How to control false smut of rice?
(1) agricultural control:
Choose disease-free seeds to prevent seed transmission: in disease-free areas, avoid transporting seeds from disease-free areas, and leave seeds in disease-free areas to prevent seeds from carrying bacteria to spread diseases.
Treat seeds to reduce the source of infection: if seeds carry bacteria, treat seeds. The methods are as follows: 1. Selecting seeds with 10% salt water can eliminate more than 95% diseases. During operation, the liquid level should be higher than the seed surface by more than 20 cm, and the seeds should be stirred up and down quickly and fully, and then the diseased particles floating on the water surface should be removed. Immediately after bleaching, wash the seeds with clear water, then soak the seeds to accelerate germination. Second, seed disinfection: soaking seeds in 300-500 times of strong chlorine solution for 12 hours; Or soak the seeds with 5000 times of soaking spirit.
Implement crop rotation to reduce the amount of bacteria in the soil: try to avoid excessive concentration of seed fields and continuous cropping for many years, and implement crop rotation for more than 2 years in seriously ill fields. After harvesting, the diseased fields should be deeply cultivated and the bacteria on the soil surface should be buried in the soil. Manure should be fully decomposed before application to prevent the fertilizer from carrying bacteria into the field, so as to reduce the number of bacteria in the soil.
Sow in time and coordinate the meeting of flowering period: Taneda hybrid rice should avoid low temperature and rainy weather by adjusting sowing date and heading and flowering period, and at the same time, use 920 and other regulatory hormones to make parents meet at this flowering period, so as to shorten the susceptible period and reduce the incidence.
Rational fertilization, enhance plant stress resistance: increase the application amount of phosphorus and potassium fertilizer, and avoid excessive and late application of nitrogen fertilizer.
(2) Chemical control: general field control 1 time is enough; Hybrid rice Taneda and highly susceptible varieties (combinations) need to be controlled for 2 ~ 3 times. The optimum control period is 1 time; If you take the medicine twice, the first time is at the early flowering stage, and the second time is once every 2 ~ 3 days. If 1 time is processed at the beginning, the end, or the beginning of filling, the effect will be better. The dosage and water consumption should be strictly controlled when using drugs. Too much or too little water consumption will affect the seed setting rate or the effect of disease prevention and conservation. Commonly used drugs and dosages are as follows:
20% triadimefon emulsion: 25% triadimefon wettable powder per 667 m2 100 ~ 125ml or 75 ~100g per 667m2.
40% mirex gel suspension concentrate: 200ml per 667m2.
50% carbendazim wettable powder: 667 m2 100g.
Power failure of composite agent1:300ml per 667m2.