2019 ASHS Annual Conference

Fruit set is low in olives. Olives produce an abundant number of flowers, 10% to 25% of which remained after petal drop and set fruit. Major fruit drop occurs during the 5-7 weeks after full bloom, leaving a final fruit set of 1% to 2%. One hypothesis of low fruit set in olives is that the short life-span of olive flowers limits the stigma receptivity, ovule longevity, and effective pollination period (EPP). Ethylene is involved in multiple aspects of floral senescence an abscission. Amionoethoxyvinylglycine (AVG), an active ingredient of ReTain(TM), acts as an ethylene inhibitor. AVG competitively inhibit the activity of ACC (1-aminocyclopropanecarboxylate) synthase, which is a key enzyme in the ethylene biosynthesis pathway. The purpose of this study is to evaluate the effects of ReTain(TM) (AVG) application at bloom on flower ethylene production, flower longevity, fruit set, and yield of oil olive trees.