Chemical Fruit Thinning with Armothin(R) Sprays to Reduce Fruit Set in `Loadel' Cling Peach

• Published in: HortScience Vol. 30; no. 4; p. 854
• Main Authors: Southwick, Stephen M, Yeager, James T
• Format: Journal Article
• Language: English
• Published: 01.07.1995
• ISSN: 0018-5345; 2327-9834
• DOI: 10.21273/HORTSCI.30.4.854B

Hand-thinning is required every season to ensure large fruit size of `Loadel' cling peach in California. Hand-thinning is costly. Chemical thinning could help to lower costs of hand-thinning. Armothin® {[ N,N -bis2-(omega-hydroxypolyoxyethylene/polyoxypropylene)ethyl alkylamine], AKZO-Nobel, Inc., Chicago; AR} was sprayed at 80% of full bloom (FB), FB and FB + 3 days. The spray volume was 935 liters·ha –1 . Concentrations of AR were 1%, 3%, and 5% AR applied at FB. No damage to fruit was noted. Leaf and fine shoot phytotoxicity were seen at 5% AR. The amount of time needed and number of fruits thinned were reduced by those same treatments. Salable yield and fruit size after AR treatments equaled those found on hand-thinned controls. Armothin® shows promise for chemical thinning of peach when used as a bloom spray that damages flowers, thereby reducing fruit set. An experimental use permit was issued for use of AR for stone fruit thinning in California during 1995.