Wheat is used principally for human consumption. It is converted into flour for the production of bread and other bakery products. It is used as “chapatti” (unleavened pan baked bread) in India. Wheat belongs to the genus Triticum and there are over 30,000 species and varieties. The principal wheats of commerce are the common or bread wheat (T.aestivum); macaroni wheat (T.durum) and club wheat (T.compactum). | Composition | | Processing | | Value Addition |
Wheat types: Wheat types may also be classified as hard or soft, and as strong or weak. ‘Strong’ wheats produce large loaf volume, good crumb structure and good keeping qualities. Such wheats have a high protein content. Hard wheats are thus employed for the production of flour for making bread. ‘Weak’ wheats have a low protein content and form only a small loaf with coarse crumb structure. The flours of weak wheats are good for biscuits and cakes, although unsuitable for bread-making. COMPOSITION Carbohydrates: Amongst carbohydrates of wheat, practically all of the starch is in the endosperm, while the soluble sugars are costly found in the germ. The carbohydrates of bran are largely cellulose and hemi cellulose. Minerals: Wheat is a good source of mineral nutrients. It contains a significant amount of iron, phosphorus, magnesium, manganese, copper and zinc. Whole wheat is a good source of thiamine and nicotinic acid, but is relatively poor in riboflavin. Protein: The proteins of wheat may be divided into two major groups-the non-gluten protein albumins and globulins, and gluten proteins (mainly gliadins, glutenins and insoluble residual proteins. Wheat proteins are rich in glutamic acid and low in tryptophan. Glutamic acid and aspartic acid are present in the amide form as glutamine and asparagine. The high concentration of amide is important in determining the characteristic of the gluten. The bran and germ proteins have a higher content of essential amino acids than the inner endosperm proteins. Thus the biological value of endosperm proteins is much less than that of the whole wheat protein. Lipids: The wheat germ oil is produced commercially and it is rich in vitamin E. The oil is also rich in essential fatty acids. PROCESSING
MILLING OF WHEAT
Wheat is consumed mostly in the form of flour obtained by milling the grain while a small quantity is converted into breakfast foods, such as wheat flakes, puffed wheat and shredded wheat. The traditional procedure for milling wheat in India has been stone grinding (chakki) to obtain whole meal flour (atta). This method results in a 90-95 per cent extraction rate flour which retains almost all the nutrients of the grain while simultaneously eliminating that part of the grain which is most indigestible like cellulose, and physic acid which binds and carries away minerals.
In modern milling, wheat is first subjected to cleaning to remove various types of impurities together with damaged, shrunken and broken kernels which are collectively known as ;screenings’. Impurities that adhere to the grain are removed by washing or by dry scouring which loosens the impurities which are then blown away by an air current. Next, the cleaned wheat is subjected to conditioning.
Finally, the cleaned and conditioned wheat is subjected to milling to separate the endosperm from the bran and germ, and to reduce the endosperm to flour fineness to obtain the maximum extraction of white flour from the wheat. The reduced endosperm is known as flour (white flour) and the germ, bran and residual endosperm obtained as by-products are used primarily in animal feeding. BY PRODUCTS OF WHEAT Whole wheat flour The bran and germ are separated in making white flour or maida. Maida bakes more uniformly into a loaf of a greater volume and it is more bland in taste and more easily digested. It can be stored in an airtight container in the refrigerator. Maida It contains the finely ground bran, germ and endosperm of the whole kernel. Whole wheat products have a distinctive flavour and coarser texture than those made from white flour. Because of the higher fat content of the germ, whole wheat flour is more difficult to keep and sometimes becomes rancid in storage under poor conditions.
| Semolina It is coarsely ground endosperm and its chemical composition is similar to that of white flour. It is used in the manufacture of macaroni products. It is roasted before storing to save it from insets and worms. Wheat bran It increases the stool weight by increasing the water holding capacity of the bran. Wheat bran prevents constipation and may lower the risk of colon cancer Glutamic acid: It is derived from wheat. A familiar compound of glutamic acid is "mono sodium glutamate", a salt like product generally available and used to bring out the flavour of other foods or seasonings. Percentage composition of nutrients in different parts of Wheat Kernel | Nutrients | Endosperm | Bran | Germ | | Protein | 70-75 | 19.0 | 8.0 | | Thiamine | 3.0 | 33.0 | 64.0 | | Riboflavin | 32.0 | 42.0 | 26.0 | | Niacin | 12.0 | 86.0 | 2.0 | | Pyridoxine | 6.0 | 73.0 | 21.0 | | Pantothenic acid | 43.0 | 50.0 | 7.0 |
NUTRITIVE VALUE OF WHEAT | Food | Energy
K.cal | Protein
g | Fat
g | Carbohydrates
g | Calcium
mg | Iron
mg | Carotene
mcg | Thiamine
mg | Riboflavin
mg | Niacin
mg | Wheat Flour
(Whole) | 341 | 12.1 | 1.7 | 69.4 | 48 | 4.9 | 29 | 0.49 | 0.17 | 4.3 | | Wheat Flour (refined) | 348 | 11.0 | 0.9 | 73.9 | 23 | 2.7 | 25 | 0.12 | 0.07 | 2.4 | Wheat Bread
(White) | 245 | 7.8 | 0.7 | 51.9 | 11 | 1.1 | - | 0.07 | - | 0.7 | Wheat Bread
(White) | 245 | 7.8 | 0.7 | 51.9 | 11 | 1.1 | - | 0.07 | - | 0.7 |
Wheat provides in addition to energy (calories), considerable quantities (20 percent) of the human requirements of proteins, B-vitamins, calcium and iron. Whole wheat are nutritionally superior to refined grains, richer in dietary fiber, antioxidants, protein, minerals (including magnesium, manganese, phosphorus, and selenium), and vitamins(including niacin, vitamin B6, and vitamin E). The greater amount of dietary fiber helps to reduce the incidence ofcancer, digestive system diseases, gum disease, coronary heart disease, diabetes, and obesity. The higher fiber content also results in a modest caloric reduction in whole grain foods. Some of these protective effects occur because carbohydrates from whole grains are digested and enter the bloodstream more slowly (as measured by the glycaemic index). Application of FYM of Compost Spread 12.5 t/ha of FYM or compost on the unploughed field. Application of Fertilizers - Apply NPK fertilizer as per soil test recommendation as far as possible. If soil test recommendation is not available, adopt a blanket recommendation of 80:40:40 NPK kg/ha.
- Apply half of N and full dose of P2O and K2O5 basally before sowing and incorporate in the sowing line.
Top Dressing Apply remaining half of N at crown root initiation stage (15-20 DAS). Irrigation Management Forming Beds and Channel Form beds of size 10 m2 or 20 m2. The irrigation channels are to be provided sufficiently. Water Management The crop requires 4 - 6 irrigations depending on the soil type and rainfall.
Wheat crop requires minimum of 5 irrigations at the following critical stages. I – Immediately after sowing
II – Crown root intiation : 15-20 DAS
III- Active tillering stage : 35-40 DAS
IV- Flowering stage : 50-55 DAS
V- Grain filling stage : 70-75 DAS - Crown root initiation and flowering are the most critical stages.
- Water stagnation should be avoided at the time of germination.
- Weed Management
Spray Isoproturon 800 g/ha as pre-emergence spraying 3 days after sowing followed by one hand weeding on 35th day after sowing. If herbicide is not applied, give two hand weedings on 20th and 35th day after sowing.
| Critical period of weed control | 15 – 30 DAS | | Cultural method | a) Hand Hoeing
b) Inter cultivation
c) Criss-cross sowing | | Chemical method | - 2, 4D (1 – 1.5 kg ai/ha)
- MCPA (1 – 1.5 kg ai/ha) dissolved in 700 – 800 litres applied at 25 – 30 DAS Efficiency can be increased by mixing urea@ 3%
- Mixture of Isoproturon (0.75 kg ai/ha) and 2, 4D (0.4 kg ai/ha) during 30- 35 DAS
| | Remarks | II. Complimentary weed control methods - Cultivars
- Seedling age /planting method
- Fertilizer management
- Cropping system
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Wheat Diseases Powdery mildew: Erysiphe graminis var. tritici Symptom: - Greyish white powdery growth appears on the leaf, sheath, stem and floral parts.
- Powdery growth later become black lesion and cause drying of leaves and other parts.
| | MILDEW IN LEAF | MILDEW IN KERNEL | MILDEW IN STEM | |
| | Life cycle of Erysiphe graminis | | 
LIFE CYCLE Management: - Spray Wettable sulphur 0.2% or Carbendazim @ 500 g/ha
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Loose Smut: Ustilago tritici Symptom: - The entire inflorescence, except the rachis, is replaced by masses of smut spores.
- These black teliospores often are blown away by the wind, leaving only the bare rachis and remnants of other floral structures.
|  | | LOOSE SMUT | |
| | Life cycle of Ustilago tritici | | 
LIFE CYCLE Management: - Treat the seed with Vitavax @ 2g/kg seed before sowing.
- Burry the infected ear heads in the soil, so that secondary spread is avoided
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Stripe Rust/Yellow Rust:Puccinia striiformis Symptom: - The pustules of stripe rust, which, contain yellow to orange-yellow urediospores, usually form narrow stripes on the leaves
- Pustules also can be found on leaf sheaths, necks, and glumes.
- Survival : Both survive on stubbles and volunteer crops
- Alternate host : unknown
- Spread : uredospores from hill
|  | | YELLOW RUST | |
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Urediniospores of Puccinia striiformis (400X) | |
LIFE CYCLE | Teliospores of Puccinia striiformis (400X) |
| Management: - Mixed cropping and crop rotation
- Avoid excess “N”
- Sulphur dusting @ 35-40 kg/ha
- Mancozeb @ 2g/lit
- Resistant varieties
- Lerma Rojo, Safed Lerma,
- Sonalika and Chotil
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Leaf Rust /Brown Rust: Puccinia recondita Symptom: - The postules are circular or slightly elliptical, smaller than those of stem rust, usually do not coalesce, and contain masses of orange to orange-brown Urediospores
- Infection sites primarily are found on the upper surfaces of leaves and leaf sheaths and occasionally on the neck and awns
- Survival : Both survive on stubbles and volunteer crops
- Alternate host : Thalictrum sp.
- Spread : uredospores from hills
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Urediniospores of Puccinia recondita (400X) | |
| | | LIFE CYCLE | Teliospores of Puccinia recondita (200X) |
Management: - Mixed cropping with suitable crops.
- Avoid excess dose of nitrogenous fertilizers.
- Spray Zineb at 2.5 kg/ha or Propioconazole @ 0.1 %.
- Grow resistant varieties like PBW 343, PBW 550, PBW 17
Stem Rust: Puccinia graminis tritici Symptom: - Pustules (containing masses of urediospores) are dark reddish brown - occur on both sides of the leaves, on the stems, and on the spikes
- Pustules are usually separate and scattered, heavy infections -coalesce
- Prior to pustule formation, "flecks" may appear. Before the spore masses break through the epidermis, the infection sites feel rough to the touch
- As the spore masses break through, the surface tissues take on a ragged and torn appearance
- Survival : Both survive on stubbles and volunteer crops
- Alternate host : Berberis spp.
- Spread : uredospores from hills
| | | STEM RUST | |
| Life cycle of Puccinia graminis tritci: | | |
Urediniospores of Puccinia graminis tritci | |
Teliospores of Puccinia graminis tritci |
| | LIFE CYCLE |
Management: - Mixed cropping and crop rotation
- Avoid excess nitrogen
- Sulphur dusting @ 35-40 kg/ha
- Mancozeb @ 2g/lit
- Resistant varieties
- Lerma Rojo, Safed Lerma,
- Sonalika and Chotil
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