Focus on preventing the 6th generation of small leaf rollers

Currently, the early-season rice crop is in the panicle-blossoming stage, with 20,200 hectares of ripened rice; the mid-season and late-season rice crop is mainly in the panicle differentiation-development stage. This is a particularly important stage, directly affecting the yield and quality of the final crop. However, according to a report from the Department of Crop Production and Plant Protection, the source of the 6th generation of small leaf rollers in the fields is very high (3-5 times higher than the 2024 Summer-Autumn crop).

Officers of the Department of Crop Production and Plant Protection check the density of leaf rollers in the field and evaluate the effectiveness after spraying.

Currently, the 6th instar adult leaf roller have begun to breed, with high density of 1-3 individuals/m2, in some places over 10 individuals/m2; adults continue to breed from now until September 15, larvae are expected to hatch from September 10-22, with common larvae density of 70-150 individuals/m2, in some places over 300 individuals/m2, causing severe damage over a large area of ​​rice fields.

In addition to leaf rollers, other pests such as the fifth generation of two-spotted stem borers, brown planthoppers, white-backed planthoppers, leaf blight and sheath blight are also increasing.

To ensure production safety and avoid major losses in productivity and output, the Department of Agriculture and Environment requires localities to direct timely spraying of the 6th generation of small leaf rollers in areas with a worm density of 20 larvae/m2 or more, when the larvae are mainly at the 1st and 2nd instars. The peak prevention period is expected to be from September 10 to September 22 (specifically, in the old Ha Nam and Nam Dinh areas, the spraying period is from September 10 to September 17; in the old Ninh Binh area, from September 12 to September 22).

After spraying for 3-5 days, check again. If the density of surviving worms is 20/m2 or more, spray again immediately.

Besides leaf rollers, it is necessary to focus on preventing other pests such as stem borers, brown planthoppers, white-backed planthoppers and diseases.

News and photos: Duc Thuan

Source: https://baoninhbinh.org.vn/tap-trung-phong-tru-sau-cuon-la-nho-lua-6-250915095558082.html