BARLEY. The cultivated varieties of barley are grouped into three species or races, viz. (1) six-rowed barley tichon L.) ; (2) Bere, Bigg or four-rowed barley (H. vulgare L.) and (3) two-rowed barley (H. distichon L.).
The axis of the ear of barley is notched on opposite sides throughout its length. At each notch there are three spikelets each containing a single flower, so that along the whole ear there are six longitudinal rows of flowers, three on one side and three on the other. In six-rowed barley all the flowers are fertile, the ear when ripe possessing six longitudinal rows of grains closely and regularly packed. The ears are short and grow erect, with com paratively long, thin grains, which are chiefly used as food f or farm animals. This race is not widely grown.
In Bere all the flowers are fertile and the ears bear six rows of grain as in the previous race ; these are, however, not so closely packed and are arranged less regularly along the axis. The central grains of each triplet form two longitudinal rows on opposite sides of the ear, the two lateral grains of the triplets forming two loosely constructed double rows, the ear appearing unsymmetrically f our rowed. Bere is widely cultivated and a form of it is frequently grown in the British Isles under the name Winter Barley.
In two-rowed barleys only the central flower of each spikelet is fertile, the lateral pair of flowers are either missing or imperfect, producing stamens only. The ripe ear, instead of being more or less hexagonal in cross section as in the preceding races, is com pressed and has but two rows of grain. Three sub-races of two rowed barley are recognized, viz. (a) Battledore, Fan or Peacock barley (H. Zeocriton L.) ; (b) Broad erect-eared barley (H. dis tichon var. erectum) ; (c) Narrow bent-eared barley (H. disti chon var. nutans).
Sub-race (a) is short-strawed with erect ears of closely set grains the awns of which spread out like an open fan when ripe. Fan Barley, now an uncommon kind, was grown extensively in the 17th and 18th centuries; it is suited to the stiffer class of soil on which it often gives a good yield of grain of fair quality.
The ears of sub-race (b) grow erect with closely packed grains which jut out from the axis at a somewhat wide angle, giving it a broad appearance. Barleys of this sub-race are suited to soils in high condition, on which they give good yields of large plump grain; examples are the Goldthorpe and Plumage varieties.
In sub-race (c) the ears are long and narrow, with grains set on the axis at an acute angle and more widely separated from each other than in (b). When ripe they bend over, sometimes hanging downwards parallel to the straw. In this sub-race are the best malting barleys, of which Chevallier, Hanna, and Old Common are examples.
Various hybrids have been produced between representatives of the several two-rowed sub-races, with a view to securing varie ties combining the high quality of one group with the stiff straw and good yield of another ; examples of hybrid barleys are Sprat Archer and Plumage-Archer.
Much evidence exists in support of the conclusion that barley was one of the first cereals cultivated by man. Grains of six rowed barley have been discovered in Egypt dating from pre dynastic and early dynastic periods ; similar examples from pre historic times have been found among the pile-dwellings of Swit zerland. Two-rowed barleys are also of great antiquity.
There is little doubt that the cultivated two-rowed barleys have been derived from Hordeum spontaneum C. Koch., a wild annual species found in dry situations in Transcaucasia, Asia Minor, Syria, Palestine and Persia. The wild plant closely resembles the cultivated two-rowed race in most morphological characters but possesses a brittle rachis, the ear breaking up into separate spike lets when ripe. It is often assumed that the six-rowed races have also originated from the two-rowed wild plant. Regel, however, states that a wild six-rowed species is sometimes found with the two-rowed H. spontaneum and considers that it is from this that the six-rowed cultivated barleys have descended.
Barley is one of the most widely distributed cereals, being culti vated in all temperate regions of the world, as well as in Asia Minor, Egypt, North Africa and other sub-tropical countries. It is one of the hardiest of cereals and crops have been grown at the extreme northern limits of cultivation, near the Arctic Circle and often within it, reaching latitude 71°N. in Norway and 70°N. in Finland. These results are possible owing to the adaptability of the crop to a short vegetative period of 6o-7o days, and to long duration of sunshine. On the high mountains of northern India and Tibet it is cultivated up to an elevation of 14,000f t.
The straw of barley is of little economic value and is used on the farm chiefly as food for stock or as litter. It is for the grain that the crop is grown, and large quantities are utilized in the preparation of malt for the manufacture of beer and spirits. For this purpose the grains should be plump, thin-skinned, of high germination capacity, and of uniform pale colour ; they should be rich in starch and have a comparatively low protein-content (from 9-1o%). Samples with thick husk, high protein-content, or those which have become discoloured and are otherwise unsuited for malting, are extensively employed in the feeding of farm animals.
Barley flour contains little or no gluten to which the bread making qualities of wheat flour is due, and from it a porous loaf cannot be made; nevertheless, in many countries barley is an important article of human diet.
In all races of cultivated barley the true grain, or caryopsis, lies between two chaffy scales, the flowering glume and palea, and when ripe becomes fused with these so that it cannot be freed from them without a special milling operation. In all races, how ever, there are forms in which the grain is quite free and only loosely enclosed in the chaff, and on thrashing is as easily sepa rated from the latter as a wheat grain. These are termed "naked" barleys, the grains of which are of brown or dark purple colour and superficially resemble large, somewhat flattened wheat grains, but are more pointed at both ends than the latter. In a rare form of naked barley, sometimes named "Himalayan barley" or "Nepal wheat" (H. tri f urcatum Jacq) the flowering glume is terminated by a peculiar short, three-pronged structure instead of the single • long beard met with in all other kinds of barley. In Japan the naked barleys take second place to rice as food, and in India, Tibet and some parts of Europe barley is also a valuable food. The term "pot barley" is applied to the grains from which the husk has been removed by coarse grinding, the rounded grains of "pear) barley," used in soups, being obtained by continuing the grinding until the husk has been completely cleared away.
Cultivation.—The cultivation and management of the barley crop requires great skill. The best samples for malting purposes are grown on light calcareous and sandy loams in warm districts with a moderate rainfall. On alluvial soils and clays larger yields may be obtained, but these are of inferior quality and only suit able for feeding stock. In many districts barley follows roots or potatoes, but where the roots are fed off with sheep receiving cake there is a danger of the crop becoming rank, leading to the pro duction of thick-skinned, dark-coloured grain of inferior malting quality. On soils in high condition on account of previous treat ment, a crop of spring wheat or oats is often taken with advantage before the barley. Shallow ploughing to a depth of not more than 3 or 4in., and the reduction of the soil to a fine tilth before sow ing are important operations. The seed which should be of good germinating quality and true to varietal type, is drilled rather than broadcast in order to secure uniformity in depth of the seed and distance between the rows, both of which conditions conduce to that evenness of germination and growth which is essential to success. The amount of seed sown varies from 2-3 bushels per acre, according to the date of sowing, which is generally carried out in spring (Feb. to March), although autumn sowing has given good results.
Highly manured crops rarely give good malting barley, but phosphatic and potassic fertilisers are generally useful. The appli cation of more than small dressings (l-icwt. per acre) of nitrate of soda, sulphate of ammonia, or other nitrogenous manures is risky.
The crop is cut when the ears are thoroughly ripe. The average yield of grain is about 36 bushels per acre in the British Isles (40.6 in 1938), with from 15-2ocwts. of straw per acre.
Various insect pests, such as wireworm, Hessian fly, and frit fly damage the barley crop, and several parasitic fungi attack it ; of the latter perhaps the most prevalent are the covered and naked smut-fungi (species of Ustilago), which destroy the grain, and the leaf stripe fungus (Helminthosporium) which injures the leaves and often leads to so-called "blind" plants from which imperfectly formed or totally aborted ears are produced. See MALT.
Next to wheat, barley is the most widely distributed of the cereal crops though the area devoted to its cultivation is very much less. Russia contains nearly one-third of the total acre age, and the countries which come next in order of comparative acreage are the United States, Spain, Rumania, Germany, Canada, Algeria, former Poland, Morocco, former Czechoslovakia, France, Argentina, Great Britain and Hungary.
Barley has been grown in Great Britain from the earliest days of settled agriculture. Under the common-field system of the middle ages it was one of the regular corn crops, being then, as now, usually sown in the spring. It was the last of the regular cereals to be sown. It was essentially the "drink-corn" and from it ale was made, although sometimes wheat and honey were mixed with it to make the traditional English beverage. Hops were not introduced until the early part of the 16th cen tury. The two-rowed barley is stated to have been used only for brewing, the coarser four-rowed variety, known as "drage," being used partly for brewing, partly for feeding pigs and poultry. For feed corn barley and oats were often sown together. Barley is sometimes termed "here," especially in Scotland, but the term is properly applied to the common or four-rowed variety, which in modern practice is grown only on the poorer soils.
Nearly all the barley grown in Great Britain is in England and Wales, Scotland having less than 1o% of the total acreage. Fifty years ago there were about 2 a million acres in Great Britain but this has been reduced to 14 million. The reduction, however, has been considerably less, both absolutely and relatively, than that of wheat. The crop now occupies about 12% of the arable area of England and Wales. The total annual production is about one million tons, of which three-fifths are grown in the eastern and north-eastern counties.
Production of barley in the U.S.A. averaged 234,895,000bu. annually in the ten-year period 1927-36; in 1938 it was estimated at 252,139,00o bushels. Minnesota, North and South Dakota, California, Wisconsin, Nebraska are chief producing States.
The importation of barley into Great Britain and Northern Ire land in 1938 amounted to an estimated 19,862,000cwts. as com pared with 17,io7,000cwts. imported in 1935. The chief sources of supply are the United States, Canada and Chile. Russia, which before the War sent large quantities, began about 1925 to come back into the trade. Barley is still, as in the middle ages, the chief "drink-corn," being largely used for the manufacture of beer and whiskey.
Regarded either from the agricultural or the economic point of view there are two classes of barley, one described as "malt ing" and the other as "feeding." No definite line can be drawn between the two classes.