Bacterial leaf spot of pepper

Chili peppers are not native to China, but since being introduced to China, they have been grown all over the country and play a very important role in the combination with various ingredients. During the growth process of peppers, bacterial leaf spot disease is very likely to occur, which will greatly affect the yield of peppers. And if one plant gets sick, it will quickly spread to a large area. First of all, we need to understand the symptoms of bacterial leaf spot disease of pepper, and take timely treatment measures when symptoms appear.

Pepper bacterial leaf spot symptoms

It occurs in spots in the field, mainly damaging the leaves. The disease occurs on the leaves of mature plants, initially appearing as small, irregular, water-soaked yellow-green spots, which expand into reddish brown or dark brown to rust color. The spots are membranous and vary in size. When dry, the spots are mostly reddish brown. The disease spreads very quickly. Even if individual or most leaves on a plant become infected, the plant can still grow. In severe cases, most of the leaves will fall off. The boundary between bacterial leaf spot and healthy area is obvious, but not raised, which is different from scab.

Pepper bacterial leaf spot--pathogen

Pseudomonas syringae pv.aptata Young.Dye&wi1kie Pseudomonas syringae is suitable for the pathogenic type and belongs to bacteria. The suitable temperature for development is 25-8℃, the highest is 35℃ and the lowest is 5℃. When the temperature and humidity are suitable, diseased plants appear in large numbers and spread rapidly. It is difficult to find the diseased plants and the damage is non-continuous.

Bacterial leaf spot disease of pepper

It spreads through wind, rain or irrigation water and invades through leaf wounds. The disease is more serious when it is planted continuously with cruciferous vegetables such as sweet (hot) peppers, beets, and cabbage, and the disease is easily seen spreading after rain. It usually starts in June in Northeast China and North China, spreads rapidly during the hot and rainy season from July to August, and spreads slowly or stops after September when the temperature drops.

Pepper bacterial leaf spot--control methods

(1) Rotate crops with non-sweet (hot) peppers, cabbage and other cruciferous vegetables for 2-3 years.

(2) Level the land. Ridge cultivation is recommended in the north, while high ridges and deep trenches are recommended in the south. Drain water promptly after rain to prevent water accumulation and flooding.

(3) Seed disinfection: Mix the seeds with 50% copper succinate wettable powder or 50% dichlorodiphenyltrichloroethane wettable powder at a concentration of 0.3% by weight of the seeds before sowing.

(4) Remove diseased and damaged parts or deep plow the soil promptly after harvest.

(5) At the early stage of the disease, spray 500 times diluted 50% copper succinate wettable powder, 300 times diluted 14% copper chelate aqueous solution, 400-500 times diluted 77% chlorambucil wettable powder, 1:1:200 Bordeaux mixture or 72% agricultural streptomycin sulfate soluble powder or 4000 times diluted streptomycin sulfate, once every 7-10 days, and continue to control 2-3 times.