Welcome to our blog on Common Cotton plant diseases and control! This article will explore the causal organisms, damage symptoms, spread, treatment options, prevention strategies, and management techniques for these diseases. Join us as we provide accurate information on protecting your cotton plants and ensuring a healthy yield. Let’s dive in!
Major and Common Cotton Damaging Diseases
Cotton is a perennial shrub in the Malvaceae family, consisting of four species: Gossypium hirsutum, Gossypium barbadense, Gossypium arboreum, and Gossypium herbaceum. G. hirsutum dominates global cotton production, comprising about 90% of it. The plant features spirally arranged leaves with lobes, single flowers, and oval seed capsules called “bolls.” These bolls split open to expose white cotton fibers and seeds. Cotton is typically cultivated as an annual plant, reaching heights of 1-1.5 m, and its origin is uncertain but spans regions from Mexico to Australia.
List of Ten Major and Common Diseases of Cotton
- Angular Leaf Spot (Black Arm Disease): Causes black spots on leaves, leading to defoliation and reduced yield.
- Vascular Wilt Disease: Blocks water movement in the plant, resulting in wilting, yellowing, and plant death.
- Grey Mildew (Dahiya Disease): Fungal infection causing gray patches on leaves, reducing photosynthesis and boll development.
- Anthracnose Disease: Fungus attacks stems, leaves, and bolls, causing dark lesions and premature boll shedding.
- Root Rot Disease: Pathogens attack cotton roots, causing rot, stunted growth, and nutrient deficiency.
- Boll Rot Disease: Fungal infection affecting bolls, causing rot, premature opening, and reduced fiber quality.
- Leaf Spot (Blight Disease): Fungal or bacterial infection causing spots on leaves, leading to defoliation and yield loss.
- Reddening (Lalya Disease): Virus-induced chlorosis, resulting in leaf reddening, stunted growth, and yield reduction.
- 2,4-D Injury Disease: Herbicide damage causing leaf curling, growth abnormalities, and yield decline.
- Tobacco Streak Virus Disease: Viral infection causing leaf mosaic, boll deformation, and yield reduction.
Angular Leaf Spot or Black Arm Disease Control in Cotton
- Causal Organism: Xanthomonas axonopodis pv. malvacearum (Smith) Vauterin.
- Symptoms: Small water-soaked spots on cotyledons and leaves, turning angular and brown to black. Stem, petioles, and branches develop elongated dark lesions. Bolls may have sunken black lesions, leading to premature falling-off and lint discoloration.
- Spread: Through infected leaves, bolls, twigs, water, and wind.
- Treatment: Field sanitation, seed delinting, streptomycin sulfate or Agrimycin seed soaking, and streptomycin sulfate + Copper oxychloride spray.
Vascular Wilt Disease Control in Cotton
- Causal Organism: Fusarium oxysporum f. sp. vasinfectum (Atk.) Snyder and Hansen.
- Symptoms: Yellowing and death of cotyledons and leaves, drooping of leaves and shoots, yellowing, browning, and plant death.
- Spread: Through soil-borne inoculums.
- Treatment: Field sanitation, crop rotation, mix cropping, and use of resistant varieties.
Grey Mildew or Dahiya Disease Control in Cotton
- Causal Organism: Imperfect stage: Ramularia areola Atk. Perfect stage: Mycosphaerella areola.
- Symptoms: Pale, translucent spots on older leaves, restricted by veinlets. Leaves turn yellowish brown and fall prematurely.
- Spread: Airborne conidia.
- Treatment: Destruction of infected plant debris, dusting with sulfur or propiconazole spray. <