1-Aminocyclopropane Carboxylic Acid Shows Promise as a Chemical Thinner for Apple

• Published in: HortScience Vol. 47; no. 9; pp. 1308 - 1311
• Main Authors: SCHUPP, James R, KON, Thomas M, WINZELER, H. Edwin
• Format: Journal Article
• Language: English
• Published: Alexandria, VA American Society for Horticultural Science 01.09.2012
• Subjects: Agronomy. Soil science and plant productions; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Agricultural chemical product; biennial bearing; 1-Aminocyclopropanecarboxylic acid; Cyclopropane derivatives; Horticulture; Rosaceae; Malus ×domestica; Climacteric; Malus domestica; Defruiting; Temperate zone; Organic acids; Abscission; fruit thinning; crop load; Carboxylic acid; Dicotyledones; chemical thinner; Angiospermae; Plant growth substance; Flowering; Biosynthesis precursor; Fruit tree; Ethephon; Organic compounds; Cultural practice; ACC; flower initiation; Floral initiation; Pome fruit; Organic phosphonate; fruit abscission; α-Aminoacid; Apple; Metabolic precursor; Fruit crop; Aminoacid; agrichemicals; Spermatophyta; Plant thinning
• ISSN: 0018-5345; 2327-9834
• DOI: 10.21273/hortsci.47.9.1308

The objective of these studies was to evaluate the efficacy of several concentrations of 1-aminocyclopropane carboxylic acid (ACC) for thinning apple at the standard growth stage for chemical thinning timing and a late thinning growth stage. ACC was applied at concentrations of 0, 100, 300, or 500 mg·L −1 to ‘Golden Delicious’/Bud.9 apple trees at 10 mm or 20 mm fruit diameter. Treatments were applied to the point of drip to individual whole trees in a completely randomized design with five (2010) and six (2011) replications. When ACC was applied at 20 mm, there was a linear dose relationship between concentration and fruit thinning in both years. ACC was ineffective at 10 mm. The naturally occurring compound ACC shows potential for use as a reliable late chemical thinner for apple.