Organic Aminoethoxyvinylglycine Is an Effective Alternative for Reducing Apple Preharvest Drop

Organic apple ( Malus × domestica Borkh.) growers lack effective strategies to manage preharvest drop. For susceptible cultivars, yield losses caused by drop can exceed 30% at the beginning of harvest. To address this issue, a formulation aminoethoxyvinylglyine (AVG) designed for organic use was developed and compared with commercially available AVG formulation. We evaluated effects interactions application number on fruit maturity in 2017 2018. selected 30 pairs mature ‘Oregon Spur II Red Delicious’/‘M. 111’ trees planted Mountain Horticultural Crops Research Extension Center Mills River, NC, USA. Trees were spacing 2.7 6.1 m, trained central leader, received plant protectant sprays that adhered local recommendations throughout growing season. Both formulations applied 132 mg⋅L −1 3 or + 1 weeks before anticipated An untreated control also included comparison. The experiment had six replicates randomized complete block design 2 augmented factorial treatment structure. A one-way analysis variance performed single degree freedom contrasts used compare groups interest. During both years, conventional equally reducing delaying softening starch hydrolysis one year, increasing applications reduced cumulative drop, delayed harvest, internal ethylene concentrations. Inconsistencies responses across years may be explained, part, abnormally warm temperatures observed approved appears promising management technology efficacy similar AVG.