Table 1. Ethephon usage at the Horticultural Research Center 

 of application and harvest date. 



Date 



Application date Harvest date 



Days from 

 application to harvest 



August 20, 1974 



August 27, 1975 



August 16, 1976^ 



August 23, 1977 



August 30, 1978^ 



August 20, 1979 



August 29 



September 2 



August 2 5 



September 2 



September 7 



August 29 and 

 September 3 



9 

 6 



9 



10 



8 



9 

 14 



y 



1 pint of ethephon + 20 ppm 2,4,5-TP 



Applied earlier than usual because fruit were needed in late August 



Application date was delayed because of rain. 



Edward Roberts and Sons, Hillside Orchard, Granville . The Roberts' 

 harvest 10 ,000 to 12,000 bushels of ethephon- treated Mcintosh 

 apples each fall for immediate sales. Beginning the last week of 



August or the first week of September, they apply ethephon to 

 ferent set of trees every 2 or 3 days, depending upon the wea 



a dif- 

 ther . 



In 1979, the first 2 sprays of ethephon were applied at 1/2 

 pint per 100 gallons of water at IX (Table 2). (However some years 

 only 1/3 pint of ethephon per 100 gallons of water was used on the 

 earliest spray dates. The higher rate was used in 1979 in order to 

 enhance a quicker response.) The next 5 ethephon sprays in 1979 were 

 applied at 1/3 pint. Sprays applied September 4 or later were applied 

 at 1/4 pint. 



NAA at 10 ppm is used with the ethephon sprays for pre-harvest 

 drop control. They prefer NAA because it hastens ripening less than 

 2,4,5-TP. 



The ethephon-sprayed fruit are examined twice daily, starting 5 

 days after spraying, to determine color development . The fruits are 

 harvested when they obtain 50 to 601 red color , which is generally 

 6 to 7 days after the ethephon application (Table 2) . (They believe 

 that by waiting for more color, condition on the retail counter is 

 sacrificed. ) 



