Consideration for high density planting with dwarf rootstocks in apple in China
MA Bao-kun,XU Ji-zhong,SUN Jian-she (College of Horticulture,Hebei Agricultural University,Baoding,Hebei 071001 China)
High density planting with standard rootstocks has been the main growing form for apple in China. Such growing form brings many problems to the apple production,such as low yield per hectare,poor fruit quality,difficult extension for using some techniques and high cost for the fruit production. Practise both in domestic and abroad indicate that using dwarf rootstocks for high density planting has many advantages,such as early fruiting,high yield per hectare,top fruit quality,little cost,simple techniques and easy to extend. So it is the inevitable trend for apple production in China to use dwarf rootstocks for high density planting. Some problems had been found in apple production with dwarf rootstocks in the past years in China,including improper selection for dwarf rootstock,deep planting and unsuited techniques to the dwarf rootstocks. These limited the effect of dwarf rootstock. The necessary and available conditions of high density planting with dwarf rootstocks at present are discussed in this paper from the apple growth and bearing habit and climatic conditions of apple producing areas in China. Based on the authors growing apple experiences and some problems existed in the high density planting with dwarf rootstock,in this article some key techniques for high density planting of apple with dwarfing rootstocks are given,including raising planting materials,orchard establishment,and training and pruning. In addition,the successful examples for high density planting with dwarf rootstocks are introduced as well.