h lo ro p h e n o x y *

a c e t i c a c i d a t 30 ppm when a p p l i e d d u r i n g p e r i o d s when n i g h t

12

# # # # # $ # # # # Se*#' S b lè lr

W w a a t a r a i f r u i t s e t was

’ t e e iè a w •âmrâ&g t h e e a r l y s p r i n g i n M ic h ig a n ,

They

#%#%W t h a t hormone s p r a y s may s e r v e t o i n c r e a s e y i e l d o f t e m s t e e s w â e r e o n â i t i o n s w here p o o r f r u i t s e t may o c c u r , 2*eââ©eh (S â l r e p o r t e d t h a t c o n s i d e r a b l e i n j u r y and d e e r e a s e i n y i e l d were e v i d e n c e d when e i t h e r 2 - c h l o r o p h e n o x y p r s p i e a i c o r S j 4 i i ^ t r i e 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 was eombimed w i t h an i n s e e t i o i d a l e f u n g i o i d a l t r e a t m e n t o f C o p p er ÏJyâre 4 0 » 5 p o u n d s ; l e a d a r s e n a t e , 3 p o u n d s ; a r a s s e l i s p r e a d e r , 6 o u n c e s ; and w a t e r , 50 g a l l o n s , and a p p l i e d a s a W h o l e - p la n t s p ra y *

F o l i a g e g ro w th was c o m p l e t e l y i n h i b i t e d

w i t h t h e se c o n d a p p l i c a t i o n o f 2 , 4 , 5 - t r i c h l o r o p h e n o x y ® p ro p io n ic a c id i n co m b in a tio n w ith an i n s e c t i c i d a l ® f u n g i c i d a l t r e a t m e n t when a p p l i e d a s a w h o l e - p l a n t s p r a y .

C lu ste r

s p r a y s o f t h e two ho rm ones gave i n c r e a s e s i n f r u i t s e t .

The

w h o l e - p l a n t i n s e c t i c i d a l - f u n g i c i d a l s p r a y was u s e d a s a c o n ­ t r o l tre a tm e n t,

T h e r e f o r e , i t was n o t o b s e r v e d w h e th e r t h e

i n j u r y was due to t h e horm ones o r t h e c o m b in a t i o n o f horm ones and i n a e c t i e i d e - f u n g i c i d e , Hormone I f f s e t s on P o l l e n G e r m in a ti on a n d Tube Grow th A d d i e o t t (1 ) t e s t e d t h e e f f e c t of t h i r t y - t h r e e p u r e g ro w th s u b s t a n c e s on p o l l e n g e r m i n a t i o n and t u b e g ro w th i n TrUPSaolum and Mi 1 1 a ,

S ix te e n o f t h e t h i r t y - t h r e e c h e m ic a l

s u b s ta n c e s s i g n i f i c a n t l y in c re a s e d g e rm in a tio n a n d /o r tu b e g r o w th ,

fie fo u n d t h a t p o l l e n g e r m i n a t i o n and t u b e g ro w th

13

|||S $„Seà ,-ss , W® : i i s t S a ^ S

p ro c e sse s lu t h a t

i a # t # a e # 9 one s s s e f f e e t e â w h e r e a s t h e o t h e r was

in sife e te â * j a t h e s e t e s t s hy A â à l e o t t , i n â o l e a e e t i e an d t r a u m a t i c a c i d s , t h e n a t u r e l p l a n t horm ones u s e d , d i d n o t a f r e e t p o lle n g e rm in a tio n ,

i n d o l e a o e t i c a c i d , h o w e v e r, d i d s i g n i ­

f i c a n t l y i n c r e a s e p o l l e n tu b e g ro w th . K e l a t i o n s h i p o f A uxin t o Tomato F r u i t D ev e lo p m e n t C M stafso n (6 ) d e t e i m i n e d t h e a u x i n c o n c e n t r a t i o n o f n a t u r a l and hormone s e t f r u i t s w hich w ere 1*5 and 6 . 0 cm. i n sin® r e s p e c t i v e l y b y u s e of t h e Avena b i o a s s a y .

He

fo u n d t h a t t h e i n d o l e a c e t i e a c i d e q u i v a l e n t was h i g h e r i n c o n c e n t r a t i o n w i t h n a t u r a l l y - s e t f r u i t s t h a n t h o s e p ro d u c e d w i t h s p r a y s o f p h e n y l a o e t i e a c id *

L a r g e s t am oun ts o f a u x i n

w ere fo u n d i n s e e d and j e l l y a r o u n d t h e s e e d s w i t h t h e am ount d e c r e a s i n g i n t h e o r d e r o f p l a c e n t a , c e n t r a l a x i s , p a r t i t i o n s and p e r i c a r p i n t h e e a s e o f n a t u r a l l y - s e t f r u i t s . The l a r g e s t c o n c e n t r a t i o n o f a u x i n was fo u n d i n th e c e n t r a l a x i s an d p a r t i t i o n s i n t h e c a s e o f h o r m o n e - s e t f r u i t s * .

He

c o n c lu d e d t h a t a u x i n o t h e r t h a n t h a t ad d ed a r t i f i c i a l l y was fo u n d i n f r u i t s t h a t h a v e b ee n p ro d u c e d by t r e a t i n g t h e f l o w e r s w i t h p h e n y l a o e t i e a c i d t h a t was n o t a c t i v e i n t h e 4#®na t e s t . R e s u l t s r e p o r t e d by M uir (1 8 ) i n d i c a t e , fro m t e s t s i n t h e Avena b i o a s s a y , t h a t no a u x i n was p r e s e n t i n o v a r i e s

14

f e r tS I S s s tS s s - e s e e p t t a th e bound form .

H is d a ta

@&@we€ $&#t a g r e a t amemnt ©f1 a u x in was p r e s e n t a f t e r 'g e n rt|lS sa S ta n .

t h i s fo rm a tio n was th o u g h t to be due to

an emsfme sy ste m r e le a s e d th ro u g h p o l l i n a t i o n . gn stefso m (S) made grow th s t u d i e s on d e v e lo p in g tom ato f r u i t s and found t h a t th e grow th p a t t e r n fo llo w e d a sigm oid e u rte ,

In a l a t e r ex p erim en t G u sta fso n (7) r e p o r te d t h a t

n a t u r a l and hormone s e t f r u i t s do n o t p a r a l l e l each o th e r i s grow th.

15

4- .

@@aea?al s a t e ^ la l s and Methods A # s y a t h e t i e P r i a i t - s e t t i n g horm ones i n a l l e x p e r i -

BààâSs a f t h i s r e s e a r c h w ere l a b o r a t o r y o r c o m m e rc ia l p r e p a r a t i o n s mt e i t h e r g - e h l o r o p h e n o x y a e e t i e o r B - n a p h th o x y a è e tie a c id s ,

The p r e p a r a t i o n s w e r e j g - e h l o r o p h e n o x y a e e t i e

a c i d a t 50 ppm i n w a t e r w i t h 500 ppm o f earbo w ax (PG A -Cerbo); ^ C h l e r o p h e n o x y a e © t i e a c i d a t 50 ppm i n an a l c o h o l and w a t e r ( PCA)^i B ^ n a p h th o x y a c e t i e a c i d a t 50 ppm i n w a t e r w i t h 500 ppm o f earb o w ax ( BEOA’-C arbo ) $ B - n a p h t hoxya e e t i e a c i d a t % 50 ppm i n an a l c o h o l and w a t e r ( BNOA) » T hese horm ones w i l l s u b s e q u e n t l y be r e f e r r e d t o b y t h e a b b r e v i a t i o n s i n p a r e n t t h e s e s t h r o u g h o u t a l l e x p e r im e n ts ,.

C o n c e n tra tio n s o f each

c h e m ic a l i n s o l u t i o n w i l l be g i v e n i n e a c h e x p e r i m e n t s i n c e t h e d i l u t i o n v a r i e d i n some t e s t s . The hormone s p r a y s w ere a p p l i e d t o i n d i v i d u a l to m a to f l o w e r s i n t h e g r e e n h o u s e e x p e r i m e n t s w i t h a n a s a l a to m i& e r. F lo w e r c l u s t e r s p r a y s i n th e f i e l d e x p e r i m e n t s w ere a p p l i e d w i t h a h an d p r e s s u r e s p r a y e r , w h e re a s t h e w h o l e - p l a n t h o r ­ mone a p p l i c a t i o n s i n th e f i e l d were made w i t h a k n ap s a c k sp ray er. Tomato p l a n t s w ere sp a c e d f o u r f e e t a p a r t i n rows f i v e f e e t a p a r t i n t h e 1948 f i e l d e x p e r i m e n t s and t h r e e f e e t ^C om m ercial p r e p a r a t i o n " S u r e S e t * , Dow C h e m ic a l Company, M id la n d , M ic h ig a n . & C om m ercial p r e p a r a t i o n "No S e e d * . S c i e n c e P r o d u c t s com pany, © hi©ago, I l l i n o i s .

16

####% l i t 3T0 WS ftT® f e e t e p a r t i n 1 9 4 9 .

F iv e p l a n t p l o t s

s e p l S e e t a i s i x t i m e s w e re m seà i n a l l f i e l d e x p e r i m e n t s , S t n s e t h e e x p e r i m e n t a l d e s i g n s w ere n o t g e n e r a l l y c o n s i s ­ t e n t , th e d e s ig n ty p e i s g iv e n i n eaeh e x p e rim e n t. In th e e a r ly m ark et f i e l d as m a rk e ta b le and e u l l s .

t e s t s , to m a to e s w ere g rad ed

I5he t o m a to e s fro m t h e l a t e

c a n n i n g e x p e r i m e n t s w e re g r a d e d a s U .S . Mo. 1> U .S . No. 2 , and a n i l s .

A l l f r u i t s h a r v e s t e d fro m b o t h e a r l y m a r k e t

and l a t e c a n n in g e x p e r i m e n t s w ere c o u n te d an d w e ig h e d t o d e t e r m i n e y i e l d and a v e r a g e s i x e o f f r u i t s .

They w ere e u t

i n h a l f a l s o to exam ine f o r s e e d c o n t e n t and i n t e r n a l c o l o r . I n e a e h g r e e n h o u s e e x p e r i m e n t , tom ato p l a n t s w ere grown i n e i g h t i n c h p o t s on b e n c h e s ♦

T r e a t m e n ts i n t h e s e

e x p e r i m e n ts w e re r e p l i c a t e d f o u r t i m e s i n a ra n d o m is e d b l o c k d e s i g n w i t h one to m ato p l a n t s e r v i n g a s one r e p l i c a t e f o r each tr e a tm e n t.

R e c o r d s o f h a r v e s t e d f r u i t s w ere t a k e n

t h e same a s i n t h e f i e l d e x p e r i m e n t s .

I n a l l g re e n h o u s e

and f i e l d e x p e r i m e n t s , u n t r e a t e d p l a n t s w ere u s e d a s c o n tro ls.

F lo w e r s w ere ta p p e d when i n f u l l bloom t o f a c i l i ­

t a t e p o l l i n a t i o n on a l l p l a n t s o f e a c h t r e a t m e n t i n t h e g reen h o u se. The p o s i t i o n a l s t e r i l e m u ta n t o f t h e Jo h n B aer v a r i e t y was u s e d i n e x p e r i m e n t s w here c o m p le te c o n t r o l o f s e l f p o l l i n a t i o n was d e s i r e d . L a r s o n and

B aur

T h i s m u ta n t was d e s c r i b e d b y

(1 7 ) a s h a v i n g f l o w e r s t h a t p r o d u c e good

p o lle n i n s u f f i c i e n t q u a n tity to e f f e c t s e l f - f e r t i l i z a t i o n

17

bù'fc t h e p o l l e n s e e s e t t h e e n d s o f t h e a n t h e r s s i m p l y f a i l t o ©pen w i t h t h e r e s u l t t h a t u n d e r n a t u r a l c o n d i t i o n s t h e r e i s no c h a n c e f o r s e l f - p o l l i n a t i o n *

In th e c o n tr o l

t r e a t m e n t s , i t was p o s s i b l e t o o b t a i n f r u i t s e t by h and p o llin a tio n .

O t h e r to m a to v a r i e t i e s t e s t e d a r e l i s t e d

u n d e r e a c h e x p e rim e n t* A l l f i e l d and g r e e n h o u s e e x p e r i m e n t s w ere c o n d u c te d a t L a f a y e t t e , I n d i a n a , e x c e p t on e f i e l d e x p e r im e n t i n n o r t h e r n I n d ia n a * M a t e r i a l s and m eth o d s u s e d i n t h e l a b o r a t o r y e x p e r i ­ m en ts w ere n o t common to e i t h e r g r e e n h o u s e o r f i e l d e x p e r i ­ m e n ts and t h e r e f o r e a r e g i v e n i n d e t a i l i n e a c h e x p e r i m e n t under la b o ra to ry s tu d ie s .

18

F ie ld S tu d ie s E x p e r im e n t Humber 1 .

E f f e c t o f Hormone S p r a y s on a

C an n in g to m a to v a r i e t y i n 1 9 4 8 . F o u r hormone t r e a t m e n t s — PCA, PC À -C arbo, BHOA and BHÔA-Carbo, w ere a p p l i e d a s c l u s t e r s p r a y s t o R u t g e r s tom a­ to e s i n 1948.

t o e s e horm one t r e a t m e n t s w e re a p p l i e d a t

v a r i o u s t i m e s when f l o w e r c l u s t e r s w ere i n bloom ( T a b le 1)♦ I n t h e t r e a t m e n t i n w h ich " a l l c l u s t e r s " w ere s p r a y e d t h e a p p l i c a t i o n s w ere made on J u l y 6 , 1 5 , 1 9 , a n d 27 and A u g u st 5 . and 1 3 .

t o e " e a r l y c l u s t e r s " w ere s p r a y e d on J u l y 6 "M id d le c l u s t e r s " r e c e i v e d t h e horm one t r e a t m e n t s

on J u l y 19 and 2 7 , and " l a t e c l u s t e r s " w e re s p r a y e d A u g u s t 5 . t o e d a t a i n T a b le 1 i n d i c a t e t h a t u n d e r t h e c o n d i t i o n s o f t h i s e x p e r im e n t f r u i t - s e t t i n g horm ones w e re n o t b e n e f i ­ c i a l i n i n c r e a s i n g th e t o t a l y i e l d o f h a r v e s t e d f r u i t s ,

to e

e n v i r o n m e n t a l c o n d i t i o n s , h o w e v e r, w e re c o n d u c iv e t o good se ttin g as is

shown by t h e h i g h y i e l d s ,

to e te m p e ra tu re

r e c o r d d u r i n g t h e p e r i o d o f f r u i t s e t t i n g shown i n F i g u r e 1 i n d i c a t e s t h a t th e t e m p e r a t u r e was n e a r optim um f o r f r u i t se t.

A lth o u g h t h e r e w ere no s i g n i f i c a n t d i f f e r e n c e s b e tw e e n

t r e a t m e n t s , some s e e d l e s s f r u i t s w e re h a r v e s t e d fro m t h e h o r m o n e - t r e a t e d p l a n t s i n d i c a t i n g t h a t some w ere s e t a s a r e s u l t o f t h e hormone t r e a t m e n t .

T h ere was no a p p a r e n t

d i f f e r e n c e i n i n t e r n a l c o l o r i n g o f f r u i t s fro m t r e a t e d and u n tre a te d p l a n t s ,

19

T a b le 1*

Mark®lia b le Y ie ld o f R u t g e r s Tom atoes T r e a t e d W ltà Hormones a t l a f a y e t t e , I n d i a n a . 1 9 4 8 .

T r e e tm e n ts

A ll C lu s te rs io n s p e r acre

Time o f A p p l i d a t i o n o f T r e a t m e n ts M idd le L a te E a rly C lu s te rs C lu s te rs C l u s t e r s A v e ra g e (o n ly ) (o n ly ) (o n ly ) Tons p e r Tons p e r Tons p e r Tons p e r acre aere acre acre

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1 8 ,7

1 3 ,8

IS .5

1 3 .5

1 3 .1

BHOA

1 3 .8

1 1 .0

1 3 .5

1 3 .6

1 2 ,7

PGA-Garbo

1 1 .6

1 3 .1

IS .2

1 2 .9

1 2 ,5

PGA

1 5 ,0

1 3 .7

1 3 .8

1 3 .7

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if i g u r e 1 . Maximum and minimum tem ­ p e r a tu r e s d u rin g f r u i t s e t t i n g p e rio d o f o a im in g to m ato e x p e r i m e n t, L a f a y e t t e , I n d ia n a * 1 9 4 8 ,

31

Humber S #

E a r l y M a rk e t T e s t W ith Hormone

T r e a t m e n ts i n C o m b in a tio n W ith a F u n g i c i d e i n 1 9 4 9 . Tomato s e e d s o f t h r e e v a r i e t i e s — R u t g e r s , V a l i a n t , an d E a r l 1 a n a X V a r i a n t t a n Fx h y b r i d ) w w e re p l a n t e d i n t h e g r e e n h o u s e on M arch 3 3 , 1 9 4 9 , i n o r d e r t o a e c u r e p l a n t s t h a t w ould b lo s s o m d u r i n g t h e p e r i o d ©f e o o l n i g h t t e m p e r a ­ t u r e s w h ic h , a c c o r d i n g t b W ittw e r ( 5 1 ) , a r e u n f a v o r a b l e f o r n a t u r a l f r u i t se t#

% e p l a n t s w e re ^ h e r d e n e d ^ o f f i n a

c o l d fra m e and t r a n s p l a n t e d i n t h e f i e l d on May 1 3 , 1 9 4 9 . The hormone p r e p a r a t i o n s PGA and BHOA w ere a p p l i e d a s whol e - p l a n t s p r a y s .

As a d d i t i o n a l t r e a t m e n t s , e a c h was

com bined w i t h a f u n g i c i d a l s p r a y c o n s i s t i n g o f P a r z a t e ( z i n c e t h y l e n e b i s d i t h i o e a r h a m a t e ) a t two p o u n d s p e r one h u n d re d g a l l o n s o f w a t e r .

The v a r i e t i e s and t r e a t m e n t s

w e r e .r a n d o m iz e d i n a s p l i t - p l o t d e s i g n *

The t r e a t m e n t s

made up t h e s u b ^ p l o t a w i t h v a r i e t i e s c o n s t i t u t i n g t h e m ain p lo ts. Hormone t r e a t m e n t s were made on J u n e 5 , 1 4 , and 2 4 , 1949.

The h a r v e s t b e g a n on J u l y 1 2 .

The f r u i t s w ere

p ic k e d a t m ark et m a t u r i t y , t h a t i s , th e p e r io d j u s t p r i o r t o c o m p le te c o l o r i n g .

S u b s e q u e n t p i c k i n g s w e re made f r e ­

q u e n t l y t o n o t e a n y horm one e f f e c t , s u c h a s r a p i d i n c r e a s e or d ec rease in y ie l d .

H a r v e s t i n g was t e r m i n a t e d on

A u g u st 5 , 1 9 4 9 , f o r V a l i a n t and E a r l i a n a X V a l i a n t b u t c o n t i n u e d t h r o u g h S e p te m b e r 3 0 , 1 9 4 9 , f o r R u t g e r s . a n a l y s i s o f t h e e a r l y y i e l d s i s shown i n T a b le 3 .

The

T a b le g*

[email protected] M a r k e t a b l e Y ie ld T h ro u g h J u l y 35 and P e r c e n t a g e o f S e e d l e s s F r u i t s o f T h re e Tomato T a r i © t i e s W ith Hormone S p r a y T r e a tm e n ts • 1949*

T r e e t me n F u n g i ­ PCA C o n tro l : PCA & c id e # : F u n g i­ % seed*s e e d - : c id e V a rie tie s le ss : le s s lb s* lb s. ;lb s. lb s. a c r e a c r e acre îacre 484

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3300

F v a l u e f o r t r e a t m e n t s and f o r v a r i e t i e s s i g n i f i c a n t a t t h e 1 p e r cen t le v e l* F v a lu e f o r i n t e r a c t i o n of tre a tm e n ts x v a r i e t i e s n o t sig n ific a n t*

as w e re l a r g e I n e r e a s e s ip. y i e l d f o r horm one t r e a t m e n t s op a l l t h r e e v a r i e t i e s »

T h is i s p a r t i c u l a r l y

i n t e r e s t i n g s i n c e t h e t r e a t m e n t s w e re a p p l i e d t o t h e e n t i r e p la n t*

In a d d itio n ,

t h e hormone p l u s f u n g i c i d e t r e a t m e n t s

w ere j u s t a s e f f e c t i v e a s t h e hormone t r e a t m e n t s a lo n e * The i n t e r a c t i o n o f v a r i e t i e s x t r e a t m e n t s was n o t s i g n i f i c a n t w h ic h i n d i c a t e s t h a t th e horm o n es w ere e q u a l l y e f f e c t i v e on a l l v a r i e t i e s .

Went an d G o sp e r (3 0 ) and

W ittw e r , S t a l l w o r t h , and H o w ell (3 8 ) o b s e r v e d t h a t t h e tim e I n t e r v a l s fro m s e e d i n g t o a n t h e s i s and fro m f r u i t s e t t o m a t u r i t y v a r i e d o n l y a few d a y s b e tw e e n e a r l y , m i d s e a s o n and l a t e v a r i e t i e s .

T h ey s t a t e d t h a t th e d a t e when t h e

f i r s t f r u i t s e t o c c u r r e d v a r i e d c o n s i d e r a b l y b e tw e e n v a r i e ­ t i e s d e p e n d in g on n i g h t t e m p e r a t u r e s .

The d a t a i n T a b le 3 ,

h o w ev e r, show t h a t t h e e a r l y v a r i e t i e s . V a l i a n t and J S a r l i ­ an a X V a l i a n t p r o d u c e d much g r e a t e r y i e l d s w i t h th e horm ones* S in c e a l l v a r i e t i e s were s t a r t e d t o g e t h e r and grown u n d e r i d e n t i c a l c o n d i t i o n s and s i n c e no i n t e r a c t i o n e x i s t e d f o r hormone t r e a t m e n t s x v a r i e t i e s , t h e r e a p p a r e n t l y was some d i f f e r e n c e i n tim e o f a p p e a r a n c e and number o f f lo w e r s o c c u r r i n g b e tw e e n t h e d i f f e r e n t v a r i e t i e s .

•

The r e s u l t s do

show t h a t t h e h o r m o n e - t r e a t e d R u t g e r s p l a n t s p ro d u c e d n e a r l y a s many f r u i t s a s d id u n t r e a t e d p l a n t s o f V a l i a n t * P r a c t i c a l l y a l l f r u i t s h a rv e ste d in th e f i r s t p ic k in g o f h o r m o n e - t r e a t e d p l a n t s o f a l l t h r e e v a r i e t i e s w ere s e e d l e s s , w i t h t h e number o f s e e d l e s s f r u i t s d e c r e a s i n g r a p i d l y

24

th ro u g h J u ly 23.

The p e r c e n t a g e o f s e e d l e s s f r u i t s

o lo se ly

a p p r o x im a te d t h e p e r c e n t a g e o f i n c r e a s e i n y i e l d w i t h h o r w mone t r e a t m e n t s .

T h is i n d i c a t e s t h a t th e e f f e c t o f th e

hormone s p r a y s was i n t h e p r o d u c t i o n o f f r u i t s w i t h o u t s e e d s w h ic h w ou ld n o t h a v e s e t n a t u r a l l y .

H ow ever, t h e te m p e r a ­

t u r e r e c o r d shown i n F i g u r e 2 shows t h a t minimum t e m p e r a t u r e s w ere i n t h e r a n g e o f t h o s e w h ich w ere o b s e r v e d b y Went and . G o sp er (2 0 ) a s b e i n g f a v o r a b l e f o r e a r l y to m a to f r u i t s e t , F i g u r e 5 shows t h e i n t e r n a l c o l o r i n g o f some o f t h e s e e d l e s s f r u i t s h a r v e s t e d fro m h o r m o n e - t r e a t e d p l a n t s .

The

g r e e n p u l p seem ed t o b e a s s o c i a t e d w i t h s e e d l e s s f r u i t s . The g r e e n p u l p , w h ic h o c c u r r e d i n t h e e a r l y s t a g e o f r i p e n ­ in g , alm o st c o m p le te ly d is a p p e a re d a t th e f u l l r i p e s ta g e a s shown i n t h e same f i g u r e , F i g u r e s 4 , 5 , and 6 show t h e am ount o f f r u i t s e t w h ich o c c u r r e d on t h e f i r s t f r u i t c l u s t e r f o l l o w i n g horm one t r e a t ­ m ents o f PCA, BNOA and t h e c o n t r o l r e s p e c t i v e l y ,

%here w ere

more f r u i t s s e t and t h e y w ere somewhat l a r g e r i n s i z e on t h e t r e a t e d p l a n t s a s com pared t o t h e u n t r e a t e d p l a n t s . As shown i n T a b le 5 t h e c o n t r o l p l a n t s gave a s g r e a t a y i e l d f o r t h e e n t i r e p e r i o d t h r o u g h A ug ust 5 a s d id t h e h o r ­ mone t r e a t m e n t s .

N a t u r a l f r u i t - s e t a p p a r e n t l y o c c u r r e d on

t h e s e c o n d and s u b s e q u e n t f l o w e r c l u s t e r s a s w e l l a s , i f n o t b e t t e r t h a n , w i t h horm one s p r a y s . i n t h e t o t a l y i e l d o f to m ato f r u i t s

T h e re was no d i f f e r e n c e t h r o u g h S e p te m b e r 20

fro m R u t g e r s b e tw e e n h o r m o n e - t r e a t e d and u n t r e a t e d p l a n t s .

35

110

i 3

§ Q

■ 50 -

40

JUNE

P E R IO D

F i g u r e 3 . Maximum an d minimum te m p e r a ­ t u r e s d u r i n g p e r io d when b o t h e a r l y m a r k e t and c a n n in g to m a to v a r i e t i e s w ere s e t t i n g f r u i t . L a fa y e tte , In d ia n a . 1949♦

figure 3. Tsrpical internal color of a pink ripe fruit (left) and a completely ripe fruit produced with hormones. The fruits have no seed.

figure 4. fruit set on the first cluster of a plant of farliane X Valiant follow ing whole-plant sprays of 30 ppm of 2 ,-chlorophenoxyacetic acid*

figure 5. fruit set on the first cluster of a plant of farliana X Valiant follow­ ing whole-plant sprays of 50 ppm of ti-naphthoxyacetic acid*

29

Figure 6» Fruit aet on the first cluster of a control plant of Farliana X Valiant*

The Marketable and Total Yields Through August 5 of Three 1er la ties of Tomatoes Receiving Hormone and Hormone Hus Fungicide Treatments. 1949.

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m m b e e 3*

E a r l y M a rk e t Hormone ^ e s t i n

n o r th e r n I n d ia n a . 1949. I n a o o p e r a t i o n w i t h t h e A s s i a t a n t C o u n ty A g e n t, Lake C o u n ty , Crown P o i n t , I n d i a n a , an e x p e r i m e n t was e o n d u o te d t o d e t e r m i n e t h e v a l u e o f PCA f o r im p ro v in g t h e f r u i t s e t on e a r l y m a r k e t t o m a to e s i n n o r t h e r n I n d i a n a . t h e v a r i e t i e s t e s t e d w ere S o u t h l a n d , 2 1 , R u t g e r s , E a r l i a n a and E a r l i a n a X P r i t o & a r d (a n

h y b r id 1*

The f i r s t

t h r e e v a r i e t i e s w ere s e n t t o t h e H o r t i c u l t u r e D e p a r t m e n t , P u rd u e U n i v e r s i t y , b y t h e A s s i s t a n t C o u n ty A g en t a s t h e t h r e e m ost p o p u l a r to m a to v a r i e t i e s i n t h a t c o u n t y .

2 1 indi**

c a t e s a n unnamed v a r i e t y s e l e c t e d by a Lake C o u n ty to m a to g ro w e r,

E a r l i a n a was s e l e c t e d b e c a u s e o f e a r l i n e s s ; how ever*

th e q u a l i t y i s p o o r .

The t o m a t o h y b r i d u s e d h a s b e e n

recommended f o r e a r l y m a r k e t p r o d u c t i o n . The s e e d s o f t h e f i v e v a r i e t i e s w ere p l a n t e d on A p r i l 8 a t L a f a y e t t e , I n d i a n a , and t h e p l a n t s * a f t e r b e i n g h a r d e n e d i n a c o l d f r a m e , w e re t r a n s p o r t e d to Lake C o u nty and p l a n t e d i n t h e f i e l d on May 3 1 , 1 9 4 9 .

The v a r i e t i e s and t h e horm one

and c o n t r o l t r e a t m e n t s w ere a r r a n g e d i n a s p l i t - p l o t d e s i g n w i th t r e a t m e n t s m aking up t h e s u b p l o t s a n d v a r i e t i e s fo rm ­ i n g th e m ain p l o t s . The horm one s p r a y was a p p l i e d to f l o w e r c l u s t e r s o f a l l v a r i e t i e s when two o r m ore f l o w e r s o f t h e f i r s t c l u s t e r h ad opened on a n y v a r i e t y .

The f i r s t s p r a y was a p p l i e d on

Ju n e 1 8 , 1 9 4 9 , w i t h two a d d i t i o n a l s p r a y s a p p l i e d a t w e e k ly in te rv a ls.

52

T a b l e 4 shows t h a t l a r g e i n c r e a s e s i n e a r l y y i e l d w ere p ro d u c e d fro m h o r m o n e - t r e a t e d p l a n t s ; h o w e v e r, t h e r e was no i n c r e a s e i n t h e y i e l d t h r o u g h A u g u s t 2 2 ,

E a rly v a r ie ­

t i e s g av e s i g n i f i c a n t i n c r e a s e s i n y i e l d o v e r l a t e r v a r i e -