Formerly plowing was done with a bent stick or wooden plow, the wheat was sown broadcast by hand, the crop was cut with the cradle and bound in sheaves by hand, and finally thrashed with the flail or by the trampling of horses_ Improvements in machinery, as steam and gang plows, seeders, reapers, self-binders and thrash ers, have greatly reduced the cost of production and increased the world's supply of wheat Equally as great have been the advances in transportation, storage and milling facilities. Wheat is now transported in specially con structed freight cars and boats, and stored in large elevators in which 120,000 bushels are placed in one compartment, when formerly it was often transported on horse or mule k its bags, loaded and unloaded by hand and stored in small bins and granaries. The milling proc ess has developed from crushing between two stones to reduction by steel rolls.
Wheat is subject to a number of diseases, as rusts, smut and other vegetable parasitic dis eases, many of which have been studied and are now in part capable of being controlled The smuts are destroyed by treating the seed wheat with chemicals which kill the smut spores, while the rusts are held in check by destroying the host plants, as the barberry, upon which the parasite spends part of its cycle of life. There are a number of insect pests which often cause great destruction of the crop, as grasshoppers, frit flies, Hessian flies and chinch bugs. Eco nomic entomologists have done much to save the wheat crop from insect ravages.
The wheat kernel is surrounded by a seed pod composed of cellulose which constitutes the ouster layer and is called the pericarp. and covering or episperm, which is just within the pericarp, consists of the outer and inner integuments. The pe.risperm or third bran layer is a thin mass of collapsed cells. The aleurone layer — so-called gluten cells — is composed mainly of nitrogenous matter and lies within the three-bran layers. The endosperm of floury portion constitutes about 80 per cent of the •heat kernel and is within the three-bran layers and aleurone cells. The germ or embryo plant is stored in the lower part of the kernel where its outline can be traced by the indentations, the germ makes up about 6 per cent of the offal of the kernel, or about per cent of the entire kernel, the bran layers about 12. The relation of the different parts. one to the other, as bran to endroperr in different kit, and vari eties of wheat, some producing a lay 1. amount
of flour than others and some mo, bran.
The character of the wheat, or glutinous, is determined largely by , 1 and cli mate A forcing growing se on and a fertile soil b a tendency to produ. glutinous wheat, while the opposite conditions produce starchy wheat. When hal d luting seed wheat is sown in regions which product rely soft wheats, the hard wheat •radnallv nges its character and in about two years oecomes starchy. Whether a wheat is hard or soft de pends upon the amount and character of its gluten. Hard wheats usually contain over 12 per cent gluten, of which 45 to 65 per cent is in die form of gliadin, an alcohol soluble protein, while soft wheats contain less gluten, but gluten of a higher gliadin content.
Extenive experiments have been performed by Lewes and Gilbert of Rothamsted, England, to determine the influence which different kinds of fertilisers have upon the wheat crop. They have shown that fertilizers influence the yield more than the percentage composition of wheats and that it is not possible by means of fertilizers *me to increase materially the amount of starch or gluten. Climatic conditions affect the em end that it is not possible by mean, of fertilizers Wheats grown upon the same soil in different years show greater variations in composition than wheats grown the same year but differently flub limed.
Different varieties of wheat when grown trader the same conditions arc fairly constant in composition. In protein content, wheats range from 7 to 18 per cent. The most nitro genous wheats do not necessarily make the most glutenous flours, as frequently a large por tion of the nitrogen is in the germ and offals.
The grading of wheat is based entirely upon the physical qualities as weight per bushel, color and plumpness. Smut and blemishes. caused by unfavorable climatic conditions, are also considered ingrading wheat. When new wheat is stored in elevators, a slight fermenta tiontakes place known as 'sweating.' %Mt is sound this change is slightly beneficial for flour production, as it improves the qualities of the flour. Unsound wheats, as those which are bleached, frostcd, immature and sprouted, usually have a somewhat different composition from fully matured wheat. Such *heats may contain a larger amount of soluble proteids, soluble carbohydrates, and organic acids than normal wheats. Damaged wheats generally yield a smaller amount of flour as well as flour of poor keeping qualities.