Downy mildew is a common disease in the process of planting crops. The emergence of this disease has led to a decline in crop yield and quality. This article will introduce the prevention and control methods of crop downy mildew in detail. Cause Downy mildew is commonly known as white mold, downy mildew, etc. The disease is prone to epidemic in rainy weather, high air humidity, or long duration of condensation. In the year with a higher average minimum temperature, the incidence is heavier. Under the conditions of early sowing, de-fertilization or serious viral disease, the incidence is heavy. symptom Mainly harmful to the leaves, the surface of the leaves in the early stage of the disease appeared grayish white, yellowish yellow or yellow green, and the lesions were not obvious, and then expanded into yellow-brown lesions. The lesions were polygonal or irregular due to the restriction of veins, and the leaves were densely white. Frosty mildew. The lesions are connected to each other for a long time, causing the diseased leaves to partially or completely die. The diseased plants often dry out from the outer to inner layers, and only a small heart leaf ball remains in severe cases. Control method 1. It is very important to select resistant varieties. Sometimes, two types of varieties are planted in the same vegetable field, and the susceptible varieties are in a mess, while the resistant varieties are not serious. 2. Appropriate planting practice has proved that early sowing is more serious than late sowing, but late sowing often affects the heart and reduces production. Therefore, it is necessary to do so in accordance with the local climate. 3, strengthen the water management in the ground due to downy mildew in the rainy weather, air humidity, or condensation for a long time is prone to popular, so it is extremely important to control the soil moisture, the soil moisture in the field should be controlled at about 25%, Water in the ditch should be removed in time after rain or after irrigation. 4. It is necessary to use pesticides against the mouth to prevent and control the use of agents for downy mildew. Metalaxyl and chlorothalonil have good control effects on downy mildew. 5, clean the countryside should pay attention to check the seedlings, if found that the symptoms of the plant should be timely rooted with soil to dig up the diseased plant, and away from the field for deep burial treatment, the soil where the diseased plant is disinfected with quicklime, The spread of anti-pathogens spread. More pesticide knowledge , please pay attention to China Pesticide Network KMP Cat Parts,Cat Engine Parts,KMP Cat Stamping Parts,Custom KMP Cat Parts,CAT Spare Parts JINING SHANTE SONGZHENG CONSTRUCTION MACHINERY CO.LTD , https://www.stszcmparts.com
Method for controlling crop downy mildew