Effects of Planting Density and Bearing-Branch Composition on the Yield of Sweet Cherry Grown by Hedge-row Training

Abstract

To improve the yield of sweet cherries (Prunus avium L.) grown by hedge-row training, the following two methods were compared: increased numbers of spurs and bouquet spurs to improve the spur composition and narrowed row intervals to increase planting density. To develop spurs and bouquet spurs, 30 cm long branches were positioned at 30 cm intervals on lateral branches in addition to the conventional spur development from 5 cm current shoots. Although this measure decreased the number of bouquet spurs, it increased the total number of spurs including the conventional short spurs to improve the yield to 1,024 kg·10 a⁻¹ from 557 kg·10 a⁻¹ using conventional hedge-row training. However, this method decreased solar radiation in the tree crowns thereby lowering fruit quality. In contrast, increasing planting density from 3-m intervals to 2- or 1.5-m intervals did not affect fruit quality. Moreover, in contrast to a yield of 588 kg·10 a⁻¹ when row intervals were 3 m, the row intervals narrowed to 2 m and 1.5 m improved the yield to 881 kg·10 a⁻¹ and 1,101 kg·10 a⁻¹, respectively. The above results show that decreasing row intervals is an effective method for increasing the yield of sweet cherries grown by hedge-row training without lowering fruit quality.