20 CIRCULAR 867, U. S. DEPARTMENT OF AGRICULTURE 



Table 6. — Effectiveness of naphthaleneacetic acid sprays for thinning 

 certain varieties of apples 



Variety 



Baldwin: 

 Orchard 1. 



Orchard 2 . 



Delicious: 

 Orchard 1 



Orchard 2. 

 Orchard 3. 



Delicious: 

 Orchard 1 _ _ 



Do. 



Orchard 2__ 

 Orchard 3 _ - 

 Orchard 4__ 



Duchess 



EarlyMcIntosh: 

 Orchard 1 



Orchard 2___ 



Golden 



Delicious: 

 Orchard 1 



Orchard 2___ 



Do 



Golden 



Delicious: 

 Orchard 1 _ . 



Do__ 



Orchard 2. 

 Do._ 





Spray 



\ear 



concen- 





tration 





P.p. m. 



1947 



1 10 

 \ 20 





1947 



20 





5 



1946 



10 





10 



1947 



/ 7 



1947 



10 





( 10 





10 



1946 



1 15 





20 





> 30 





10 



1948 



20 





20 



1948 



15 



1948 



f 10 



\ 20 



1948 



15 





1 10 



1945 



15 





( 20 



1948 



20 



1948 



20 

 1 50 



1948 



( 15 

 \ 20 



1948 



15 



\ 20 



1949 



20 



1945 



15 



1946 



/ 15 

 I 15 



1946 



J 15 

 \ 15 



1948 



J 20 

 { 20 



Growth stage 

 when applied 



Fullbloom__. 



Calyx 



do 



do 



do 



9 days after 



calyx. 

 Full bloom. __ 



Calyx 



do 



Full bloom _ _ 



Calyx 



do 



do 



do 



do 



do 



First cover *_ 



Calyx 



do 



do 



do 



do 



do 



do 



Early calyx __ 



Late calyx 



21 days after 

 calyx. 



Calyx 



do____. 



do 



do 



do 



Full bloom. 



Calyx 



Full bloom. 



do.___ 



Calyx 



do..._ 



First cover 



Fruits 



per 100 



blossoming 



spurs 



Check Sprayed 



Number 



33 

 33 

 26 



53 

 53 

 53 



64 

 64 

 33 



55 

 55 

 55 

 55 

 55 

 66 

 66 

 66 

 64 

 42 

 42 

 66 

 24 

 19 

 19 



32 

 50 

 50 



41 

 41 

 59 

 59 

 63 



109 



109 



99 



100 



100 



94 



94 



Number 



20 

 19 



35 

 24 

 30 



19 



17 



2 



51 

 44 

 38 

 27 

 11 

 45 

 14 

 43 

 29 

 10 

 1 

 6 



18 

 15 

 13 



3 

 35 



12 



31 

 23 

 28 

 32 

 30 



69 

 67 



73 

 91 

 75 

 32 

 36 



Reduc- 

 tion 



fruit- 

 set 



Percent 



39 



42 

 69 



34 

 55 

 43 



70 

 73 

 94 



7 

 20 



31 

 51 

 80 

 31 

 79 

 34 

 54 

 76 

 98 

 91 

 25 

 21 

 36 



90 

 30 



76 



24 

 44 

 52 

 46 

 52 



37 

 38 

 26 

 9 

 25 

 (56 

 62 



State and 

 literature 

 reference 



New York (39). 



> New York {22). 

 r NewYork(S0). 



Washington(5). 



Washington. 

 Michigan (41 ) . 



Massachusetts 



' (40). 



New York. 



•Washington(J) 

 •Washington 



