Integrated Management of Blight Disease in Crops

Blight disease can affect various types of crops, significantly reducing their yield. Controlling this disease is essential to ensure good harvests and to protect farmers from economic losses. Blight disease is primarily of two types: early blight and late blight. Through this post, let's explore in detail the causes, symptoms, and control measures for this disease.

Crops Affected by Blight Disease

• Blight disease affects a wide range of crops, including grains, pulses, oilseeds, vegetables, and fruits. Some of the most affected crops are potatoes, tomatoes, eggplants, onions, chilies, coriander, wheat, barley, maize, sorghum, chickpeas, pigeon peas, soybeans, peanuts, and grapes.

Types of Blight Disease

Blight disease in crops primarily occurs in two forms:

• Early Blight: This disease appears in the early stages of crop development and affects leaves, stems, and fruits.
• Late Blight: This disease occurs in the later stages of crop development and is most commonly seen in tuber crops like potatoes.

Damage Caused in Crops due to Blight Disease

• Leaf Scorching: The leaves of the crop first turn yellow and then scorch, eventually falling off.
• Impact on Fruit Quality: Fruits from affected plants deteriorate in quality, resulting in lower market prices.
• Reduction in Crop Yield: Blight disease can severely impact plant growth, potentially reducing crop yield by more than 50%.
• Economic Loss: Farmers face significant financial losses due to reduced production.

Causes of Blight Disease

• The main cause of this disease is fungi.
• Excess moisture and water accumulation in the field accelerate the spread of fungi.
• Late blight disease spreads more in cool weather when the temperature drops.
• Plants become weak due to a lack of nutrients in the crop, making them more vulnerable to this disease.
• The use of seeds infected with this disease during sowing is a major cause of its spread.

Symptoms of Early Blight

• Early blight is caused by a fungus called Alternaria solani.
• This disease causes significant damage to crops.
• Symptoms of this disease begin to appear 3 to 4 weeks after sowing.
• Small spots start appearing on the lower leaves of plants affected by this disease.
• As the disease progresses, the size and color of the spots also increase.
• With the increased severity of the disease, the leaves shrivel and begin to fall.
• Brown and black spots also start appearing on the stems of the plants.
• The size of the tubers remains small.

Methods of Controlling Early Blight Through Chemical Methods

• Apply 600 to 800 grams of Mancozeb 75% WP (Indofil M-45, Dhanuka M-45, UPL Uthane) per acre of field.
• Use 2 ml of Tebuconazole 38.39% SC (Bayer Buonos) per liter of water.
• Apply 300 ml of Azoxystrobin 11% + Tebuconazole 18.3% SC (DeHaat Azytop) per acre of field.
• Use 600-800 ml of Propineb 70% WP (DeHaat Zinacto, Bayer Antracol, Katyayani Propi) per acre of field.
• Apply 300-600 grams of Carbendazim 12% + Mancozeb 63% WP (DeHaat Saabu, Katyayani Samartha, Anshul Dost, Dhanuka Sixer) per acre of field.

Symptoms of Late Blight

• Late blight is caused by a fungus called Phytophthora.
• Infected plants’ leaves start wilting from the edges.
• Brown and black spots appear on the affected leaves.
• Fungal growth resembling cotton appears on the underside of the leaves.
• This disease reduces crop yield, and the tubers may not develop fully.
• The disease spreads rapidly, and the entire crop can be destroyed within a few days.

Methods of Controlling Late Blight Through Chemical Methods

• To control this disease, spray 200 ml of Azoxystrobin 18.2% + Difenoconazole 11.4% SC (DeHaat Synpact) per acre of field.
• Mix 300 ml of Azoxystrobin 11% + Tebuconazole 18.3% (DeHaat Azytop, Adama Custodia) in 150 liters of water and spray it per acre to control this disease.
• Use 600-800 grams of Mancozeb 75% WP (DeHaat DeM-45, Indofil M 45) per acre of field.
• Apply 300-600 grams of Cymoxanil 8% + Mancozeb 64% WP (DeHaat Versate, Katyayani ELPI) per acre of field.
• Use 800-1250 grams of Metalaxyl 8% + Mancozeb 64% WP (Katyayani Meta-Manco, Skyn Crop Care Radar 72) per acre of field.

Integrated Disease Management to Control Blight Disease

Crop Rotation: Continuous onion farming in the same field increases the likelihood of this disease. To protect the onion crop from this disease, adopt crop rotation.

Selection of Disease-Free Seeds: Use disease-free, healthy seeds for onion farming.

Selection of Resistant Varieties: Sow varieties that are tolerant or resistant to blight disease.

Proper Sanitation: Remove and destroy crop residues like leaves, stems, fruits, or severely infected plants affected by blight disease from the field. Controlling weeds is also essential.

Destroying Infected Plants: Burn and destroy severely infected plants to prevent the spread of the disease.

Proper Irrigation: Avoid excessive irrigation of onion crops. Ensure proper drainage to prevent waterlogging in the field. Do not transfer water from the affected field to another field.

Proper Storage: To prevent the spread of the disease, store onions in a cool and dry place.

Which agri-inputs do you use to control blight disease? Let us know your answers in the comments. If you found the information in this post helpful, don’t forget to like and share it. For more information on protecting crops from pests and diseases, follow the 'Agri Doctor' channel now.

Frequently Asked Questions (FAQs)

Q: What is disease management?

A: Disease management refers to the process of preventing and treating diseases in crops. Integrated disease management involves various measures like cultural, biological, and chemical methods to effectively manage diseases in a sustainable and environmentally friendly manner.

Q: What is disease management in crops?

A: Disease management in crops includes controlling and treating diseases that affect crop health and yield. It involves practices such as adopting crop rotation, sowing disease-free seeds or tubers, and using biological and chemical treatments.

Q: Which medicine should be used for blight disease?

A: Before using medicines for controlling blight disease, it is important to consider factors like the type of disease and the crop. For appropriate medication, you should consult your local agricultural expert.