About Wheat (2)

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Commercial Use

Wheat output in 
Harvested wheat grain that enters trade is classified according to grain properties for the purposes of the commodities market. Wheat buyers use these to decide which wheat to buy, as each class has special uses, and producers use them to decide which classes of wheat will be most profitable to cultivate.
Wheat is widely cultivated as a cash crop because it produces a good yield per unit area, grows well in a temperate climate even with a moderately short growing season, and yields a versatile, high-quality flour that is widely used in baking. Most breads are made with wheat flour, including many breads named for the other grains they contain like most rye and oatbreads. The popularity of foods made from wheat flour creates a large demand for the grain, even in economies with significant foodsurpluses.
Utensil made of dry wheat branches for
loaves of br
In recent years, low international wheat prices have often encouraged farmers in the USA to change to more profitable crops. In 1998, the price at harvest was $2.68 per bushel. A USDA report[42] revealed that in 1998, average operating costs were $1.43 per bushel and total costs were $3.97 per bushel. In that study, farm wheat yields averaged 41.7 bushels per acre (2.2435 metric ton / hectare), and typical total wheat production value was $31,900 per farm, with total farm production value (including other crops) of $173,681 per farm, plus $17,402 in government payments. There were significant profitability differences between low- and high-cost farms, mainly due to crop yield differences, location, and farm size.

In 2007 there was a dramatic rise in the price of wheat due to freezes and flooding in the northern hemisphere and a drought in Australia. Wheat futures in September, 2007 for December and March delivery had risen above $9.00 a bushel, prices never seen before.[43] There were complaints in Italy about the high price of pasta.[44] This followed a wider trend of escalating food prices around the globe, driven in part by climatic conditions such as drought in Australia, the diversion of arable land to other uses (such as producing government-subsidised bio-oil crops), and later by some food-producing nations placing bans or restrictions on exports in order to satisfy their own consumers.

Other drivers affecting wheat prices include the movement to bio fuels (in 2008, a third of corn crops in the US are expected to be devoted to ethanol production)[citation needed] and rising incomes in developing countries, which is causing a shift in eating patterns from predominantly rice to more meat based diets (a rise in meat production equals a rise in grain consumption—seven kilograms of grain is required to produce one kilogram of beef).[45]

Production and Consumption

Worldwide wheat production
In 2003, global per capita wheat consumption was 67 kg, with the highest per capita consumption (239 kg) found in Kyrgyzstan.[46] In 1997, global wheat consumption was 101 kg per capita, with the highest consumption (623 kg per capita) inDenmark, but most of this (81%) was for animal feed.[47] Wheat is the primary food staple in North Africa and the Middle East, and is growing in popularity in Asia. Unlike rice, wheat production is more widespread globally though China's share is almost one-sixth of the world.

In the 20th century, global wheat output expanded by about 5-fold, but until about 1955 most of this reflected increases in wheat crop area, with lesser (about 20%) increases in crop yields per unit area. After 1955 however, there was a dramatic ten-fold increase in the rate of wheat yield improvement per year, and this became the major factor allowing global wheat production to increase. Thus technological innovation and scientific crop management with synthetic nitrogen fertilizer, irrigation and wheat breeding were the main drivers of wheat output growth in the second half of the century. There were some significant decreases in wheat crop area, for instance in North America.[48]

Better seed storage and germination ability (and hence a smaller requirement to retain harvested crop for next year's seed) is another 20th century technological innovation. In Medieval England, farmers saved one-quarter of their wheat harvest as seed for the next crop, leaving only three-quarters for food and feed consumption. By 1999, the global average seed use of wheat was about 6% of output.

Several factors are currently slowing the rate of global expansion of wheat production: population growth rates are falling while wheat yields continue to rise, and the better economic profitability of other crops such as soybeans and maize, linked with investment in modern genetic technologies, has promoted shifts to other crops.

Farming System

In the Punjab, India, and North China, irrigation has been a major contributor to increased grain output. More widely over the last 40 years, a massive increase in fertilizer use together with the increased availability of semi-dwarf varieties in developing countries, has greatly increased yields per hectare. In developing countries, use of (mainly nitrogenous) fertilizer increased 25-fold in this period. However, farming systems rely on much more than fertilizer and breeding to improve productivity. A good illustration of this is Australian wheat growing in the southern winter cropping zone, where, despite low rainfall (300 mm), wheat cropping is successful even with relatively little use of nitrogenous fertilizer. This is achieved by 'rotation cropping' (traditionally called the ley system) with leguminous pastures and, in the last decade, including acanola crop in the rotations has boosted wheat yields by a further 25% [49]. In these low rainfall areas, better use of available soil-water (and better control of soil erosion) is achieved by retaining the stubble after harvesting and by minimizing tillage.[50]

Future Contracts

Wheat futures are traded on the Chicago Board of TradeKansas City Board of Trade, and Minneapolis Grain Exchange, and have delivery dates in March (H), May (K), July (N), September (U), and December (Z).[51]

Geographical Variation

There are substantial differences in wheat farming, trading, policy, sector growth, and wheat uses in different regions of the world. In the EU and Canada for instance, there is significant addition of wheat to animal feeds, but less so in the USA.

The two biggest wheat producers are China and the EU, followed currently by India, then USA. Developed countries USA, Canada, Australia, the EU and increasingly Argentina are the major exporters with developing countries being the main importers, although both India and China are close to being self-sufficient in wheat. In the rapidly developing countries of Asia, Westernization of diets associated with increasing prosperity is leading to growth in per capita demand for wheat at the expense of the other food staples.

In the past, there has been significant governmental intervention in wheat markets, such as price supports in the USA and farm payments in the EU. In the EU these subsidies have encouraged heavy use of fertilizers inputs with resulting high crop yields. In Australia and Argentina direct government subsidies are much lower.[53]

Agronomy

Crop development

Wheat at the anthesis stage (face view)
Wheat normally needs between 110 and 130 days between planting and harvest, depending upon climate, seed type, and soil conditions (winter wheat lies dormant during a winter freeze). Optimal crop management requires that the farmer have a detailed understanding of each stage of development in the growing plants. In particular, spring fertilizersherbicidesfungicidesgrowth regulators are typically applied only at specific stages of plant development. For example, it is currently recommended that the second application of nitrogen is best done when the ear (not visible at this stage) is about 1 cm in size (Z31 on Zadoks scale). Knowledge of stages is also important to identify periods of higher risk from the climate. For example, pollen formation from the mother cell, and the stages between anthesis and maturity are susceptible to high temperatures, and this adverse effect is made worse by water stress.[54] Farmers also benefit from knowing when the 'flag leaf' (last leaf) appears, as this leaf represents about 75% of photosynthesis reactions during the grain filling period, and so should be preserved from disease or insect attacks to ensure a good yield.
Several systems exist to identify crop stages, with the Feekes and Zadoks scales being the most widely used. Each scale is a standard system which describes successive stages reached by the crop during the agricultural season.

Diseases

Wheat spikelet with the three
anthers sticking out
There are many wheat diseases, mainly caused by fungibacteria, and viruses.[55] Plant breeding to develop new disease-resistant varieties, and sound crop management practices are important for preventing disease. Fungicides, used to prevent the significant crop losses from fungal disease, can be a significant variable cost in wheat production. Estimates of the amount of wheat production lost owing to plant diseases vary between 10–25% in Missouri.[56] A wide range of organisms infect wheat, of which the most important are viruses and fungi.

The main wheat-disease categories are: 

Seed-borne diseases: these include seed-borne scab, seed-borne Stagonospora (previously known as Septoria), common bunt (stinking smut), and loose smut. These are managed with fungicides.
Pests

Wheat is used as a food plant by the larvae of some Lepidoptera (butterfly and moth) species including The FlameRustic Shoulder-knot,Setaceous Hebrew Character and Turnip Moth. Early in the season, birds and rodents can also cause significant damage to a crop by digging up and eating newly planted seeds or young plants. They can also damage the crop late in the season by eating the grain from the mature spike. Recent post-harvest losses in cereals amount to billions of dollars per year in the USA alone, and damage to wheat by various borers, beetles and weevils is no exception. [57] Rodents can also cause major losses during storage, and in major grain growing regions, field mice numbers can sometimes build up explosively to plague proportions because of the ready availability of food.[58] To reduce the amount of wheat lost to post-harvest pests, Agricultural Research Service scientists have developed an “insect-o-graph,” which can detect insects in wheat that are not visible to the naked eye. The device uses electrical signals to detect the insects as the wheat is being milled. The new technology is so precise that it can detect 5-10 infested seeds out of 300,000 good ones. [59] Tracking insect infestations in stored grain is critical for food safety as well as for the marketing value of the crop

References
1.   a b Belderok, Bob & Hans Mesdag & Dingena A. Donner. (2000)Bread-Making Quality of Wheat. Springer. p.3. ISBN 0-7923-6383-3.
2.   ^ "FAOSTAT". 2007. Retrieved 2009-05-05.
3.   ^ Cauvain, Stanley P. & Cauvain P. Cauvain. (2003) Bread Making. CRC Press. p. 540. ISBN 1-85573-553-9.
4.   ^ Palmer, John J. (2001) How to Brew. Defenestrative Pub Co. p. 233. ISBN 0-9710579-0-7.
5.   ^ Neill, Richard. (2002) Booze: The Drinks Bible for the 21st Century. Octopus Publishing Group - Cassell Illustrated. p. 112.ISBN 1-84188-196-1.
6.   ^ Department of Agriculture Appropriations for 1957: Hearings ...84th Congress. 2d SessionUnited States House Committee on Appropriations. 1956. p. 242.
7.   ^ Smith, Albert E. (1995) Handbook of Weed Management Systems. Marcel Dekker. p. 411. ISBN 0-8247-9547-4.
8.   a b Bridgwater, W. & Beatrice Aldrich. (1966) The Columbia-Viking Desk Encyclopedia. Columbia University. p. 1959.
9.   ^ Lev-Yadun S et al. (2000) The cradle of agriculture Science288471:1602-3 PMID 10858140
12. ^ Heun MR et al (1997) Site of Einkorn Wheat Domestication Identified by DNA Fingerprinting Science 278:1312-4 DOI: 10.1126/science.278.5341.1312
13. ^ Ă–zkan H et al. (2002) AFLP analysis of a collection of tetraploid wheats indicates the origin of emmer and hard wheat domestication in southeast Turkey Molecular Biology and Evolution19:1797-1801 (2002) PMID 12270906
14. ^ Tanno, K Willcox, G (2006) How fast was wild wheat domesticated? Science 311 1886 DOI 10.1126/science.1124635 PMID 16574859
15. ^ Diamond J (1997) Guns, Germs and Steel, A short history of everybody for the last 13,000 years. Viking UK Random HouseISBN 0-09-930278-0
16. ^ Direct quotation: Grundas ST : Chapter: Wheat: The Crop, inEncyclopedia of Food Sciences and Nutrition p6130, 2003; Elsevier Science Ltd
17. ^ Belderok B et al. (2000) Bread-Making Quality of Wheat Springer p 3 ISBN 0-7923-6383-3
§  Cauvain SP, Cauvain P (2003) Bread Making CRC Press p 540ISBN 1-85573-553-9
§  Bergen R 'American wheat beers' In Brewing Techniques
§  FAOSTAT Agricultural statistics 2005 data values
18. a b c Hancock, James F. (2004) Plant Evolution and the Origin of Crop Species. CABI Publishing. ISBN 0-85199-685-X.
19. ^ Hoisington D et al. (1999) Plant genetic resources: What can they contribute toward increased crop productivity? Proc Natl Acad Sci USA 96:5937-43 PMID 10339521
20. ^ Basra, AS (1999) Heterosis and Hybrid Seed Production in Agronomic Crops Haworth Press pp 81-82 ISBN 1-56022-876-8
§  Condon AG et al.(1990) Genotypic variation in carbon isotope discrimination and transpiration efficiency in wheat. Leaf gas exchange and whole plant studies Australian Journal of Plant Physiology 17: 9 - 22 doi:10.1071/PP9900009
22. ^ Scientists publish key wheat genome Yahoo! News, August 27, 2010, Retrieved August 27, 2010
23. a b Bajaj, Y. P. S. (1990) Wheat. Springer. pp. 161-63. ISBN 3-540-51809-6.
24. ^ Basra, Amarjit S. (1999) Heterosis and Hybrid Seed Production in Agronomic Crops. Haworth Press. pp. 81-82. ISBN 1-56022-876-8.
25. a b Potts, D. T. (1996) Mesopotamia Civilization: The Material Foundations Cornell University Press. p. 62. ISBN 0-8014-3339-8.
26. ^ Nevo, Eviatar & A. B. Korol & A. Beiles & T. Fahima. (2002)Evolution of Wild Emmer and Wheat Improvement: Population Genetics, Genetic Resources, and Genome.... Springer. p. 8. ISBN 3-540-41750-8.
27. ^ Vaughan, J. G. & P. A. Judd. (2003) The Oxford Book of Health Foods. Oxford University Press. p. 35. ISBN 0-19-850459-4.
28. ^ Moon, David, "In the Russian Steppes: the Introduction of Russian Wheat on the Great Plains of the UNited States," Journal of Global History 3 (2008), 203-225
30. ^ International Starch Institute, TM 33-1www - ISI Technical Memorandum on Production of Wheat Starch. Retrieved August 11, 2008.
31. ^ van Heel D, West J (2006). "Recent advances in coeliac disease"Gut 55 (7): 1037–46. doi:10.1136/gut.2005.075119.PMID 16766754PMC 1856316.
33. ^ Fasano, A; Berti I, Gerarduzzi T, et al. (2003). "Prevalence of celiac disease in at-risk and not-at-risk groups in the United States: a large multicenter study"Arch Intern Med. 163 (3): 286–292. doi:10.1001/archinte.163.3.286PMID 12578508.
34. ^ Presutti, John; et al. (2007-12-27). "Celiac Disease"American Family Physician 76 (12): 196–1802.
35. ^ Hill, I. D., Horvath, K., and Fasano, A., Epidemiology of celiac disease. 1: Am J Gastroenterol. 1995 Jan;90(1):163-4
36. ^ USDA
37. ^ raw, uncoocked
38. ^ germ, crude
39. ^ white, long-grain,regular, raw, unenriched
40. ^ sweet, yellow, raw
41. ^ white, flesh and skin, raw
42. ^ Ali MB (2002) Characteristics and production costs of US wheat farms (SB-974-5 ERS, USDA.)
43. ^ "Wheat futures again hit new highs" article by Victoria Sizemore Long in The Kansas City Star September 28, 2007
44. ^ "Wheat Prices Send Italian Pasta Costs Up" Associated Pressstory by Colleen Barry, September 13, 2007 By COLLEEN BARRY – Sep 13, 2007
45. ^ "Broker picks in the soft commodities sector" inCompareShares April 2, 2008
47. ^ CIMMYT World wheat facts and trends 1998-9.
48. ^ See Chapter 1, Slafer GA, Satorre EH (1999) Wheat: Ecology and Physiology of Yield Determination Haworth Press Technology & Industrial ISBN 1560228741.
54. ^ Slafer GA, Satorre EH (1999) Wheat: Ecology and Physiology of Yield Determination Haworth Press Technology & Industrial ISBN 1560228741. pp 322-3
§  Saini HS et al. (1984) Effect of heat stress during floral development on pollen tube growth and ovary anatomy in wheat (Triticum aestivum L.) Australian Journal of Plant Physiology10:137-144 doi:10.1071/PP9830137
56. ^ "G4319 Wheat Diseases in Missouri, MU Extension". Muextension.missouri.edu. Retrieved 2009-05-18.
60. ^ "ARS, Industry Cooperation Yields Device to Detect Insects in Stored Wheat". USDA Agricultural Research Service. June 24, 2010.

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