Wheat (A. S. Hwoete White In Distinction From Rye And Other Dark-Colored Grains), a cereal, triticum vulgare, which has been cultivated from the earliest antiquity, and now furnishes the principal breadstuff in all civilized countries. The wheat genus, triticum (the classical name), belongs to the subtribe of grasses called hordeinoe, from barley, which is in structure closely related to wheat, and rye also belongs in the same division; all these have their one- to many-flowered spikelets on opposite sides of a zigzag jointed stem or rachis, which is excavated to form a notch at each joint. In triticum there is but a single spikelet at each joint, its two glumes placed transversely, and it is from three- to severalflowered; the lower palet is pointed, or furnished at the tips with an awn of variable length; stamens three. Besides the grainproducing species, all of which are annuals, there are several with perennial roots, which by some botanists have been placed in a distinct genus, agropyron, the most important of which is the troublesome T. repens. (See Couch Grass.) Wheat has a dense four-sided spike; the turgid spikelets are three- to fiveflowered, with ventricose, blunt glumes; the palets awned or awnless, and the grain free from the upper palet, with a longitudinal furrow on one side, very turgid on the other, and hairy at the top.
The spring and winter wheats, which have been sometimes described as distinct, are only forms produced by cultivation, as it has been repeatedly demonstrated that by a few years' successive growing spring wheat may be converted into the winter variety, and vice versa. Like other cereals, wheat is not certainly known in the wild state, and its origin has been the subject of much speculation; some suppose it to be a plant now extinct in the wild state, others that it is the cultivated form of what are now regarded as distinct wild species. De Candolle is disposed to accept the testimony of travellers who say they have found T. vulgare in various parts of Asia in localities where it was not likely to have escaped from cultivation. About 1855 M. Fabre asserted that he had established by experiment the fact that wheat was cegilops ovata (a common grass in southern Europe), developed by cultivation; he asserted that by successive sowings he had produced forms of oegilops which pass for species, and by continuing this course for 12 years produced perfect wheat. His experiments are not credited, as the grass is now known to have been accidentally or otherwise hybridized with wheat.
The varieties of wheat are very numerous, one French experimenter having cultivated over 150, and another 322. The plant differs in stature, habit, and foliage, in the size and shape of the spike or head, the number of flowers in the spikelet, the shape and size of the floral envelopes, the presence or absence of a beard or awn and its character, and the size, form, color, and hairiness of the grain. So widely different are some of the varieties, which have retained their identity through centuries of cultivation, that some botanists think they must have originated from four or five distinct species; other kinds vary greatly with the character of the soil. The mention of wheat in the Old Testament, and its culture by the ancient Egyptians, are proofs of its antiquity, and Chinese history declares that it was introduced into China by the emperor Shin-nung about 2700 B- C. - The limit to the successful cultivation of wheat is not determined so much by the cold of winter as by the temperature of summer, 57.2° being the minimum mean temperature in which it will mature. The southern limits vary between 20° and 25° N, and S. latitude, though at a sufficient elevation it may be grown near the equator.
Wheat is largely cultivated in most European countries; some which a few years ago were exporters do not now raise enough for their own consumption; the principal wheat-exporting countries at present, besides the United States, are Russia, Denmark, Hungary, Turkey, and Chili. In the United States wheat growing has regularly extended westward; in some of the older states an improvident course of agriculture exhausted the land until remunerative crops could no longer be raised; in the lack of a system of rotation the soil became stocked with the seeds of weeds, and the increase of destructive insects added to the difficulties which made it necessary to seek new land; but where better farming prevailed, the crop is still profitably grown. The new prairie soil of the western states allows the crop to be raised without the expense for fertilizers to which the eastern farmer is subjected, though this is in great measure offset by the cost of transporting western grain to market. The chief wheat-growing states and their production in 1873 were Iowa, 34,600,000 bushels; Illinois, 28,417,000 Minnesota, 28,056,000; Wisconsin, 26,322,000 California, 21,504,000; Indiana, 20,832,000 Ohio, 18,567,000; Pennsylvania, 15,548,000 Michigan, 14,214,000; Missouri, 11,927,000 Tennessee, 7,414,000; Kentucky, 7,225,000 New York, 7,047,000; Virginia, 5,788,000 Maryland, 5,262,000; Kansas, 4,330,000; Nebraska, 3,584,000; Oregon, 3,127,000; North Carolina, 2,795,000; West Virginia, 2,657,000; Georgia, 2,176,000; and New Jersey, 1,948,000. The total production of the United States in 1874 was 309,102,700 bushels, from 24,967,027 acres, averaging 12.3 bushels to the acre.
Nothing in the history of our agriculture is more striking than the remarkable increase of wheat growing on the Pacific coast, especially in California, where the crop in 1850 was only 17,200 bushels, most of the grain consumed being at that time brought from Chili. Both soil and climate are most favorable to its culture; 2,000 to 4,000 acres is a moderate size for a wheat farm, and those ten times as large are not rare. The climate is so rainless in summer that the bags of grain may be stacked up in the open field for weeks, without fear of injury. - Probably not more than a dozen varieties are in general cultivation in this country, though each is apt to have several local names, and a variety if long cultivated in one district may seem much unlike the same that has been grown for several years in a different locality. New sorts are frequently offered as superior in productiveness to all others; but every good farmer knows that the more productive the wheat, the better must be the soil. Spring wheat is sown and harvested the same year, while winter wheat is sown in autumn, usually in September, when it germinates, and the plant grows until stopped by cold weather; it remams dormant during the winter, and renews its growth in the spring, ripening about midsummer.
These groups are subdivided into white and red or amber varieties, and these again into bald and bearded wheat. Among the spring varieties, the China, also called tea wheat (as it is said to have come from a grain found in a box of tea), Mediterranean spring, and Canada club are leading kinds. Of winter wheats the white varieties are most esteemed; the most prominent of these are: the Diehl, bald and early ripening; the Clauson or Seneca, with a red chaff and white grain; Boughton (often called Oregon), white Michigan, white Mediterranean, and Soule's. Among the "red or amber varieties are the red Mediterranean, one of the best for ordinarysoils, the amber, the Fultz, the Witter, and others. Formerly spring wheats brought a lower price than the others, but since the recent introduction of what is called the "new process" of grinding, in which the grain is first deprived of its outer covering, they are preferred for some kinds of flour, and bring as much or more than the winter kinds. Wheat in a rotation is sown on a turned clover sod, or on land which has been heavily manured the previous year for a corn or root crop; fresh stable manure is objectionable, but artificial fertilizers are used, and lime, where there is much organic matter in the soil, is beneficial; careful cultivators take great pains to clean their seed wheat from other seeds, and to get rid of all the light kernels; where smut is apprehended, the seed is wetted with a solution of sulphate of copper or strong brine, to kill the fungus spores.
The seed is sown broadcast, or preferably by means of a drill, which deposits it in rows and covers it; when sown broadcast it is harrowed or ploughed in. In spring the winter wheat is harrowed. The weeds most troublesome to wheat in this country are the cockle (lychnis githago), of the pink family, and chess or cheat (bromus secalinus), which is sometimes so abundant that ignorant persons believe it to be degenerate wheat. In some of the New York wheatgrowing counties gromwell (lithospermum arvense), there called red-root, is one of the most serious obstacles to the farmer. Rust and smut are minute vegetable forms which often cause serious damage to the stalk and grain. (See Fungi.) Wheat is liable to be injured by several insects. (See Hessian Fly, Weevil, Wheat Fly, and Wheat Moth.) - The history of most of the wheat-growing portions of this country shows a regular decrease in the yield; counties in the state of New York in which the average yield at the beginning of the century was 20 to 30 bushels to the acre, now return 5 to 7 bushels; in the fertile soil of Ohio the average diminished in 50 years from 26 bushels to half that amount; and so long as there remain new lands to be cultivated this will probably continue to be the case.
That this decrease is due to the lack of a proper system of agriculture is shown by the fact that in England, where the land has been under cultivation for centuries, the average yield is 36 bushels to 'the acre. Seeds of wheat retain their vitality from 3 to 7 years; the stories of "mummy wheat," which is said to have germinated after remaining thousands of years in the tombs of Egypt, are now discredited; the cunning Arabs have even supplied credulous travellers with mummied maize grains and dahlia tubers, neither of which were known before the discovery of America. - Besides triticum vulgare, a few other species are cultivated in some countries, but have not been found desirable in this. The Egyptian wheat (T. turgidum) has heavy heads which bend over to one side, and hairy spikelets; forms of. it have been somewhat cultivated in England, on low lands, but it yields an inferior flour. The onegrained wheat (T. monococcum), also called St. Peter's corn, has but one fertile floret in the spikelet, the grain of which ripening gives the head much the appearance of barley; its cultivation is confined to the mountainous portions of Europe. Spelt wheat, or spelt (T. spelta), bears a similar name in several European languages, and is much cultivated on the continent; it has a flat spike, which readily breaks up at the joints, and the grain is adherent to the palet or husk; it is only rarely grown in this country by Europeans, who have been accustomed to it at home. - Wheat properly stands at the head of food grains, as it contains, besides a large amount of starch, nitrogenous principles, and those mineral elements required by the animal system; the grain raised in different countries or on unlike soils, as well as that of the different varieties, shows considerable variation in the proximate constituents.
The average of recent analyses gives in 100 parts: water, 14.4; mineral matter, or ash, 2; albuminoids, 13; carbohydrates, 67'6; crude fibre, 3; fat, 1.5. The important constituents vary between the following extremes: albuminoids, from 10.7 to 21.5; carbohydrates, 60-2 to 70.2; crude fibre, 1.7 to 83. As to the mineral constituents, the average of 78 analyses gives the percentage of ash in the grain at 2.07; this chiefly consists, in 100 parts, of potash 31.1, soda 3.5, magnesia 12.2, lime 3.1, phosphoric acid 46.2, with sulphuric acid, chlorine, etc. - Wheat is mostly consumed in the form of flour, the composition of which depends greatly upon the manner of grinding. When a thin cross section of a wheat grain is examined with the microscope, the surface is found to consist of three layers of cells, the innermost being of longer cells than the outer two; these together form the hull or bran; just within these are cells containing aleurone (a convenient collective name for those granules which consist mainly of albuminoids), and within these are cells having starch as their chief content, though aleurone and mineral matters are more or less scattered throughout the grain, of which the starch cells make up the body.
It is evident that the quality of the flour will depend upon that of the wheat, and the method by which its parts are separated in the mechanical operation of flouring; millers exercise much skill in so mixing the different varieties as to produce flour of a uniform quality. The finest flour is that which most nearly approaches pure starch, though not the most nutritious. After grinding, the Whole as it comes from the mill passes into a long cylinder or bolt; this is an octagonal frame, sometimes over 30 ft. long, about 3 ft. in diameter, inclining § in. for each foot in length, and arranged to revolve; it is covered with bolting cloth, a sieve-like silken fabric of various degrees of fineness, that near the upper end of the bolt having the closest mesh; the meal from the mill, being deposited at the upper end of this, is separated into different degrees of fineness, while the coarser portions pass out at the lower end. The fine flour, about 80 per cent, of the grain, passes through the upper portion of the bolt, while the coarser appears lower down, and is known as middlings, pollard, and by various other local names; the coarsest is shorts and bran.
In fine flour the percentage of starch is much greater, and that of the albuminoids and earthy matters less, than in the whole grain; consequently this is not so nutritious as a flour which more nearly represents the wheat itself. Various expedients have been used for producing a flour which shall contain more albuminoids and phosphates than fine flour; the well known Graham flour should consist of the whole wheat ground fine, but much that is sold under this name is merely bran and shorts subjected to a second grinding; properly prepared, Graham flour is very nutritious, but, owing to the amount of crude fibre it contains, irritates the bowels of weak persons. Of late there have been several processes invented, which propose to first remove the inert hull or bran and then grind the decorticated grain; flour prepared in this manner is as fine as any other, and contains much more of the nutritive principles. Whole wheat, prepared by soaking, and afterward boiled with milk and sweetened, was formerly used as food in England under the name of frumity. In this country wheat, first carefully freed from its hairs and all foreign substances, is coarsely ground, and is much used as a dietetic preparation under the name of crushed or cracked wheat, or wheaten grits.
The wheat of southern countries contains a larger percentage of albuminoids than any other, and is used to make macaroni, a favorite food in southern Europe, and imported into this country in considerable quantities. (See Macaroni.) Bran and shorts are valuable food for domestic animals, especially for milch cows; bran contains a larger percentage of albuminoids, fat, and phosphates than whole wheat, and more starch remains with it than is generally supposed. Wheat straw, while it is wasted or even burned to get rid of it by improvident farmers, is of value as food, especially to mix with the more concentrated foods, such as Indian meal and oil cake. The threshing machines break up the straw quite short, and this prevents its being utilized for many of the purposes for which hand-threshed straw may be employed. (See Straw).
Winter Wheat - Bald and Bearded.
1. Spelt (Triticum spelta).
2. St. Peter's Corn (Triticum monococcum).
Part of Section of a Wheat Grain, magnified.