Microclimate Characteristic And Cold Resistance Of Fruit Tree In Xinjiang Intercropping Orchard

In order to understand the relationship between the micro-climatic differences in different intercropping orchards and fruit trees overwintering,apricot,walnut and almond were the test objects as three main cultivated fruit trees in Xinjiang intercropping orchards in this paper. Determining and analyzing the phenophase, illumination and humidity regular pattern of different fruiter and intercrops. Artificial cold treatment on dormant twigs of different intercroping system fruiter. Determining the change law of twigs on electrolyte leakage, free proline, malondialdehyde and other cold-related physiological indexes and analyzing their cold resistance characteristic of the fruit trees in different conditions. The results are as follows:(1). The phenophase of fruiter and intercrops existed overlap and stagger. The overlapping and interlacing time of wheat to apriot, walnut and almond was55d-60d. The cotton phenophase was entirely overlaped with three fruiter, influence time was180d-190d. Repeated sowing corn had a obvious influence on the light and temperature of the apricot orchards. The overlapping and interlacing time was120d to walnut, the influence time of spring sowing corn and apricot to almond was140d. The influence time of tomato and pepper to apricot and almond were60d and90d respectively. The overlapping and interlacing time of phenophase lead to difference on the fertilizer and water management time of fruiter and intercrops. The comparison shows that the wheat, fertilizer and water management cycle and apricot, almond and walnut smaller contradiction; tomatoes, peppers, followed by; cropping corn, cotton and other contradictions larger.(2). The diurnal variation of canopy PAR within the intercropping system showed that the diurnal variation had no difference in different intercropping system, was obvious "single peak" curve. PAR values were different in different density intercropping system, showing the obvious spacing effect, and showing the canopy opened, branch group structure, canopy density and other factors affected canopy to accept light. The PAR value was higher in upper canopy than lower canopy in the day. The optical amount of crown all positions showed regular pattern in the day, the crown east mainly accept the light during8:00～12:00. The east, south and west of crown obviously accept the light during14:00～16:00. There was no difference in all position during18:00～20:00. The apricot-wheat intercropping system in the spacing of4m×5m and the walnut-wheat intercropping system in the spacing of4m×6m all showed uniform distribution in illumination, the planting density and crown branch structure were reasonable. In the intercropping system, the fruit trees morphological index, such as tree height, crown width, and the space in the row were the main factors affecting light. Interrowcrop changed community structure of system, especially the row density and collocation species had an direct effect on plant accepting light. The fruit trees in the intercropping system and the crops both constituted characteristics by light of space of the fruit trees in the system.(3). The leaf area index in the intercropping system showed that in the same space, the smaller the crown width, the smaller the LAI. The same old fruit trees, the wider the space, the smaller the LAI. In the same space in the row, the crops height and planting density influenced directly LAI, the short stem crops, such as wheat, cotton and tomato had a smaller effect on the fruit trees accepting the light, a bigger effect on corn after planting. In the different space in the row, the smaller the space, the higher the crop height, and had a bigger effect on forestry by light. (4). The daily temperature and humidity changes showed that the temperature changes between the air and the earth’s surface were the same, temperature variation was inversely correlated with humidity variation, and their time were the same when the maximum value and minimum value appearing. By comparing the same space in the intercropping and the only crops system, shade of fruit trees and interrowcrop had an effect on decreasing temperature and increasing humidity. In the different space system, the smaller the space, the wider the crown width, and the temperature and the humidity were higher in the more intensive interrowcrop system.(5). The determination about the cold resistance of the dormant branches showed that In the process of low temperature stress, the electrical conductivity of apricot, walnut and almond assumed "S" the shape curve growth. About annual apricot(white apricot,saimaiti,kumaiti), the LT50of the dormant branches was between-25.32℃and-20.11℃,-25.32℃and-20.11℃,-28.75℃and-25.72℃respectively. About annual walnut (xin2), the LT50of the dormant was about-18℃.About annual almond (sha che no1), the LT50of the dormant branches was between-28.75℃and-25.72℃. MDA content in the tested branches as well as free Pro content with decreasing temperature rise occurred changes reflect the sensitivity of plants to chilling injury, indicating that MDA content as well as the free Pro content closely related to plant stress resistance ability. The tests showed that the LT50value of apricot, almond branches was higher as the intercrops were tomatoes and pepper. At the same time, these branches were higher sensitivity to low temperature,weak cold. Inter-crops corn system, apricot, walnut, almond branches, their electrolyte leakage, MDA content increased significantly with temperature change, a large range of free Pro content changes, weak cold. Crops, fruit trees had stronger cold tolerance within the system of cotton and wheat intercropping compared with corn, tomatoes,etc intercropping. This result was consistent with the result of restore growth intuitive observation dormant branches.