Grown across 3 million hectares in kharif and summer seasons across MP, Andhra Pradesh, and Tamil Nadu, urad is the essential ingredient of the South Indian diet and the protein companion of the rice bowl.
5 Major Threats and Their Control
For educational purposes only. Recommended crop varieties are location-specific. Always verify chemical and variety recommendations with your local KVK or State Agriculture Department.
1. Yellow Mosaic Virus (MYMV)
The Threat:
- Yellow mosaic in urad is identical in mechanism and visual expression to moong yellow mosaic.
- Transmitted by whiteflies, causing complete growth arrest and pod set failure.
- In AP and Telangana urad belt, epidemic years produce 60% losses in susceptible varieties.
- Spreads rapidly through whitefly populations moving between adjacent fields of urad, moong, and soybean.
- Insecticide spraying after infection is ineffective and counterproductive, as it kills natural whitefly predators and facilitates further spread.
The Solution:
- Use resistant varieties recommended by ICAR-IIPR — KU-300, T-9, and Pant U-30 carry MYMV resistance.
- Treat seed with Imidacloprid 70 WS (Systemic Insecticide — Neonicotinoid, IRAC Group 4A) @ 7 g/kg.
- Remove and burn symptomatic plants within 15 days of detection to eliminate virus reservoirs.
- Monitor whitefly adults using yellow sticky traps and base vector management decisions on trap catches rather than visible disease symptoms.
2. Anthracnose
(Colletotrichum lindemuthianum)
The Threat:
- Anthracnose produces dark, sunken, water-soaked lesions on pods — particularly at pod tips and margins.
- Lesions later turn dark brown and significantly reduce seed quality.
- Infected seeds show dark discoloration and wrinkled surfaces, reducing germination rate and market value.
- Primarily seed-borne, entering new fields through infected planting material.
- Spreads through rain splash from infected soil and crop debris in humid conditions.
The Solution:
- Use certified, disease-free seed purchased from a registered source.
- Treat seed with Carbendazim 50 WP (Systemic Fungicide — Benzimidazole, FRAC Group 1) @ 2.5 g/kg before sowing.
- Rotate away from previous legume fields, as Colletotrichum survives in crop debris for 1–2 seasons.
- Spray Carbendazim 50 WP @ 1 g/litre at first pod appearance in humid years as a preventive or early-infection treatment.
3. Leaf Crinkle Virus
(transmitted by aphids)
The Threat:
- Leaf crinkle virus causes severe leaf distortion — leaves become puckered, crinkled, and reduced in size.
- General stunting of the plant occurs with dramatic reduction in pod set.
- Affected plants produce few or no pods and remain vegetative long after healthy neighbours have begun podding.
- The virus is primarily seed-borne, introduced into new fields through infected planting material.
- Spreads within a season through the aphid Aphis craccivora, which moves between infected and healthy plants.
The Solution:
- Use only certified, disease-indexed seed from a registered source — seed health testing before purchase is critical.
- Manage aphid vectors with Dimethoate 30 EC (Systemic Insecticide — Organophosphate, IRAC Group 1B) @ 1.5 ml/litre in the early vegetative stage (10–20 days after sowing) when primary aphid colonisation occurs.
- Remove and destroy symptomatic plants immediately upon detection to eliminate both the virus reservoir and the aphid source within the crop.
4. Waterlogging
The Threat:
- Urad is highly sensitive to waterlogging — even 2–3 days of standing water causes root anaerobia, leaf yellowing from nutrient lockout, and root rot from opportunistic Pythium and Fusarium species.
- In flat, clay-heavy vertisols of Andhra Pradesh, heavy kharif rains can leave fields waterlogged for days, consistently reducing urad yields by 15–20% in affected seasons.
- Waterlogging also creates moist conditions that favour fungal collar rot and bacterial wilt, compounding the damage.
The Solution:
- Prepare raised beds @ 30 cm height before sowing — elevates the root zone above the waterlogged soil horizon and requires no recurring input cost.
- Maintain open drainage channels throughout the season.
- After heavy rain, drain excess water within 24 hours — delayed drainage increases the duration of anaerobic stress.
5. Root Knot Nematode
(Meloidogyne incognita)
The Threat:
- Root knot nematode infects feeder roots and creates characteristic galls — swollen, knobbly protrusions on the root surface — that interfere with water and nutrient absorption.
- Infected plants appear stunted and show interveinal yellowing, mimicking nutrient deficiency.
- Heavily infested plants may wilt in warm afternoon temperatures and recover slightly in the evening, resembling Fusarium wilt symptoms.
- The nematode is most severe in sandy, light-textured soils of AP, Telangana, and TN, which allow free movement of juvenile nematodes.
- Documented losses range from 10–20%.
The Solution:
- Apply Carbofuran 3G (Nematicide / Systemic Insecticide — Carbamate, IRAC Group 1A) @ 10 kg/ha to the soil at sowing.
- Intercrop with marigold (Biological Nematode Suppressant — trap crop) at one row per 4 rows of urad — marigold roots release thiophene compounds that suppress nematode populations and reduce soil inoculum for the following season.
- Soil solarisation with clear polyethylene mulch during May–June reduces nematode density through soil heating.
Ph.D. in Agricultural Engineering.