SummaryThe conventional cultivation methods for sweet cherry involve two difficult problems; The trees become too tall and take over 10 years before bearing substantial fruit. We examined the Y-trellis training method to resolve these problems, and found that the Y-trellis training could solve the problems on a practical level; reducing the number of years until bearing fruit and lowering the height of the trees. In the present study, a new cultivation method by hedge-row training was tried to reduce the period till bearing fruit, create smaller trees and produce higher yields compared with those by Y-trellis training. In this training, the harvest started in the fourth year after planting; the target tree shape was attained in the fifth year; and the yield increased markedly. The fruits obtained from hedge-row training and the Y-trellis had higher quality, larger size and more favorable surface color, as well as their smaller variances, compared to those with open-center training.

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.

The purpose of this study was to examine the effects of summer pruning on the improvement and uniformity of the quality of fruit hedgerow-trained sweet cherry trees. The photosynthetic activity and translocation and distribution of photosynthates before summer pruning were compared with those after summer pruning to identify changes. Photosynthetic activity was measured in the basal part of current shoots 30 days after summer pruning. Photosynthetic activity did not change in response to weak sunlight, but it responded to changes in the photoenvironment to a 32% increase of strong sunlight from the level before summer pruning. The amount of 13 C translocation to fruit from various parts of the current shoots was in the following descending order: basal part > middle part > tip. The basal part provided the largest amount of 13 C translocation to fruit.Summer pruning further increased the rate of translocation to fruit from leaves in the basal part of current shoots. These data clearly show that current shoot management by summer pruning is an effective method to produce mass in sweet cherry.Key Words：assimilation, current shoot, matter production, palmette training