Study On Berry Abscission Of Thompson Seedless In Xingjiang

Grape is one of the fruit trees with earliest cultivation and widest distribution in the world, accounting for 1/5 of the total fruit output in the world, only second to orange, ranking the second place in the world. Xinjiang is China's major grape production area, with the largest area and output in China, and Thompson Seedless grape is the major grape variety in Xinjiang. Abscission after grape picking is the common problem in production of Thompson Seedless fresh grape, in this study, the author designs the comprehensive nutrient solution formula test and application method combination test aiming at the problem of abscission of Xinjiang Thompson Seedless grape, and aims at providing technical basis and method for solving the problem of abscission of Xinjiang Thompson Seedless grape and improving the quality of Thompson Seedless grape.Through respectively applying 3 plant growth regulators,1 nutrient element and 1 pruning measure on Xinjiang Thompson Seedless grape before and after the flowering stage, the author studied the influence of different treatments on the abscission of Thompson Seedless grape. The results show that the effect of gibberellin on increasing the single fruit weight of grape is obvious, and this conclusion is consistent with the study result of the predecessors; and indicators (tensile resistance, pressure resistance, fruit stalk and fruit stem) related to abscission show that the gibberellin has certain effect on reducing the abscission rate of grape, and the best treatment period of gibberellin is before 2 weeks after the blossom of grape. Forchlorfenuron treatment can increase the single fruit weight of grape, and also increase the value of the indicator related to abscission, and the optimal treatment period for forchlorfenuron to reduce the abscission rate is from the flowering stage to 2 weeks after the blossom. Paclobutrazol treatment can increase the single fruit weight of grape, reduce the pressure resistance of grape fruit, reduce the length and thickness of grape stem, and reduce the width of the grape stalk. Calcium nitrate treatment can improve the tensile resistance of fruit, reduce the length and diameter of stems, and increase the single fruit weight of grape, and the suitable applying period of calcium nitrate shall be 6 weeks after the blossom. Ring peeling treatment can increase the single fruit weight of grape, and the optimal ring peeling time for increasing the single fruit weight is before the blossom or after the blossom; and ring peeling will reduce the pressure resistance of grape fruit, improve the tensile resistance, and increase the length of fruit stalk, and the optimal ring peeling time for improving the tensile resistance is the 20th day after the blossom. The 5 treatments basically have no influence on the grape fruit type index, and can increase the single fruit weight and reduce the abscission rate to different extents. However, the optimal treatment periods of the five factors are different.A comprehensive nutrient solution is developed to solve the problem of abscission of Thompson Seedless grape, and contains 14 components, namely gibberellin, potassium nitrate, ammonium sulfate, magnesium sulfate, potassium dihydrogen phosphate, calcium chloride, manganese sulfate, zinc sulfate, copper sulfate, boric acid, potassium iodide, cobalt chloride, citric acid and tween respectively, which are mixed according to certain proportion and method. The result of the test of applying the comprehensive nutrient solution on Xinjiang Thompson Seedless grape before and after the flowering stage shows that the comprehensive nutrient solution has certain effect on increasing the bunch weight, single fruit weight, fruit pressure resistance, tensile resistance, fruit stem, fruit stalk index, sugar content, etc. of Xinjiang Thompson Seedless grape, and can greatly reduce the abscission rate of bunch, especially has obvious effect on improving the index related to the grape storage and transport performance. The main components of comprehensive nutrient solution include gibberellin and other mineral nutrients, and most studies show that gibberellin has obvious effect on increasing the size of grape fruit, however, the improper concentration and application time will make the fruit stem stiff and crisp, reduce the pressure resistance and tensile resistance, increase the abscission rate, reduce the sugar content, etc., especially, the pure application of gibberellin will cause the aforesaid problems. This test result shows that the side effect of the gibberellin can be reduced and the grape storage and transport performance can be improved by being matched with other nutrients. The comprehensive analysis of the test result shows that the optimal treatment of applying the comprehensive nutrient solution is to apply 100mg/L comprehensive nutrient solution for 3 times 10 days before and after the blossom, and 20 days after the blossom; or apply 100mg/L comprehensive nutrient solution for 4 times after the blossom of Thompson Seedless grape,10 days after the blossom,20 days after the blossom and 30 days after the blossom; and the application of 1.5% calcium nitrate 20 days before harvest will have better effect.Postharvest 1-MCP treatment test results show that:during the storage period, the fruit tensile resistance and pressure resistance of Thompson Seedless grape are not continuously reduced, there are 2 rising processes, and the reason is unclear yet; 1-MCP has certain effect on improving the grape fruit tensile resistance, 0.1μL/L is the optimal concentration of 1-MCP to improve the grape fruit tensile resistance; 1-MCP can obviously improve the grape fruit pressure resistance, with the optimal concentration of 1μL/L, followed by 0.1μL/L; and 1-MCP can increase the content of soluble solid of grape.