Unit 5: Crop Production Package of Practices for Kharif Fibre Crops - Subjective Questions

Origin and domestication

Cotton belongs to the genus Gossypium and family Malvaceae. It has multiple centres of origin because different cultivated species were domesticated independently.

• Gossypium arboreum and G. herbaceum are diploid Old World cottons associated with the Indian subcontinent and Africa-Arabia, respectively.
• Gossypium hirsutum originated in Central America and Mexico.
• Gossypium barbadense originated in tropical South America.
• Archaeological evidence shows that cotton was used in the Indus Valley civilisation several thousand years ago.

Geographical distribution

Cotton is grown mainly in tropical and subtropical regions between approximately N and S latitudes. Major producing countries include India, China, the United States, Brazil, Pakistan, Turkey and Australia.

In India, cotton is cultivated in three major zones:

• Northern zone: Punjab, Haryana and Rajasthan
• Central zone: Gujarat, Maharashtra and Madhya Pradesh
• Southern zone: Telangana, Andhra Pradesh, Karnataka and Tamil Nadu

Maharashtra, Gujarat and Telangana are among the leading cotton-growing states of India.

Cotton is one of the most important commercial fibre crops and is popularly called white gold.

Economic importance

• Cotton fibre is the principal raw material of the textile industry.
• Cotton cultivation, processing, ginning, spinning, weaving and garment production generate substantial rural and industrial employment.
• Cotton yarn, fabrics and garments contribute significantly to domestic trade and export earnings.
• The crop supports several associated industries, including oil extraction, livestock feed, paper and cellulose manufacturing.

Major products and uses

• Lint: Used for yarn, cloth, absorbent cotton, medical dressings and household textiles.
• Cottonseed: Contains oil that is refined for edible and industrial purposes.
• Cottonseed cake: Used as livestock feed and organic manure after suitable processing.
• Linters: Short fibres left on the seed are used in cellulose, rayon, paper, explosives and pharmaceutical products.
• Stalks: Used as fuel, compost, particle board and paper pulp.
• Hull: Used as roughage in animal feed.

Thus, almost every part of the cotton plant has commercial or agricultural value.

Climatic requirements

• Cotton requires a warm, frost-free growing season of about 180-200 days.
• The optimum temperature for growth is approximately .
• A temperature of about favours germination, while warm days and cool nights support boll development.
• An annual rainfall of about 500-1000 mm, if well distributed, is generally suitable.
• Heavy rainfall, prolonged cloudiness and high humidity during flowering and boll opening encourage shedding, pests and diseases.
• Bright sunshine and dry weather are essential during boll maturation and picking.
• Frost and extreme temperatures seriously damage the crop.

Soil requirements

• Cotton grows best in deep, fertile and well-drained soils with good moisture-holding capacity.
• Deep black cotton soils or Vertisols are especially suitable for rainfed cotton because they retain moisture.
• Irrigated cotton also performs well on alluvial and medium-textured loam soils.
• A soil pH of about 6.0-8.0 is generally favourable, though cotton tolerates moderate salinity better than many field crops.
• Waterlogged, highly acidic, shallow and poorly drained soils should be avoided because cotton is sensitive to prolonged stagnation.

Four cultivated species of cotton are commercially important.

Diploid species,

• Gossypium arboreum: Asiatic or desi cotton
• Gossypium herbaceum: Levant or desi cotton

Tetraploid species,

• Gossypium hirsutum: American upland cotton
• Gossypium barbadense: Egyptian or extra-long-staple cotton

Desi cotton and American cotton compared

G. barbadense produces superior extra-long-staple fibre but requires favourable management and climate.

Cotton varieties and hybrids are selected according to agro-climatic zone, irrigation, season, fibre requirement and pest situation.

Examples of important cultivars

• Desi cotton: AKA-7, PA-255, RG-8 and HD-123
• American upland cotton: MCU-5, LRA-5166, LH-2108, Suraj and F-1861
• Extra-long-staple cotton: Suvin and DCH-32
• Hybrid cotton: H-4, Varalaxmi and regionally recommended Bt hybrids

Selection criteria

• Suitability to the northern, central or southern cotton zone
• Adaptation to rainfed or irrigated conditions
• Duration and fit within the local cropping system
• Boll size, lint percentage and seed-cotton yield
• Staple length, strength, fineness and uniformity of fibre
• Resistance or tolerance to sucking pests, bollworms and major diseases
• Tolerance to drought, salinity or waterlogging where relevant
• Compact plant type and suitability for high-density planting or mechanical picking
• Availability of certified seed and compliance with current regional recommendations

Because cultivar recommendations change with location and pest resistance, farmers should use varieties or approved hybrids recommended by the state agricultural university or agriculture department.

Land preparation

• Give one deep ploughing to break the hard layer and expose soil-borne pests.
• Follow it with two or three harrowings to obtain a fine, firm and weed-free seedbed.
• Form ridges and furrows or broad beds in irrigated and heavy-soil areas to improve drainage.

Seed preparation and treatment

• Acid-delint fuzzy seed where recommended to facilitate accurate sowing and reduce seed-borne infection.
• Treat seed with an approved fungicide or biological agent against seed and soil-borne diseases.
• Treat with a recommended insecticidal seed dresser where sucking pests are expected.
• Inoculate with beneficial microorganisms only after chemical treatment has dried.

Sowing time

• Rainfed cotton is generally sown with the onset of the monsoon.
• Irrigated northern cotton is commonly sown during April-May.
• Sowing periods in central and southern India vary with monsoon arrival and local recommendations.

Seed rate and spacing

• Varieties commonly require about 12-20 kg fuzzy seed per hectare; delinted seed requires less.
• Hybrids are usually dibbled at a lower seed rate of about 1.5-3.0 kg per hectare.
• Common spacing ranges from cm for compact varieties to cm for vigorous hybrids.
• Gap filling and thinning should be completed early to maintain the recommended plant population.

Exact values must be adjusted for seed type, germination percentage, plant architecture and local recommendations.

Nutrient management practices

• Apply well-decomposed farmyard manure or compost, commonly 5-10 tonnes per hectare, during land preparation where available.
• Determine fertilizer requirements through soil testing and the expected yield level.
• Apply the full dose of phosphorus and potassium and a portion of nitrogen at sowing.
• Split the remaining nitrogen between square formation and flowering or early boll development.
• Place fertilizers near the active root zone without allowing direct contact with the seed.
• Correct deficiencies of zinc, boron, magnesium or other micronutrients only on the basis of soil or plant diagnosis.
• Include legumes, crop residues and biofertilizers as parts of integrated nutrient management.

Importance of balance

• Adequate nitrogen promotes vegetative growth, fruiting branches and boll development.
• Phosphorus supports root growth, early establishment and reproductive development.
• Potassium improves boll filling, fibre quality, water regulation and stress tolerance.
• Excess nitrogen causes rank vegetative growth, delayed maturity, boll shedding and increased pest incidence.
• Nutrient deficiency reduces boll number, boll weight and lint quality.

Therefore, balanced and split nutrient application improves nutrient-use efficiency, crop maturity, yield and fibre quality.

Irrigation management

• Provide irrigation according to soil moisture, rainfall and crop stage; avoid fixed schedules where rainfall is uncertain.
• Flowering, boll formation and boll development are the most moisture-sensitive stages.
• Avoid both prolonged drought and waterlogging because they cause shedding of squares, flowers and young bolls.
• Furrow or alternate-furrow irrigation reduces unnecessary wetting, while drip irrigation improves water and fertilizer-use efficiency.
• Stop irrigation sufficiently before the final picking to promote boll opening and avoid late vegetative growth.

Weed management

• Keep the crop weed-free during the critical early period, approximately 20-60 days after sowing.
• Carry out hand weeding, hoeing or intercultivation at suitable intervals.
• Use locally recommended pre-emergence or post-emergence herbicides at label rates when required.
• Combine herbicides with mechanical or manual methods for integrated weed management.

Intercultural operations

• Thin excess seedlings and fill gaps soon after establishment.
• Hoeing improves soil aeration, controls weeds and conserves moisture.
• Earthing-up supports plants and facilitates irrigation.
• Topping or growth regulation may be adopted in vigorous crops according to the cultivar and production system.

Harvesting and picking

• Cotton is ready for picking when bolls are fully open and the lint is dry and fluffy.
• Pick only during dry weather after the morning dew has disappeared.
• Carry out several pickings at intervals because bolls do not open simultaneously.
• Keep clean, healthy cotton separate from stained, insect-damaged or rain-affected cotton.
• Use clean cloth bags and avoid contamination with leaves, soil, plastic and other foreign matter.

Post-harvest handling

• Dry seed cotton in a clean place to a safe moisture level before storage.
• Store different varieties and grades separately.
• Ginning separates lint from seed, after which lint is pressed into bales.
• Grading is based on staple length, strength, fineness, colour, cleanliness and maturity.

Yield

Yield varies widely with species, cultivar, rainfall, irrigation and crop management. Rainfed crops may produce roughly 1.0-2.0 tonnes of seed cotton per hectare, while well-managed irrigated hybrids may produce about 2.5-4.0 tonnes per hectare or more under favourable conditions. The lint yield can be estimated as:

For example, 3000 kg of seed cotton with a ginning percentage of 35 gives 1050 kg lint per hectare.

Integrated crop management coordinates agronomic, nutritional, water and plant-protection practices throughout the crop season.

Major components

• Select a certified, locally adapted variety or hybrid with the required fibre quality and duration.
• Sow on time at the recommended spacing to establish an optimum plant population.
• Use crop rotation, summer ploughing, clean seed and seed treatment to reduce pests and diseases.
• Apply organic manure and soil-test-based fertilizers in balanced and split doses.
• Conserve rainwater through ridges, furrows, broad beds, mulching or intercultivation.
• Irrigate at critical reproductive stages and provide drainage after heavy rain.
• Keep the field weed-free during the early critical period.
• Monitor the crop for sucking pests, bollworms and diseases; conserve natural enemies and use pesticides only at economic threshold levels.
• Remove severely infested plant parts and destroy crop residues after the final picking.
• Pick fully opened bolls in dry weather and prevent contamination during storage and ginning.

These practices improve boll retention, boll weight, ginning percentage and fibre properties while reducing production costs, pesticide residues and avoidable yield losses.

Jute is a bast fibre crop belonging to the genus Corchorus and family Malvaceae. Two species are commercially cultivated.

Origin

• Corchorus capsularis, known as white jute, is generally associated with the Indo-Myanmar region, with India considered an important centre of origin and diversity.
• Corchorus olitorius, known as tossa jute, is considered to have originated in Africa and later spread to South Asia.

World distribution

Jute is concentrated in the warm, humid alluvial plains and delta regions of South Asia. India and Bangladesh are the principal producers. Smaller areas occur in Nepal, Myanmar, China and some Southeast Asian and African countries.

Distribution in India

• West Bengal accounts for the largest area and production.
• Assam, Bihar, Odisha, Meghalaya and Tripura are other important producing states.
• The crop is especially suited to the Ganga-Brahmaputra delta and adjoining river basins because of fertile alluvial soils, humid weather and abundant water for retting.

The geographical concentration of jute reflects its combined requirements for warm weather, sufficient rainfall, fertile soil and accessible retting water.

Jute is an important natural bast fibre and is often called the golden fibre because of its colour, lustre and commercial value.

Economic importance

• It supplies raw material to the jute textile and packaging industries.
• Cultivation and processing provide employment in farming, retting, fibre extraction, transport and manufacturing.
• Jute products contribute to export earnings and support rural livelihoods in eastern India.
• As a renewable, biodegradable and recyclable fibre, jute can replace some synthetic packaging materials.

Uses

• Traditional products: Gunny bags, hessian cloth, sacking, ropes, twine and carpet backing
• Diversified products: Shopping bags, floor coverings, curtains, handicrafts, home furnishings and decorative fabrics
• Industrial products: Geotextiles, composite materials, insulation, pulp, paper and packaging boards
• Agricultural uses: Mulch mats, nursery products, erosion-control fabric and biodegradable containers
• By-products: Jute sticks are used for fuel, fencing, thatching, charcoal, paper pulp and particle board
• Tender leaves of C. olitorius are also consumed as a vegetable in some regions.

Jute's low carbon footprint and biodegradability increase its importance in sustainable manufacturing.

Climatic requirements

• Jute requires a warm, humid climate with a frost-free growing period.
• A temperature range of about is favourable for rapid growth.
• Approximately 1200-2000 mm of well-distributed rainfall is suitable, though irrigation can compensate for early-season moisture shortage.
• Relative humidity of about 70-90% promotes vigorous vegetative growth.
• Intermittent rain and sunshine favour crop development, whereas drought after sowing causes poor establishment.
• Standing water for long periods is harmful, although established white jute tolerates temporary water stagnation better than tossa jute.

Soil requirements

• Fertile, deep and well-drained new alluvial soils are ideal.
• Loam to clay-loam soils rich in organic matter support high biomass and fibre yield.
• C. capsularis is relatively tolerant of low-lying and imperfectly drained conditions.
• C. olitorius performs better on higher, well-drained land.
• A slightly acidic to neutral soil, approximately pH 5.0-7.5, is generally suitable.
• Highly acidic, saline, coarse sandy and persistently waterlogged soils restrict growth and fibre production.

Both species are annual bast fibre crops. Their fibres occur in the secondary phloem of the stem and are extracted after retting. Species selection should be based on land elevation, drainage, sowing period and required fibre quality.

Examples of white jute varieties

• JRC-212
• JRC-321
• JRC-7447
• JRC-80

Examples of tossa jute varieties

• JRO-524, also known as Navin
• JRO-632
• JRO-7835
• JRO-204, also known as Suren
• JRO-8432

Factors governing selection

• Species suitability for lowland or upland conditions
• Recommended sowing period and sensitivity to premature flowering
• Duration and compatibility with preceding and succeeding crops
• Fibre yield, fineness, strength, colour and lustre
• Resistance or tolerance to diseases, insect pests and abiotic stresses
• Suitability for rainfed or irrigated production
• Response to fertilizers and ability to maintain stand under local soil conditions
• Availability of certified seed and current regional recommendation

A high-yielding variety should not be selected solely on yield potential. It must match the local land situation, drainage, growing season, retting facilities and market demand for fibre quality.

Land preparation

Jute seeds are very small, so the crop requires a fine, firm and level seedbed. The field is ploughed repeatedly, clods are broken, weeds and stubbles are removed, and the surface is levelled to ensure uniform shallow sowing.

Seed treatment

• Use certified seed with high germination.
• Treat seed with a recommended fungicide or biological seed-treatment agent to reduce seedling diseases.
• Seed may be mixed with dry sand or fine soil to obtain uniform distribution during broadcasting.

Sowing time

• White jute is generally sown from February to April, depending on pre-monsoon rain and irrigation.
• Tossa jute is commonly sown from March to May after temperatures become favourable.
• Exact dates vary with variety, location, rainfall and cropping sequence.

Method, seed rate and spacing

• Jute may be broadcast or line-sown, but line sowing facilitates weeding, thinning and uniform crop growth.
• A seed rate of about 4-6 kg per hectare is commonly used for line-sown crops; broadcasting generally requires more seed.
• Rows are usually spaced about 20-30 cm apart.
• After emergence, seedlings are thinned to approximately 5-10 cm within the row.
• Seed should be placed shallowly, generally about 2-3 cm deep, because deep sowing reduces emergence.

Nutrient management

• Apply farmyard manure or compost during final land preparation to improve soil structure and moisture retention.
• Base fertilizer doses on soil-test results and local recommendations.
• Apply the full recommended phosphorus and potassium and part of the nitrogen at sowing.
• Top-dress the remaining nitrogen after thinning or weeding when soil moisture is adequate.
• Avoid excessive nitrogen because it may cause lodging, delayed maturity and coarse fibre.
• Supply sulphur and micronutrients where a diagnosed deficiency exists.

Water management

• Ensure adequate moisture for germination and early establishment.
• Give light irrigation during dry periods, particularly after sowing and fertilizer top-dressing.
• Drain excess rainwater promptly because prolonged waterlogging damages roots, especially in tossa jute.
• Stop unnecessary late irrigation as harvest approaches.

Weed management

• The first 4-6 weeks are critical because young jute seedlings compete poorly with weeds.
• Thin and weed the crop about 15-20 days after emergence and repeat as necessary.
• Line sowing permits wheel hoeing and mechanical interculture.
• A locally recommended herbicide may be integrated with hand weeding.

Timely thinning, weeding and top-dressing together establish an optimum population and support rapid, uniform stem growth.

Harvesting

• Jute grown for fibre is generally harvested around the early pod or small-pod stage, approximately 100-120 days after sowing depending on the variety.
• Earlier harvesting produces finer fibre but lower yield, while delayed harvesting increases yield but makes fibre coarse and less lustrous.
• Plants are cut close to the ground or uprooted in flooded fields.
• Harvested stems are tied into bundles and kept in the field briefly for leaf shedding.

Retting process

1. Bundles are placed horizontally in clean, slow-moving or stagnant soft water.
2. They are submerged with logs, bamboo or other non-staining materials.
3. Microorganisms decompose pectins and other gummy substances binding the fibre to the stem.
4. Retting commonly takes about 10-20 days, depending on water temperature, quality and stem maturity.
5. When fibres separate easily, they are stripped from the stem, washed thoroughly and dried in the shade or mild sunlight.

Factors affecting quality

• Variety and crop maturity at harvest
• Stem uniformity and bundle size
• Water temperature, depth, cleanliness and pH
• Retting duration and microbial activity
• Method of extraction, washing and drying

Under-retting makes fibre difficult to extract, whereas over-retting weakens and discolours it. Ribbon retting and microbial retting can reduce water use and improve uniformity.

Harvest stage and retting determine both the quantity and market grade of jute fibre.

Effect of harvest stage

• Pre-flowering harvest: Produces very fine and soft fibre, but stem biomass and total fibre yield are low.
• Flowering to early-pod stage: Usually provides the best compromise among fibre yield, fineness, strength and lustre.
• Late-pod or seed stage: Produces more stem biomass, but fibre becomes coarse, woody and less lustrous.

Effect of retting

• Proper retting removes gummy materials and permits clean fibre separation.
• Under-retting leaves bark and woody matter attached, resulting in hard, defective fibre.
• Over-retting allows excessive microbial decomposition, reducing fibre strength and causing dark colour.
• Clean, sufficiently deep water at a warm temperature promotes uniform retting.
• Stagnant, muddy or iron-rich water may produce dark or stained fibre.

Yield expression

Fibre recovery may be expressed as:

A well-managed crop commonly yields about 2.0-3.5 tonnes of dry fibre per hectare and 5-8 tonnes of dry sticks per hectare, although actual yield varies with species, variety, soil fertility, weather and management.

Both are major commercial kharif fibre crops. Cotton quality depends strongly on clean picking and ginning, whereas jute quality depends strongly on harvest maturity, retting water and retting duration.