Black gram, also known as urad, is an important pulse crop widely cultivated across India for its high protein content and soil-enriching qualities. However, one of the major challenges faced by farmers during its cultivation is the attack of whiteflies. These tiny insects not only suck the sap from plants but also spread viral diseases like the Yellow Mosaic Virus (YMV), which can severely reduce crop yield. Therefore, managing whitefly in black gram is crucial for maintaining healthy growth and achieving good production.
1. Identification of Whitefly
Whiteflies are small, soft-bodied insects about 1–2 mm in size. They appear white due to the powdery wax on their wings. They usually stay on the underside of leaves, where they feed by sucking plant sap. When disturbed, they fly in clusters, making them easily visible to farmers.
2. Symptoms of Whitefly Damage
Yellowing and curling of leaves due to sap sucking.
Stunted plant growth and reduced flowering.
Honeydew secretion on leaves, which encourages sooty mould development, reducing photosynthesis.
Spread of Yellow Mosaic Virus, which causes bright yellow patches on leaves and leads to premature drying of the crop.
If the crop shows these symptoms, it’s important to act immediately to prevent further spread.
3. Conditions Favoring Whitefly Attack
Whiteflies thrive in warm, dry weather and are more active during the early and mid-growth stages of the crop. Dense planting, excessive nitrogen application, and presence of weed hosts like wild moong or urd also favor rapid multiplication of the pest.
4. Integrated Management Practices
a. Cultural Practices
Timely sowing: Early sowing of black gram (before the monsoon peak) helps escape severe whitefly and YMV attack.
Crop rotation: Avoid continuous cultivation of black gram or other pulses in the same field. Rotate with cereals like rice, wheat, or maize.
Weed control: Remove alternate host weeds such as Parthenium, Cassia tora, and Euphorbia from field borders and bunds.
Balanced fertilization: Avoid overuse of nitrogen-rich fertilizers. Instead, use a balanced dose of N:P to promote healthy and resistant plants.
Rogueing: Uproot and destroy infected plants showing yellow mosaic symptoms to prevent virus spread.
b. Use of Resistant Varieties
Planting resistant or tolerant varieties is one of the best ways to manage whitefly problems. Farmers should prefer locally recommended YMV-resistant black gram varieties such as PU-31, IPU-2-43, and Pant U-19 (depending on region and availability).
c. Mechanical and Biological Control
Install yellow sticky traps (5–6 per acre) to attract and trap adult whiteflies.
Encourage natural enemies like Encarsia formosa (a parasitic wasp) and ladybird beetles that feed on whiteflies.
Spraying neem-based formulations (neem oil 2–3%) can help repel and reduce whitefly populations naturally.
d. Chemical Control
If infestation crosses the economic threshold level, use selective insecticides like acetamiprid, thiamethoxam, or imidacloprid at recommended doses. Spray in the early morning or evening when the pest is active. Rotate insecticides from different groups to prevent resistance buildup. Always avoid unnecessary or frequent spraying.
5. Post-Harvest Measures
After harvest, remove and destroy crop residues to eliminate breeding sites. Deep summer ploughing helps expose and kill pupae and eggs hiding in the soil.
Conclusion
Effective management of whitefly in black gram requires a combined approach of timely sowing, clean cultivation, use of resistant varieties, and balanced pest control measures. By regularly monitoring the crop and taking preventive steps early, farmers can minimize pest damage, protect their plants from yellow mosaic disease, and ensure a better yield and income from black gram cultivation.
