WHEAT

Wheat is a cereal grain in which the kernel is separated by milling into flour, bran, and germ. it is used in all types of farinaceous foods. see flour; wheat flour.

Wheat, along with rice and corn, forms one of the most extensively available foods grown in a wide variety of regions of the world.
Wheat is believed to have been in existence for over a few thousand years, and originated in and around Iran, Iraq and Turkey.
Wheat is a member of the grass family. The plant grows to a height of around a meter and has narrow green leaves. When wheat seeds germinate, they develop a seminal root system. The first leaf, protected by the coleoptile, is thrust through the soil upwards. As other leaves develop, the plant grows in height. At the base of each leaf is a bud which can develop into a tiller. Each tiller can develop into a mature stem which holds the wheat head. The latter contains seeds edible for humans. The kernel, or the seed, is divided into three parts: the endosperm, the bran and the germ (embryo). The endosperm constitutes over 80% of the seed, and is rich in protein (gluten being an important component), carbohydrates, iron and Vitamin B (riboflavin, niacin and thiamine). Bran constitutes 15 % of the kernel weight and holds Vitamin B, fiber, Mg, Zn, Mn, folic acid and protein. Whole wheat flour contains bran. The germ, which has high quality protein, accounts for 2% of the kernel weight, and is also present in whole wheat flour. Foods made out of whole wheat have more vitamin, fiber and proteins.
Ideal conditions for wheat cultivation are temperate grasslands with 30 to 90 cm of rain and relatively cool temperatures, especially during its early growing stages. During the later stages, the kernel growth is encouraged by sunny days.
Today, wheat is grown in many parts of the world. USA, China, the erstwhile USSR and India being the prime producers. India, for instance, produces about 12% of the world wheat.
The modem wheat, as we know it today, is the natural cross between the Triticum spp and the goat grass (Aegilops spp). The Triticum monococcum or the einkorn wheat is believed to have been the first to be cultivated. This later evolved into emmer wheat. Over years of hybridization, bread wheat (Triticum aestivum) and durum wheat (Triticum turgidum) are now widely cultivated.
Wheat is used in the making of bread, pastries, breakfast cereal, spaghetti, noodles, pasta, sauces, gravies, etc. These and other wheat products are high in energy and low in fat. But in the process of refining, the bran chaff and the germ are removed, leaving behind only starch in the final product.
There are two crops of wheat worldwide. One is the winter wheat (Sept-Oct) and the other is the spring wheat (mid-May). Wheat that is grown in limited rainfall areas is called hard wheat. It has a higher protein content. Adequate rainfall favors soft wheat which has a lesser protein content.
The need to increase the yield per hectare has encouraged research in biotechnology, plant breeding and genetic engineering. These initiatives have opened up a few areas of conflicting view-points which seem to have ethical and moral overtones.
Wheat is prone to many foliar-, soil- and seed-borne diseases throughout its growth. Many fungal, viral and bacterial diseases affect wheat yields worldwide. Rust diseases (leaf rust and stem rust), loose smut, powdery mildew, take-all, etc. affect almost all areas. Fungal diseases are categorized on the part of the affected plant, and thus, there are leaf and stem pathogens (like rusts, mildew) and seed related pathogens (like smut and bunts diseases).
Rust disease which is a fungal disease, is of two kinds, namely, leaf rust and stem rust. Leaf rust is caused by Puccinia recondita tritici and is more common and destructive than stem rust, caused by Puccinia graminis tritici. Leaf rust may cause up to 50% of the yield loss, if infection is not controlled in time. The spread of rust occurs in late winter or early spring. The fungi causing the rust disease go through several spore stages in their life cycle and some of the stages are completed on alternate or collateral hosts. Humid and wet conditions, with warm temperatures, favor infection which spreads as strong winds transport the spores.
Since wheat is grown in large areas throughout the world, there may be peculiar management practices prevalent under specific local conditions. However, broadly, there are some recommended practices such as crop rotation, planting management, crop residue management, volunteer wheat, nitrogen management and wheat varieties - which can yield a healthy crop.
The twin objectives of farmers and researchers alike have been to increase productivity of crops, and control the losses by diseases. There are two approaches toward achieving high yields in environment friendly conditions from the same plot of land: organic farming, and conventional farming with the use of chemical fertilizers. Both approaches have yielded expected results. Conventional farming methods include the incorporation of synthetic fertilizers and the use of genetically modified varieties of wheat by customizing land races of a plant to suit the local conditions. Such varieties can result into cultivars exhibiting favorable properties of early maturity, heat tolerance, etc. Many research stations, established worldwide, develop seed banks and preserve germplasm for plant breeding, to produce robust, disease-resistant and high yielding varieties. There are many research institutes that focus on the objective of developing modem wheat cultivars.
Organic farming is cultivation of a crop without the use of synthetic fertilizers. Organic farmers rely on the use of naturally available sources of minerals for supplying nutrients to crop.