Control of Yellow Stem Borer Plus Sheath Blight in Paddy Field
Paddy or rice is an important crop for human consumption and for the economy of many countries. However, pests and diseases can cause significant yield losses to rice farmers. Two of the most damaging rice pests are the yellow stem borer (Scirpophaga incertulas) and sheath blight (Rhizoctonia solani). The yellow stem borer feeds on the stem of rice plants, while sheath blight infects the sheath that surrounds the stem. Both pests can cause significant damage to the rice crop, reducing the yield and quality of the grains. In this article, we will discuss the control of yellow stem borer plus sheath blight in paddy field.
1. Cultural Control
Cultural practices can help to reduce the incidence and severity of yellow stem borer and sheath blight. These include:
– Crop rotation: Alternating rice with other crops can break the life cycle of the pests and prevent them from building up populations in the soil.
– Field preparation: Proper land preparation, such as plowing and leveling, can help to avoid waterlogging and reduce fungal growth that favors sheath blight.
– Seed selection: Using healthy and disease-free seeds can prevent the entry of pathogens into the field and reduce the spread of diseases.
– Sanitation: Removing crop residues and weeds can eliminate the breeding grounds of pests and diseases, and reduce the risk of their recurrence.
2. Chemical Control
Chemical control can be used to manage yellow stem borer and sheath blight in paddy field. However, it should be done with caution, as excessive use of pesticides can harm the environment and human health. The following are the recommended chemicals and their application for controlling the two pests.
Yellow Stem Borer
– Insecticides: Apply granular insecticides like Carbofuran at 33-40 kg/ha at the time of transplanting. Spraying insecticides like monocrotophos or chlorpyrifos can also be done when pest infestation is high.
– Biopesticides: Bacillus thuringiensis (Bt) can also be used to control yellow stem borer.
Sheath Blight
– Fungicides: Apply fungicides like Carbendazim, Hexaconazole, Propiconazole, Tebuconazole, or Tricyclazole.
– Biofungicides: Use of biofungicides like Trichoderma and Pseudomonas can also be done.
– Integrated Pest Management (IPM): Implementing an IPM approach to sheath blight is recommended. This approach includes cultural control, biocontrol, and chemical control where necessary.
3. Biological Control
Biological control is an alternative method for controlling yellow stem borer and sheath blight in paddy field. It involves using natural enemies of the pests to suppress their populations. The following are the biocontrol options for the two pests:
Yellow Stem Borer
– Parasitoids: Release Trichogramma japonicum or T. pretiosum to manage borer infestation.
– Predators: Release predators such as spiders, ants, and earwigs to feed on the eggs and larvae of the borer.
Sheath Blight
– Biocontrol agents: Use microbial agents like Trichoderma, Pseudomonas, Bacillus, and Streptomyces that are antagonistic to the fungi that cause sheath blight.
– Natural enemies: Release predatory nematodes, lacewings, and ladybirds that feed on the fungal pathogens and their spores.
In conclusion, the control of yellow stem borer plus sheath blight in paddy field requires an integrated pest management strategy that includes cultural, chemical, and biological control practices. Rice farmers should be aware of the risks of excessive pesticide use, and should follow the recommended guidelines for their safe and effective use to minimize the environmental and health impact. By implementing the appropriate pest management practices, rice farmers can increase their yields and secure their livelihoods.