What causes apple rot disease?
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Weak Tree Vigor: The occurrence of rot disease is closely related to the vigor of the tree. Weakened trees are highly susceptible to disease. The main causes of tree weakness include old age, pest infestation, and overloading with fruit.
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Low Organic Matter: Most orchard soils have an organic matter content of less than 1%, coupled with repeated applications of chemical fertilizers, leading to soil compaction and hindrance of root activity, severely affecting tree growth.
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Excessive Wounding: Some orchards indiscriminately prune many large branches throughout the year, resulting in uneven wounds that are not properly protected. Exposed to sunlight, these wounds are difficult to heal, leading to disease.
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Adverse Weather: Sudden temperature changes in early winter and early spring, especially severe freezing at branch junctions, make frozen tissues susceptible to disease. Trees that experience drought in winter or lack frost protection are also prone to freezing, which can lead to disease outbreaks.
Methods to Prevent and Treat Apple Rot Disease
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Eliminate Disease Sources: After careful examination of the branches for disease, promptly remove dead branches, dig out dead trees, saw or prune dry diseased branches and wood, and scrape off diseased bark to reduce the number of pathogens. When scraping bark, lay plastic sheeting or cloth around the trunk to collect scraped bark, insect eggs, etc., and burn them together with pruned diseased branches and bark.
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Chemical Control: Currently, safe drugs for controlling this disease include Rotenone, 843 Recovery Agent, Bacteriophage Qing, Bactericidal Mie, Lime Sulfur, and Sinanong. Spraying Bactericidal Mie No. 2 at 200 times dilution before sprouting can form a strong protective film on the tree surface, effectively killing overwintering pathogens. Sinanong has a strong bactericidal effect, can basically kill bacteria on the surface of branches, and has a strong control effect on latent pathogens in branches. It can also control dormant pests. Using 45% Sinanong 400 times dilution to prevent branch diseases, the control efficiency can reach over 85%.
Above is the introduction to the causes of apple rot disease. There are many reasons for the occurrence of apple rot disease, so it is essential to do well in all aspects of apple orchard management.