What are the comprehensive control measures for rice blast?

(1) It is an economical and effective measure to select varieties with strong disease resistance and disease tolerance and improve the seed retention system. At the same time, it is necessary to rationally distribute varieties and constantly update disease-resistant varieties.

(2) Seed treatment: Rice seeds should be selected from disease-free fields or lightly diseased fields. Germ-bearing seeds, especially late rice diseases, are one of the main sources of infection of seedling leaf blight, and seeds should be disinfected. Soak the seeds in 500 times of strong chlorine solution for 12 hours, then rinse them with clean water, and then soak them or accelerate germination directly; Use 2 ml of seed soaking spirit, add water 10 kg, soak seeds for 6 kg, soak seeds for 2 ~ 3 days, accelerate germination and sow directly.

(3) Strengthening cultivation management: The key to prevent seedling leaf blight is to sow properly and cultivate strong, old, healthy, disease-free or light seedlings. In the early stage of Honda, base fertilizer should be sufficient, and attention should be paid to the coordination of nitrogen, phosphorus and potassium to promote the growth balance of rice plants. Putting the field in time before the peak tillering period can enhance the disease resistance of plants, control the occurrence and development of leaf blast, and thus reduce the chemical control area. Full water irrigation at heading stage can meet the needs of flowering period, and wet irrigation at filling stage is beneficial to yellow ripening of green stalks and reduce the incidence. In areas and fields prone to diseases, spike fertilizer should not be applied or used with caution, so as not to aggravate the disease and reduce production.

(4) Chemical control: In perennial epidemic areas of rice blast, chemical control strategies should be adopted to suppress seedling blast, leaf blast and ear neck blast. When transplanting rice, 750 times of rice koji (20% tricyclazole wettable powder 100g, water 70-80kg) is used to soak the seedlings for 3-5 minutes, and then the seedlings are taken out and stacked for 20-30 minutes before transplanting, which can basically control the field leaf blast and reduce the occurrence area and control times of the field leaf blast. The focus of chemical control is panicle neck blast, because it has great influence on rice yield and quality. If the weather forecast is low temperature and rainy during the rest period, it must be controlled immediately. If the weather is favorable for the disease to continue to occur, spray it again during grouting. Commonly used drugs are: 275% tricyclazole powder 20 ~ 30g per 667m; Or 40% Fuji 1 (also known as isoprothiolane) emulsifiable concentrate or wettable powder, spraying 270 ml of water 500 times every 667 meters; Or 40% carbendazim gel suspension 2 100ml per 667m or 275ml per 667m of 2% kasugamycin aqueous solution.