Topdressing and pruning recommended postharvest management measures for controlling diseases and insect pests and early ripening apples

Early ripening apple harvest is an important stage for apple leaf photosynthesis to store nutrients for apple trees, and it is also an important period for pest control. In production, flowering without fruit, more flowers and less fruit, serious physiological fruit drop, small fruit deformity and so on are closely related to insufficient storage nutrition and postharvest diseases and insect pests of apple trees. Therefore, after harvest, it is necessary to prune, fertilize and control diseases and pests in time, so as to restore tree potential, increase nutrient accumulation, reduce overwintering diseases and pests, and lay the foundation for flowering and fruiting and high yield next year. The specific measures are as follows:

Apple pruning

Post-harvest pruning:

Pruning apples in time after harvest can control the growth of branches and promote the strength of trees. Pruning is mainly based on thinning, retraction, heart-picking and strong branch-pulling. Cut off the upright and useless long branches, multi-head competition, disease and insect branches in time; the weak branches after proper retraction; the strong and long branches with room for growth can take heart-picking and twisting branches; if the angle is not suitable, pull the branches to make the apple trees ventilated and transparent, save nutrition, reduce consumption and promote flower bud differentiation.

Fertilizer and water management:

Fruit trees blossom and bear fruit, consume a lot of nutrients, resulting in the weakness of apple trees. After apple harvest, timely supplement of nitrogen, phosphorus, potassium quick-acting fertilizer, increase the application of organic fertilizer, appropriate water. At this time, fertilization, high soil temperature, fast microbial decomposition, strong root absorption, can quickly replenish nutrition to apple trees and accumulate nutrients for next year's high yield. The amount of fertilizer applied accounts for about 60% of the annual amount of fertilizer. The annual fertilizer application amount of apple trees should be determined according to tree age, tree potential, yield and fertilizer type. the general principle is that 100kg of apple requires 100,200kg of farm organic fertilizer, 1 kg of pure nitrogen, 0.5 kg of pure phosphorus and 1 kg of pure potassium.

Pest control:

The purpose of controlling diseases and insect pests after apple harvest is to ensure the healthy growth of apple leaves. Apple leaves are nutritious processing plants for apple trees. Trees are supported by leaves and fruits depend on leaf length. It is particularly important to protect leaves. During this period, it is necessary to prevent brown spot, anthracnose, ring disease, rot, heart-eating insects, red spiders, leaf moths and so on. If the prevention and control is not timely, it will harm the apple trees and lead to early defoliation. Therefore, prescribe the right medicine according to the condition of the disease and insect. Fungicides can be used with tocopherol, polyantimycin, Bordeaux liquid, Dasheng MMI 45, mancozeb and so on. Insecticidal and acaricidal agents can be used, such as kung fu, diflubenzuron, peach Xiaoling, acarine and so on. After scraping off the spot of rot disease, you can smear it with 50% 100-fold solution of Shiduqing or humic acid copper rehabilitation agent.

Orchard recommendation:

No-tillage apple orchard can plant white clover and alfalfa after fruit harvest, which can improve soil, improve soil fertility, adjust orchard temperature and humidity, and enhance soil permeability. At the same time, fix the nitrogen in the air and reduce the amount of chemical fertilizer. Eliminating soil tillage is a new technology adapted to simplified management.