How to prevent and control apple canker in summer? These methods must be mastered
How to prevent and control apple canker in summer? Please introduce the methods. In the prevention and control of apple tree canker, for many years attention has been paid to spring control while summer and autumn control has been neglected, resulting in a high recurrence rate of the disease and making it impossible to eradicate completely. However, according to the occurrence pattern of canker, changing the single spring scraping and chemical treatment to mainly summer and autumn control, combined with spring control...
How to prevent and control apple canker in summer? Please introduce the methods
In the prevention and control of apple tree canker, for many years attention has been paid to spring control while summer and autumn control has been neglected, resulting in a high recurrence rate of the disease and making it impossible to eradicate completely. However, according to the occurrence pattern of canker, changing the single spring scraping and chemical treatment to mainly summer and autumn control, combined with spring control, and performing bridge grafting on large cankers, can achieve good control results.
1. Occurrence pattern The pathogen of apple canker is a weakly parasitic fungus. It overwinters on the bark as mycelium, pycnidia and cirrhi, and the pathogen spores spread and cause damage by rain splashing. Summer is the period of active growth for apple trees, which is unfavorable for the pathogen to expand and cause disease; however, the falling bark layer and dying tissues in other parts create good conditions for the spread and infection of canker, and after the pathogen invading the bark expands there, it forms very small superficial canker spots. When the tree enters the dormant period, its vitality declines, the disease develops faster, and a small peak of disease occurrence appears, with obvious symptoms, but expansion is slow during deep dormancy. 2. Control measures Scraping: Based on the characteristic that pathogen spores spread by rain in summer, in summer and autumn scrape off the dying tissues of the falling bark layer, dry stubs on the tree and diseased and pest-damaged branches, then apply a 50-fold dilution of 4% Nongkang 120 fruit tree formula liquid to eliminate the latent infection sites of the pathogen. In combination with the control of other fruit tree diseases, carefully spray 4% Nongkang 120 fruit tree formula at 600-800 times dilution or 1:2:200 Bordeaux mixture 3-4 times each year, to eliminate the pathogen during the latent infection period and fundamentally control the disease during the dormant period.
Next, after scraping off the canker spots in spring, apply a 50-fold dilution of 4% Nongkang 120 fruit tree formula or 9281 or 834 rehabilitation agent.
Mud wrapping: Apply loess mud on the canker spots, about 1 cm thick, then wrap tightly with plastic film (about 10-15 cm wide). Generally after 2-3 months the canker spots fall off and callus tissue forms around them.
Strengthening tree vigor Strengthening tree vigor and improving disease resistance are fundamental measures for controlling canker. Reasonably adjust the fruit load: improve site conditions and implement scientific fertilization; control in autumn and irrigate in spring, with rational irrigation; timely control diseases and pests that cause early leaf drop, and timely control root diseases, so as to achieve the goal of strengthening trees and preventing disease.
Bridge grafting for large cankers Large cankers are difficult to heal completely in a short time and seriously affect the transport of nutrients in the tree. Therefore, after scraping large cankers, carry out bridge grafting promptly, which helps restore tree vigor and prolong lifespan.
Click to get more apple tree planting techniques
Click to get more fruit planting techniques