Abstract
We designed a method of limb girdling with renewal pruning included in cane pruning to improve the pigmentation of berry skin, and avoid a decrease in tree vigor due to the girdling treatment in ‘Queen Nina’ grape. The pigmentation of berry skin with a 12-mm girdling treatment on primary scaffold limbs at 35 days after full bloom was superior to a 4-mm girdling or control non-girdling treatment (girdling was performed for the renewal pruning trees). The cluster number per shoot was significantly increased in trees undergoing renewal pruning, compared with cordon-spur pruning. The berry weight from trees with renewal pruning was significantly lower than in those with cordon-spur pruning. Berry skin pigmentation was superior in the girdling-treatment trees, but there was no significance in the pruning methods. The carbohydrate concentration was significantly higher in the 2–5-mm-diameter roots on the girdling of renewal pruning trees than that of cordon-spur pruning trees. Renewal pruning may be effective to relieve the root stress of poor nutrient accumulation by girdling treatment of the primary scaffold limbs.
