Proactive measures to prevent and control rice blast disease.

(Baonghean) - Following thunderstorms with strong winds, bacterial leaf blight has emerged and is tending to spread, causing widespread damage to the summer-autumn rice crop. Currently, the province has 1,443.1 hectares of rice infected with bacterial leaf blight. If effective control measures are not proactively implemented, it will severely impact rice yields.

Rice blast disease began appearing and spreading rapidly in the summer-autumn rice crop in the rural communes of Quynh Luu district from July 10-12. A few days after a thunderstorm, Ms. Nguyen Thi Loan, from Hamlet 5 (Quynh Giang commune), went to check on her field and saw that her rice, which was in the heading stage, had yellowing and wilting leaves. Following guidance from the commune and hamlet agricultural extension officers, she purchased Starwiner 20WP and sprayed it. After 5 days, she sprayed it again, and simultaneously refrained from applying additional nitrogen fertilizer and other growth stimulants or foliar fertilizers to the infected rice crop. Thanks to this, her family's rice crop has now turned green again.

Spraying pesticides to control bacterial leaf blight in Dien Dong commune (Dien Chau district).

According to residents of the Quỳnh Lưu district's agricultural area, this year's rice blast disease has been quite unusual. The disease appeared early, spread very quickly within just a few days, and showed very clear symptoms. In the communes of Quỳnh Giang, Quỳnh Diễn, Quỳnh Hoa, Quỳnh Hồng, Quỳnh Hậu, etc., the disease appeared simultaneously. The most severe cases occurred in dry, water-scarce areas at the end of the irrigation canals. Mr. Nguyễn Tiến Liên, Head of the Quỳnh Lưu District Plant Protection Station, said: Due to the rapid spread of the disease, immediately after receiving reports from residents and conducting inspections, the district's Plant Protection Station issued a document guiding disease control measures, assigned officers in charge of the affected areas to work directly with the communes, made announcements via the public address system, and organized simultaneous spraying. By July 17th, spraying was basically completed on the entire 750 hectares of infected land (including 200 hectares severely infected, with an infection rate exceeding 40%). “To date, inspections have not revealed any further spread of the disease. However, in the past few days, an additional 27 hectares of rice fields in the semi-mountainous areas of Tan Son, Quynh Tam, and Quynh Tan have been affected, particularly in rice fields in the tillering and heading stages, with a high density of infection in healthy, green rice paddies. We have instructed farmers on disease control measures; if the infection is mild, they can use fine lime powder sprinkled early in the morning to limit the spread. In addition, in areas where the disease has been temporarily controlled, regular inspections must continue, and if there is rain and wind, further control measures must be implemented. Although the disease has not yet appeared on new leaves, it can easily spread if there are thunderstorms or strong winds because the source of the disease is already present,” said Mr. Nguyen Tien Lien.

Dien Truong commune is one of the first localities in Dien Chau district to experience rice blast disease. The entire commune has 50 hectares of rice affected, mainly high-quality rice varieties such as Bac Thom and AC5, which are in the heading stage. The commune has guided farmers to spray with specific pesticides and has initially managed to control the disease. Dien Chau district currently has 561 hectares of rice affected by rice blast. Mr. Le The Hieu, Head of the Plant Protection Station, said: The source of the disease was present before, but only sporadically, not spreading due to the lack of rain and wind. However, after the thunderstorm, the disease started to spread more strongly. Initially, only over 10 hectares were affected in outlying communes such as Dien Truong, Dien Doai, Dien Hong… but later it appeared in inland communes such as Dien Hoa, Dien Hanh… In response to this situation, the Plant Protection Station organized quick training for officials from the commune vice-chairmen, plant protection officers, agricultural extension officers, and heads of rice-growing cooperatives on disease control measures. To date, the disease has been basically brought under control and is not spreading further. Currently, the rice plants are in the late heading and flowering stage. If the disease does not spread further, the yield will be ensured. However, if there is rain and strong winds that tear the leaves, the disease will reappear and spread. Therefore, Dien Chau is continuing to deploy officials to cordon off affected areas, closely monitor the situation to detect the disease early, and advise farmers to only proceed with fertilization after the rice plants are free of disease, prioritizing increasing the amount of potassium in the rice crop.

According to information from the Provincial Plant Protection Sub-Department, bacterial leaf blight has currently emerged and is spreading, causing widespread damage to summer-autumn rice crops in the tillering to heading stages. The province currently has over 1,443.1 hectares infected, of which 292.5 hectares are severely infected. The infected areas are concentrated in the districts of Quynh Luu (747 ha), Dien Chau (561 ha), Yen Thanh (113 ha), Tan Ky (10 ha), etc. The disease prevalence rate is 10-20%, reaching 30-40% in some areas, and in some localized regions, the rate exceeds 50%. Currently, brown spot disease has also emerged, damaging 1,730.5 hectares of rice in the heading stage in the districts of Dien Chau, Yen Thanh, Quynh Luu, Hung Nguyen, Nam Dan, etc., with a high rate of 30-40% in some areas. According to forecasts, the disease will continue to spread and cause increasing damage, especially in fields with dense planting and excessive nitrogen fertilization.

According to Mr. Trinh Thach Lam, Head of the Agricultural Plant Protection Department - Provincial Plant Protection Sub-Department: District plant protection stations need to focus on assigning staff to closely monitor fields to investigate, detect, estimate, and forecast diseased areas and areas at high risk of infection in a timely manner. At the same time, they should advise on timely and specific technical control measures for all levels of government, coordinate with relevant departments and agencies in the area to organize, direct, and guide farmers in controlling the disease when it first appears using one of the following pesticides: Xanthomix 20WP, Starwiner 20WP, Xantoxin 40WP, Totan 200WP... according to the recommended dosage, and re-spray after 5-7 days if the disease continues to develop. In particular, absolutely no nitrogen fertilization, growth stimulants, or foliar fertilizers should be used on rice fields that are already infected or currently infected.

Phu Huong