Solutions for prevention of rice leaf-folder in rice

Harmful agents:

Small leaf-folder scientifically known as Cnaphalocrosis medinalis, Guenee.

Worms have 5 ages. The young worms are capable of releasing silk and folding the rice leaves horizontally. Worms inside can wreak havoc around the clock 

Symptoms and effects:

• Rice worms release silk and roll along the rice leaves sticking to the 2 edges of the leaves into a cylinder to make a nest.
• Worms located inside, feed on upper epidermis and leaf’s chlorophyll (not lower epidermis) along leaf veins forming long white streaks, these streaks can be linked together in patches.
• Therefore, when the rice plant is severely damaged, the leaves become white, then if it is heavily rained or flooded, it will rot, severely reducing the photosynthetic ability of the leaves, making the rice yield significantly reduced.
• At all growth stages of rice plants, there is a possibility of being damaged by small leaffolders, but the most obvious damage is usually at the tillering and flowering stages (when leaves are damaged, it will seriously reduce rice yield).

Prevention measures:

To be effective in managing rice leaf-folders, many measures should be combined:

• If possible, only do 2 rice crops or rotate rice with other crops
• Do not sow too thickly, fertilize in balance and pay attention not to over-fertilize with nitrogen to avoid the situation that the rice is too big and green, attracting worms to roll leaves into the field.
• Should clear grass along the shore because that is the residence of leaf-folders.
• Limit spraying in the period of 30 days after sowing to protect natural enemies in the field and at this time, the rice plants are also in the leafing stage, so they are able to recover without losing yield.
• However, if the density of leaf-folders appears to the threshold of about 20 insects/m2, farmers should apply the last measure, which is to spray insecticide. Particularly in the period of flowering, the density of leaf-folders is about 6-9  insects/m2, must be sprayed immediately to ensure rice yield.

Chemical measures: can use chemical drugs such as MAP WINNER 5WG product to prevent harmful leaf-folders in the field.

MAP WINNER 5WG is a broad-spectrum insecticide and disease of biological origin, effective in preventing and controlling resistant pests, with little effect on natural enemies, safe for plants, and effective against both leaf-folders and spiders. thrips, …

• Map Winner 5WG insecticide is easy to use, dissolves quickly, does not fly dust, has little effect on natural enemies in the field, suitable for IPM and clean fruit trees.
• It has the ability to escape very quickly, strong, low dose and control cost, helping to achieve high efficiency.
• Dosage used: 80 g/ha
• Mixing method: 2 – 3 gr / 16 liter.