Chaff
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Chaff (pronounced /tʃɑːf/ or /tʃæf/, both to rhyme with "half") is a term from agriculture used for the inedible, dry, scaly protective casings of the seeds of cereal grain. Chaff is a byproduct of grain production and is often used as livestock fodder, ploughed into the soil, or burnt.
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[edit] Etymology
From Middle English chaf, from Old English ceaf; related to Old High German cheva meaning husk.
[edit] Cereal chaff
In grasses (including cereals such as rice, barley, oats and wheat), the ripe seed is surrounded by thin, dry scales called glumes, lemmas and paleas, forming a dry husk, the chaff. After harvesting, the grains are separated from the chaff by techniques such as threshing and winnowing.
Domesticated types of grain have been bred to have chaff which is easily removed. For example, in wild species of wheat and in the primitive domesticated einkorn[1], emmer[2] and spelt[3] wheats, the grains are "hulled" – the husks enclose each seed tightly. Before the grain can be used, the hulls must be removed by further processing such as milling or pounding. In contrast, in free-threshing (or naked) forms such as durum wheat and common wheat, the glumes are fragile, and on threshing the chaff easily breaks up, releasing the grains.
[edit] Other meanings
- See also: Chaff (disambiguation)
[edit] Agriculture
Hay or straw cut into very short lengths is also called chaff. This is done by a machine called a chaff cutter, thus turning coarse fodder into a form more palatable to livestock.[4]
[edit] Botany
In botany, chaff refers to the thin receptacular bracts of many species in the sunflower family Asteraceae. They are modified scale-like leaves surrounding single florets in the flower-head.
[edit] Metaphor
Chaff is also used to refer to something worthless, such as in the expression "separating the wheat from the chaff", meaning to separate things of value from things of no value. For example Psalm 1 of the Bible says: "Not so the wicked! They are like chaff that the wind blows away".
[edit] References
- ^ Potts, D. T. (1996) Mesopotamia Civilization: The Material Foundations Cornell University Press. p. 62. ISBN 0-8014-3339-8.
- ^ 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.
- ^ Vaughan, J. G. & P. A. Judd. (2003) The Oxford Book of Health Foods. Oxford University Press. p. 35. ISBN 0-19-850459-4.
- ^ Agriculture
- David Teniers the Younger "The Chaff cutter", (detail) Painting of cutting chaff by hand
- Staff, A Victorian chaff cutter, Virtual Victorians, Accessed 12 May 2008.
- Staff. Modern chaff cutter, Maharashtra Industries Directory. Accessed 12 May 2008.
[edit] See also
