An annual plant of Gramineae or Poaceae family Genus Triticum Species: Triticum aestivum L. Wheat
Types: many kinds of wheat in the world today. The two most common are common wheat, Triticum aestivum, also known as bread wheat account for some 95% of all the consumed wheat in the world today; and durum wheat T. turgidum ssp. durum, which is used in pasta production. Triticum aestivum or common wheat or Bread wheat
Importance of wheat in the world • wheat, rice and corn account for 75% of the world’s grain production and 56% of the world’s food energy. • wheat is the second most-produced food among the cereal crops • Wheat grain is a staple food used to make flour for breads; cookies, cakes, breakfast cereal, pasta, juice, noodles; and for fermentation to make beer, alcohol, vodka or biofuel. • Although wheat supplies much of the world's dietary protein and food supply it contains a protein called gluten – coaliac diseases –wheat allergy (sensitive) In Bhutan • source of income, (3rd most important food crops grown in Bhutan after rice and maize). • uses same as mentioned above
In Bhutan Source: MoA, 2006: Agriculture Statistics.
Cropping system: • generally grown in dry land (53.9%) as main crop from 300m to 3000masl. • Also grown in wet land as secondary crop after rice (rice-wheat system, consists of 80%), maize, potato & in rotation with Buckwheat at higher altitude. • significant part of the wheat crop is generally cut as green fodder for cattle, the remaining is harvested to supplement food consumption. • For eg. Winter fodder up to 2500 masl & for haymaking at elevations of 3500-4000 masl.
Origin: 11000BC in middle east; 4000 BC in asia, europe and NAmeriaca..earliest grown crop. • In Bhutan: believed to have been introduced from Tibet. History: wild ancestor is Triticum boeticum, fertilized with wild grass called aegilop speltoids to give the modern wheat.
Species & Varieties • 18 species recognized • Most important to agriculture are: • T. aestivum (common wheat); T.monococcum (Einkorn or Europena wheat), T. turgidum & T. durum (durum wheat), T. compactum (club wheat); T. dicoccum (emmer wheat - wild sp. Wheat & closely related to durum wheat). Genetics: Some wheat species are diploid, with two sets of chromosomes, but many are stable polyploids, with four sets of chromosomes (tetraploid) or six (hexaploid). • T. aestivum: A hexaploid species that is the most widely cultivated in the world. • T. durum: The only tetraploid form of wheat widely used today, and the second most widely cultivated wheat. • T. monococcum (Einkorn): A diploid species with wild and cultivated variants. Domesticated at the same time as emmer wheat, but never reached the same importance. • T. dicoccon(Emmer): A tetraploid species, cultivated in ancient times but no longer in widespread use.
In India • T.aestivum or vulgare (common bread or bread wheat) – chapati & bakery products – grown all over India • T.durum (durum wheat) – suji, sphagetti & macaroni – grown in Central & South • T.dicoccum – (emmer wheat) grown in South India.
In Bhutan • Many landraces or indigenous wheat varieties replaced by Jaga ka • All wheat varieties grown in the rice-wheat system are Introduced spring wheat grown during winter 1. Sonalika: – early maturing variety – susceptible to yellow (stripe) or brown (leaf) rust. 2. Bajoka -1 & 2. 2a. Bajoka-1: recommended for medium & low alt. – matures 155-160 days – Grows to a height of 80-85cm tall • Yields 2.5 – 3.0 tons per hactare - moderately resistant to yellow and brown rusts.
Bajoka-2: • - recommended for low altitudes • - matures 150-160 days • - Grows to a height of 100cm tall • - Yields 2.5 – 3.0 tons per hac • - highly resistant to yellow and brown rusts
Dist. Features: Sonalika and Bajoka variety Sonalika: Height taller than Bajoka 1&2, Spike turns yellow, leaf blade bit bigger. In Bajoka Bajoka I spike remains white & straight until maturity while spike bends at maturity for Bajoka 2 but colour remains unchanged.
Morphology • Two distinct parts: Root and Shoot system • Root System: Pry or temporary root system Secondary root system/permanent root system • Starts with the formation of a radicle (embryonic root) at the time of seed germination – • Arises at the depth where the seed is planted • absorbs nutrients for young seedling • Growth progresses, the pry root system dies and is replaced by more permanent Secondary Root System (PRS)
Secondary Root System • Arises at the point above the PRS as the main organ of absorption of nutrients for matured seedling/plant • Arises near the soil surface at about 21-25 days after seed sowing (i.e. at the time of crown root initiation stage)
Shoot System –all parts above the ground • - Stems, leaves and inflorescence (flowering & fruiting) • Stem & inflorescence = culm 1. Stem: round & cylindrical, hollow except at the node (solid) 2. Leaves: 4 parts – Leaf sheath, leaf blade, ligule, auricle Leaf sheath: basal part of the leaf – surrounds the culm (stem) & protects the growing point and auxillary buds from weather – also provide support to culm (stem).
Leaf blade – flattened, parallel venation – function? • Ligule – soft membranous part at the junction of the sheath and the blade • Auricle – claw-like appendages projecting from the collar of the leaf. 3. Inflorescence – flowering portion – ear or head or spike – consist of spikelet, florets, kernel • spikelets are systematically arranged in a zigzag manner along a common axis (rachis) • Wheat is a monoecious plant with perfect flowers. It reproduces sexually as a self-pollinated crop.
Spikelet: composed of flowers called florets • No. of florets in a spikelet vary from 1-5 • Florets in each spikelets are enclosed by two glumes
Florets: outer covering – lemma & palea • These are hardened, modified stems that protect the floral organs. • The lemma is relatively larger than the palea. • When the spikelet is closed, the lemma partly encloses the palea. • The pointed end on top of the lemma is called an awn.
Grain or Kernel or caryopsis - fruit formed from a single carpel • - The caryopsis is popularly called a grain and is the fruit typical of the family Poaceae (or Gramineae), such as wheat, rice, and corn. • 3-10 mm in length, 3-5 mm in diameter • Embryo – rich in protein called gluten-coaliac diseases –wheat allergy (sensitive) & fats • Bran – testa or pericarp – by-product of milling & used as feeds.
Wheat germ, crudeNutritional value per 100 g Energy 360 kcal 1510 kJ Percentages are relative to USrecommendations for adults. Source: USDA Nutrient database
Rice, white, long-grain, regular, & raw Nutritional value per 100 g Energy 370 kcal 1530 kJ Percentages are relative to USrecommendations for adults. Source: USDA Nutrient database
Growth Stages http://weedsoft.unl.edu/documents/GrowthStagesModule/wheat/wheat.htm# http://sanangelo.tamu.edu/agronomy/wheat/whtmang.htm (Refer)
Jointing Stage • Is a part of the veg. stage, characterized by: • Stem elongation • Most tillers have formed by this stage and the secondary root system is developing • Plants begin to grow erect from its previous prostate growth • the number of spikelets per spike (head size) is determined. • The first node just above the soil surface is visible on the main stem followed by second node as well as nodes on tillers • rapid spike expansion take place. • Flag leaf becomes visible just after the second node on main stem
At the boot stage, the head is developed and can be seen in the swollen section of the sheath of the flag leaf.
Heading and Flowering Heading - At this stage awns are visible and heads are emerging through the slit of the flag leaf sheath, with approximately 50% of heads emerged from the flag leaf in a given area. Flowering • At this stage heading is complete. • Flowering begins about 3 to 5 days after heading, first on the main stem followed by on the tillers.
Ripening - This stage denotes physiological maturity. This is followed by kernel ripening and grain drying.
Climatic requirement • – Wide adaptability • Prefer areas with cool, moist weather during growing period followed by dry, warm weather. • Optimum temperature range for ideal germination of seed is 20 – 25 degree Celsius • Can germinate in the temp range of 3.5 – 35 deg.C • Areas with warm and damp climate are not suited for wheat growing.
Cloudy weather, with high humidity and low temp. is conducive for rust attack. • Requires about 14 -15 deg. C at the time of grain filling & is crucial for yield • Temp above 25 deg C tend to affect yield Soils: SOIL • Soil type is the most important local physical feature affecting cropping potential and management practices. • Wheat grown in variety of soils • Preferred soil types are clay loam & heavy soils with good drainage.
Eg. Gangetic alluvium of UP and Bihar, Indus alluvium of Punjab and Haryana etc. Field Preparation - Requires a well pulverized soils for good germination • Field after the harvest of previous crop should be properly ploughed and harrowed 2-3 times followed by planking • Pre-sowing irrigation (wetland) 7-10 days before sowing seed is needed for proper germination.
Light leveling is required before sowing seed. • In rain-fed areas (dry land) – FP should be done with care as conservation of moisture is dependent on it. • Fields are deep ploughed and done planking • Usu. done in evening times and furrow should be kept opened whole night to absorb moisture from dew. • Planking should be done in the morning
Seed and sowing • Certified seed of right variety suitable for a particular locality should be selected • Seeds should be treated with Vitavax @ 2.5g/kg seed to control loose smut. Time of Sowing • One of the important aspects in obtaining good yields of wheat • Varies widely over the wheat growing areas • Depends on soil temperature, irrigation facilities and duration of wheat varieties
Rainfed wheat is sown in 2nd week of Oct – beginning of November. • Irrigated varieties sown in the beginning of November • Sonalika (short duration variety) is sown sometimes in the month of Dec. • However, when wheat is sown in the month of Dec., there is a drastic reduction in yield.
Method of sowing: Four methods • Broadcasting – uniformly broadcast and then covered by harrowing (commonly practiced in Bhutan) • Behind local plough – commonly practiced in India – seeds are dropped by hand into furrows that have been opened with last plough • Drilling – sown by seed drill by dropping seeds at uniform depth - Results in uniform germination - Seed drill may be bullock or tractor driven
4. Dibbling: – used in case supply of seeds is limited – done with the help of a small implement called “Dibbler” • Not commonly used – time consuming Management practices Manures and Fertilizers: • MF both play an impt roles in crop prodn – impt in wheat cultivation • About 5 t/ha of well decayed FYM at final
- land preparation and is mixed well - for better yield supplement with inorganic fertilizers @ 50:30:20 NPK kg/ha - half of N and all of P & K should be applied basally while the rest of the N should be top-dressed at first irrigation Seed rate: 100-130 kg/ha Spacing: 20 - 22.5 cm between rows is recommended & when sowing is delayed a closer spacing of 15-18cm adopted. Irrigation - Adequate soil moisture is required for normal dev. of wheat plant at all stages of growth.
A total 5 irrigation – crown root initiation (CRI) (20-25); tillering stage (40-45); jointing (booting) stage (70-75); flowering (90-95); dough stage (110-115). • vary depending on soil type, winter rainfall, amount of water applied per irrigation; 3 sufficient. • The crown root initiation (CRI) stage and heading stage are the critical stages when plant suffers most due to moisture stress. • 1st Irrigation: 20-25 or 25-30 days (hilly areas like Bhutan) after sowing i.e. at the CRI stage. • Delay avoided – upset root growth, tillering, heading and yield.
2nd Irrigation: at booting or jointing stage (70-75 days after sowing) • 3rd Irrigation: At milk stage (90-100 days)
Harvesting - when leaves and stems turn yellow and become fairly dry – before it is dead ripe. Done manually using serrated sickle In villages using 2 short sticks called “Khrip or Kreow”
Harvesting • Usually done by cutting the head with sickle or cutting the entire stem • The cut stem with ears are bundled up and hanged to dry • When dry, ears are cut from the peduncle and beaten with stick or crushed with feet.