Q. 

 O 



a: 



Q 

 LU 



> 



< 



-J 



o 



100 



80 



60 



40 



20 







CONTROL 

 WASHOFF NONE 

 WASHOFF 1HR 

 WASHOFF 4 HR 

 WASHOFF 8 HR 



3 4 5 6 7 8 9 



WEEKS AFTER AVG APPLICATION 



10 



Figure 2. Effects of AVG as the ReTain formulation and simulated rain on ReTam-treated trees on cumulative 

 drop of Marshall Mclntosh/M.26 apples. 2000. 



application resulted m reduced drop control and a 

 modification of the reduction in red color and lowering of 

 soluble solids normally associated with ReTain use. In 

 2000, washing trees even as soon as 1 hour after application 

 resulted in no reduction in drop control and a minima! effect 

 on the intensity of red color as indicated by a small reduction 

 in the number of fruit that were judged to be US Extra Fancy. 

 Different fomiulations of AVG were used in the tAvo years 

 may have been a contributing factor. However, we believe 

 that the major factor responsible for the extreme rainfastness 

 demonstrated in 2000 was the use of Silwet. There are a 

 number of citations in the literature that demonstrate that the 

 use of Silwet with other agricultural chemicals imparts 

 rainfastness. 



In a previous report we emphasized tliat the use of a 

 recommended surfactant was important to achieve the 

 maximum response from ReTain. The results from this 

 investigation provide another convincing reason to use a 



recommended surfactant when applying ReTain. 



Based upon previous experience, the window of 

 opportunity to apply ReTain is reasonably wide. However, 

 weather during August can be quite fickle and very 

 unpredictable. It appears that the use of Silwet or possibly 

 Sylgard 309 with ReTain provides a certain amount of 

 insurance that if rain or a shower follows soon after 

 application, one can expect nearly 100% response to 

 ReTain. 



The commercial application of ReTain in 2000 

 confimied that ReTain is an effective drop-control 

 compound and harvest-management tool. It effectively 

 retarded preharvest drop for at least 7 weeks after 

 application, into early October, and significantly retarded it 

 well beyond that time. Further, it retarded the loss of flesh 

 firmness and delayed ripening, which would allow 

 scheduling of harvest or extending the harvest season in a 

 pick-your-own operation. 



ic 'k 'k ic i: 



60 



Fruit Notes, Volume 65, 2000 



