2025 Volume 24 Issue 1 Pages 45-52
We investigated the effects of the intentional alternate bearing method on fruit weight, shoot structure, leaf photosynthetic ability, and carbohydrate content of the leaf in loquat (Eriobotrya japonica (Thunb.) Lindl.) cultivar ‘Mogi’ from 2019 to 2022. The treated (intentional alternate bearing) trees were divided into fruit-producing (fruiting shoot) and non-fruit-producing (non-fruiting shoot) areas, and compared with non-treated (conventional bearing) trees. Fruit weight was heavier on the treated trees than non-treated trees in all years, and this influenced the fruiting quantity per tree in 2019. In contrast, the numbers of fruit clusters and total shoots per tree were higher than on non-treated trees in 2021. This suggests that the intentional alternate bearing method for loquat can increase the fruit weight compared with the conventional bearing method. The shoot diameter and number of leaves were influenced by the interaction between treatments and years, with different effects between the groups. Although the total yield for three years was almost the same between treated and non-treated trees, the yearly yield increased progressively in treated trees. It is considered that the increase in the number of shoots from adventitious buds, resulting in an increased number of fruit clusters in treated trees. Photosynthetic rates, stomatal conductance, and transpiration rates of fruiting shoot leaves in treated trees were higher than those of non-fruiting shoots and non-treated trees. The Sum of the starch and sugar contents was the highest in non-fruiting shoot leaves of non-treated trees and the lowest in fruiting shoot leaves of treated trees. These findings suggest that the photosynthetic ability of the fruit-producing area was related to the increase in fruit weight, and carbohydrate accumulation in non-fruit-producing areas was related to fruiting and fruit quality.
