Cotton refers to the soft, fluffy, and fibrous material that comes from the seeds of various species of the cotton plant, particularly Gossypium hirsutum and Gossypium barbadense. It is one of the most important and widely cultivated fibre crops globally.
Cotton fibres are natural cellulose fibres composed primarily of pure cellulose, along with small amounts of proteins, waxes, and other substances. These fibres are highly prized for their desirable properties, such as softness, breathability, absorbency, and strength. Cotton fibres have a unique structure with twists and convolutions, which give them their characteristic resilience and versatility.
Cotton is widely used in the textile industry to produce a wide range of products, including clothing (such as shirts, pants, dresses, and underwear), bed sheets, towels, curtains, and various types of fabrics. It is valued for its comfort, durability, and ability to absorb moisture.
Cotton cultivation is a major agricultural industry in many countries, particularly in regions with warm climates and suitable soil conditions. It requires proper management practices, including irrigation, pest control, and harvest techniques, to maximize yield and quality.
Botany of Cotton
Cotton (Gossypium spp.) is a shrubby plant that belongs to the Malvaceae family. It is primarily cultivated for its fibres, which are used in the textile industry to produce fabrics and various cotton-based products. Here are some key aspects of the botany of cotton:
- Plant Structure: Cotton plants are typically herbaceous perennials, but they are commonly grown as annuals in commercial cultivation. They have a woody stem at the base, which gives rise to multiple branches and leaves. The height of the plant can vary depending on the variety and growing conditions.
- Leaves: The leaves of cotton plants are broad and lobed, with a distinct palmate or palmately lobed shape. They are arranged alternately along the stem. The leaves are typically green in colour and have a rough texture due to the small hairs present on the leaf surface.
- Flowers: Cotton plants produce large, showy flowers. Each flower has five petals that are typically white or yellow in colour. The flowers are borne on short stalks and have a bell-shaped or cup-shaped appearance. The flowers are pollinated by insects, primarily bees.
- Fruit/Capsule: After pollination, the flowers develop into fruit capsules known as bolls. The bolls are spherical or oval-shaped structures that contain cotton fibres. Each boll usually contains several seeds, which are surrounded by fluffy white or creamy-coloured fibres.
- Fibres: The fibres of cotton are the most economically valuable part of the plant. They are single-celled trichomes that grow from the surface of the seeds within the bolls. The fibres are made of cellulose and are known for their softness, strength, and ability to absorb moisture.
- Varieties: There are several species of cotton, but the two primary species cultivated for commercial purposes are Gossypium hirsutum (upland cotton) and Gossypium barbadense (extra-long staple cotton or Pima cotton). Different cotton varieties exhibit variations in plant height, fibre length, yield potential, and resistance to pests and diseases.
Cotton is a warm-season crop that requires a long growing period and favourable climatic conditions. It is cultivated in many countries worldwide, particularly in regions with warm temperatures and adequate water availability. Cotton cultivation involves various agronomic practices, including planting, irrigation, pest and weed control, and harvesting, to maximize fibre production and quality.
Characteristics of Cotton:
- Diocot: Cotton is a dicotyledonous plant, meaning it has seeds that contain two embryonic leaves (cotyledons) upon germination. Dicot plants typically have net-like veins in their leaves.
- C3 Pathway: Cotton follows the C3 photosynthetic pathway, which is the most common pathway in plants. It involves the initial fixation of carbon dioxide (CO2) into a three-carbon compound during photosynthesis.
- Short-day plant: Cotton is considered a short-day plant, meaning it requires a specific photoperiod (day length) to initiate flowering. It typically requires longer nights or shorter days to induce the flowering process.
- Indeterminate: Cotton plants are classified as indeterminate. This means that they continue to grow and produce vegetative growth and flowers throughout the growing season until environmental conditions or management practices cause them to stop.
- Partially cross-pollination: Cotton exhibits partial cross-pollination, meaning that it has both self-pollination and cross-pollination mechanisms. While cotton flowers are capable of self-pollination, they also rely on external agents like insects, primarily bees, for cross-pollination.
Types of Cotton
- Gossypium arboreum – Desi Cotton: Desi cotton is a type of cotton derived from the species Gossypium arboreum. It is primarily grown in the Indian subcontinent. Desi cotton plants are typically smaller in stature compared to other types of cotton, and the fibres they produce are shorter in length.
- Gossypium hirsutum – American Cotton: American cotton, also known as upland cotton, is derived from the species Gossypium hirsutum. It is the most widely cultivated type of cotton globally. Gossypium hirsutum cotton plants are well-adapted to various environmental conditions and are known for their high fibre yield and quality.
- Gossypium barbadense – Egyptian Cotton: Egyptian cotton comes from the species Gossypium barbadense. It is highly regarded for its long staple fibres, which are soft, strong, and lustrous. Egyptian cotton is often associated with luxury textiles and is known for its superior quality and performance in the textile industry.
- Gossypium herbaceum – Indian Cotton: Indian cotton is derived from the species Gossypium herbaceum. It has been cultivated in the Indian subcontinent for centuries. Indian cotton plants have a shorter stature compared to Gossypium hirsutum, and the fibres they produce are generally shorter in length.
These types of cotton differ in their genetic characteristics, fibre properties, and adaptability to different growing regions. Each type has its unique qualities and is valued for specific applications in the textile industry.
Production Technology
Time of sowing
| Plants per acre | Plant to Plant distance | |
| 1st April to 30th April | 17000 | 12 inch |
| 1st May to End May | 23000 | 9 inch |
Varieties of Cotton
| Varieties | Year of Release | Sowing Time | Yield Potential (Maunds/Acre) | Recommended Areas |
| FH-152 | 2018 | 1st April-31st May | 35 to 40 | All Areas of Punjab |
| RH-662 | 2018 | 1st April-31st May | 35 to 40 | DG Khan & Bahawalpur Divisions |
| RH-668 | 2018 | 1st April-31st May | 35 to 40 | DG Khan & Bahawalpur Divisions |
| SLH-8 | 2018 | 1st April-31st May | 35 to 40 | All Areas of Punjab |
| FH-326 | 2017 | 1st April-31st May | 35 to 40 | Faisalabad, DG Khan & Bahawalpur Divisions |
| FH-Lalazar | 2016 | 1st April-31st May | 35 to 40 | All Areas of Punjab |
| MNH-988 | 2016 | 1st April-31st May | 35 to 40 | All Areas of Punjab |
| VH-305 | 2016 | 1st April-31st May | 35 to 40 | All Areas of Punjab |
| BH-184 | 2016 | 1st April-31st May | 35 to 40 | All Areas of Punjab |
| RH-647 | 2016 | 1st April-31st May | 35 to 40 | All Areas of Punjab |
| VH-327 | 2016 | 1st April-31st May | 35 to 40 | DG Khan & Bahawalpur Divisions |
B.T. varieties of Cotton
- IUB-2013, 222,
- BS-15, 20
- CIM-600, 602, 598
- 663,343,
- CYTO-179
- MNH-886, 1016,1020
- 1026, 1035,
- FH-114, 142,490
- FH-Lalazar, Super
- RH-668
- NIAB-1048, 545, 878
Non-BT Varieties of Cotton
- MNH-786
- Niab Kiran
- Sito 124
- CIM 610
- CIM 620
- GS Ali 7
B.T varieties with Non-B.T
Non-BT varieties are compulsory with BT varieties So B.T varieties should not develop immunity against insects. 10% of the total Cotton cultivated land must be occupied by non-BT varieties.
Land Preparation
The crop and weed residues should be chopped and mixed with the soil at the time of the first ploughing. One deep ploughing will help for better crop establishment. Two ploughings with successive plankings must be done before sowing for seedbed preparation.
Laser land levelling is compulsory before cotton sowing for water saving and uniform crop stand.
Cotton Sowing Methods:
1) Drill sowing
- Cotton cultivated with Kharif drill with row to row distance of 2.5 feet
- Seed depth should be 2-2.5 inch
- With one-foot crop height earthing up should be done in drill sown crop
Drill sowing has the following advantages:
- Water saving
- Better weeds control
- Nutrient use efficiency can be improved
- Better yield can be maintained in each picking
2) Bed Sowing
It has two types
I. Machine sowing
- Land should be levelled for machine sowing
- Sowing on dry beds
- Irrigation should be applied immediately after sowing at 2 inches below the seeds
II. Manual sowing
- Irrigation should be applied before seed sowing in furrows about 6-7 inches
- Immediately after irrigation seeds should be placed one inch above the actual water level
Major seed distributor of Cotton
- Punjab and Sindh Seed Corporation
- CCRI Multan
- CRS Faisalabad
- NIAB Faisalabad
- CEMB
Cotton Seed Rate
| Germination | Linted seed | Without lint (kg/acre) |
| 75% or above | 6 | 8 |
| 60% | 8 | 10 |
Soil condition
- Loamy or clay loam soil is suitable
- Better organic matter must be present there
- Better water holding capacity is necessary
Irrigations requirements of Cotton
Drill Sowing
- First irrigation should be applied after 30-35 days of sowing and then after each 10-12 days
Bed Sowing
- First irrigation should be applied after 3-5 days of sowing
- Other irrigations should be applied after 6-9 days
Fertilizer for Cotton
| Soil type | Nitrogen | Phosphorus | Potassium |
| Weak soil | 100 kg | 40 kg | 38 kg |
| Medium soil | 90 kg | 35 kg | 38 kg |
| Fertile | 80 kg | 30 kg | 38 kg |
Apply Zinc Sulphate (33%) @ 5 kg /acre and Boric acid 17% @ 3.5 kg/acre if there is any deficiency reported.
Note: The fertilizer doses can be adjusted according to the level of soil fertility
Always Remember: Never use Zinc and Boron by mixing with insecticides
Cotton crop Insects and Pests
Cotton plants are susceptible to various insect pests that can cause damage to the crop. Some of the major insect pests of cotton include:
- Jassid (Amrasca devastans): Jassids are sap-sucking insects that can cause significant damage to cotton plants by piercing and sucking the plant sap. Heavy infestations can lead to stunted growth, leaf curling, and reduced yield.
- Whitefly (Bemisia tabaci): Whiteflies are small insects that feed on the underside of cotton leaves, causing yellowing, wilting, and reduced plant vigour. They also secrete honeydew, promoting the growth of black sooty mould on the plants.
- Thrips (Thrips tabaci): Thrips are tiny insects that feed on cotton leaves, buds, and flowers. They cause damage by rasping and sucking plant tissues, resulting in distorted growth, silvery patches, and flower drop.
- Grasshopper: Grasshoppers are voracious feeders that can cause extensive damage to cotton plants by consuming leaves, stems, and reproductive structures. Large populations can lead to severe defoliation and reduced yield.
- Armyworms: Armyworms, including the fall armyworm (Spodoptera frugiperda) and the cotton armyworm (Spodoptera litura), are caterpillar pests that feed on cotton foliage. They can cause defoliation, skeletonization of leaves, and damage to bolls.
- Dusky Cotton Bug (Oxycarenus spp.): Dusky cotton bugs are sap-sucking insects that primarily infest the bolls of cotton plants. They feed on developing seeds, causing damage to the cotton fibres and reducing the quality of the harvest.
- Red Cotton Bug (Dysdercus spp.): Red cotton bugs are piercing-sucking insects that feed on cotton bolls. They pierce the bolls and feed on the developing seeds, leading to boll damage, shedding of squares and bolls, and reduced yield.
- Mealybug: Mealybugs are small insects covered in white, waxy filaments. They feed on cotton plants by sucking sap from leaves, stems, and bolls. Severe infestations can lead to stunted growth, leaf yellowing, and distorted bolls.
- Spotted Bollworm (Earias spp.): Spotted bollworm larvae feed on cotton bolls, causing damage by tunnelling into the boll and feeding on the developing seeds. This can result in boll shedding, reduced fibre quality, and economic losses.
- Pink Bollworm (Pectinophora gossypiella): Pink bollworm is a serious pest that attacks cotton bolls. The larvae bore into the bolls, feeding on the seeds and causing damage. It can result in boll rot, seed loss, and reduced fibre quality.
- American Bollworm (Helicoverpa armigera): American bollworm larvae feed on various parts of the cotton plant, including leaves, squares, flowers, and bolls. They can cause significant damage and economic losses by feeding on the reproductive structures of the plant.
Insect/Pest Control:
Pests can be managed by local integration of various tactics like
- Use of Resistant varieties
- Modification of pest environment (Removal of alternate food sources, timely sowing.
- Conservation and utilisation of biocontrol agents (Parasitoids, Predators etc)
- Balanced use of fertilizers and when necessary, appropriate and timely use of insecticide
Cotton Disease & Control
Bacterial Leaf Blight of cotton
Bacterial blight in cotton, also known as seedling blight, angular leaf spot, and boll rot, is caused by Xanthomonas citri pv. malvacearum (formerly referred to as Xanthomonas campestris pv. malvacearum and Xanthomonas malvacearum).
Boll Rot
It is a complex disease caused by several fungal pathogens viz., Fusarium moniliforme, Colletotrichum capsici, and Aspergillus flavus. Symptoms of boll rot include the appearance of very small light brown spots on bolls which then become dark brown or black and join together. The boll rot first appears as wet spots which makes bolls black. On the infected boll, fungi may develop. In severe cases of attack, the bolls can drop from the plant.
Sooty Mold
Sooty mold, also called blotch or black mold, plant disease characterized by splotchy black stains or coatings on leaves, stems, and fruit.
Root Rot
This fungal disease is also known as Phymatotrichum root rot, Texas root rot and Ozonium root rot. It is caused by one of the most destructive fungal plant disease organisms, Phymatotrichum omnivorum. The first symptoms are slight yellowing or bronzing of the leaves. The upper-most leaves wilt within 24 to 48 hours after bronzing, followed by wilting of the lower leaves within 72 hours. Permanent wilt occurs by the third day, followed by death. The leaves remain firmly attached to the plant.
CLCv
Cotton leaf curl disease (CLCuD) is a viral infection of cotton and other susceptible host plants that is transmitted by silver leaf whitefly (Bemisia tabaci). Early symptoms include deep downward cupping of the youngest leaves accompanied by swelling and darkening of leaf veins. Later stages of infection involve the upward or downward curling of leaf margins, accompanied by leaf yellowing or mosaic.
Control:
- Seed treatment with available seed dresser like “Topsin M” (70%) WP
- Planting of resistant varieties
- Balanced fertilizer application & Crop rotation
- Field sanitation and proper water management.
Harvesting
- The harvest of the main crop (planted in June) began in September, with a peak harvest in October.
- It is an indeterminate crop so four to five pickings are done for its proper harvesting.
- Picking should be started after 40-50% opened and done between 10 am to 4 pm for only fully opened bolls.
- Never go for it in rainy weather.
- Should be done from bottom to top.
- Different varieties should be stored separately in dry conditions.
Major recommendation
- Only approved varieties should be sown in their respective areas
- Decide seed rate according to its germination percentage
- Always use seed treatments before sowing
- Irrigation should be applied according to the varietal recommendation
- Fertilizer plans must be followed for each variety
- Timely picking should be done
- In boron deficiency: use 3kg boric acid/4.5 kg (10.5%) Borex per acre at soil preparation.
- Storage moisture should not be more than 10%