Pear scab is also called scab and mildew, and it is one of the main diseases of Yangxian Liyuan. After the onset, the early leaves of the pear trees are caused, and the fruit forms a deformed fruit after being damaged. It has no commercial property and weakens the tree potential, directly causing less fruit in the second year and reducing production. In order to reduce losses, we will make preparations for the prevention and control work on the basis of this year's pear black spot disease.
I. Symptoms Pear scab can infect all green and young tissues of pear trees, mainly harming leaves and fruits, and also harming bud scales, petioles and fruit stalks, which are harmful from flowering to fruit picking. The lesions turn yellow at the beginning, then become brown and die and grow green mold.
Second, the disease conditions Pear scab is affected by many factors: First, meteorological conditions. Spring rainfall is early, rain is heavy, and humidity is conducive to the invasion and spread of pathogen spores. Rainy days last for 48 hours, rainfall is more than 5 mm, relative humidity is above 70%, temperature is 5-30 °C, conidia begins to germinate, the most suitable temperature is about 22 °C; the second is the amount of pathogens. There are many pathogens, the incidence is heavy, and vice versa; the third is variety resistance. China's white pear system is susceptible to disease, and Western pear has strong disease resistance. My Cangxi Sydney, Yangshan Pear, Jinhua Pear, and Early Crisp pear varieties have poor disease resistance. The golden pear and Fengshui pear varieties have strong disease resistance; the fourth is the comprehensive management level of the orchard. Where the tree is strong, the ventilation and light transmission in the garden is good, and the incidence is light, otherwise the incidence is heavy. Black spot is generally similar to the conditions in which black spot disease occurs.
Third, the law of infection Pear black spot disease with conidia or mycelium in the axillary bud scales, leaves over the winter. In the following year, as the temperature in the spring rises, the pear trees begin to grow. The pathogens first develop from the scales or petioles of the flower buds, and then gradually spread from the affected parts to the surrounding leaves, new shoots and fruits. It has the characteristics of multiple reinfections, which can cause harm from flowering to fruit picking. After the leaves are damaged, there are round or irregular yellow lesions between the main and lateral veins of the leaf back. After that, black mold spots grow and expand into misty lesions, which cause early leaves when severe. In the early stage of fruit onset, yellowish round spots were formed. After the gradual enlargement, the diseased part showed depression. After the black mold grew, the lesions were corked, hard, cracked, and lost in food value. Fruit stalks, petioles appear black oval concave spots, covered with black mold. My diseased spot appeared in early May, and the disease appeared in the late May, and the onset of the disease was from June to July.
Fourth, prevention and treatment methods In general, cultivation management should be strengthened. The prevention and control of pear black spot disease should grasp two key links: one is to deal with wintering bacteria and remove the source of infection; the other is to protect the fruit when the fruit is near mature, and prevent infection in the later stage. In the production, we will reduce the occurrence of black spot disease by strengthening soil, fertilizer and water management, thinning flowers and thinning, rationally trimming, increasing ventilation and light transmission, and maintaining a robust tree. Specific measures are:
Qingyuan. After the fruit is harvested, the leaves are removed in time, the fruit is deeply buried or burned intensively, and the diseased fruit and the cut off disease are burned in the tree to reduce the amount of pathogenic bacteria.
Fruit bagging. Before the deadline of May 20th, select the inner black double-layer paper bag with the spray bag, and pay attention to tighten the bag mouth to reduce the risk of black spot disease and increase the value of the commodity.
Chemical control.
The key period of drug treatment is the germination period before June, the flowering period, the disease tip emergence period, and the 15 days before fruit picking. Specifically, when the bud is sprouting, the tree is subjected to "bathing" or Xiansheng 600 times liquid spray with 1-3 wave of sulphur stone sulphur mixture.
After falling flowers, the stage of the diseased tip is selected by using Fuxing 8000 times liquid or Shigao 800 times liquid in time for spraying. In the future, according to the condition, Shigao, Xiansheng, Green Shield, agricultural anti-120 fruit trees, special spectrum mites, and multi-moulders will be combined with other pests and diseases every 20 days or so, and rotation and spraying will be carried out. The residual effect period will be selected 15 days before fruit picking. The shorter net bacteria 1000 times liquid prevention and prevention, preventing the disease caused by black spot disease.
I. Symptoms Pear scab can infect all green and young tissues of pear trees, mainly harming leaves and fruits, and also harming bud scales, petioles and fruit stalks, which are harmful from flowering to fruit picking. The lesions turn yellow at the beginning, then become brown and die and grow green mold.
Second, the disease conditions Pear scab is affected by many factors: First, meteorological conditions. Spring rainfall is early, rain is heavy, and humidity is conducive to the invasion and spread of pathogen spores. Rainy days last for 48 hours, rainfall is more than 5 mm, relative humidity is above 70%, temperature is 5-30 °C, conidia begins to germinate, the most suitable temperature is about 22 °C; the second is the amount of pathogens. There are many pathogens, the incidence is heavy, and vice versa; the third is variety resistance. China's white pear system is susceptible to disease, and Western pear has strong disease resistance. My Cangxi Sydney, Yangshan Pear, Jinhua Pear, and Early Crisp pear varieties have poor disease resistance. The golden pear and Fengshui pear varieties have strong disease resistance; the fourth is the comprehensive management level of the orchard. Where the tree is strong, the ventilation and light transmission in the garden is good, and the incidence is light, otherwise the incidence is heavy. Black spot is generally similar to the conditions in which black spot disease occurs.
Third, the law of infection Pear black spot disease with conidia or mycelium in the axillary bud scales, leaves over the winter. In the following year, as the temperature in the spring rises, the pear trees begin to grow. The pathogens first develop from the scales or petioles of the flower buds, and then gradually spread from the affected parts to the surrounding leaves, new shoots and fruits. It has the characteristics of multiple reinfections, which can cause harm from flowering to fruit picking. After the leaves are damaged, there are round or irregular yellow lesions between the main and lateral veins of the leaf back. After that, black mold spots grow and expand into misty lesions, which cause early leaves when severe. In the early stage of fruit onset, yellowish round spots were formed. After the gradual enlargement, the diseased part showed depression. After the black mold grew, the lesions were corked, hard, cracked, and lost in food value. Fruit stalks, petioles appear black oval concave spots, covered with black mold. My diseased spot appeared in early May, and the disease appeared in the late May, and the onset of the disease was from June to July.
Fourth, prevention and treatment methods In general, cultivation management should be strengthened. The prevention and control of pear black spot disease should grasp two key links: one is to deal with wintering bacteria and remove the source of infection; the other is to protect the fruit when the fruit is near mature, and prevent infection in the later stage. In the production, we will reduce the occurrence of black spot disease by strengthening soil, fertilizer and water management, thinning flowers and thinning, rationally trimming, increasing ventilation and light transmission, and maintaining a robust tree. Specific measures are:
Qingyuan. After the fruit is harvested, the leaves are removed in time, the fruit is deeply buried or burned intensively, and the diseased fruit and the cut off disease are burned in the tree to reduce the amount of pathogenic bacteria.
Fruit bagging. Before the deadline of May 20th, select the inner black double-layer paper bag with the spray bag, and pay attention to tighten the bag mouth to reduce the risk of black spot disease and increase the value of the commodity.
Chemical control.
The key period of drug treatment is the germination period before June, the flowering period, the disease tip emergence period, and the 15 days before fruit picking. Specifically, when the bud is sprouting, the tree is subjected to "bathing" or Xiansheng 600 times liquid spray with 1-3 wave of sulphur stone sulphur mixture.
After falling flowers, the stage of the diseased tip is selected by using Fuxing 8000 times liquid or Shigao 800 times liquid in time for spraying. In the future, according to the condition, Shigao, Xiansheng, Green Shield, agricultural anti-120 fruit trees, special spectrum mites, and multi-moulders will be combined with other pests and diseases every 20 days or so, and rotation and spraying will be carried out. The residual effect period will be selected 15 days before fruit picking. The shorter net bacteria 1000 times liquid prevention and prevention, preventing the disease caused by black spot disease.
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