Cotton cultivation is widespread across various states of India. With proper planning, the crop is generally cultivated efficiently. However, in many cases, it has been observed that the expected yield is not achieved in proportion to the area cultivated during the Kharif season. If we ask cotton-growing farmers about the reasons behind this yield reduction, their immediate response often points to the incidence of multiple fungal diseases. These diseases not only reduce yields but also significantly increase input costs. Cotton crops are affected by a variety of fungal diseases such as Anthracnose (boll rot), Leaf Blight, Leaf Spot, Root Rot, Alternaria (Grey Mildew), Wilt, and Boll Rot.

1) Symptoms and Spread of Anthracnose Disease:

Anthracnose affects the cotton crop in the seedling and boll development stages.

In the first stage, if the disease infects the seedling, the plants die. Circular reddish spots appear on the cotyledons. Lesions or blotches also appear on the tender stem near the soil surface, leading to seedling death. A distinct feature of this disease is that once the plant emerges, it does not show infection on the leaves or branches. In the second stage, the disease directly affects the bolls. Greasy brownish spots appear on the bolls or leaf margins. These spots become sunken with raised edges, gradually covering most of the boll. The cotton lint inside becomes tightly adhered to the seed. The disease primarily spreads through infected or contaminated seeds and old crop residues. It proliferates rapidly under warm and humid conditions.

2) Symptoms and Spread of Leaf Blight Disease:

Blight disease can appear at any stage from sowing to boll formation. Initially, greenish spots appear on the underside of the leaf near the midrib, turning reddish and later blackish. As the disease progresses, leaves begin to wither and fall. Spots also appear on the bolls and leaves, and as they turn brown, the quality of cotton crop begins to decrease. The disease spreads mainly through fungus-infected seeds and residues from the previous crop. It also spreads aerially, especially in warm and humid climates.

3) Leaf Spot disease Symptoms and Spread:

This fungal disease initially appears on the leaves. Small, round spots appear, which gradually increase in size and merge under favorable conditions, forming larger lesions. Concentric rings are visible within the spots upon close observation. Infected leaves gradually begin to fall. This disease is most severe in damp environments.

4) Root Rot disease Symptoms and Spread:

Root rot in cotton is caused by a soil-borne fungus that enters through the roots. Due to fungal infection, roots fail to absorb water and nutrients, eventually causing plant death. Affected plants suddenly wilt and dry out and can be easily uprooted by hand. The root appears decayed, with the bark peeling off. The inner stem and root tissue become brown or black. Small black fungal bodies are visible within the inner layers of the root. This disease is spread through infected seeds and contaminated soil. It persists for long periods in the soil and intensifies under high temperature and low soil moisture.

5) Symptoms and Spread of Alternaria (Grey Mildew) Disease:

If Alternaria infects cotton, the disease first affects older leaves, where brownish, irregular-shaped blotches appear on the underside. These spots appear between the leaf veins as angular or irregular patches. In severe cases, leaves turn brown and fall, leading to major yield losses. The disease spreads from decaying plant litter and is highly influenced by weather changes. It also spreads through airborne fungal spores.

6) Symptoms and Spread of Boll Rot Disease:

Boll rot occurs due to a combination of fungi and bacteria, often entering through holes caused by bollworms. Infected bolls begin to rot and their growth stops. Cotton quality deteriorates, seed quality reduces, and the germination capacity of such seeds is lost. This disease causes substantial losses in both quality and yield.

Control Measures for Fungal and Bacterial Diseases in Cotton: 

While planning for cotton cultivation, it is essential to have proper crop management in place from the very beginning, as these diseases can spread rapidly. This leads to increased costs and a significant reduction in yield, often resulting in total crop failure.

A) Preventive Measures:

Deep ploughing the field at least one month before sowing helps expose soil-borne fungi to sunlight and disturbs the soil structure to bring buried nutrients to the surface, promoting healthy plant growth. Avoid using old seeds. Always use properly treated, disease-free seeds to prevent fungal infections. Completely remove crop residues and debris from previous seasons to prevent fungal build-up. For diseases like Root Rot and Wilt, maintaining proper water management and drainage is crucial. As soon as disease symptoms appear, plan fungicide applications. Use resistant seed varieties for better crop protection. Perform earthing-up operations on time to ensure proper soil aeration, preventing excess humidity that supports fungal growth.

B) Kay Bee Bio’s Best Solution for Fungal and Bacterial Disease Control in Cotton:

To effectively manage fungal and bacterial diseases such as Anthracnose, Leaf Blight, Leaf Spot, Alternaria, and Boll Rot, timely foliar application is essential.

We can use Fungo Raze 2 ml and Bacto Raze 1 ml per liter of water over the cotton crop for foliar spray. and for soil-borne diseases in cotton, like root rot and wilt disease, we can use Kay Bee Bio’s Root Fit 750 ml and Bacto Raze 250 ml per acre in 200 liters of water and apply via drenching or drip if available. This treatment helps eliminate a wide range of fungal and bacterial pathogens from the crop and promotes healthy, vigorous, and disease-free cotton plants.