Department of Horticultural Science, Kyungpook National University1
Planning and Coordination Division, National Institute of Horticultural and Herbal Science, RDA2
Apple Research Institute, National Institute of Horticultural and Herbal Science, RDA3
Fruit Research Division, National Institute of Horticultural and Herbal Science, RDA4
College of Agriculture and Life Science, Kyungpook National Unviersity5
Department of Herbal Medicine Resource, Kangwon National University, Dogye Campus6
7Department of Horticultural Science, Chonbuk National University7
Department of Horticultural Science, Mokpo National University8
This study investigated the effects of flower and fruit thinning agents on fruit set and harvested fruit quality attributes in ‘Gamhong’ apples. Lime sulfur, MaxCel (1.9% BA), and Fruitone (3.5% NAA) were applied either at post-bloom or fruitlet stages to mature ‘Gamhong/M.9’ trees. In 2011, the numbers of fruits per cluster in terminal flowers were 1.74, 0.82, and 1.15 for the control, lime sulfur, and Maxcel (applied at 10-mm fruit stage) treatments, respectively. The percentages of single fruit per cluster were 36.0, 47.9, and 48.7% for the control, lime sulfur, and Maxcel (10 mm) treatments, respectively, while the percentages of clusters with three fruits per cluster were 22.9, 1.4, and 5.8%. In lateral flowers, fruit numbers per cluster were 1.20, 0.36, and 0.50 for the control, lime sulfur, and Maxcel (10 mm) treatments, respectively. In 2012, all the thinning treatments showed a positive effect on flower and fruit thinning, compared with the control. Moreover, the treatment with thinning agents did not affect fruit quality. Overall, the results suggest that a single application of flower or fruit thinning agents would be sufficient, rather than the mixed application of thinning agents, based on the observed decrease in fruit setting.
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