Warning of rice blast disease and leaf roller damage on rice

According to a recent investigation by the provincial Department of Crop Production and Plant Protection, rice blast disease and leaf roller are currently appearing and causing damage to rice fields.

Specifically: Rice blast disease mainly appears locally in areas of good green rice, susceptible varieties such as: TBR 225, LT2, Bac Thom No. 7, Dai Thom 8, BC15, Nep... Disease rate in high places: 5-10%, in rare cases: 30-50% of leaves. Up to now, the total area infected with rice blast disease in the whole province is 25.9 hectares, mainly concentrated in Hoa Lu, Yen Mo, Yen Khanh, Nho Quan districts.

Small leaf rollers are also causing local damage to areas of green rice, with a common density of 7-10 individuals/m2; in some places, it is over 100 individuals/m2, mainly concentrated in Yen Mo, Yen Khanh, and Kim Son districts.

Experts warn that with the current gloomy, warm, humid weather combined with the existing source of disease in the fields, pests and diseases will continue to spread widely. Therefore, localities, cooperatives and farmers must regularly check the fields, detect and take timely preventive measures when the threshold is reached.

For small leaf rollers: spray on fields with a density of over 20 worms/m2 for early spring tea and over 50 worms/m2 for late spring tea when the second instar larvae hatch. Expected spraying time is from April 5-10, 2024.

For fields with leaf blast disease, immediately stop applying fertilizers, especially nitrogen fertilizers or any growth stimulants. Spray on fields with a disease rate of 3% or more of leaves. Fields with severe disease must be sprayed twice. For neck blast disease, spray according to the rice flowering rate in fields that have been infected with leaf blast disease, susceptible varieties, and green fields near the source of the disease when the rice has 3-5% flowering.

News and photos: Nguyen Luu

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