First, the occurrence of frost damage in fruit trees
1, tender shoots freeze damage. As the fruit trees stop growing late and immature shoots are developed, their tissues are not full, and the protective tissues are not developed, and they are prone to freezing injury and death.
2, branches freeze damage. Normally developed shoots can also be frozen when the temperature is too low. The appearance of some shoots did not change significantly, but the color of the xylem was dissected and then the black heart was formed. The frozen shoots sprouted late, the leaves were thin or deformed, and the growth was abnormal.
3, branches freeze damage. The frozen cortex was subsided or cracked, and the interior was brownish black and the tissue died. In severe cases, large shoots also died.
4, frozen root and neck damage. Roots and stems are the roots of fruit trees. The roots of the fruit trees are relatively poor in cold resistance. The roots and cortices of the fruit trees become dark and die after being frozen, and lightly occur in the local parts, while the heavy ones form a black ring and surround the stem, and the whole plant dies.
5, root freeze injury. In underground roots, freezing damage is not easily detected, but it seriously affects the growth of the aboveground parts. The phenomenon of budding late or irregular in the spring, or dry shrinkage after putting the leaves. The outer cortex of the frozen root system turned brown, and the cortex separated from the xylem and even fell off.
Second, preventive measures
1, promptly clear the snow on the tree. Because the fruit trees have not fallen leaves, the snow covers the branches and leaves of the canopy, increasing the weight of the branches and leaves and causing the branches to bend and break.
2, after the snow smoke antifreeze. In the early evening of the heavy snow, it should be in the park, with 6 piles per acre of orchard and the temperature rises. After the sun comes out on the 2nd day, smoking stops. For 2 to 3 consecutive nights, there is a good effect of freezing and preventing frost. .
3, fruit trees root soil cover. After the snow, the trunk is planted around the tree plate, and the height of the soil is 20-25 cm. After the temperature rises in the early spring, the soil will be opened and the roots and necks of the fruit tree will be reduced. However, the soil should not be taken from the tree tray to prevent the root system from being exposed to freezing.
4, tree bandage. According to the changes in the weather, before the arrival of the cold current, use the straw rope to wind the trunk, main branch, or bind the trunk with straw.
5, potting frozen water. If the water is not irrigated, timely filling of the fruit trees with winter water before freezing in the snow will not only promote the growth and development of the fruit trees, but also keep the ground temperature relatively stable during the winter, so as to reduce the freezing damage.
6. The trunk is painted white. Immediately after the snow, the white trunk of the fruit tree and the main branch are uniformly painted white by the whitening agent, so that the temperature of the tree body is stable, there will be no freeze-thaw, no frost, no frost, and the pathogen and worm in the trunk will be killed. Eggs and adults. The proportion of whitening liquid is: 100 parts of lime, 10 parts of sulfur powder, 10 parts of salt, 1 part of vegetable oil, and 200 parts of clear water.
7. Strengthen the cultivation and management work in the coming year. Timely fertilization, watering, restoring tree vigor. At the same time, the trees are susceptible to pests and diseases after being chilled and should be promptly controlled.
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