Wheat powdery mildew occurs mainly on the leaves, but it can also occur on leaf sheaths, stems and ears of plants. Generally, there are more positive lesions on the leaf than on the back of the leaf, and the lower leaf has more disease than the upper leaf. The surface of the diseased layer was accompanied by a layer of white powdery mildew. The diseased part first appeared white filamentous mildew, gradually expanded and combined with each other, showing a long oval-shaped moldy plaque, and when it was severe, it could cover most or all of the leaves. The mold layer can reach a thickness of about 2 mm and gradually becomes powdery. Later, the mold layer gradually turned from white to gray with black particles. The leaves turn yellow early and the curls die. Severely diseased plants often dwarf and cannot head. The occurrence and development of wheat powdery mildew are closely related to meteorological conditions, breed resistance and cultivation and management. When the temperature is between 15-20°C and the relative humidity of the field is above 70%, the disease develops rapidly. Where the fog is heavy, the temperature in the early spring rises seriously, and the humidity in the field is conducive to infection. Excessive application of fertilizer and water, wheat overgrowth, population density is too large, airtight, humidity in the field, young plants, low disease resistance, but also very prone to powdery mildew.
Prevention and control method 1 The selection of disease-resistant varieties can effectively inhibit the occurrence of wheat powdery mildew. Currently, it should be based on the selection of disease-resistant varieties. 2 Immediately after the wheat harvest, the volunteer wheat will be eradicated in various occasions to eliminate the initial infection source. 3Appropriate close planting, semi-precision sowing with proper amount, appropriate late sowing, and improving plant disease resistance. 4 pay attention to the reasonable application of nitrogen fertilizer, formula fertilization, timely drainage and irrigation. 5 timely chemical control: When the general rate of wheat powdery mildew reaches 10% or the disease index reaches 5%-8%, it should be controlled by the chemical. Per acre 15% triadimefon 50 grams plus "Tianda 2116" Zhuang Miaoling against water 30 kg, in the early spring spray once to basically control the hazards, and can effectively prevent and control freeze injury and stripe rust and powdery mildew. In areas where there is a high incidence of disease, 15% triadimefon can be used for seed dressing at a seed weight of 0.12% to control the condition of the seedlings, reduce the amount of overwintering bacteria, reduce the incidence of disease, and to prevent the spread of smut, if the same amount of dip is added The type "Tianda 2116" will be even better.
Red Chili,Seafood Hotpot Seasoning,Black Pepper Spices,Dried White Pepper
Chinese Seasoning (Shandong) Trading Co.,Ltd , https://www.zt-trading.com