The effect of Aminoethoxyvinylglicine (AVG), available commercially as Retain®, was evaluated in Fuji Suprema apples during four growing seasons. The application time and the concentration of AVG in a single or multiple sprays were studied to evaluate the effect of AVG on fruit ripening delay, preharvest drop control, fruit production, mean fruit weight, fruit firmness, soluble solids, total iodine-starch, fruit skin color, 'water core' incidence, fruit crack and sun scald incidence. The AVG was applied one, two, four weeks before the harvest point and at harvest time in concentrations ranging from 60 to 120 g ha-1. All treatments delayed fruit ripening, and applied twice and one week before the harvest point concentrated on the same harvest date. The maturation delay was accompanied by the maintenance of firmness and starch degradation. The mean fruit weight increased significantly compared to the control treatment. The development of fruit red color was delayed in proportion to the maturation delay. The AVG applications with different concentrations and application times in one or two times did not differ in relation to fruit drop before harvest in 'Fuji' apples, but all treatments with AVG were significantly lower than the control treatment.
Malus domestica; growth regulator; harvest management; fruit abscission; fruit quality
