What are the comprehensive control methods of apple tree rot?

Once rot occurs in the process of apple tree planting, it will have a great impact on the yield and quality of apple trees, so growers must understand the symptoms and comprehensive control methods of apple tree rot, and try their best to minimize the damage.

Symptoms of apple rot

In the early stage of apple tree rot, the cortex of the tree will turn brown slightly in the diseased part, and the disease boundary tissue is obvious. After the disease spot gradually expands, the disease site expands and softens, pressing with the finger will appear depression, at the same time, the yellow-brown liquid will flow out, and the scar of the disease site will be dry and sunken in the later stage, which will become dark brown. There are many small brown granular substances on the diseased bark. When it rains or the weather is wet, these small black spots often overflow orange-yellow filamentous curls. When the apple tree rot is serious, it will cause the leaves on the branches of the fruit tree to turn yellow and even wither.

The pathogens causing apple tree rot are weak parasites, whose hyphae, meristematic sporangia and ascomycetes pass through the winter in the bark of apple trees or in the scars of old diseases.

Infection may occur in spring, summer and autumn, but in May and September each year as the peak of the disease, spores will continue to spread with the help of wind and rain, encounter scarred apple trees, coupled with a suitable environment, will induce rot, especially old fruit trees and apple trees with weak growth are more prone to the disease.

2. Comprehensive control of apple tree rot.

1. Strengthen the comprehensive management and strengthen the tree potential. Comprehensive control should be carried out on the basis of robust trees and the elimination of pathogens. First of all, pay attention to the application of organic fertilizer in autumn, increase the application of phosphorus and potassium fertilizer, spray trace fertilizer and a variety of nutrients, recommend and improve soil fertility between rows to promote root development. Secondly, strengthen measures to protect leaves and roots, timely control a variety of diseases and insect pests, freeze injury; third, expand the cultivation of virus-free and disease-resistant varieties, determine reasonable cultivation density and reasonable tree shape, and carry out reasonable pruning to ensure ventilation and light transmission; fourth, reasonable load to prevent tree weakness. promote the healthy growth of trees.

2. Get rid of germs in time. Clear the garden in time after fruit harvest, sweep the fallen leaves, remove the diseased and dead branches and insect branches, scrape off the rough, old and warped skin, clean up the rotten bark debris scraped from the diseased branches and destroy them in a centralized manner. Reduce the number of pathogens and lay a good foundation for the prevention and control of rot.

3. Regular examination and timely treatment should be achieved. Rot should be examined regularly and treated as soon as it is found. Scratch the scar of a small disease, scratch the scar of a major disease, apply medicine in time, and reexamine and treat the wound treated by smear. Commonly used smear agents: flank, Guokangbao, tebuconazole, flusilazole, propiconazole, Letu No. 2, stone sulfur mixture and so on.

4. Bridging. When the scraping scar of rot disease is large, it directly affects the transport of nutrients. In order to prevent the weakening of the tree, it is necessary to bridge the tree to make up for the lack of nutrient transport and protect the tree.