How to Kill the Rice White-Tip Nematode? A Detailed Guide to Control Methods

After the rice white-tip nematode infests rice, it causes the leaf tips to form a characteristic white tip that then necroses, and the invasion of this pest brings serious economic losses to farmers. How does the rice white-tip nematode spread? How do you kill it?

1. How the rice white-tip nematode spreads

The rice white-tip nematode overwinters as adults and larvae hidden between the glumes and the rice grains, so infected seed is the main primary infection source of this disease. The nematode cannot survive for long in water or soil, so transmission through irrigation water and soil is relatively limited.

When seeds are soaked for sprouting, the nematodes inside the seeds begin to become active. After infected seeds are sown, the nematodes mostly become free in the water and soil, but most of them die; a few encounter young buds or seedlings, invade through the gaps of the coleoptile and leaf sheath, remain latent inside the leaf sheath, pierce and suck the tissue sap with their mouthparts, and live as ectoparasites. As the rice grows, the nematodes gradually move upward and their numbers gradually increase. Before the early booting stage, the more toward the upper leaf sheaths of the plant, the greater the number of nematodes. When the young panicle forms, they invade the panicle and concentrate in large numbers inside and outside the glumes of the young panicle. The nematodes in diseased grains are mostly concentrated in plump grains, accounting for about 83%-88% of the total number of nematodes carried; in blighted grains they account for only 12%-17%. Females can reproduce 1-2 generations during the rice growing period.

2. How to kill the rice white-tip nematode

1. Use disease-free seed, strengthen quarantine, and strictly prohibit the transfer of seed from diseased areas.

2. Establish disease-free seed fields and select and retain disease-free seed.

3. Pre-soak the rice seed in cold water for 24 hours first, then move it into warm water at 45-47°C for 5 minutes, then move it into warm water at 52-54°C for 10 minutes, then cool it immediately, sprout it and sow it.

4. Soak 6 kg of rice seed for 48 hours in a 550-fold dilution of Xianjunqing; or soak the seed for 24-48 hours in a 1000-fold dilution of 50% fenitrothion emulsion; or soak the seed for 20 hours in a 500-fold dilution of 18% bisultap, then remove, wash clean and sprout. A 5000-fold dilution of 10% Jinzhongling EC can also be used to soak the seed for 120 hours; once the sprouts emerge, sow without washing, and it also controls bakanae disease. Soak the seed for 72 hours in a 0.5% hydrochloric acid solution, then rinse the seed 5 times with clean water. Or use a 500-fold dilution of 40% ethyl acetate emulsifiable concentrate to soak 50 kg of seed for 24 hours, then rinse with clean water.

5. During seed soaking with Xianjunqing and Jinzhongling, avoid light and stir frequently. Because temperatures are higher in southern regions, the soaking time can be appropriately shortened.

6. Apply 250 g of 10% fenamiphos granules per mu mixed with 10 kg of fine soil, broadcasting once at the 2-3 leaf stage of the seedlings.

Control of the rice white-tip nematode needs to be done promptly in the early stage, nipping the pest problem in the bud.