Method for preventing and controlling rot disease of dried pear trees after cortex rot and alcohol smell

Pear tree rot disease, also known as smelly skin disease, dry rot disease, mainly harms the main branches and lateral branches of pear trees, especially at the intersection of sunny branches and branches. The injured part is long oval or irregular-shaped disease spot, the initial water stains, slightly raised, cortical rot brown, give off alcohol smell, under pressure, overflow reddish brown juice. After gradually drying and sinking, cracks appeared at the junction of disease and health, yellow filaments (spore horn) gushed out after rain, and the skin gradually warped up. In serious cases, the branches or even the whole tree will die.

Pear tree rot

I. the cause of occurrence

The pathogen of pear rot overwintered in the diseased tissue with mycelia, conidia and cysts. In the growing season, the spores spread by wind and rain, and invaded from various wounds, dead tissues, lenticels, petiole scars and fruit stalk scars.

Causes: (1) the existence of pathogens; (2) continuous planting of susceptible pear varieties; (3) suitable climatic conditions; (4) poor management.

II. Prevention and control countermeasures

1. Strengthen cultivation and management, increase application of organic fertilizer, enhance tree potential and improve disease resistance.

2. Pruning reasonably, controlling the amount of fruit, according to pear tree age, tree potential, soil fertility and other conditions, do a good job of flower and fruit thinning, soil fertilizer and water management, so as to make the pear tree load reasonable and put an end to the fruit year.

3, heavy scraping, scraping the epidermis of the diseased trunk with a scraper during the dormant period, scraping until the white-green healthy skin is exposed, pay attention to scraping the diseased tissue, and scrape the branches and other areas carefully and carefully to prevent the bark from being scraped through.

4. Scrape off the diseased tissue and rough bark on the trunk and main branch, spray a fungicide with permeability and long residual period, eradicate the latent rot bacteria on the bark, prevent bacterial infection and prevent the disease. Spray 40% Fumei arsenic wettable powder 50 times or 5% chlorothalonil 200 times at the base of the trunk and branches of the pear tree. After picking the fruit, spray again in late autumn and winter.

5. in the early stage of the disease, curettage should be done in time when the disease spot is small. Focus on summer and autumn and winter and spring before the disease, curettage must be clean, there is no rot under the bark, only scraping epidermis disease layer tissue, deeper lesions, xylem and diseased skin should be scraped clean, scraped after applying medicine. Reagent selection: (1) smear with Baume 5-10 degree stone sulfur mixture or 1% copper sulfate. (2) smear the wound of pear tree with "artificial bark".

Prevention and control of pear tree rot

6. In late autumn, clear the fallen leaves of pear trees, remove diseased fruits and withered branches, and reduce the source of overwintering bacteria; from winter to early spring, combined with pruning to remove diseased shoots and diseased branches, and concentrate on burning; in the early stage of the disease, remove diseased flowers and diseased shoots in time. From February to March, the diseased bodies were collected and scraped, taken out of the garden, buried or burned, and the source of the disease was removed.

7. When the incidence of pear tree rot is high. Spray directly with Dictylofenac: methyl topiramate: water = 16 / 1 / 800.