How to control pepper stem rot?

The disease only harms the stem base of pepper, and usually occurs at the fruiting stage. At the early stage of the stem basal cortex, there was no obvious lesion outside, and the whole plant above the stem basal cortex wilted and the leaves were pale. The cortex at the base of the stem gradually changes from light brown to dark brown, surrounding the base of the stem, and the diseased part loses water, dries and shrinks. Due to the high degree of lignification at the stem base, the shrinkage is not obvious. In the longitudinal section of the diseased stem base, the xylem darkens and the vascular bundle does not change color; Cross-cut the base of the diseased stem, and no milky mucus overflowed after moisturizing; The cortex is not easy to peel off; Roots and roots do not rot; In the later stage, the leaves turn yellow and die, and many residual branches do not fall off. The disease developed slowly and the whole plant died in about 10 ~ 15 days.

(2) the law of incidence

The pathogen overwinters in the soil in the form of mycelium or sclerotia. At the beginning of the following year, overwintering hyphae directly invaded the stomata or epidermis of the host. The hyphae produced at the infected site are spread by water flow and farm tools. The highest temperature of pathogen development is 40 ~ 42℃, the lowest is 13 ~ 15℃, and the suitable pH is 3.0 ~ 9.5, and it develops well under strong acid conditions. Rainy weather, wet ground, poor ventilation and light transmission, stem basal cortex damage, easy to get sick.

(3) Prevention and control measures

① Cultivation with high ridges is not suitable for furrow irrigation; Drainage in time, remove the diseased plants. ② Cultivate strong seedlings. Strict disinfection of seeds and nutrient soil; Spraying 0. 1% potassium dihydrogen phosphate or 8000 times of plant chemicals after emergence; Spraying 600 times solution of 75% chlorothalonil wettable powder or 500 times solution of 50% thiram wettable powder at seedling stage. (3) Take medicine in time at the early stage of onset. You can choose 40% seed dressing double wettable powder, mix 8 ~ 10g of medicine per square meter of topsoil with dry fine soil, and then apply it to the stem base of the diseased plant to cover the diseased part. Or 600 times of 75% chlorothalonil wettable powder; Or 40% seed dressing double powder 800 times suspension spraying; Or 200 times of 50% thiram wettable powder solution.