A Study On Cold Resistance And Frost-proof Technology Of Peach Blossom&Young Fruit Stage In Ningxia Irrigation Area

Against the background of global warming,the risk of frost in the peach blossom and young fruit period is increasing.In this study,the main peach varieties planted in Ningxia Irrigation District were used as test materials to carry out a test study on cold resistance of peach blossoms and young fruits under low temperature stress.The physical and chemical anti-frost effects of peach blossom were also evaluated to provide scientific support for improving the frost monitoring and early warning level as well as anti-frost ability of peach tree.The main results were as follows:1.As the temperature decreases,the electrolyte leakage rate of flower organs and young fruits show a slow-fast-slow pattern,and the overall change curve is of the "S" type.The electrolyte permeability of young fruit increases significantly earlier than that of flower organs.The semi-lethal temperatures of peach blossom organs and young fruit are-4.08? and-3.05 ? by using the conductance method and Logistic equation fitting.2.As the temperature decreases,the antioxidant enzyme activities in peach blossom and young fruits represents a downward trend after the first rise.The POD activity in peach blossom organs and young fruit reaches the peak at the same temperature,while the SOD and CAT activity in peach blossom organs reaches the peak at a lower temperature than that in young fruit.3.As the temperature decreases,the content of osmoregulation substances in peach organs and young fruits increases first and then decrease.Peach blossom organs and young fruits can resist low temperature damage by increasing osmoregulation substances.Soluble proteins and soluble sugars in the early stages of cooling,play a major role in resisting low temperatures.In the later stage,the low-temperature freezing damage is mainly resisted by increasing the soluble sugar content.The main osmotic regulators in peach blossom organs reaches a peak when the temperature is lower than that of young fruit.4.Low temperature stress will increase the permeability of peach blossom and young fruit membranes.With the decrease of temperature,MDA content of peach organs and young fruits show a slow-fast-slow growth trend.When MDA content of the young fruit increase significantly,the temperature is higher and the degree is larger than that in peach blossom organs.5.The experiment is performed by spraying chemical anti-frost reagents to resist the frost of peach blossom such as "Bihu","Tianda 2116" and " Zhifu".Physiological indexes are measured and the defense effect of three anti-frost agents with the membership function method is comprehensively evaluated.The result of anti-frost effect is "Tianda 2116">"Bihu">"Zhifu".6.Effect of physical frost protection on orchard heating:On sunny and windless frost day,the temperature of the orchard ground raises about 0.70? by releasing artificial smoke bombs that can effectively resist frost.