Pests and Diseases Management in Cotton: Causes, Symptoms, Chemical, and Biological Control

The textile industry’s backbone is Cotton, a commercial crop that employs most of the population and earns foreign exchange. Throughout the world, Cotton is infested with 1326 species of insect pests, making it one of the more complex crops in terms of insect pests. Despite this, cotton production suffers significant losses because it is susceptible to 162 insect pest species.

Pests and Diseases Management in Cotton
Image Source

Pests and diseases management in Cotton

Fruit and boll feeders of Cotton crop
American bollworm

It is a significant pest from July to October and February to April. Moths are stout, yellowish brown with a dark speck area on the forewings, which have grayish wavy lines and a black kidney-shaped mark. However, the hind wings are whitish with a blackish patch along the outer margin.

There are dark gray-yellow stripes along the sides of the larva’s body, which is about 35 mm long, greenish-brown, and has a greenish-brown color. In the beginning, the larvae feed on the leaves. Afterward, they thrust their heads into bolls and leave the rest of their bodies outside. A single larva can damage 30-40 bolls. Bolls have large circular entry holes.

Biological control
  • Nuclear Polyhedrosis Virus (NPV) is applied at 3 x 10 12 POB/ha in the evening hours at the 7th and 12th week after sowing.
  • It is crucial to conserve and enhance natural predators and parasitoids to control pests effectively.
  • Release of Trichogramma spp. At 6.25 cc/ha was conducted three times from 45 days after harvest at 15-day intervals
  • Chelonus Blackburnii, an egg-larval parasitoid, and Chrysoperla carnea, a predator, should be released at a rate of 100,000/ha at the 6th, 13th, and 14th weeks after sowing.
  • To effectively control Helicoverpa, apply ULV sprays of NPV at 3 x 10 12 POB /ha with 10% cotton seed kernel extract, 10% crude sugar, and 0.1% each of Tinopal and Teepol.
Chemical control
Dosage per
Endosulfan 35 EC200 ml
Phosalone 50 EC2.5 L
Quinalphos 25 EC2 L
Carbaryl 50 WP2.5 kg
Bacillus thuringiensis
serovar kurstaki 5WP
750 grams to 1 kg
Spinosad 45 SC160-220 ml
Bifenthrin 10% EC800 ml
  • Avoid indiscriminate application of insecticides, primarily synthetic pyrethroids.
  • When spraying, use insecticides that are comparatively safer than natural enemies at the correct dosage and alternate insecticide groups every few sprays. 
  • When mixing insecticides, avoid combining them. 
  • Use spraying equipment such as a hand compression sprayer, backpack sprayer, and mist blower for proper coverage with the required amount of spray fluid.
Pink bollworm

It is a significant pest that is active from October to November. Moths with blackish spots on their forewings are dark in color. Hind wings have deeply fringed margins. Approximately 8-9 mm is the length of the wing. When young, the caterpillars are creamy yellow but turn pink as they grow and are 8-10 mm long with distinctive brown heads. Shoots, flower buds, leaves, and green bolls are among the parts of the plant where eggs are laid.

Caterpillars feed on flower buds, panicles, and bolls to cause damage. Larvae feeding inside seed kernels seal the entry holes with excreta. Eventually, they damaged the two adjoining seeds by cutting window holes in them. Immature bolls and buds that have been attacked drop off. Lint is destroyed, and ginning percentage and oil content are reduced.

Biological control
  • Releasing egg parasites Trichogramma chilonis, Bracon elechidae, Elasmus johnstoni, or pupal parasite Microbraconlefroyi would keep Pink bollworm populations in check.
  • Encourage predators such as Chrysoperla zastrouviearabica and Scymnus sp. Alternatively, release Triphles tantilus or Pyremotesventricosus (mites).

In case you missed it: Best Fertilizer for Cotton: Organic, Compost Manure, Liquid, NPK, and Schedule

Cotton Farming
Image Source
Chemical control
  • When seeds are treated with hot water, hibernating larvae are killed. Use Aluminium phosphide to treat the seeds.
  • Insecticides such as Chlorpyriphos20 EC, Endosulfan35 EC, or Triazophos40 EC can be used to control these worms at a rate of 2.5 l/ha.
Spotted bollworm

From 35 to 110 days after planting, the pest attacks the crop. About 25 mm is the length of the wings of moths of species. E insulana has grassy green forewings, while E vitella has pea-green forewings with a wedge-shaped white band running from the base to the outer margin. E vitella larvae are about 20 mm long, spiny, and brownish with white streaks dorsally and pale yellow ventrally, and E insulana larvae are greenish-white with black marks and orange spots on the prothorax.

By boring into growing shoots, buds, flowers, and bolls, the caterpillars cause damage. Flowers and buds fall off the attacked shoots, which wither, droop, and eventually die. As a result of rot setting, infested bolls do not shed or open prematurely, and the quality of the lint is spoiled. Occasionally, pupation occurs in the bolls, impairing their development.

Biological control
  • At 35 to 70 days, release the egg parasitoids Trichogramma chilonis and T brasiliensis, as well as larval parasites Chelonus blackburni and Bracon brevicornis.
  • Encourage and conserve the activity of the spiders Thomisus sp. and Neosiana sp.
Chemical control
  • Use insecticides such as Endosulfan35 EC or Triazophos40 EC at 2.5 l/ha or Cypermethrin10 EC at 600-800 ml/ha.
  • Repeated use of conventional sprays should be avoided. From 45 days of crop age, apply Neem-based insecticides such as 5% Neem seed kernel extract or commercial Neem-based formulations at 500-600 ml/ha.

Sap feeders of Cotton crop

These pests attack crops during their first 50 days of life, and winter is the worst season for an attack. A summer adult is about 3mm long and greenish-yellow, but a winter adult is about 4mm long and reddish-brown. Two black spots can be seen on the vertex of the hind portion of the forewings. A nymph’s color is greenish-yellow, and its shape is wedge-shaped. In adults and nymphs, the sap is sucked from the underside of the leaves and kills the plants. A severe infestation causes the leaves to turn pale, rust red, curl downwards, and dry up.

Biological control
  • A predator, such as Chrysoperla zastrouviearabica or Coccinella septempunctata or Syrphus or Scymnus sp, should be released.
  • It is crucial to conserve spiders like Distinaalbida and ants like Camponotus sp.
Chemical control
  • Only use chemical pesticides if the pest population exceeds the economic threshold.
  • You can spray methyl Demeton 25 EC or dimethoate 30 EC on the surface.

Cotton aphid

From June-October and February-April, the pest is active. The insects have a pair of tubular structures and are light yellowish green, greenish black, or brownish. Most adults have wingless bodies, but some have thin transparent wings. The cool weather and humid conditions promote rapid growth, while heavy rains wash away aphid colonies. Light with low intensity promotes longevity, while light with high intensity reduces it.

Aphid infestations can cause yellow leaves, necrotic spots on leaves, and stunted shoots; aphids secrete a sticky, sugary substance called honeydew that encourages mold growth in plants. Plants are weakened when adults and nymphs suck sap from tender leaves, twigs, and buds. Several punctures are made by each aphid, which excretes honeydew, which encourages the growth of sooty mold on twigs and leaves, leaving them blackened.

Biological control
  • Release Chrysoperla zastrouviearaabica, Coccinella septumpunctata, or Syrphus / Scymnus species as predators.
  • It is essential to conserve spiders like Distinaalbida and ants like Camponotus sp.

In case you missed it: Make Lakhs with Cotton Farming, Find Out Simple Facts and Techniques

Cotton Farm
Image Source
Chemical control
  • A dose of midacloprid (5 g/kg seed) will keep the crop free of sucking pests for over a month.
  • Only use chemical pesticides if the pest population exceeds the economic threshold.
  • Spray Dimethoate30EC or Methyl O Demeton25EC at 500-700 ml/ha once the population reaches the economic threshold
  • It is generally only necessary to treat aphid infestations with insecticides if they are incredibly high. Plants can tolerate low and medium levels of infestation. Insecticidal soaps or oils, like neem or canola oil, are usually the best control methods; always read the labels for specific instructions before applying.

Thrips f Cotton

May through September is the peak season for the pest. Slender, yellowish brown, and 1 mm long, the adults are 1 mm long. The abdomen is curved at the tip, and the abdominal segments are transversely banded with dark brown lines. In males, there are no wings, and in females, there are long, narrow strap-like wings fringed with hair.

Leaf tissues are lacerated when the nymphs and adults sucking sap from the lower surface of the leaf are lacerating. Older leaves turn brown on the upper side and silvery white on the lower side. Eventually, leaves become curled, wrinkled, and dry.

Biological control
  • Promote the activity of parasitoids Thripoctenusbriu, Triphlepstantilus, and Campsid sp.
  • 1.25 lacs of Trichogramma chilonis should be released per hectare, and 1-2 grubs of Chrysoperella should be released per plant.
  • The early stage of Chrysoperla zaastrouviearabica should be released with two larvae per plant, and the later stage should be released with four larvae per plant.
  • Release Cheilomenes sexmaculata at a random rate of 1.5 lakh adults per hectare.
Chemical control
per hectare
methyl -o-demton1500 ml
Trizophos 40 EC1500 ml
Dimethoate 30 EC750 ml
Cartap hydrochloride1 kg
Ethofenprox 10 EC1 kg

White Fly

Throughout the year, the pest is present. Crops are generally infested between November and February. On the undersurface of the leaves, nymphs and adults are sluggish creatures. In nymphs, the body is pale yellow; in adults, the body is yellowish with a white waxy coating. There is a noticeable length to the hind wings. Insecticide treatments prevent outbreaks of sticky Cotton and reduce the chance of yield loss by detecting whitefly movement into cotton fields using sticky traps.

In addition to eating the cell sap, the nymphs and adults excrete honeydew, which interferes with normal photosynthesis. Leaf veins become translucent and thickened due to chlorotic spots, and they may drop prematurely in severe cases. Lint is contaminated with sooty mold.

Biological control
  • Encourage parasitoids such as Encarsia shafeei or Eretmocerou smundus.
  • Use predators such as Chrysoperla zaastrouviearabica, Melochilus sexmaculatus, Coccinella septempunctata, Brumus sp., or Scymnus sp.
  • Release Chrysoperla zastrouviearabica at two larvae/plants at the early stage and four larvae/plants at the later stage.
  • In the crop canopy, release 1.5 lakh Cheilomenes sexmaculata adults at random.
  • Neem products should be sprayed at 1500 parts per million.
Chemical control
  • At fortnightly intervals, spray insecticides such as Imidacloprid, Monocrotophos36 WSC or Quinalphos 25 EC or Methyl-o-Demeton25 C or Aephate, Trizophos, or Profenophos.
  • It is possible to restrict or rotate the use of synthetic pyrethroids (Cypermethrin or Decamethrin) with conventional insecticides.
  • Imidacloprid treatment at 5 grams per kilogram of seed
Chemical compoundDosage per hectare
Neem oil + Teepol3-3.5 L + 500 ml
Fish oil resin soap1.4-1.5 Kg

Foliage and shoot feeders of Cotton crop

From July to November, this minor pest is active. A dull yellow adult moth with an abdomen of buff crimson and black spots has profuse hairs. These caterpillars have hairy heads, are brownish-orange to yellow, and are 40-45 mm long. Pupation occurs in cocoons, soil, or plant debris where eggs are laid in clusters on the underside of leaves. In six to twelve weeks, the life cycle is completed.

In case you missed it: Cotton Seed Germination Period, Temperature, Process

Image Source
Biological control

Release larval parasite Apanteles diacrisiae.

Chemical control
Chemical compoundDosage per hectare
Methyl Parathion 2%30 kg/ha
Malathion 5%30 kg/ha
Chlorpyriphos 20 EC1.5 lit/ha
Endosulfan 35 EC1.25 lit/ha

Cotton diseases


Plants can suffer from anthracnose at all growth stages, affecting all tissues. Infected seedlings produce small reddish to light brown circular spots with black necrotic margins on cotyledons and primary leaves. Developing lesions on the collar region can cause the stem to girdle, causing seedlings or young plants to wilt and die.

Knotting and shredding bark may occur in mature plants due to infection and colonization. Small, circular, water-soaked spots can rapidly enlarge into sunken, yellow-to-brown lesions in humid conditions. The lint becomes disorganized and brittle and turns yellow to brown. Furthermore, infected bolls will cease to grow, dry up, and burst prematurely.

Chemical control and management

If possible, integrate preventive measures with biological treatments. Seeds can be treated with fungicides at a rate of 2g/kg of seeds to help reduce the incidence of the disease. At 2.5 ml/l of water, foliar sprays of mancozeb and copper oxychloride at the boll formation stage will also lower the gravity of symptoms.

Grey or Areolate mildew

When the crop is nearing maturity, the disease appears on the undersurface of the bottom leaves. The lower surface develops irregular to angular pale translucent lesions that measure 1-10 mm (usually 3-4 mm). Specks of light green or yellow-green color appear on the upper surface of the lesions.

On the lower surface, conidiophores of the fungus appear as a frosty or whitish-grey powdery growth. When several spots merge, white to gray powdery growth covers the entire leaf surface. The upper surface may also develop white or gray powdery growths. The infection spreads to the plant’s upper leaves, causing the entire plant to be affected. As a result of the damage, the leaves turn yellowish brown, dry up from the margin, cup inward, and drop prematurely.

Chemical control and management
Chemical compoundDosage per hectare
Carbendazim250-375 Grams
Wettable sulfur1.25- 2.0 kg
  • Infected crop residues should be removed and burned.
  • The cotton plants that were self-sown during the summer should be rogued out.
  • Fertilizers and manures containing nitrogen should not be applied excessively.
  • Adopt the correct spacing based on soil conditions and varieties.

In case you missed it: Organic Cotton Production; Cultivation Practices

Cotton Plant
Image Source
Boll rot

Aspergillus flavus, Fusarium moniliforme, Colletotrichum capsici, Rhizopus nigricans, Nematospora nagpuri, and Botryodiplodia species are the causes. Small brown or black dots appear on the bolls, which later enlarge to cover the entire boll. During the infection, seeds and lint rotate in the body and spread to inner tissues.

Neither the bolls burst open, nor do they fall off prematurely. Some cases of rotting occur externally, resulting in rotting of the pericarp, which leaves the internal tissues undamaged. Depending on the fungus involved, there are many fruiting bodies of fungi on the affected bolls

Chemical control and management
  • Keep the spacing as optimal as possible.
  • Fertilizer should be applied in the recommended doses.
  • From the 45th day, spray Copper oxychloride 2.5kg and an insecticide for bollworms every 15 days. It is necessary to spray two or three times.
Root rot

Cotton crops are affected by root rot caused by the pathogen Rhizoctonia solani. A typical root rot symptom appears at the maturity of the plant. Plants wilt suddenly in patches, which is the most prominent symptom. Initially, all the leaves droop suddenly and die within a few days.

There is rotting throughout the entire root system of the affected plants, except for the tap root and a few lateral roots. In the affected plant, the bark shreds and even extends above ground. The woody portions of plants may become black and brittle when badly affected. Many dark brown sclerotia can be seen on the wood or the bark that has been shredded.

Chemical control and management
  • Seeds should be treated with 4 grams of Trichoderma viride per kilogram.
  • Carbendazim 0.1% should be drenched on the spot.
  • Ten tons/ha of farm yard manure or 150 kilograms/ha of neem cake can be applied.
  • Make sure the crop escapes the high soil temperature conditions by sowing early or late.
  • The soil temperature can be lowered by intercropping with moth beans or sorghum.
Leaf blight

Symptoms may occur at any stage of plant development but are most severe when plants are 45-60 days old. Spots measuring 0.5 to 6 mm in diameter may appear on the leaves, ranging from pale brown to irregular. Concentric rings surround the central lesion of each spot. As several spots merge, they form blighted areas, and the affected leaves become brittle and fall off. It is also possible to see stem lesions. Spots may appear on bracts and bolls in severe cases.

In case you missed it: Cotton Cultivation Project Report, Farming Cost, Profit

Cotton Farming in India
Image Source
Chemical control and management
  • The infected plant residues should be removed and destroyed.
  • At the first indication of the disease, spray Mancozeb 2 kg or Copper oxychloride 2 kg/ha. It is recommended to give four to five sprays every 15 days.


Cotton can be suspected to attack by numerous insects, pathogenic fungi, bacteria, viruses, and nematodes. Its succulent foliage, flowers, and extended fruiting period make Cotton an attractive host for many insects and the diseases they carry. Proper management and control methods can prevent these problems and reduce the effect on yields.


Please enter your comment!
Please enter your name here