Cotton (Gossypium sp) is one of the most important fibre and cash crop in India. It is vulnerable to infections by pathogens like fungi, bacteria and viruses. All parts of the plants are infected and crop losses are common in the crop. Cotton diseases can significantly reduce crop yield and cotton quality leading to reduced profits for farmers.   The severity of yield loss depends on the type of disease, the timing of infection, and the environmental conditions. The estimated average yield loss due to cotton diseases in India ranges from 10% to 15%. However, in severe outbreaks, yield losses can be as high as 50% or more. Effective disease management can help minimize crop losses and improve yield.  The Major Diseases of Cotton having significant impact on cotton yield are as follows; Fusarium Wilt of Cotton: Scientific name of causal agent: Fusarium oxysporum f.sp. vasinfectum  Stage of occurrence: Affects at all stages of the crop  Fusarium Wilt of Cotton Symptoms:  Initially the symptoms appear as yellowing and browning of cotyledons and the base of petiole shows brown ring  It is followed by wilting and drying of the affected seedlings  Affected plant’s leaves loses turgidity, gradually turns brown, droops and finally drops off  Tap roots are usually stunted with a smaller number of lateral roots.  Vascular tissues show browning or blackening symptom and black streaks or stripes may extend upwards to the branches and downwards to the roots  Affected plants become stunted with fewer bolls which are very small and opens before attaining maturity  Favourable conditions for Fusarium wilt infection in cotton:  Soil temperature of about 20 – 30°C, warm and dry weather followed by rain, high dosage of nitrogen and phosphatic fertilizers, black soils with high alkaline reactions, and wounds caused by nematode and grubs of ash weevil are favourable conditions for fusarium wilt infestation in cotton.  Verticillium wilt of Cotton: Verticillium wilt in cotton Scientific name of causal agent: Verticillium dahliae  Stage of occurrence: Square and boll formation stage  Verticillium Wilt of Cotton Symptoms:  Early infection leads to stunted growth of the plant  ‘Bronzing of veins’ followed by yellowing of leaves and interveinal chlorosis  It is followed by yellowing of leaves and interveinal chlorosis  Affected leaves dry up giving scorched appearance  Drying of leaf margins and areas between the leaves gives “Tiger stripe” or “Tiger claw” appearance  Branches remain barren due to falling of affected leaves  When infected stems and roots are split open, pinkish appearance of woody tissue can be seen  Affected plants may produce smaller bolls with immature lint  Favourable conditions for Verticillium wilt infection in cotton:  High nitrogen fertilization, heavy soil with alkaline reaction, low soil temperature (15-20°C), excessive soil moisture or poor drainage in soils, lack of crop rotation and presence of host crops like tomato, brinjal, chilli, bhendi can create favourable conditions for verticillium wilt infection.  Management of Fusarium wilt and Verticillium wilt disease in cotton:  Product name  Technical content  Dosage (per acre or per lit water)  Biological Management  Nanobee 7 Star Bio Fertilizer Beneficial Lyophilized Microbes Consortia: 1.5 %  Mix 25-50 gm/lit of water and keep it in shade for 3-5 hr. Then mix it in 200 lit of water  Amruth Almonas Bio Fungicide Pseudomonas sp  2ml/lit water  Terra Fungikill Herbal formulation    2 ml/lit water  Ecoderma Bio Fungicide Trichoderma viride  Seed treatment: 10 gm/lit water  Soil application: 2 – 3 kg Ecoderma +150 – 200 kg FYM  Chemical management   Benmain Fungicide Carbendazim 50% DF  Soil drenching: 2 gm/lit water  Amistar Fungicide Azoxystrobin 23% SC  Drenching/Spraying: 0.5 – 1 ml/lit water  Ridomil Gold Fungicide Metalaxyl 4% + Manconzeb 64%    Soil application: 1 – 1.5 gm/lit water  Taqat Fungicide Hexaconazole 5% + Captan 70% WP  Drenching: 2 gm/lit water  Roko fungicide Thiophanate Methyl 70% w/w  Foliar spray: 1 gm/lit water   Drenching: 2 – 4 gm/lit water  Dithane M45 fungicide Mancozeb 75% WP  Spraying: 2 – 2.5 gm/lit water    Root rot of Cotton: Root rot in cotton Scientific name of causal agent: Rhizoctonia bataticola  Stage of occurrence: Seedling to vegetative stage  Root Rot of Cotton Symptoms:  3 types of symptoms caused by the pathogen – Seedling disease, sore shin and root rot    Seedling stage:   Germinated seedling affected by the fungus shows black lesions on hypocotyl  Causes girdling of stem and death of affected seedling  Sore shin stage:  Dark reddish-brown canker appears on stem near soil surface, later turning black  Drying of leaves and entire plant due to plant breakage at the collar region  Root rot:  Bark of affected plant shreds and may extend above ground level  Dark brown sclerotia appears on the wood or on the shredded bark  Entire root system becomes rotted, plants dry and can be easily pulled out  Favourable conditions for root rot infection in cotton:  Heavy rainfall followed by dry weather, high soil temperature of about 35 – 39°C, presence of host crop like vegetables, growing cotton after cultivation of oilseeds and legumes, wound caused by nematodes and ash weevil grubs increases root rot disease incidence.  Management of root rot disease in cotton:  Product name  Technical content  Dosage (per acre or per lit water)  Biological Management  Nanobee 7 Star Bio Fertilizer Beneficial Lyophilized Microbes Consortia: 1.5 %  Mix 25-50gm/lit of water and kept it in shade for 3-5 hr. Then mix it in 200 lit of water  Multiplex Nisarga Trichoderma viride 1.5% WP   1 – 2 kg Multiplex Nisarga + 100 kg FYM  Ecomonas Bio Pesticide Pseudomonas fluorescens  Drenching:10 gm/lit water  Soil application: 10 – 15 gm/lit  Anand Dr Bacto’s Herz Spores and conidia of Mycoparasitic Fungi  10 ml/lit water  Chemical Management  Vitavax powder 75% Fungicide Carboxin 37.5% + Thiram 37.5% DS  Seed treatment: 3 gm/kg seed  Dhanustin Fungicide Carbendazim 50% WP  Drenching: 0.5 – 0.75 gm/lit water  Sprint Fungicide Mancozeb 50% + Carbendazim 25% WS  Drenching: 2.5 to 3 gm/lit water  Katyayani Samartha Carbendazim 12% + Mancozeb 63% WP  Spraying: 1.5 – 2 gm/lit water    Areolate mildew / Grey Mildew of Cotton: Scientific name of causal agent: Ramularia areola   Stage of occurrence: Seedling to Reproductive stage   Symptoms of Areolate or Grey mildew in cotton:  Irregular to angular pale translucent lesions appear on the lower surface of affected leaf  Light green or yellow green specks appear on the upper leaf surface  Whitish grey powdery growth appears on the lower surface, later coalesce and cover the entire leaf surface  Under severe infection, white/grey powdery growth may occur on the upper leaf surface  Affected chilli leaves dry up from margin, curl inward, turn yellow and fall off prematurely.  Favourable conditions for Grey / Areolate mildew infection in cotton:  Wet humid conditions, Low temperature (20 – 30°C), close planting, very early or very late sowing of cotton, intermittent rains and excessive application of nitrogenous fertilizers may increase grey mildew infection in cotton field.  Management of Grey mildew in cotton:  Product name  Technical content  Dosage (per lit water)  Biological Management  Amruth Abacil Liquid Bacillus subtilis 2% A.S  1 ml/lit water  Chemical Fungicide  Amistar Top Fungicide Azoxystrobin 18.2% + Difenoconazole 11.4% SC  Foliar: 1 ml/lit water  Taqat Fungicide Hexaconazole 5% + Captan 70% WP  Foliar: 2 gm/lit water  CM 75 Fungicide Carbendazim 13%+Mancozeb 63%  Foliar: 1.5 gm/lit water  Bavistin Fungicide Carbendazim 50% WP  Foliar: 0.5 ml/lit water  Ergon Fungicide Ergon 44.3% SC  Foliar: 0.6 ml/lit water    Anthracnose of Cotton: Symptom of anthracnose on cotton boll Scientific name of causal agent: Colletotrichum gossypii  Stage of occurrence: All growth stages  Anthracnose of Cotton Symptoms:  This disease affects all parts of the cotton plant  Small reddish circular spots appear on the cotyledon and primary leaves of seedlings  Causes seedlings to wilt and dry  In affected mature plants, stem splitting and shredding of bark can be seen  “Boll spotting” is the most cotton symptom  Sunken, circular, reddish-brown spots appear on the bolls and the infected boll stops to grow, burst and dry up.   Favourable conditions for Anthracnose infection in cotton:  Prolonged rainfall during the boll formation stage, presence of crop debris, weed hosts and close planting may be favourable for anthracnose infection in cotton.  Management of Anthracnose in cotton:  Product name  Technical content  Dosage (per lit water)  Biological Management  Terra Fungikill Herbal formulation    2 ml/lit water  Sonkul Sun Bio Monus Pseudomonas fluorescens  5 ml/lit water  Chemical Management  Borogold Fungicide Combination of Nano Silver Particles & Peroxy Acid  Spraying; 1.5 gm/lit water  Turf fungicide Carbendazim 12 % + Mancozeb 63 % WP  Drenching/Spraying: 1.8 – 2.5 gm/lit water  Taqat Fungicide Hexaconazole 5% + Captan 70% WP  Drenching: 2 gm/lit water  Splash Fungicide Chlorothalonil 75% WP    Spray: 2 ml/lit water  Dhanustin Fungicide Carbendazim 50% WP  Drenching/Spraying: 0.5 – 0.8 gm/lit water    Alternaria leaf blight of Cotton: Alternaria leaf blight on cotton Scientific name of causal agent: Alternaria macrospora  Stage of occurrence: Vegetative and Reproductive stage  Alternaria leaf blight of Cotton Symptoms:  Small, brown, irregular or round spots appear on the leaves  Central lesion of each spot may be surrounded by concentric rings  These spots coalesce together, and form blighted areas  Affected cotton leaves become brittle and fall  In case of severe infection, spots may appear on bracts and bolls.  Favourable conditions for Alternaria leaf blight infection in cotton:  High humidity, temperature of about 25 – 28°C, intermittent rainfall, wet foliage, dense planting and presence of crop residues due to lack of field sanitation create favourable conditions for Alternaria leaf blight infection in cotton.  Management of Alternaria leaf blight in cotton:  Method of Application of Chemicals – Spraying  Product name  Technical content  Dosage (per lit water)  Biological Management  Sanjeevni Bio fungicide Trichoderma Viride  Seed treatment: 8 – 10 gm/50 ml (per kg seed)  Soil drenching: 5 – 10 kg/lit  Ecomonas Bio Pesticide Pseudomonas fluorescens  Foliar: 8 – 10 ml/lit water  Chemical Management   Tilt fungicide Propiconazole 25 % EC  1 ml/lit water  Bavistin Fungicide Carbendazim 50% WP  0.5 ml/lit water  Avtar fungicide Zineb 68% + Hexaconazole 4%  1 gm/lit water  Amristar Top Fungicide Azoxystrobin 18.2% + Difenoconazole 11.4% SC  1 ml/lit water  Dithane M45 fungicide Mancozeb 75% WP  2 – 2.5 gm/lit water  Tata Ishaan Fungicide Chlorothalonil 75% WP  2.5 gm/lit water  Priaxor Fungicide Pyraclostrobin 333gm/ltr + Fluxapyroxad 167 gm/ltr SC  0.6 ml/lit water  Nativo Fungicide Tebuconazole + Trifloxystrobin 75 WG (50% +25% w/w)  0.2 – 0.5 gm/lit water    Bacterial blight of Cotton:  Scientific name of causal agent: Xanthomonas campestris pv.malvacearum  Stage of occurrence: Seedling to harvest  Bacterial blight of Cotton Symtoms: 5 common phases of symptoms are noticed.  Seedling blight: Water soaked, irregular or circular lesions appear on the cotyledons, which may spread to petiole and stem causing withering and death of seedlings  Angular leaf spot: Small, dark green, water-soaked lesions develop on the under surface of leaves and become angular when restricted by veinlets and veins. Later, the lesions turn to reddish brown colour and becomes visible on both sides of the leaf  Vein blight/Vein necrosis/Black vein: Blackening of veins and veinlets gives ‘blighting appearance’. The presence of bacterial oozes on the lower side of the leaf. Affected leaves show crinkling appearance, withering and are twisted inward.  Black arm: Black lesions are developed on stem and branches, causing premature drooping of leaves, cracking of stem and gummosis, leading to die back  Boll rot: Dark black, sunken and irregular spots appear on the bolls. It leads to premature bursting of bolls. The spread of bacterium inside the bolls causes yellow staining of lint.  Favourable conditions for Bacterial blight infection in cotton:  Optimum soil temperature of 28°C, relative humidity of 85%, early sowing, high atmospheric temperature of 30 – 40°C, delayed thinning, late irrigation, poor tillage, K-deficiency in soil and rains followed by bright sunshine are highly favourable parameters for bacterial blight infection.  Management of Bacterial blight in cotton:  Product name  Technical content  Dosage (per lit water)  Biological Management  Spot Bio Fungicide Pseudomonas fluorescens  10 ml/lit water  Biofix Kito Star Fatty acids and stabilizers  1 – 2 ml/lit water  V-Kure Eugenol, Thymol, potassium salts, cationic surface agent, sodium salts & preservatives  1.5 – 2 gm/lit water  Chemical Management  Turf fungicide Carbendazim 12 % + Mancozeb 63 % WP  Foliar: 1.8 – 2.5 gm/lit water  Vitavax powder 75% Fungicide Carboxin 37.5% + Thiram 37.5% DS  Seed treatment: 3 gm/kg seed  Dithane M45 fungicide Mancozeb 75% WP  Spraying: 2 – 2.5 gm/lit water  Avtar Fungicide  Zineb 68% + Hexaconazole 4% WP  Foliar: 1 gm/lit water    Sudden Wilt or Para Wilt of Cotton: Exact cause of this physiological disorder is still unknown  Stage of occurrence: Flowering and fruit filling stage  Sudden wilt disease or Para Wilt of Cotton Symptoms:  Premature death of top leaves, followed by collapse of the plant  Within few hours of heavy rainfall or soil saturation, wilting of leaves can be seen  If sunshine is brighter and hot, leaves may immediately dry  Wilted plants shed all the leaves and are left only with small immature fruits  Under cloudy weather, leaves turn yellow and die with no or little wilting  Favourable conditions for Para wilt infection in cotton:  Excessive water or sudden rainfall, poor soil drainage, bright sunshine or hot air temperature may create conditions favourable for para wilt incidence  Management of Para wilt or Sudden wilt in cotton:   The exact cause of this disorder is still unknown. Preventive measures can be taken to minimize the para wilt incidence to some extent. Some of the measures include growing wilt tolerant varieties, accurate management of irrigation, reducing waterlogging conditions by providing adequate drainage and maintaining optimum vegetative growth by avoid using excessive of FYM and fertilizers.  Leaf curl disease of Cotton Scientific name of causal agent: Cotton leaf curl virus  Stage of occurrence: All stages  Vector: Whitefly  Leaf curl disease of Cotton Symptoms:  ‘Upward and downward curling’ of leaves and thickening of veins  Enation can be noticed on the underside of the leaves  In severe cases, all the leaves curl and the plant growth is retarded  Leads to reduced boll bearing capacity  Favourable conditions for Leaf curl virus infection in cotton:  Primary source of spread is Whitefly (Bemisia tabaci). Presence of alternate hosts like chilli, bhendi, tomato, warm temperature, late planting can be favourable for leaf curl virus infection.   Management of Leaf curl virus in cotton:  Spread of leaf curl virus disease can be managed by controlling the vector whitefly, which spreads the virus. The following chemicals can be used to control whitefly in cotton.  Product Name  Technical Content  Dosage (per lit water)  Mechanical Management  Tapas Yellow Sticky Trap 11 cm x 28 cm  4 – 6/acre  Biological Management  Amruth Alestra Liquid Verticillium lecanii  2 ml/lit water  T.Stanes Nimbecidine Azardiractin 300 PPM (EC formulation)  5 ml/lit water  Chemical Management  Lancer Gold Insecticide Acephate 50 % + Imidacloprid 1.8 % SP  0.4 ml/lit water   Pager Insecticide Diafenthi uron 50% WP  1.2 gm/lit water  Ulala Insecticide Flonicamid 50 WG  0.3 gm/lit water  Actara Insecticide Thiamethoxam 25 % WG  0.5 gm/lit water  Kaitaku Insecticide Acetamiprid 20 % SP  0.1 – 0.2 ml/lit    Tobacco streak virus in Cotton Tobacco streak virus in cotton Scientific name of causal agent: Tobacco streak virus  Stage of occurrence: All stages  Vector: Thrips (Thrips tabaci)  Tobacco streak virus in Cotton Symptoms:  Ring like purplish necrotic spots appear on the leaves  Chlorotic streaks develop on the leaves  Stunted growth   Favourable conditions for Tobacco streak virus infection in cotton:  Presence of weed hosts, high temperature (25 – 30°C), infected plant debris may create favourable conditions for tobacco streak virus disease spread in cotton crop.  Management of Tobacco streak virus in cotton:  Spread of Tobacco streak virus disease can be managed by controlling thrips, which spread the virus. The following chemicals can be used to control thrips in cotton.  Product name  Technical content  Dosage (per lit water)  Mechanical Management  Tapas Yellow Sticky Trap 22 cm x 28 cm  6 – 8/acre  Biological Management  Pesto Raze Bio-insecticide Botanical Extracts  2 ml/lit water  Control TRM Bio-pesticide Organic blend of botanical extracts    2 ml/lit water  Econeem Plus Azadiractin 10000 ppm  2 ml/lit water  Chemical Management  Summit Insecticide Spinetoram 11.7 % SC  0.5- 1ml/lit water  Admire Insecticide Imidacloprid 70% WG  0.3 gm/lit water  Karate Insecticide Lambdacyhalothrin 5% EC  1.5 ml/lit water  Nurelle D Insecticide Chlorpyriphos 50% + Cypermethrin 5% EC  2 ml/lit water  Katyayani Thioxam Thiamethoxam 25% WG  0.4 gm/lit water   Shinzen Plus Insecticide Fipronil 5 % SC  3 gm/lit water  Osheen Insecticide Dinotefuran 20 % SG  0.6 – 0.8 gm/lit water  Marshal Insecticide Carbosulfan 25% EC  2.5 ml/lit water    (Note: Refer to the product label to find the right time of Application and more details of the product)  Discover effective strategies in our guide to enhance your cotton crop’s health and yield. Click here to read Management Of Insect Pests In Cotton.