Repeated applications of NAA control preharvest drop of ‘Delicious’ apples

Abstract

‘Delicious’ apple (Malus domestica Borkh.) trees were treated with NAA, at concentrations of 0-20 mg I“1,7 d before harvest, or on five occasions during the final 60 d before harvest. Although the response varied with the experiment, repeated NAA applications delayed fruit abscission more than single applications, but two or three applications were as effective as five. Five applications of NAA at concentrations of 5-20 mg T1 had little influence on flesh firmness, soluble solids concentration, or starch index at harvest or after four months of storage.