- Author: CHEN Xiaodan, WANG Lei, MA Chao, ZHANG Caixi, YAN Yujie, BI Siyun, WANG Jie, PENG Yongzheng, XU Wenping, WANG Shiping
- Keywords: Sweet cherries; Shanghai area; UFO systems; Root restriction; Planting angle;
- DOI: 10.13925/j.cnki.gsxb.20150532
- Received date:
- Accepted date:
- Online date:
PDF （） Abstract（）
Abstract: 【Objective】Sweet cherries have been introduced to south China, including Shanghai since1980 s. However, their commercial production is limited by poor fruit set despite that production has been improved by the application of hydrogen cyanamide, low chilling varieties and rain- shelters in recent years. A long rainy season and high water table in Shanghai usually result in poor fruit set and fruit cracking during growing season. It has been reported that rain shelters effectively control spindling and fruit cracking and increase fruit quality. In addition, the traditional non-dwarfing rootstocks normally lead to vigorous vegetative growth, poor fruit set, labor intensive tree management and difficulty in growing the crop under rain shelters. In recent years, the upright fruiting offshoots(UFO) system was developed by Washington State University, and shown to have many advantages, such as fast canopy establishment, simple pruning, and saving labor. To produce commercial sweet cherries under rain shelters in Shanghai, China, the varieties of sweet cherries, rootstocks and supporting systems need to be evaluated for fruit production. In the current study, a modified UFO system with rain-shelters and dwarfing rootstock‘Gisela 5'under rooting- zone restriction was evaluated for optimizing the planting angle, seedling quality, pruning strategy and rootstock-scion combination.【Methods】The dwarfing rootstock‘Giesla 5'and seven scion varieties, including‘Tieton'‘Sunburst'‘Zaoganyang'‘Zaodaguo'‘Hongdeng'‘Brooks' and‘Summit'were selected for the experiment. Branching rate and shoot types were used as vegetative growth parameters for evaluating the modified UFO systems. The cherry trees for each treatment were divided into 2groups: the root restriction group and the conventional planting group with planting angle >30° or ≤30°.The seedlings were divided into pruned(cutting back) and non-pruned groups. Trunk diameter, branch diameter, branch length and the diameters and lengths of vertical shoots were measured. Branching rate was calculated as the percentage of vertical shoots developed in 2014 against the number of leave buds formed on the trunk in 2013. Shoot types were classified according to shoot length: water shoot(>60 cm), wood shoot(30-60 cm), long shoot(15-30 cm), medium shoot(5-15 cm), short shoot(<5 cm), and fruiting spur(