As the climatic conditions continue to change, the atmospheric temperature rises year by year, which has an adverse effect on the growth of kiwifruit. In the hot summer season, kiwi leaves and fruits are prone to burns, which is very unfavorable for tree growth and fruit enlargement. To burn the hazard, it is necessary to strengthen the standardized management of the orchard, improve the small ecology in the field, regulate the robust growth of the tree, enhance the resistance and reduce the damage.
First, the effect of high temperature on kiwifruit
1. Influence on the blade In June and July, under high temperature and low humidity conditions, the blade is resistant to high temperature. When the temperature reaches 35 °C or above, the relative humidity is lower than 40%, and the peripheral blade of the thin leaf layer is strongly illuminated. When exposed directly, the leaf margin is chlorotic, followed by partial wilting and death, resulting in leaf burns.
2, the impact on the fruit, strong light, high temperature persistence, strong light direct parts of the peel, pulp burns, tissue necrosis, round, oval plaque, brown, dark brown, deep and flesh, forming sub-fruit, easy to drop fruit.
Second, the occurrence of high temperature daily burning
The daily burning caused by strong light and high temperature mainly occurs in young gardens with early trees and early orchards. Leaf curtain layer and humidity are also important factors in the occurrence of daily burning. The orchard has thick grass, thick leaf layer, low light transmittance, light and suitable light and light; the damage of clear tillage orchard, young garden and tree is serious; the probability of fruit damage is high in the first half of June, and the damage is heavy; The leaves suffered heavy losses from late July to July.
Third, the cause of high temperature daily burning
1. The kiwifruit leaves are larger in relation to the special structure of the leaves. To some extent, the leaves can play a shade, but the physiological structure of the kiwi leaves is special. Because there are no two guard cells in the leaf hole, the tree cannot be The amount of water transpiration of the body is effectively controlled. When the temperature is too high and the water absorbed by the roots does not meet the transpiration requirements, the water in the tree loses its balance. The first part that shows the loss of water is the leaf edge with the largest distribution of leaf holes.
2, related to climate and phenological period Because the Zhouzhi is located in the Loess Plateau, the climate is relatively dry, and continuous high temperature above 35 °C begins in June every year. This period is the peak period of kiwi fruit growth. Fruit development and new shoot growth require a lot of nutrients and water. At this time, the leaves are tender, the skin is thin, and if the nutrients and water are insufficient, the tree will be relatively weak and resistant. The force is reduced. Therefore, June and July are the peak periods of daily burning; in August, the tree body is flourishing, the maturity of leaves and fruits is increased, and the daily burning is reduced.
Fourth, take measures to prevent high temperature hazards
1. Orchard grass is one of the effective ways to prevent high temperature hazards. According to the comparison survey between Qingnengyuan and raw grassland, when the temperature of Qingnengyuan reached 35 °C, the temperature of the grass orchard was about 30 °C, and the temperature difference was 5 °C.
2. In the first half of June, the exposed naked young fruit will be bagged and protected, and covered with cloth, weeds and other coverings.
3, the cultivation of robust trees, reasonable retention of fruit, scientific pruning has a certain role in preventing high temperature burns.
4, maintain the field humidity, reasonable irrigation, conditional availability for sprinkler irrigation and cooling.
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