Prevention of blast disease on spring rice

(Baonghean) -If every year, around the end of February, the rice blast disease begins to appear and cause damage to spring rice, this year the weather is warm, the rice plants grow well, and right from the Lunar New Year, the disease has appeared and developed. Prevention is an urgent task for farmers today.

Since the Lunar New Year, 8 sao of rice belonging to Mr. Nguyen Van Can's family (Thai Loc hamlet - Nghi Thai) has started to have rice blast disease. He worriedly said: The area infected with rice blast is mainly on Xi23 rice variety and it happened earlier than every year. Although he has sprayed pesticides according to the instructions of the commune's agricultural extension officers, Mr. Can is still not assured because since after Tet until now, the infected area has continued to increase, and the weather has been rainy and humid, making it very difficult to prevent and control.

Spraying pesticides on spring rice in Nghi Thai, Nghi Loc.

As one of the two localities with the largest area infected with rice blast disease (along with Vinh City), by February 22, 2013, Nghi Loc district had 120 hectares in 16 communes infected with rice blast disease, of which over 11 hectares were severely infected. According to the Deputy Head of the District's Agriculture Department, Dong Thanh Binh: The disease appeared before Tet in Nghi Phong commune; however, since the days after Tet, the disease has developed and spread very strongly to other localities due to favorable weather conditions, sunny and rainy, high humidity. Many communes such as Nghi Thai and Nghi Phong have hundreds of hectares infected with the disease. The district has organized the first round of preventive spraying on over 70 hectares of lightly infected areas and is currently continuing to direct the spraying of the remaining areas and areas at risk of infection. However, in recent days, the work of preventing rice blast disease has encountered many difficulties due to continuous cold rains, spraying chemicals is not effective, and the risk of the disease developing into a widespread epidemic is very high. To minimize damage caused by the disease and prevent the risk of rice blast disease at the neck stage, Nghi Loc advocates destroying areas infected with the disease at a rate of over 50%; the remaining areas, if heavily infected, must be sprayed multiple times with a higher concentration or change the drug if necessary to increase specificity.

Currently, spring rice is in the tillering period, but even before Tet, leaf blast disease has been occurring and causing damage to rice in most districts. By February 20, in Nghi Loc and Vinh City, 186.1 hectares were infected (Nghi Loc over 120 hectares, Vinh City nearly 66 hectares), of which 12.75 hectares were severely infected, with a common disease rate of 3 - 5%, high in places 15 - 30% and in some areas up to 50 - 70%. The infected area is mainly concentrated on early spring rice varieties such as Xi 23, Xi 30, TL 6, BC 15,....

This spring crop, the rice blast disease appeared earlier than usual. The reason is that since planting until now, the weather has been mainly sunny and warm, the rice plants have grown very quickly. In the face of the strong outbreak of the disease, the Plant Protection Department has directed the spraying of preventive measures on infected areas. However, according to Mr. Nguyen Dinh Huong (Deputy Head of the Provincial Plant Protection Department), in the coming time, the weather will gradually warm up, alternating with cold air waves, high humidity accompanied by rain, combined with farmers fertilizing rice to produce tillers, which are favorable conditions for the rice blast disease to arise, spread and cause serious damage over a wide area. Especially on sandy soil, light loam, semi-mountainous areas, planting varieties with high infection levels such as Xi 23, Xi 30, BC 15, AC 5, Khai Phong, IR 17494, glutinous rice,... and on fields with unbalanced fertilization and excess nitrogen fertilization.

To effectively prevent rice blast disease, not allowing the disease to spread and cause serious damage on a large scale, farmers need to closely monitor the fields to promptly detect the outbreak of the disease in the fields and prevent the disease. In particular, farmers need to pay attention to temporarily stop nitrogen fertilization in rice fields that have been infected and damaged, and keep enough water in the fields. Do not let them dry out to limit nitrogen loss, help the rice grow and develop healthily, and increase resistance to disease. In fields with diseased areas, absolutely do not use foliar fertilizers and nitrogen fertilizers. If the disease is mild, just add lime and continue to monitor for spraying unless the infection rate is 3-5% with one of the following drugs: Katana 20SC, Beam 75WP, Filia 525SE, Vista 72.5 WP, Bump 650WP, Kabim 30WP, Ensino 40 SC, ... according to the recommended amount. After a week, check again. If the disease continues to appear, spray again 5-7 days after the first spray. When the disease stops developing, fertilize again.

Article and photos: Phu Huong