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

【Objective】The objective of the experiment is to investigate the productivity and light quality in two high density M26 dwarf rootstock apple orchards in central China and give some management guidance for the high density dwarf rootstock apple planting.【Method】 The technical parameters of individual trees,group parameters as shoots number and composition,the percentage of the land covered by canopy were determined,and the light quality in the canopy,crop production and fruit quality were investigated.【Result】 Slender spindle(SS) orchard has 54 thousands shoots per 667m2.Coverage rate is 76%.The ratio of long,medium and spur shoot is 1﹕1﹕8.The fruit yield is 3 263 kg/667m2.The light interception is 58%.The ratio of canopy which has good illumination is 65%.The first grade fruit accounts for 85%.Modified slender spindle(MSS) orchard has 93 thousands shoots per 667m2 and the coverage rate is 77%.The ratio of long,medium and spur shoot is 1﹕2﹕7.The fruit yield is 3 931 kg/667m2.The light interception is 73%.The ratio of canopy which has good illumination is 35%.The first grade fruit accounts for 85%.【Conclusion】Apple orchard with M26 dwarf rootstock trained as SS and MSS tree form may be useful to the management of the similar orchards in central China.