576 Effects of NAA-800 and Retain on Fruit Retention and Quality of `Rome Beauty' and `Delicious' Apples

Abstract

Effects of various combinations of NAA-800 and Retain on fruit retention, yield, and harvest and post-storage fruit quality of `Rome Beauty' and `Delicious' apples were studied over one to three seasons. Retain and NAA-800 often reduced preharvest fruit drop as compared to control. Fruit from trees that received Retain at 123.6 g a.i./ha, or 61.8 g a.i./ha plus NAA-800 showed lower starch degradation pattern (SDP) at harvest and higher firmness. Retain treated fruit had lower evolved ethylene and respiration. Application of Retain at 61.8 g a.i./ha plus NAA-800 delayed fruit maturity, and the effects on fruit quality at harvest was comparable to the effects of this chemical at 123.6 g. a.i./ha. However, after storage, fruits from trees receiving Retain at 123.6 g a.i./ha often were firmer. Split applications of NAA-800 did not show major improvement in delaying fruit maturity over a single application. Application of NAA-800 at 585 mL/ha tended to reduce fruit firmness and increase fruit SDP. These fruits some times tended to have better color. Results on fruit color varied from year to year.