Investigation On Adaptability Of Several Apple Rootstocks In Xinjiang Area

As an important temperate deciduous fruit tree and economic crop in China,apple is of great significance in promoting poverty reduction program and improving regional economic development.Xinjiang Uygur Autonomous Region is an important apple commercial area of China.The unique climate and soil condition in Xinjiang requires special rootstock of apple.In the paper,with the objective to select ideal apple rootstocks in the region,the growth performance of several apple rootstocks(including dwarf root stocks)were studied.The main results were as following:(1)Among the 8 varieties tested,in Urumqi,the frost damage indices of 7 varieties were below than10%.Except ‘M.hupehensis’,the 7 varieties were suitable to develop in Northern Xinjiang area.In fact,‘M.robusta’,‘M.baccata(L).’,‘M.pumila’ and ‘M.xiaojinensis’ were of greater hardiness levels than‘M.sieversii’,‘M.cv.Sparker’ 、 ‘M.spectabilis’.The greatest frost damage index of ‘M.hupehensis’(41.0%)demonstrated that the variety was of poor cold resistance.The relative conductivity of one-year-old shoots was an ideal index to study apple shoot hardiness due to greatly significant correlation(R=0.83**)with frost damage index.(2)The physical and chemical characteristics of soil in Southern Xinjiang Area were investigated.With four apple rootstocks as material,the suitability in the calcareous soil was evaluated.We found‘M.xiaojinensis’ and ‘M.robusta’ were of thick green leaves and no iron deficiency symptom.Therefore,a slight aymptoms of chlorosis was observed in ‘M.robusta’ in late growth season.In a conclusion,‘M.xiaojinensis’ is suitable for Southern soil due to its strong resistance to iron deficiency.(3)The survival rate of five dwarf rootstock combinations planted in calcareous soils of Southern Xinjiang region was studied.The chlorophyll content,total iron content and scion growth potential were determined.The results showed that the average survival rate of stock was more than 70%.The results showed that the five rootstocks combinations were all suitable fin calcium soil in Southern Xinjiang.‘KM23’,‘SH6’ and ‘Y-1’ were of more stronger than other two dwarf rootstocks.‘M.sieversii’ could be used as an ideal base rootstock in apple dwarfing culture in South Xinjiang.