1997 Volume 66 Issue 2 Pages 273-281
Effects of ethephon application on the fruit ripening of 'Hayward' kiwifruit [Actinidia deliciosa (A. Chev.) C. F. Liang and A. R. Ferguson var. deliciosa] on the vine were investigated.
In 1990, when 200 ppm ethepon (dissolved with 50% ethanol) was applied at approximately 6-, 5-, 4-, 3-, 2- and 1-week prior to commercial harvest, the 4- and 3-week treatments made the fruits edible. Brix, flesh firmness, and titratable acidity of the fruits were about 13%, 0.61.2 kg/cm2 and 1.11.2%, respectively. On the other hand, 50% ethanol application was ineffective on fruit ripening. When ethephon was applied at various concentrations 3 weeks before commercial harvest, the 50 and 100 ppm treatments were ineffective on fruit ripening, whereas the 500 ppm treatment hastened fruit ripening more than the 200 ppm treatment.
In 1991, when fruits were treated with 200 ppm ethephon, they did not ripen as fast and uniformly as they did in 1990. We attribute the difference to the lower air temperature and shorter duration of sunshine during the 1991 experiments. From the above results, we postulated that the air temperature and duration of solar radiation after ethephon application strongly affect the kiwifruit ripening on the vine.
