Thinning apples and stone fruit with the naturally occurring compound 1-aminocyclopropane carboxylic acid

S. McArtney, P. Petracek, P. Francescatto, K. Forney
There is a need to identify and commercialize new flower and fruit thinning agents for crop load management in apple (Malus × domestica Borkh.) and stone fruit production systems. 1-aminocyclopropane carboxylic acid (ACC) is the immediate precursor of ethylene in plants and the active ingredient in a new flower and fruit thinning agent registered by the United States Environmental Protection Agency. Data are presented to demonstrate the thinning activity of ACC application to apples during the normal window for fruitlet thinner applications (10-12 m fruit diameter) and at a late stage when fruit are less sensitive to thinners (18-20 mm). Surprisingly, the thinning activity of ACC on ‘Gala’ apples was higher at the later application timing. Application of ACC to various peach and nectarine (Prunus persica) cultivars during bloom reduced fruit set and the time required for hand thinning, and increased fruit weight at harvest compared to a hand thinned control. These results suggest that ACC can provide apple and stone fruit growers with a new tool for crop load management that has unique benefits.
McArtney, S., Petracek, P., Francescatto, P. and Forney, K. (2022). Thinning apples and stone fruit with the naturally occurring compound 1-aminocyclopropane carboxylic acid. Acta Hortic. 1344, 23-28
DOI: 10.17660/ActaHortic.2022.1344.5
https://doi.org/10.17660/ActaHortic.2022.1344.5
ACC, ethylene precursor, fruit set, peach, nectarine, apple
English

Acta Horticulturae