FRUIT NOTES - July & August 1953 



HORl'/iONES FoR PF.EHARVEST DROP COriTROI, 



l.'ith a good crop of Mcintosh on the trees this year, growers are expected to 

 be interested in keeping the drop of sound apples at a minimum. There was a time 

 when one had only a single stop-drop material (naphthalene ace tic acid - NAA) but now 

 one can make a choice between two or possibly three materials. The materials 2,ii,5- 

 TP (Color--Set, Color-Lok, Color-Stik, etc.) has been available for the past two 

 years and many of you are acquainted with it. In addition, a new material, 2,U,'?-T , 

 ivill be available froTi at least one source this fall for trial use on Mcintosh only . 

 A discussion of each material follows: 



InIAA 



trated. 



1. Apply just as the drop of many-seedea, blemish-free fruit commences, 



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



3. Used at single or double strength {k to 8 oz. per 100 gallons), it will 

 reduce the rate of drop from 7to 12 days on Mcintosh, If single strength is ueed, 

 longer holding can be obtained by repeat applications every 5-7 days. It causes less 

 direct ripening to fruit than 2,it,5-TP but the higher the concentration of NAA used 

 and the greater the number of applications the greater the ripening effect. 



5. It is still a good material for l.iclntosh if it has given satisfactory 

 control in the past and the block can be picked within 7to 12 days after spraying, 



2,U,5-TP 



1. For best drop control of dclntosh apply when drop commences (same timing 



as NAA). 



2. When used at 20 ppm (read the label) it will reduce rate of drop for 

 about 3 weeks after application on Mcintosh. Do not use higher concentrations. 



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

 if available. It may be concentrated safely up to 3X. 



U. If you want a good storage Mcintosh apple, pick the fruit within 2 weeks 

 of spraying, even thouj^h fruit is not dropping, to keep ripening effect at a minimum, 



5. For drop control on late varieties such as Baldwin, Rome, and Delicious, 

 apply before the leaves become injured by frost. It can be applied to such varieties 

 2 or Ii vreeks before harvest, 



6, If used to hasten ripening and improve color of early and midseason 

 varieties, apply about 3 weeks ahead of harvest date. Apples from trees high in 

 nitrogen mil be ripened more than fruit from trees at lower nitrocen levels . Do not 

 use 2,U,5-TP for improving color on regular Gravenstein, Duchess, and Milton since 

 color is not greatly improved and the fruit may become mushy and worthless. It has 

 been used for this purpose with some success on Early Mcintosh and liYealthy, To 

 hasten ripening of late apples apply 5 to 6 vreeks ahead of harvest. Beware of over- 

 ripeness, splitting, and water-core when used as a ripener . The ripening effect is 



