Renewal Method of Lateral Branches Using Water Sprouts in Japanese Apricot

Abstract

Recently, the acreages Japanese apricot have been increased for being known of the medical functions. However, the increase of tree height, overgrowing trees and light deficiency at the bottom of canopy induced the poor fruit quality and higher labor charges. This study was conducted to assess the effects of training time, angle and length of water sprout on tree growth, the shoot-curbing, and the occurrence of new shoot for 2 years. Water sprouts were trained on 5, and 25 June, and 15 July with three varying angles of 30°, 45° and 60°, and cut at three lengths (50, 80, 110_) after harvest. Compared to control, the treatment on June 25 showed the highest values of 76%, 82% of internode and shoot length respectiely. In the treatment of training angle, shoot length was 71% in both 30° and 45° but heavily limited to 36% in 60° with comparing to control. The occurrence of shoots showed 18.1, 24.6, and 36.3 in treatment of 50, 80 and 110 cm, respectively, and in 80 cm, the number of shoot with diameter more than 0.5 mm, which is suitable for bearing mother branch, was higher. The best result was obtained in method of branch training with 45° and heading-back 80 cm at height on 15 June for the renewal of lateral branch.