Evaluation of Productivity and Light Quality in Two High Density Dwarf Rootstock Apple Orchards in Central China

[Objective] The aim of the study is to investigate the productivity and light quality in two high density M26 dwarf rootstock apple orchards in central China so as to provide some management guidance for close planting of dwarf rootstock apples.[Method] The technical parameters of individual trees and group parameters as shoot number and composition and canopy coverage were determined,and the light quality in the canopy,fruit production and quality were investigated.[Result] Slender spindle (SS) orchard has 54 thousands shoots per 667 m2.Coverage rate is 76%.Leaf area index is 1.9.The ratio of long,medium and spur shoots is 1∶1∶8.Fruit yield is 3 263 kg/667 m2 with 85% first grade fruit.Light interception in the canopy is 58% while the ratio of canopy with good light is 65%.Modified slender spindle (MSS) orchard has 93 thousands shoots per 667 m2 and the coverage is 77%.Leaf area index is 3.3.The ratio of long,medium and spur shoots is 1∶2∶7.Fruit yield is 3 931 kg/667 m2 with 85% first grade fruit.The light interception in the canopy is 73% while the ratio of canopy with good light is 35%.[Conclusion] Apple orchard with M26 dwarf rootstock trained as SS and MSS tree form in medium planting density may be useful to the management of the similar orchards in Central China.