WHEAT (Triticum aestivum)

• Family: Gramineae / Poaceae
• Chromosome number (2n): 42
• Origin: Southwest Asia, especially Turkey
• Inflorescence: Known as spike or ear
• Fruit type: Caryopsis (single-seeded, dry, indehiscent)
• Seed: Also called caryopsis
• Photosynthesis type: C3
• Photoperiodism: Long-day plant
• Shelling percentage: 60%
• Test weight: 40 g (Phalaris minor: 2 g)

Nutritional Value (per 100g grain):

• Energy: ~340 kcal
• Carbohydrates: ~72 g
• Protein: ~11 g
• Fat: ~1.5 g
• Fiber: ~12 g
• Rich in B-complex vitamins, Iron, and Zinc

Global Significance:

• India ranks 2nd in world wheat production (after China).
• Major wheat-producing countries: China > India > Russia > USA > France
• Wheat is grown in temperate zones across the globe.
• In India, grown as a Rabi crop (winter crop).

Area, Production & Productivity in India

• Area: Uttar Pradesh > Madhya Pradesh > Punjab
• Production: Uttar Pradesh > Punjab > Haryana
• Productivity: Punjab (45 q/ha) > Haryana

• • High productivity in Punjab due to 100% irrigation and high fertilizer use.

Economic Importance:

• Major source of carbohydrates and protein in vegetarian diets.
• Staple food for more than one-third of the world’s population.
• Used for making bread, biscuits, noodles, pasta, cakes, chapatis, etc.
• Wheat straw is used for animal fodder, thatching, and organic mulch.
• High demand in domestic and export markets.

General Information:

• Wheat ranks 1st globally in cereals for both area and production, hence called the “King of Cereals.”
• Contains gluten, a spongy protein essential for bakery items.
• Pearling index is used to determine grain hardness.
• Clonal roots are permanent adventitious roots formed after the first leaf emerges at CRI (Crown Root Initiation) stage.
• Often intercropped with mustard, especially in North India.
• The dwarfing gene “Norin-10” was isolated from a Japanese variety by Dr. Norman Borlaug in 1960.
• In 1963, Indian government imported Mexican dwarf varieties like Lerma Rojo, Sonora-63, Sonora-64, and Mayo-64 — kickstarting the Green Revolution.
• Non-traditional wheat cultivation area includes West Bengal.
• Azotobacter is the biofertilizer recommended for wheat.
• Relative weed example: Rice in wheat field.

Classification of Wheat:

Triticum aestivum (Common Bread Wheat)

• Hexaploid (2n = 42), occupies 87% of wheat area in India.
• Best for chapatis and bakery items.
• Mexican dwarf type; responsible for green revolution.

T. durum (Macaroni/Durum Wheat)

• Tetraploid (2n = 28), 12% wheat area, mostly rainfed areas in Central & Southern India.
• Used in suji, semya, spaghetti, vermicelli.
• Varieties: Jairaj, Malavika, Meghdoot, HD 4530.

T. dicoccum (Emmer Wheat)

• Tetraploid (2n = 28), 1% area in Maharashtra, Karnataka, Andhra Pradesh, Tamil Nadu, Gujarat.
• Used in Uppumav; also called Samba wheat, Rawa, Godhumalu.

• T. monococcum and T. aegiloploid; Diploids (2n = 14), ancient wheat types with limited cultivation.
• T. spelta, T. macha, T. vulgare: Hexaploid (2n = 42) group.
• T. sphaerococcum (Indian Dwarf Wheat): Known as Club Wheat in western countries, grown in limited areas of U.P. and M.P.

Irrigation Management in Wheat:

• If only one irrigation is possible, apply at CRI.
• For two irrigations, apply at CRI and Flowering.

Climate Requirements:

• Germination temperature: 20–25°C
• Cool & moist during vegetative growth, warm & dry during grain filling.

Booting Stage: Characterized by swelling of the uppermost internode — beginning of reproductive development.

Varieties of Wheat:

1. Single Gene Dwarf: Lerma Rojo 64-A, Sujata, Girija, Sonalika
2. Double Gene Dwarf: Kalyan Sona, Sonora-64, Chhoti Lerma, HD-2009 (Arjun), HD-2329, Janak
3. Triple Gene Dwarf: Heera, Moti, Lal Badshah
4. Mutant Varieties: Sharbati Sonora (from Sonora-64), Pusa Lerma (from Lerma Rojo 64-A)
5. Others: PBW-502, Shailaja, Malviya-12
6. Latest high-yielding varieties: HD 2967, HD 3086, WH 1105, PBW 725

Seed and Sowing Information:

• Seed Rate:

• Normal: 100 kg/ha
• Late/broadcasting: 125 kg/ha
• Dibbling: 25–30 kg/ha

• Spacing: 22.5 × 10 cm
  • Depends on coleoptile length
• Sowing Time:
  • 1st fortnight of November (Irrigated)
  • 2nd fortnight of October (Rainfed)

Fertilizer Requirement (Recommended dose):

• Nitrogen: 120 kg/ha
• Phosphorus: 60 kg/ha
• Potash: 40 kg/ha
• Under rainfed: Thiourea @ 0.5% spray increases yield by 10–15%
• Best irrigation method: Check basin

Weed Management in Wheat:

Monocot Weeds:

• Phalaris minor (mimicry weed):

• Apply Isoproturon @ 0.75 kg a.i./ha at 30–35 DAS
• Alternative: Sulfosulfuron @ 20g/ha or Metasulfuron @ 4g/ha

• Avena fatua (Wild oat): Previously controlled by Tribunil (now banned due to carcinogenic effects)

Dicot Weeds:

• Chenopodium album, Anagallis arvensis, Melilotus spp.

• Apply 2,4-D (Ester Salt) @ 500 ml/ha post-emergence (30–35 DAS)
• Early spray (before 30 DAS) in dwarf varieties can cause ear malformation

• Objectionable weed: Convolvulus arvensis

Miscellaneous Facts:

• Safe storage moisture: 10–12%
• Harvesting moisture: 20–30%
• Wheat + Mustard intercropping ratio: 9:1
• Harvest index: 40–45%
  • HI = (Economic yield / Biological yield) × 100

Botanical Features:

• Ligule: Membranous structure at the collar
• Auricle: Claw-like appendages at base of the leaf
• Spikelet: Contains florets
• Lemma & Palea: Enclose the flower (outer and inner bracts)
• Awn: Extension of lemma
• Rachis: Zigzag central axis of the spike

Historical Notes on Dwarf Varieties:

• Norin 10: Brought to the USA by C. Salamon in 1948
• O.A. Vogel: Developed dwarf winter wheat “Grains”
• Norman E. Borlaug: Developed Mexican dwarf wheat at CIMMYT, Mexico
• India imported 100 kg Mexican seeds (Sonora 64, Lerma Rojo, Mayo 64) in 1963 with Rockefeller Foundation’s help
• Released in 1965 → Sparked the Green Revolution
• Later replaced by Kalyansona and Sonalika

Storage & Post-Harvest Management:

• Harvest when grains are hard and straw is yellow.
• Safe storage at moisture level below 12%.
• Controlled using fumigation: Aluminium phosphide (Phostoxin)
• Grains should be sun-dried before bagging.

Average Yield in India: National average: 35–40 quintals/ha (i.e., 3.5–4.0 tons/ha)