Courses › … › agronomy › agro202 practical crop production i ii
Lesson
04 of 15

🌾 Cotton Production Technology

Detailed guide to cotton cultivation including Bt cotton technology, varieties, fibre quality, nutrient management, IPM for bollworm and sucking pests, and harvesting.

This lesson explains practical cotton production technology with emphasis on variety choice, fibre quality, nutrient and water management, and IPM in field conditions.

Importance of Cotton

Cotton is aptly called "White Gold" — it is India's most important commercial fibre crop and one of the most significant cash crops globally. India is the largest producer of cotton in the world (surpassing China in recent years) and among the top exporters. Cotton accounts for approximately 25% of the global textile fibre market. More than 200 textile industries depend directly on cotton, and it supports livelihoods of over 60 million people in India across farming, ginning, spinning, and weaving value chains. India ranks 3rd globally in cotton area.

Botanical Classification

  • Scientific name:
    • Gossypium hirsutum — American Upland cotton (accounts for ~95% of cultivated area in India)
    • Gossypium arboreum — Desi/Indigenous cotton (shorter staple, drought tolerant)
    • Gossypium barbadense — Egyptian/Sea Island cotton (extra-long staple, premium quality)
  • Family: Malvaceae
  • Chromosome number: 2n = 52 (G. hirsutum is allotetraploid)
  • Cotton is a perennial woody shrub grown as an annual crop

Fibre Types and Quality Parameters

Staple Length Categories

  • Long staple: >30 mm (G. barbadense — Egyptian, Suvin)
  • Medium staple: 24–30 mm (most G. hirsutum varieties and hybrids)
  • Short staple: <24 mm (G. arboreum desi cotton)

Fibre Quality Parameters

Parameter Description Optimal Value
Staple length Length of fibre in mm >28 mm preferred
Staple strength Breaking strength (g/tex) >28 g/tex
Micronaire Fineness and maturity index 3.5–4.9 (ideal)
Uniformity index Consistency of fibre length >82%
Spinning consistency index (SCI) Overall spinnability >140

Climate Requirements

  • Frost-free days: Minimum 210 days required from sowing to last picking
  • Temperature: 21–35°C optimum; high temperatures (>35°C) during flowering cause boll shedding
  • Rainfall: 600–1200 mm; dry, hot weather essential for boll development and fibre quality
  • Humidity: Low humidity during boll opening prevents fibre staining and disease

Soil Requirements

  • Deep black cotton soil (Vertisols): Ideal — Maharashtra (Vidarbha), Madhya Pradesh, Gujarat
  • Alluvial soils: Punjab, Haryana (irrigated cotton belt)
  • pH: 6.5–8.0; tolerates slightly alkaline soils
  • Good drainage essential — cotton does not tolerate waterlogging

Bt Cotton Technology

Introduction in India

  • Bollgard I (Cry1Ac gene): Approved by GEAC in 2002; first Bt crop approved in India
  • Bollgard II (Cry1Ac + Cry2Ab genes): Approved in 2006; provides broader bollworm protection
  • By 2014, approximately 96% of cotton area in India was under Bt hybrids

Bollworm Complex Controlled by Bt

  • American bollworm (Helicoverpa armigera) — most important
  • Pink bollworm (Pectinophora gossypiella)
  • Spotted bollworm (Earias vittella and E. insulana)
  • Spiny bollworm (E. vittella)

Bt cotton expresses Cry toxins in plant tissues; larvae feeding on leaves and bolls ingest the toxin, which disrupts midgut epithelium, leading to larval death.

Regulatory and Policy Issues

  • Trait fee controversy: Monsanto (now Bayer) sub-licensed Bt trait to Indian seed companies for trait fee; CCI (Competition Commission of India) ruling in 2015 found anti-competitive pricing
  • Government MRP notification: Government fixes the Maximum Retail Price (MRP) of Bt cotton seed under Essential Commodities Act
  • HT-Bt cotton (Herbicide Tolerant): Illegal cultivation occurs in some states (Gujarat); not approved by GEAC; regulatory crackdown ongoing

Resistance Management

  • Refuge requirement: 20% non-Bt border rows in field; maintains susceptible bollworm population
  • Bollworm resistance to Cry1Ac developing — Bollgard II (Cry1Ac + Cry2Ab) helps delay resistance

Varieties and Hybrids

Bt Hybrids (G. hirsutum)

  • Vikram BG-II: MAHYCO; medium staple; widely grown
  • Bunny BG-II: Nuziveedu Seeds; high-yielding; south India
  • RCH-2 BG-II: Rasi Seeds; medium staple; popular in Andhra Pradesh, Karnataka
  • MRC-7017 BG-II: Mahyco; northern India
  • NCS-145 BG-II: NCML Seeds; medium staple

Desi Varieties (G. arboreum)

  • LD-327: Released by PAU Ludhiana; north India
  • Jayadhar: CICR, Nagpur; G. arboreum; drought tolerant

Seed Rate and Sowing

  • Seed rate:
    • Planting (dibbling): 0.5 kg/ha (delinted, treated Bt hybrid seed)
    • Line sowing (drilling): 2.0–2.5 kg/ha
  • Spacing:
    • Rainfed: 90×60 cm
    • Irrigated hybrid: 120×60 cm (or paired row planting 120+60 × 60)
  • Sowing time:
    • Central India (Maharashtra, MP): May–June
    • Northern India (Punjab, Haryana, Rajasthan): April–May
  • Seed treatment: Slurry treatment with Imidacloprid 70WS at 7 g/kg + Thiram 3g/kg for thrips, jassid control in seedling stage

Nutrient Management

  • Recommended NPK: 100:50:50 kg/ha (under irrigated conditions)
  • Critical stages for nutrition:
    • Square formation and boll development are most critical
  • Split N application:
    • Basal: 50% N + full P + full K
    • At 45 DAS (squaring): 25% N
    • At 80 DAS (boll formation): 25% N
  • Micronutrients:
    • Boron: 1.0 kg/ha soil application or 0.2% foliar spray at squaring — critical for pollen viability and boll set
    • Zinc: ZnSO₄ at 25 kg/ha for zinc-deficient soils
  • FYM/compost: 10–15 t/ha basal; improves water retention in lighter soils

Water Management

  • Kharif cotton: 5–6 irrigations required under rainfed-deficit conditions
  • Critical stages: Flower bud formation, flowering, boll development
  • Avoid waterlogging: Cotton is highly susceptible to root rot under flooded conditions
  • Soil moisture: Maintain field capacity throughout flowering and boll filling period

Weed Management

  • Critical weed competition period: First 45 days
  • Pendimethalin 1.0 kg ai/ha as pre-emergence herbicide (within 72 hrs of sowing)
  • Inter-cultivation with cultivator at 25–30 DAS (ridging/earthing-up)
  • 2 hand weedings or mechanical inter-row cultivation

Integrated Pest Management (IPM)

Bollworm Complex (Primary Target of Bt)

  • Bt cotton controls bollworms; non-Bt desi varieties need chemical control
  • Helicoverpa: Quinalphos or Indoxacarb; pheromone traps (5/ha) for monitoring

Sucking Pests (Not Controlled by Bt)

  • Whitefly (Bemisia tabaci): Vector of Cotton Leaf Curl Disease (CLCuD) — most devastating disease in north India; yellowing, leaf curl, vein thickening; use reflective mulch, imidacloprid spray
  • Jassid (Amrasca biguttula biguttula): Leaf curl, hopper burn; dimethoate or thiamethoxam
  • Aphid: Colony on underside; sooty mould; imidacloprid
  • Thrips: Silvering of leaves; early-stage sucking damage; imidacloprid seed treatment

Diseases

  • CLCuD (Cotton Leaf Curl Disease): Begomovirus transmitted by whitefly; resistant varieties (CLCuD-tolerant lines from CICR)
  • Bacterial blight (Xanthomonas axonopodis pv. malvacearum): Angular water-soaked lesions; use resistant varieties; Streptocycline + Copper spray
  • Root rot / Fusarium wilt: Soil-borne; crop rotation; seed treatment with Trichoderma

Harvesting

  • Duration: 150–180 days from sowing to final picking
  • 3–4 pickings at 15–20 day intervals (cotton bolls open at different times)
  • Picking criteria: Fully opened, dry bolls; avoid wet-condition picking (staining and rot)
  • Ginning Outturn (GOT): Proportion of lint to seed cotton; 35–40% is standard
  • Good GOT ensures maximum lint recovery in ginning factory

Yield Potential

  • Bt hybrid (G. hirsutum): 2–3 t/ha seed cotton (~700–1050 kg lint/ha)
  • Desi cotton (G. arboreum): 800–1200 kg seed cotton/ha

Cotton Growing States — Summary Table

State Variety Type Area (Mha) Yield (kg lint/ha)
Maharashtra G. hirsutum (BG-II) 4.2 400–500
Gujarat G. hirsutum (BG-II) 2.6 600–700
Andhra Pradesh/Telangana G. hirsutum (BG-II) 1.8 550–650
Madhya Pradesh G. hirsutum (BG-II) 0.6 450–550
Punjab/Haryana G. hirsutum (BG-II) 0.8 700–850
Rajasthan G. hirsutum (BG-II) 0.5 400–500
Karnataka G. arboreum + hirsutum 0.5 300–400

Summary Cheat Sheet

Area Key Exam Point
Economic role Cotton is a major fibre cash crop ("White Gold")
Yield drivers Hybrid selection, balanced nutrients, timely protection
IPM focus Bollworms and sucking pests need integrated management

References

2 sources • [1] [2]

Lesson Doubts

Ask questions, get expert answers