Groundnuts: Major Diseases and their Control

Groundnuts are an important crop in India. They are susceptible to various diseases that cause significant yield loss. Higher yields can be achieved by identifying the diseases that affect the crop and adopting the methods mentioned below.

Diseases and their Control Measures

Anthracnose

Symptoms

• Dark, sunken spots with distinct edges may appear on leaves, stems, and pods.
• Over time, these spots can spread, causing the entire plant to rot.
• Infection on pods leads to deep, sunken lesions that spread and eventually rot.
• The disease causes browning and decay of leaves, and in severe cases, the leaves may fall off.

Control Measures

• Avoid planting groundnuts in the same field year after year, as this can increase the buildup of pathogens.
• Cultivate resistant varieties to reduce the impact of anthracnose.
• Remove and destroy infected plant remains.
• Avoid excessive irrigation or waterlogging, as these conditions can promote disease development.
• Spray 450 gm of Carbendazim 12% + Mancozeb 63% WP per acre.
• Mix 300 ml of DeHaat Azytop (Azoxystrobin 11% + Tebuconazole 18.3% SC) in 150 liters of water and spray per acre.
• Use 800 gm of Thiram for treating seeds used per acre.

Leaf Spot Disease

Symptoms

• The first symptom of this disease appears on the leaves, where the veins of the leaves turn black.
• Gradually, the leaves turn yellow and start to dry.
• The roots of the plants begin to rot, and eventually, the entire plant wilts and dries up.

Control Measures

• Ensure proper drainage in the field.
• Plant the seedlings in the raised beds.
• Control weeds in the field.
• Select disease-resistant varieties to prevent this disease.
• Destroy infected plants to prevent the spread of the disease.
• To control this disease, spray 150 ml of Difenoconazole 25% EC per acre.
• Spraying 600 ml of Hexaconazole 5% EC per acre can control the disease.
• When the infection is severe, use 200 ml of Azoxystrobin 18.2% + Difenoconazole 11.4% w/w SC per acre for spraying in the field.
• Additionally, spraying with 2.5 gm of Carbendazim per liter of water can also be done.

Rust Disease

Symptoms

• The symptoms of this disease first appear on the leaves of the plants.
• Small spots start forming on the affected leaves.
• These spots are round and dark brown in color.
• The edges of the spots have yellow streaks.
• As the disease progresses, the leaves turn yellow and begin to fall off.

Control Measures

• Select healthy, disease-resistant seeds for sowing.
• Follow crop rotation to prevent this disease.
• Keep the field free from weeds.
• Before sowing, treat the seeds with 3 gm of Thiram 75% or Mancozeb 75% per kilogram of seeds.
• Avoid working in the field when the leaves are wet. Remove and destroy infected plants from the field.
• Spray 300 gm of DeHaat Saabu (Carbendazim 12% + Mancozeb 63%) per acre at intervals of 15 days after 40 days of sowing.
• When symptoms of the disease appear, spray 800 gm of Mancozeb 75% (Dem-45) or 700 gm of Copper Oxychloride (Blue Copper) mixed in 250 liters of water per acre.
• Use Hexaconazole 75% WG at a rate of 27 gm per acre.
• If necessary, spray 2 to 3 times at intervals of 15 days.

Root Rot

Symptoms

• This disease spreads through fungus found in the soil.
• The spores of this fungal disease can remain in the soil for many years.
• White thread-like structures are found in the roots of the plants and near the soil surface.
• Later, these structures affect other parts of the plant, forming brown spots the size of mustard seeds.
• Subsequently, the leaves turn yellow, then brown, and eventually fall off.
• In the crop, root rot disease caused by soil and seed can reduce yield by up to 40%.

Control Measures

• Perform deep plowing in the summer months (May-June).
• Adopt long-term crop rotation.
• Collect and burn the affected plants.
• Treat seeds with fungicides, such as thiram or carbendazim, at a rate of 3 gm per kilogram of seed.
• Use DeHaat Saabu (Carbendazim 12% + Mancozeb 63%) at a rate of 2.5 gm per kilogram of seed for seed treatment.
• To protect the crop from this disease, treat the seeds with 3 gm of Carbendazim 25% + Mancozeb 50% WS at the rate of 3 gm/kg of seed before sowing.
• If the disease appears in standing crops, apply Copper Oxychloride 50% WP (Tata Rallis Blitox) at a rate of 500 gm per acre through drenching or during irrigation.

What control measures do you take for diseases in your groundnut crop? Share your answers and experiences with us by commenting. For more such interesting and important information, follow the 'Agri Doctor' channel now. And if you liked the post, don't forget to like it and share it with your fellow farmers.

Frequently Asked Questions (FAQs)

Q: What are the common diseases that affect groundnuts?

A: Groundnuts in India are susceptible to several major diseases, including leaf spot, rust, and stem rot. Leaf spot causes yellowing and brown patches on the leaves, while rust and stem rot can affect plant growth and productivity. Appropriate measures should be taken to prevent and control these diseases.

Q: When should potash be applied to groundnuts?

A: Potash is an essential nutrient for the crop as it aids in the development of strong roots and improves the quality of nuts. In India, potash is applied to groundnut crops at the time of sowing or planting as a basal application and again as a top dressing 30-40 days after sowing. This helps in the development of pods and improves the yield and quality of crops. It is important to ensure that the precise amount and timing of potash application are optimized based on soil type, crop variety, and other factors.

Q: What role does sulfur play in groundnut crops?

A: Sulfur is an important nutrient for groundnut crops that assists in various physiological processes of the plant. Benefits include aiding in protein and chlorophyll synthesis and playing a role in disease resistance. In India, sulfur is applied at the time of sowing and again as a top dressing 30-40 days later. The exact amount and timing should be optimized based on soil type.

Q: When should the first watering be done for groundnut crops?

A: The timing of the first irrigation for groundnut crops depends on soil type, weather conditions, and the growth stages of the crop. Generally, it is around 10-15 days after sowing or when a good root system has been established. During this irrigation, it is important to provide adequate water to the crop, but not too much to avoid waterlogging and related problems. Subsequently, irrigation should be done at regular intervals based on soil moisture levels and weather conditions, adjusted according to the crop's development and weather.

Q: What causes Tikka disease in groundnuts?

A: Tikka disease is caused by the fungus Cercospora personatum. This fungus creates lesions on the leaves that can spread over time and affect the crop.