• Korean Journal of Plant Resources
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• v.31 no.1
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• pp.71-76
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• 2018

This study was conducted to investigate the effect of shoot twist on fruitfulness and fruit quality of 'Campbell Early' grapevine. Proper pruning and training are essential to produce a good yield of high-quality fruit and to maintain the balance between vegetative growth and fruiting. The most common problem in spur-pruned 'Campbell Early' cultivar is that vigorous buds has low fruitfulness and thereby the shoot become more vigorous the following spring because of lower crop load. Therefore, shoot twists in very vigorous 'Campbell Early' canes (above 10.0 mm) were performed on the third nodes and the $7^{th}$ nodes of each shoot at 7 days before bloom and full bloom, respectively. Sprouting date, blooming date were not significantly different among the treatments while, harvesting date was delayed approximately 3 days. However, number of berries per cluster, cluster weight and fruitfulness were significantly higher in the shoot twist treatment on the third nodes than the control that was topping alone. Combination treatments of shoot twist and topping had an additive effect on increasing cluster weight resulting in higher increase of yield by 12.1 ㎏ per vine. These results indicated that the shoot twist on very vigorous canes of 'Campbell Early' grapevine for well fruitfulness seemed to be very effective.