Co-Authors:
Fogelman, E., Department of Vegetable Research, Institute of Plant Sciences, ARO, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Redel, G., Mop-zafon, MIGAL, P.O. Box 831, Kiryat-Shmona 11016, Israel
Doron, I., Extension Service, Ministry of Agriculture, Kiryat-Shmona 10200, Israel
Naor, A., The Golan Research Institute, P.O. Box 97, Kazrin 12900, Israel
Ben-Yashar, E., Mop-zafon, MIGAL, P.O. Box 831, Kiryat-Shmona 11016, Israel
Ginzberg, I., Department of Vegetable Research, Institute of Plant Sciences, ARO, The Volcani Center, P.O. Box 6, Bet Dagan 50250, Israel
Abstract:
Russeting is one of the more important horticultural problems in apple (Malus X domestica) production worldwide. 'Smoothee' (cv. Golden Delicious), the major commercial strain grown in Israel, is susceptible to russeting. Israel's apple growing season is characterised by having a warm, dry climate, particularly during fruit set and the putative cell division stages of development. Treatment with gibberellins A4 and A7 (GA4+7) plus 6-benzyladenine (6-BA) to control russet formation has long been questioned, due to poor results in Israel. The efficacy of this hormonal treatment was re-evaluated following the induction of skin russeting by fogging trees and exposing fruit to high humidity. Fruit were most susceptible to fog-induced russeting up to 50 d after petal fall. (GA4+7) plus 6-BA treatment did not reduce fruit russeting dramatically. Multiple applications, beginning at petal fall, were effective only on fruit with slight russeting. Crop marketability was not significantly improved. Growers in a warm and dry climate, similar to Israel, should give serious consideration to the costly application of GA4+7 as a routine procedure to reduce or control russet on apples.