How to control pepper powdery mildew? Latest control measures explained in detail
Pepper powdery mildew is a fungal disease caused by powdery mildew fungi. This disease has become one of the serious diseases of peppers, seriously harming the yield and quality of peppers. Below, the editor brings you the symptoms, occurrence patterns and control methods of powdery mildew, let's take a look.
1. Symptoms
Powdery mildew mainly harms the leaf parts of peppers, and also harms tender stems and fruits. When leaves are affected, chlorotic spots of varying numbers and irregular shapes appear, and a sparse mold layer appears on the back of the leaves. The chlorotic spots begin to spread continuously, causing large-area chlorosis of the leaves. This disease hinders leaf photosynthesis, affects the normal growth of the plant, and in severe cases causes the leaves to wither and die.
2. Occurrence patterns
The powdery mildew pathogen is an endoparasitic fungus. After the disease occurs in the field, the hyphae continuously spread within the mesophyll tissue, and conidia extend from the stomata on the back of the leaves and disperse under dry conditions. It is mainly spread by spores with airflow, continuously invading new leaves, and then producing new spores at the diseased spots. After the spores mature, they fall off and spread by wind. This repeats, causing the entire field to become infected in a short time. In the early stage, powdery mildew conidia are mainly endophytic hyphae parasitism. Generally, when disease spots are found on the leaves, it is already the late stage of the disease, which brings certain difficulties to control.
3. Agricultural control
Strengthen fertilizer and water management in the field. Before planting, apply decomposed organic fertilizer or farmyard manure as base fertilizer, which can prevent pathogens and insect eggs from being brought into the field. During the plant growth period, apply more phosphorus and potassium fertilizer, apply little or no quick-acting nitrogen fertilizer, plant at a reasonable density, irrigate appropriately, ventilate frequently, pay attention to the soil moisture content, and avoid alternating dryness and wetness. When watering, try to choose sunny mornings, and drip irrigation is preferable. Remember not to irrigate with large amounts of water or irrigate outside the film. Watering is generally done once every 10-20 days, and the watering interval differs in different seasons.
4. Chemical control
In the early stage of the disease, when there are only a few chlorotic disease spots on the leaves, the pathogenic hyphae are still in the germination stage within the leaf tissue. At this time, promptly spray triadimefon, ningnanmycin, wuyiencin and other agents, once every 7-10 days, spraying 2-3 times continuously, which can effectively control the disease. In the middle stage of the disease, when white disease spots appear on the plant leaves, tender stems and fruits, the pathogenic bacteria have already developed externally and will begin to spread under suitable environments. At this time, the control agents should be increased by 15%-20%, and spraying must be comprehensive. The control agents can use flusilazole emulsifiable concentrate, kresoxim-methyl water-dispersible granules, pyraclostrobin emulsifiable concentrate, etc.
The above is an introduction to the control measures for pepper powdery mildew. We hope it can help you. If you want to learn more related knowledge, please stay tuned to us.