Comprehensive control of powdery mildew of Schisandra chinensis

1. Powdery mildew in the field mainly harms the leaves of Schisandra chinensis, and when it is serious, the fruit, petiole and stem are also damaged. In the early stage of the disease, white fine powdery mildew spots appeared, which gradually expanded and thickened the mildew layer, like a layer of flour on the leaves. The back of the mildew spot is initially a small chlorotic spot, which expands into irregular plaques with the development of the disease. In the later stage of the disease, black particles were produced in the mildew layer, resulting in mildew and grain loss of the fruit, reduction of yield and decline of quality at the same time.

two。 The incidence of powdery mildew of Schisandra chinensis belongs to the subphylum powdery mildew of Schisandra chinensis. Most of the conidia are cylindrical and a few are columnar, oval or long oval. In Fengcheng area, the pathogen overwintered on the remnant in closed cysts, and the infection of cysts and conidia occurred from May to June of the second year, and the peak period of the disease was from July to August. The disease can occur at the temperature of 20-28 ℃, and the most suitable temperature is 25-26 ℃. The disease was serious in mountain areas above 1000 meters above sea level, serious in areas with poor management, partial application of nitrogen fertilizer and over-planting, and mild in 1-2-year-old Schisandra chinensis, and severe in more than 3 years.

3. Fengcheng Schisandra chinensis mainly adopts the following control methods: ① agricultural control, strengthening field management, balanced fertilization, avoiding excessive close planting, strengthening ventilation and transparent light, removing dead branches and leaves in the field in autumn and winter, and centrally burning the diseased body. ② chemical control, during the onset of the disease with 12.5% fruit base EC 5000 times liquid uniform spray, or with 10% hyperosmotic promethazone 1000 times solution uniform spray, 33% no garden 800 times liquid uniform spray, 30% ether bromides per mu with 20 grams per mu uniform spray on water.