FRUIT NOTES 

 August 19^h 



HORIiQWV.S FOR PREHARVE5T D ROP C ONTROL OF APPU5S - 19^h REC0IIHENDATIONS 



There are no major changes In our suggestions for pre-harvest drop' con tfol of 

 apples i.'hon compared with those of a year ago. There is one ner<r materialj 2,h,<-trl- 

 chlorophenoxyacetamlde Vvhich is very effective for drop control, but it is so pronoun*- 

 oed a ripener that its use cannot be recommended at this time* 



Consequently, you' have a choice Of naphthaleneacetic acid (NAA), 2.h,'?-trichlorr 

 phenoxypropionic acid (2,it,5-TP) or 2,h,5^-.trichlorophenoryacetic acid (2,a,'?-T or 

 2,ii,5-TA), i'/e believe 2,li,5-TA is the best of the materials mentioned for I'clntosh 

 T/hen a gro\/er needs drop control beyond 2 weeks and wishes to have the least ripening' 

 of the fruit, NAA is still a good material for the grower who can harvest his Fclntosh 

 crop in 7-12 days, A discussion of each material follows! 



NAA 



1» Apply Just as the drop of 'many-seeded, blemish-free 'fruit commences,' 



2, It can be applied as dust, spray, or from airplanes. It can be concentra- 

 ted, 



3, Used at single (lOppm) or double (20ppm) strength (li-8 ozg'per 100 gallons), 

 it will reduce the rate of drop from 7-12 days on Mcintosh, If single 

 strength is used, longer holding can be obtained by repeat applications 

 every ^-7 dajro. It causes less direct ripening to fruit than 2,h,<-TP and 

 slightly less than 2,li,5«TA, but the higher the concentration of NAA used 

 and the greater the number of applications, the greater the ripening effect* 



1;, It is still a good material for '/clntosh if it has given satisfactory con- 

 trol in the past and the block can be picked vd-thin 7-12 days after spray- 

 ing* 



2^U^^-TA-For Mcintosh 



1, Apply vrhen drop commences, (Same timinfr as NAA) » 



2, Apply at 20 ppm (read label) as a spray, (It can be applied by airplane, 

 also , ) 



3, Vifill delay drop for mor6 than 3 weeks but not quite as effectively as 

 2,[i,5-TP for the first 3 weeks, ' ' 



U, 2,U,5-TA does not hasten ripening as much as 2,ii,'^-TP and not appreciably 

 more than NAA, Re member that the lon ge r a pp les bam, the softer they be - 

 Qome even if no Kornon e is us ed, P o nH le T ^he fruit, remain' unha r vest ed 

 xoo Iohf: if a' no'o'cf storane apple is " iiesired , 



5, 2,U,5-TA is not sugf^ested for other* varieties since experience with it on 

 anything but 'clntosh in the Northeast is limited, 



6, 2,U,5-TA is a brush killer at high concentrations so do not use it at con- 

 centrations above those suggested and do not use repeated applications. 



2,l4,.'?-TP 



1, For best drop control of 1 Mcintosh, apoly when drop commences (same timing 

 as NAA), 



2, llhen vised at 20 ppm (read the label) it \rill reduce rate of drop for about 

 3 weeks after application on "Iclntosh, ^o not use higher concentrations', 



3, Can be applied as a spray or from an airplane, Dust may be satisfactory, 



