Two major methods for controlling apple tree rot in early spring: clearing the orchard and scraping the lesions

    Every spring, many apple growers encounter two situations. One is that on the trunk and main branches of apple trees, some bark turns reddish-brown, water-soaked, and slightly raised, with round to oblong lesions, and the bark texture becomes soft and easy to tear, denting under hand pressure and exuding a yellow-brown juice with a strong smell of fermenting wine.

    The other mainly occurs on the branches of 2- to 5-year-old apple trees. The edges of the lesions are clear, neither raised nor water-soaked. The infected branches dry up quickly, and in the later stage, many small black dots appear on the surface of the lesions. In severe cases, it causes weakened tree vigor, death of main branches, and even dead trees and ruined orchards.

    These situations are all caused by the rot disease commonly known as bark rot or stinking bark disease. Therefore, apple growers must adopt comprehensive measures to prevent and control early spring rot in apple trees.

Apple tree

    I. Do a good job of clearing the orchard in early spring
 

    For orchards that were not cleared before winter, the fallen leaves, weeds, paper bags, and mummified fruits in the orchard should be swept up and picked up in time. Fruit trees should also be pruned, cutting off diseased and pest-infested branches and tips, scraping off the coarse old peeling bark on the main trunk of apple trees, and removing leaf clusters attached to the branches. These should be gathered and taken out of the orchard to be deeply buried or burned, blocking the entry routes of rot disease.

    II. Promptly scrape and treat the lesions
 

    As temperatures rise in early spring, the rot pathogen begins to breed and spread. Apple growers should inspect carefully. If apple trees with rot disease are found, the lesions should be scraped and treated immediately, and fungicide applied to prevent recurrence. When scraping and treating the lesions, be sure to scrape away 1 cm of healthy tissue so that the wound forms a vertical edge, which helps the wound heal. Immediately after scraping, apply Lubao Dan, Jundu Qing, lime sulfur mixture stock solution, or a concentrated salt solution of 20% or more, and at the same time thoroughly pick up all diseased bark and diseased debris. For severely affected orchards, spray 45% Shenaning aqueous solution at 400-500 times dilution before the apple trees bud.