FRUIT THINNING WITH CHEMICAL SPRAYS 



21 



Table 6. — Effectiveness of naphthaleneacetic acid sprays for thinning 

 certain varieties of apples — Continued 



Variety 



Jonathan: 

 Orchard 1 _ . 



Do___ 



Orchard 2_. 



Orchard 3_. 



Orchard 4 _ . 

 Orchard 5 _ . 



Northern Spy. 



Rome Beauty: 



Orchard 1 _ . 



Do___. 



Do_... 



Do_-_. 

 Orchard 2__ 



Wealthy 



Do 



Do 



Winesap: 

 Orchard 1 _ . 



Do___. 



Orchard 2 . 

 Orchard 3. 

 Orchard 4. 



Year 



1948 



1949 



1948 



1948 



1949 

 1949 



1947 



1946 



1947 



1948 



1949 

 1949 



1945 



1946 



1947 



1946 



1948 



1946 

 1948 

 1948 



Spray 

 concen- 

 tration 



Growth stage 

 when applied 



Calyx 



do.___ 



do_.__ 



do____ 



do____ 



do_-__ 



do____ 



First cover 



Calyx 



do____ 



do.___ 



Full bloom _ 

 Calyx 



do 



12 days after 



calyx. 



Calyx 



do 



____do 



do 



do 



Early calyx _ 



do 



do 



Calyx 



do 



12 days after 



calyx. 



do 



Early calyx - 

 Calyx 



Full bloom. _ 



Calyx 



do 



do 



Full bloom __ 



Calyx 



___ldo 



Fruits 



per 100 



blossoming 



spurs 



Check 



Number 



67 

 79 

 79 

 79 

 62 

 33 

 33 

 33 

 69 

 77 

 77 

 46 

 46 



48 

 48 



53 

 36 

 36 

 67 

 84 

 26 

 40 

 34 

 60 

 60 

 60 



60 



68 



96 

 96 

 72 

 72 

 54 

 54 



Sprayed 



Number 



38 

 76 

 72 

 62 

 42 

 27 

 8 

 18 

 36 

 53 

 48 

 27 

 23 



54 

 47 



4 

 33 

 39 

 57 

 70 

 16 

 20 



7 

 40 

 51 

 34 



31 

 59 



27 



87 



84 



18 



1 



25 



1 



1 



Reduc- 

 tion 

 in 

 fruit 



set 



Percent 



43 



4 

 9 

 22 

 32 

 18 

 76 

 45 

 48 f 

 31 

 38 

 41 

 50 



92 

 8 

 

 15 

 16 

 38 

 50 

 79 

 33 

 15 

 43 



48 

 13 

 60 



10 

 12 

 75 

 99 

 54 

 98 

 98 



State and 

 literature 

 reference 



Washington. 



New York. 



►New York (00), 

 New York (39). 



>New York. 

 Michigan (41). 



New York {22). 



>NewYork (89). 



> Washington (5) . 



> Washington. 

 Washington (5). 



> Washington. 



About 2 weeks after calyx period. 



somewhat stronger concentration than those that set lighter. How- 

 ever, this does not always hold. For example, Duchess, which is 

 a heavy-setting variety, can usually be thinned satisfactorily with 

 a weaker concentration than is required for Wealthy. 



Some of the data in table 6 indicate that, under a given set of con- 

 ditions, the same concentration thins somewhat heavier when applied 



