Studies On Shoot Treating And Top Grafting Technique For Replacing Cultivar Of Pear Tree

Aiming at different tree form, different varieties, different tree body parts, the experiment using pruning technology, such as shoot bending,pinching,wresting shoot and so on, using chemical medicament controlling technique and top grafting technique for replacing different pear cultivars studies on pear body response and how to influence pear tree yield and fruit quality, in order to getting to a series of quantization indexes and supplying theoretical basis for improvement and innovation of pear training and pruning technology. the results were showed as follows:Net photo synthetic rate, stomata conductance and transpiration rate in leaves of drawing branch angle at 70°were all the highest among the treatments, souble sugar and reducing sugar contents were both higher in leaves of drawing branch angle at 70°than control, the C/N rates in leaves and shoots of drawing branch angle at 70°and 90°were relatively high. The degrees of inhibiting shoot growth increased with increase of drawing branch angles.Using parts of summer pruning techniques and chemical medicament controlling technique to deal with shoot, both controlled the pear shoot growth and promoted flower buds differentiation. Growth inhibitor of 2000-3000mg/kg could obviously controlled shoot growth and promoted bud differentiation achieving 60 percentage; branch drawing effect was most significant to buds, flower formation rate between 70 percentage and 80 percentage. So, drawing branch is most beneficial to improve fruit yield and is a simple accurate management technology which be prone to be accepted by people. Growth inhibitor can control shoots growth, saving time and saving power.Spring top grafting should be conducted at pre-and post tree spout during middle March between early April in jianghuai region, summer grafting should be conducted from late May to early June. In several adoptive graft techniques, bark graft is widely applied because of survival rate. Rootstock diameter is not too wide and too thin. It maybe influence on healing rate of grafting uion. Better grafting bud and cion number also influence survival rate and wound healing. Too older rootstock should not be selected. Protecting with plastic belt is used after grafting.Extension leading branch and crop load effected obviously on growth and fruit quality of'Hosui'pear using horizontal trellis cultivation. The vegetative growth of the tree, fruit yield and quality were influenced by angles of extension leading branch and fruit load. While 90 angles of extension leading branch and 2 numbers per cross section area of main branch, pear tree vigor was hale, fruit quality was higher, and yield was highest.