Rice blast disease control - Some mistakes

(Baonghean) -In spring rice production, blast disease is one of the diseases that causes great damage to many rice varieties on a large scale in many localities. However, in the prevention of this disease, farmers often make some mistakes.

First mistake: Sowing too densely, especially in the sowing area. Because of fear of the rice being frozen in the early season, farmers increased the amount of seeds sown by 25-30% compared to the amount of seeds prescribed for the area or planted many spikes/clumps, with a density of 48-52 clumps/m2, increasing the density of the rice field population. In addition, unbalanced fertilization, excess nitrogen and lack of potassium increase favorable conditions for the development of rice blast disease. Farmers did not think about the double harm of rice blast disease; when rice is damaged by blast and leaves burn during the tillering period, it will potentially cause damage to the panicle neck.

Second mistake: Preventing blast too late; usually when the disease is quite common, then spraying pesticides. The best way is to regularly check the fields and when you see oil-stained spots, spray immediately. In particular, high-quality rice varieties need to be proactively sprayed early.

Farmers in hamlet 2, Bac Thanh commune (Yen Thanh) apply lime to prevent pests and diseases in rice.
Spring crop 2013. Photo: Ho Cac

Third mistake: Using drugs that do not follow the “4 rights” principle and especially using non-specific drugs with too low active ingredient content (Tricyclazole and Propiconazole). Farmers are completely dependent on drug sellers, buying whatever type is sold. Some agents, for profit, sell drugs that do not guarantee quality. Farmers do not use specific drugs, but only use cheap drugs.

Fourth mistake: Spraying with growth-stimulating fertilizer, or adding nitrogen fertilizer to some yellow rice fields while the rice blast disease is developing. This is more harmful than beneficial. The disease continues to spread widely.

Fifth mistake: Seeing the neighboring field is infected, while your own field is not, but the rice is too good, so you cut the leaves. This action creates mechanical wounds for the pathogen to spread quickly, reducing the leaf area, affecting the ability to photosynthesize. The best way is to carry out synchronous spraying for rice varieties that have signs of infection in the same field.

For the 2013 spring crop, blast disease may arise early in the period of rice tillering. In addition, some other pests may arise at the same time during the rice standing and panicle initiation stages such as brown planthoppers, brown planthoppers, etc. Localities need to regularly check fields, proactively prevent and control them, and pay special attention to areas planted with varieties such as AC5, HT1, BC15, and Khai Phong 1.

Hoang An (Department of Agriculture and Rural Development)