Unit 1: Crop Production Package of Practices for Kharif Major Cereals - Subjective Questions

Origin:

• Cultivated Asian rice, Oryza sativa, is believed to have originated in South and Southeast Asia, with the Indo-Burma region and southern China considered important centers of domestication.
• African cultivated rice, Oryza glaberrima, originated independently in West Africa.
• The major varietal groups of Asian rice are indica, japonica, and javanica.

Geographical distribution:

• Rice is mainly grown in tropical, subtropical, and warm-temperate regions.
• Major rice-producing countries include China, India, Bangladesh, Indonesia, Vietnam, Thailand, Myanmar, the Philippines, Japan, and Pakistan.
• In India, it is extensively cultivated in West Bengal, Uttar Pradesh, Punjab, Telangana, Andhra Pradesh, Odisha, Chhattisgarh, Bihar, Assam, Tamil Nadu, and Haryana.
• Rice is grown under irrigated, rainfed lowland, upland, deep-water, and coastal conditions.

Rice has great economic importance because of the following uses:

• Staple food: Rice is the principal food of a large proportion of the world's population and is an important source of carbohydrates.
• Nutritional value: Milled rice contains approximately 75-80% carbohydrates, along with protein, minerals, and small quantities of fat and vitamins.
• Industrial uses: Rice is used to manufacture starch, glucose, rice flour, breakfast foods, noodles, beverages, and pharmaceutical products.
• Rice bran: Bran is used for extracting rice bran oil, which is valued as an edible oil. De-oiled bran is used in livestock feed.
• Rice husk: Husk is used as fuel, packing material, poultry litter, and a source of silica and power generation.
• Rice straw: Straw is used as animal feed, bedding, roofing material, compost, mulch, and raw material for paper and boards.
• Employment and trade: Rice cultivation, processing, transportation, and marketing provide employment and contribute to domestic and international trade.

Climatic requirements:

• Rice is a warm-season crop requiring high temperature, humidity, and an adequate water supply.
• A temperature of about 20-35°C is suitable during crop growth.
• Germination is favored by temperatures around 20-25°C, while flowering and grain development perform well near 25-30°C.
• Bright sunshine during ripening improves grain filling, whereas very low temperature or excessive heat at flowering can cause sterility.
• An annual rainfall of about 100-200 cm, well distributed during the growing period, is suitable. Irrigation is necessary where rainfall is inadequate.

Soil requirements:

• Rice can grow in a wide range of soils, from sandy loam to heavy clay.
• Clay loam and clay soils with high water-holding capacity are most suitable for lowland rice.
• Well-drained loam soils are preferred for upland rice.
• A soil reaction of approximately pH 5.5-7.5 is generally favorable.
• Saline, alkaline, and acidic soils may be used when tolerant varieties and appropriate soil-management practices are adopted.

Rice varieties may be classified as follows:

According to duration:

• Very early varieties: Mature in less than about 100 days; suitable for drought-prone uplands and multiple cropping.
• Early varieties: Mature in approximately 100-120 days; examples include Prabhat and Sahbhagi Dhan.
• Medium-duration varieties: Mature in approximately 120-140 days; examples include IR 36, IR 64, and MTU 1010.
• Long-duration varieties: Require more than about 140 days; examples include Swarna and Pusa Basmati 1 under their recommended conditions.

According to production environment:

• Irrigated lowland varieties: IR 64, MTU 1010, and Jaya.
• Rainfed upland varieties: Sahbhagi Dhan and Vandana.
• Rainfed lowland varieties: Swarna and varieties specifically recommended for submergence-prone areas, such as Swarna-Sub1.
• Aromatic varieties: Basmati types such as Pusa Basmati 1121 and Pusa Basmati 1509.
• Stress-tolerant varieties: Varieties may be selected for drought, submergence, salinity, or problem soils.

Variety selection must be based on local climate, water availability, soil, season, crop duration, and pest and disease incidence.

The best method depends on water availability, labour cost, soil type, weed pressure, machinery, and the cropping system.

Nursery raising:

• Select healthy, pure, and well-filled seed of a recommended variety.
• Treat seed with an approved fungicide or biological agent to reduce seed-borne diseases.
• Prepare raised, wet, or dry nursery beds according to soil and water conditions.
• Apply well-decomposed farmyard manure and recommended fertilizers to the nursery.
• Sow pre-germinated seed uniformly in a wet-bed nursery and maintain adequate moisture.
• Protect seedlings from weeds, insects, diseases, nutrient deficiencies, and water stress.

Main-field preparation and transplanting:

• Plough and puddle the field thoroughly, then level it to ensure uniform water depth.
• Transplant healthy seedlings, commonly around 20-25 days old for medium-duration varieties; younger seedlings are used in SRI.
• Plant 2-3 seedlings per hill under conventional transplanting, avoiding deep placement.
• A common spacing is about 20 cm × 10-15 cm, but it should be adjusted for variety, season, fertility, and establishment method.
• Replace missing hills within about a week to maintain the desired plant population.
• Maintain shallow water initially and avoid deep flooding immediately after transplanting.

Integrated nutrient management in rice combines organic, biological, and inorganic nutrient sources.

• Apply farmyard manure, compost, green manure, or incorporated crop residues to improve soil structure and nutrient supply.
• Determine fertilizer doses through soil testing and follow regional recommendations because requirements vary with soil, variety, season, and yield target.
• Apply the entire recommended dose of phosphorus and potassium as basal fertilizer unless local recommendations prescribe split application of potassium.
• Apply nitrogen in splits to improve nitrogen-use efficiency. A common schedule is:
  • Basal application at planting
  • Active tillering stage
  • Panicle-initiation stage
• Deep placement of urea supergranules or the use of coated urea can reduce nitrogen losses in flooded soils.
• Maintain proper water control during nitrogen application and avoid applying fertilizer immediately before heavy rain.
• Correct deficiencies of zinc, iron, or sulfur after diagnosis. Zinc deficiency is commonly managed with recommended zinc sulfate application.
• Green manures, Azolla, and blue-green algae can supplement nitrogen in suitable lowland systems.

Water management:

• Level the field properly to achieve uniform irrigation and prevent stagnant deep-water patches.
• Maintain saturated soil or a shallow water layer after establishment rather than unnecessary deep flooding.
• Keep the field adequately moist during critical stages such as active tillering, panicle initiation, flowering, and grain filling.
• Use alternate wetting and drying where suitable to reduce irrigation water use without exposing the crop to severe stress.
• Drain excess water after heavy rain and remove standing water before harvest.
• Stop irrigation approximately 7-15 days before harvest, depending on soil and climate.

Weed management:

• Use clean seed, field sanitation, puddling, crop rotation, and competitive varieties as preventive and cultural measures.
• Hand weeding or mechanical weeding is commonly done around 20-25 days and again around 40-45 days after planting, depending on weed pressure.
• In direct-seeded rice, early weed control is particularly important because weeds emerge along with the crop.
• Use only locally recommended pre-emergence or post-emergence herbicides at the correct dose, crop stage, weed stage, and water condition.
• Integrating cultural, mechanical, and chemical methods provides more reliable weed control and delays herbicide resistance.

• Rice is generally harvested when about 80-85% of the grains on the panicles are mature and straw begins to turn yellow.
• Delayed harvesting increases shattering, lodging, bird damage, and losses from adverse weather; very early harvesting produces immature and poorly filled grains.
• Harvesting may be performed manually with sickles or mechanically using reapers and combine harvesters.
• Threshing should be completed promptly using manual, pedal, power-operated, or combine threshing methods.
• Clean grain by winnowing and remove broken, immature, and foreign material.
• Dry paddy to a safe storage moisture level, commonly around 12-14%, to limit insects, molds, and heating.
• Store grain in clean, dry, insect-free containers or warehouses.
• Grain yield varies widely with variety and environment. A well-managed improved crop may produce approximately 4-6 tonnes per hectare, while favorable irrigated conditions can produce higher yields.
• Yield can be expressed as:

A complete package of practices includes the following steps:

1. Variety selection: Select a high-yielding, locally recommended variety with suitable duration and resistance to major pests and diseases.
2. Seed and nursery: Use certified seed, treat it appropriately, and raise healthy seedlings in a well-managed nursery.
3. Field preparation: Plough the land, incorporate organic manure, puddle thoroughly, and level the field.
4. Transplanting: Transplant healthy seedlings of suitable age at recommended spacing and plant population. Avoid deep planting.
5. Nutrient management: Apply fertilizers according to soil-test recommendations. Apply phosphorus and potassium mainly as basal nutrients and split nitrogen between establishment, tillering, and panicle initiation.
6. Water management: Maintain shallow water after establishment, avoid prolonged deep flooding, and ensure adequate moisture during critical stages.
7. Weed management: Combine puddling, proper spacing, hand or mechanical weeding, and recommended herbicides where necessary.
8. Plant protection: Monitor the crop regularly and use resistant varieties, biological control, field sanitation, and need-based pesticides under integrated pest management.
9. Harvesting: Harvest when most grains are mature, thresh promptly, clean the produce, and dry it to safe moisture.
10. Expected yield: Under sound management, improved irrigated rice commonly yields about 4-6 tonnes per hectare or more, depending on variety and growing conditions.

Origin:

• Maize, Zea mays L., originated in Mesoamerica, particularly the region of present-day Mexico.
• It was domesticated from teosinte by indigenous communities several thousand years ago.
• Following European contact with the Americas, maize spread rapidly to Europe, Africa, and Asia.

Geographical distribution:

• Maize is cultivated from tropical lowlands to temperate regions and at elevations ranging from sea level to high-altitude areas.
• Major producing countries include the United States, China, Brazil, Argentina, India, Mexico, Ukraine, and South Africa.
• In India, important maize-growing states include Karnataka, Madhya Pradesh, Maharashtra, Rajasthan, Bihar, Telangana, Uttar Pradesh, Andhra Pradesh, and Tamil Nadu.
• It is grown during the kharif, rabi, and spring seasons, although kharif is the principal season in much of India.

Maize is often described as a multipurpose crop because it is used as food, feed, fodder, and industrial raw material.

• Human food: Grain is consumed as flour, roasted cobs, boiled sweet corn, popcorn, grits, flakes, and other processed products.
• Animal feed: Maize grain is an energy-rich ingredient in poultry, cattle, and pig feed.
• Fodder: Green maize is used as nutritious fodder and for silage preparation.
• Starch industry: Maize is an important source of starch used in food, textile, paper, pharmaceutical, and adhesive industries.
• Oil production: Maize germ is used to extract edible corn oil.
• Fermentation products: Grain is used to produce ethanol, beverages, organic acids, and industrial alcohol.
• Specialty maize: Sweet corn, baby corn, popcorn, waxy corn, and quality-protein maize have specific food and market uses.
• By-products: Cobs, husks, and stalks are used as fuel, bedding, compost, packing material, and industrial biomass.

Its high yield potential and broad adaptability make maize important for farm income, employment, livestock production, and agro-based industries.

Climatic requirements:

• Maize is a warm-season crop that grows best under frost-free conditions.
• A temperature range of approximately 21-30°C is favorable for active growth.
• Cool conditions delay germination, while very high temperature and moisture stress during flowering can reduce pollination and grain set.
• Maize generally requires about 50-100 cm of well-distributed rainfall, although the requirement varies with climate, soil, and crop duration.
• Bright sunshine supports photosynthesis and grain development.
• Waterlogging is harmful because maize roots require good aeration.

Soil requirements:

• Deep, fertile, well-drained loam to silty clay loam soils are most suitable.
• Soils should have good organic matter, water-holding capacity, and drainage.
• A soil reaction of about pH 5.5-7.5 is generally favorable.
• Strongly acidic, saline, compacted, and poorly drained soils restrict root development and nutrient uptake.
• Proper land leveling, drainage channels, and organic-matter addition are particularly important for kharif maize under heavy rainfall.

Major maize types:

• Dent corn: Kernels have a depression at maturity and are widely used for feed and industry.
• Flint corn: Kernels are hard and rounded; the crop is generally hardy and widely used as food.
• Sweet corn: Contains high sugar at the milky stage and is consumed as a vegetable.
• Popcorn: Has small, hard kernels that expand when heated.
• Flour corn: Contains soft starch and is suitable for flour preparation.
• Waxy corn: Its starch consists mainly of amylopectin and has specialized industrial uses.
• Quality-protein maize: Contains improved levels of essential amino acids, especially lysine and tryptophan.
• Baby corn: Ears are harvested before fertilization or at a very young stage for vegetable use.

Selection criteria:

• Adaptation to the local season, rainfall, soil, and temperature
• Appropriate maturity duration for the cropping system
• High and stable yield potential
• Resistance or tolerance to major insects, diseases, drought, and lodging
• Intended end use, such as grain, fodder, sweet corn, popcorn, or industrial processing
• Availability of quality seed and compatibility with local market demand

Hybrids generally offer high yield potential, but fresh certified hybrid seed should normally be purchased for each crop to maintain performance.

Land preparation:

• Prepare a fine, firm seedbed with one deep ploughing followed by harrowing and leveling.
• Incorporate well-decomposed farmyard manure during land preparation.
• Provide ridges, furrows, or drainage channels in high-rainfall and poorly drained fields.

Seed treatment:

• Use certified seed with high germination and genetic purity.
• Treat seed with recommended fungicides or biological agents against seed- and soil-borne diseases.
• Where necessary, use approved insecticidal seed treatment and micronutrient or biofertilizer inoculation according to local recommendations.

Sowing time:

• Sow kharif maize with the onset of the monsoon after sufficient soil moisture is available.
• Timely sowing reduces the risk of moisture stress, pest damage, and poor grain filling.

Seed rate and spacing:

• Grain maize commonly requires approximately 18-25 kg seed per hectare, depending on seed size, germination, spacing, and production purpose.
• A common spacing is about 60-75 cm between rows and 20-25 cm between plants.
• Sow seed at a depth of about 4-5 cm in moist soil.
• Thin excess seedlings and fill gaps early to maintain a uniform plant population.

Maize has a high nutrient demand, especially for nitrogen. Nutrient management should therefore be based on soil testing and realistic yield targets.

• Apply farmyard manure, compost, green manure, or retained crop residues to improve soil health and nutrient availability.
• Apply the full recommended dose of phosphorus and potassium at sowing, unless soil-test or regional recommendations prescribe a different schedule.
• Place basal fertilizer below and away from the seed to avoid fertilizer injury.
• Apply nitrogen in splits. A commonly followed schedule includes:
  • A basal portion at sowing
  • A second portion at the knee-high stage
  • A final portion near tasseling or pre-tasseling
• The knee-high and tasseling stages are critical because nutrient demand rises rapidly during vegetative growth and reproductive development.
• Apply top-dressed nitrogen when adequate soil moisture is present and incorporate or irrigate it where possible to reduce losses.
• Use zinc or other micronutrients only after identifying a deficiency through soil testing or crop symptoms.
• Biofertilizers such as Azotobacter or phosphate-solubilizing microorganisms may supplement, but do not automatically replace, the recommended nutrient program.

Irrigation and drainage:

• Kharif maize is largely rainfed, but supplemental irrigation should be provided during prolonged dry periods when water is available.
• The most sensitive stages are knee-high, tasseling, silking, and grain filling.
• Moisture stress during tasseling and silking causes poor pollination, fewer kernels, and major yield loss.
• Avoid over-irrigation because maize is highly sensitive to waterlogging.
• Construct surface drains in heavy soils and high-rainfall areas to remove excess water quickly.

Weed management:

• The early growth period, particularly about 20-45 days after sowing, is critical for crop-weed competition.
• Use clean seed, crop rotation, timely sowing, proper plant population, and inter-row cultivation as preventive and cultural measures.
• Carry out one hoeing or mechanical weeding around 20-25 days after sowing, followed by another operation when required.
• Earthing up after weeding supports plants, improves drainage, and reduces lodging.
• Locally recommended pre-emergence or post-emergence herbicides may be used according to weed flora, soil moisture, crop stage, and label directions.
• Integrated weed management gives more consistent control than reliance on a single method.

Maize is a monoecious crop, meaning separate male and female flowers occur on the same plant.

• The tassel, located at the top of the plant, produces pollen.
• The ear, borne in the leaf axil, contains female flowers. Each silk is connected to one potential kernel.
• During tasseling, the male inflorescence emerges and begins pollen production.
• During silking, silks emerge from the husk and receive pollen carried mainly by wind.
• After successful pollination and fertilization, ovules develop into kernels.

These stages are critical because:

• Drought or high temperature can delay silk emergence while pollen shedding occurs normally, creating poor synchronization.
• Water and nutrient stress reduce pollen viability, silk receptivity, and kernel number.
• Severe stress may increase the anthesis-silking interval and produce partially filled ears.
• Waterlogging, pests, and foliar diseases at this stage can also restrict photosynthesis and pollination.

Therefore, adequate soil moisture, balanced nutrition, and protection from major stresses around tasseling and silking are essential for high grain yield.

Rice is better adapted to saturated lowlands, whereas maize requires an aerated root zone and effective drainage. Actual yields of both crops depend on variety, environment, input management, and biotic stresses.

A complete production package for kharif maize includes:

1. Variety selection: Choose a locally recommended hybrid or composite with suitable maturity, yield potential, stress tolerance, and end-use quality.
2. Field preparation: Prepare a well-drained, fine but firm seedbed. Incorporate organic manure and provide drainage channels.
3. Seed preparation: Use certified seed and apply recommended treatments against seed-borne diseases and early insect damage.
4. Sowing: Sow promptly with the onset of the monsoon at approximately 60-75 cm × 20-25 cm spacing. Maintain uniform depth and plant population.
5. Nutrient management: Follow soil-test recommendations. Apply organic matter, basal phosphorus and potassium, and split nitrogen at sowing, knee-high, and pre-tasseling or tasseling stages.
6. Moisture management: Conserve rainfall, provide supplemental irrigation during dry spells, and prevent stress at tasseling, silking, and grain filling. Drain waterlogged fields immediately.
7. Weed control: Maintain a weed-free field during the critical early period through hoeing, inter-cultivation, earthing up, and need-based herbicides.
8. Plant protection: Monitor regularly and adopt integrated management for major insects and diseases using resistant varieties, sanitation, biological methods, and approved pesticides when economic thresholds justify treatment.
9. Harvesting: Harvest grain maize when husks dry, kernels become hard, and physiological maturity is reached. Dry cobs, shell grain, clean it, and reduce moisture to a safe storage level.
10. Expected yield: Improved kharif maize commonly produces approximately 4-7 tonnes of grain per hectare under good management, while high-performing hybrids under favorable conditions may yield more.