Doing a good job in the prevention and control of pests and diseases after the apple fruit is harvested will have a good effect on reducing the overwintering base of pests and diseases, controlling the population of pests and diseases, and reducing the degree of pests and diseases in the coming year.Not only can the tree body's resistance to adverse environments be improved, but it can also promote the differentiation of flower buds and make more fruits in the coming year.There is widespread neglect of pest control in orchards in our county after harvesting, which has caused serious harm to pests and diseases during the growing season.Attention should be paid to the following points in the prevention and control of pests and diseases after the apple fruit is harvested：
　　1. Pay attention to the work of leaf preservation.There is still one month before the fallen leaves go dormant after the apples are harvested, so it is essential to prevent disease and protect the leaves.After fruit picking, sterilization, insecticides and foliar fertilizer should be sprayed 1-2 times in a row. Through spraying, it will prevent early deciduous leaves and promote nutrient accumulation. It has a good effect.It can significantly extend the functional period of the leaves and improve the photosynthetic efficiency to facilitate the overwintering of fruit trees and the growth results of the second year. It can be sprayed with 1.5% bacteria to kill 600 times%, or 70% methyltobuzin 800 times liquid + 1.8% avermectin emulsion 5000 times liquid + urea 100 times liquid to prevent and treat early deciduous diseases, starscream, etc., prolong the leaf green period, promote leaf photosynthesis, increase tree body storage of nutrients, and enhance tree body disease resistance.
　　2. Thoroughly clear the garden.The weeds, dead branches, fallen leaves, diseased fruits and old bark crevices on tree trunks and large branches in the orchard are all wintering places for germs and pests.In order to eliminate wintering germs and pests, it is necessary to carefully clear the garden, scrape old bark, cut dead branches, remove weeds, and then burn them intensively or dig pits and bury them deeply.If there is a moth-eaten mouth on the branches, it should be clogged with medicinal mud. After the leaves are completely fallen or frozen, clean up the rotten and diseased fruits and debris in the orchard in time, and clean up the dead branches, fruits, weeds, etc. from the orchard.If the fallen leaves are to be returned to the field, they must be concentrated and rotted.Before stacking, the fallen leaves are concentrated and sprayed with 80% octathion 800 times + 75% chlorhexidine 600 times. After a week, it is mixed with farm fertilizer 1:1, and 20% superphosphate is added. Calcium phosphate is accumulated and fermented for 2-3 months before deep application.
　　3. Cut off dead branches of pests and diseases.Tree-by-tree inspection, timely cut off and concentrated burning of branches that are harmful to leafhoppers, scale insects, latent skin moths, leaf-rolling moths, powdery mildew, rot, dry rot, etc.And disinfect and protect the cutting and sawing mouth in time, first disinfect with 10 times the liquid of peroxyacetic acid or 50 times the liquid of bacterial toxin, and then apply the sealing paste.Or use 10 parts of quicklime, 1 part of stone sulfur compound, 2 parts of salt, 0.3 parts of vegetable oil and water to prepare and apply to protect it.The tools used to cut off dry rotted branches and rotted branches should also be strictly disinfected and sterilized.
　　4. Scrape off the warped skin of the branches.The warped skin and sandwiched cortex of the branches are wintering places for pests and germs such as starscream and scale insects. Therefore, scraping the warped skin to destroy the wintering places of pests and diseases can also achieve the effect of controlling pests and diseases.
　　5. Scraping to treat rotting diseases.The period from fruit harvest to early spring is the period of high incidence of new rotting disease spots. Therefore, after the fruit is harvested, the spots of rotting disease and dry rot should be carefully checked, and one place should be scraped and one place should be cured. Early detection and early scraping will not leave behind the disease.When scraping, the diseased tissue should be scraped clean. Two scraping tools should be prepared, one to scrape the diseased tissue, and the other to scrape the healthy tissue about 0.5cm deep. The spots should be scraped into a beveled fusiform shape, and then use 50% Lvheng No. 6 20g+54% Lvheng No. 3 20g +1.4%. 30ml + 2.5kg of water must be collected. After preparing by the secondary dilution method, apply the scar and surrounding good cortex 2-4 cm.Apply 2-3 times continuously at intervals of 10-15 days.Or apply 1-2 times with 843 rehabilitation agent, 2% agricultural anti-120 water agent 10 times liquid.All the diseased tissues scraped off should be cleaned up, taken out of the orchard and burned down.
　　6. Disinfection of the whole garden.After falling leaves, the tree body will enter a dormant period. You can choose 100 times the liquid of 5% mycotoxic clear water agent, or 100 times the liquid of 2% agricultural anti-120 water agent, and 21% peroxyacetic acid water agent 200 times the liquid for disinfection and sterilization of the whole garden. Before the tree germinates, spray 5 Pomeranian sulfur compound once again, which can well eliminate wintering pests and diseases and reduce the number of pests and diseases in the orchard throughout the year.
　　7. Insect-trapping belts are tied to the tree trunks.Insect-trapping belts can replace the old method of tying grass handles to tree trunks for the prevention and control of overwintering pests on tree trunks. They are easy to use and have little investment. They have a very significant effect on the trapping of pests such as harmful mites, leaf moths, scale insects, apple cotton aphids, etc., and the trapping rate of overwintering pests on tree trunks and underground can reach more than 90%.Continuous use can reduce the base of pests and reduce the amount of chemical pesticides.。Before the pest enters the overwintering period, the insect-trapping belt can be tied and fixed 10 cm under the first main branch of the trunk, and the trunk can be tied for a week without leaving a gap.After the pests enter overwintering hibernation, they are released around January and are buried or burned intensively.Do not discard it indiscriminately or reuse it next year.
　　8. The trunk is painted white.Whiten the tree trunks before the soil is frozen or in early spring.The whitening liquid should be moderately thick and thin, so that it does not flow when brushing.The formula of the whitening agent is prepared with 100 parts of lime, 10 parts of sulfur powder, 10 parts of salt, 1 part of vegetable oil, and 200 parts of water; or 10 parts of quicklime, 1 part of sulfur powder, and 40 parts of water.
　　9. Deep plowing of orchards.Deep plowing of orchard soil can pull germs and pests hiding in the soil ready to overwinter out of the ground, allowing birds to peck and freeze to death.At the same time, the number of diseased leaves and stiff fruits on the ground can be reduced, and the pests hiding in the withered grass can be buried deep in the ground. The following year, these pests are not easy to unearth and are suffocated to death.The depth of tillage should be about 30 cm.
    10. Irrigation of orchards.Before the soil is frozen, the whole garden is irrigated once, which not only allows the tree body to reserve enough water, but also helps the fertilizer to decompose.Moreover, it can destroy the living environment of wintering pests and diseases in the soil, or directly flood the wintering pests in the soil, thereby reducing the base of wintering pests and diseases.