« AnteriorContinuar »
creased in importance, they were assigned to a new bureau or division especially created for their research. The distribution of seeds and plants was begun in 1839. Since that time, over 20 divisions and bureaus have been created.1 The importance that may be attached to the activities of the department is well illustrated by its work with durum wheat. By securing its introduction and its use in manufacturing macaroni in the United States, the department practically established a new industry, in addition to extending materially the wheat producing area.
Experiment Stations.—Liebig in Germany, Boussingault in France, and Lawes and Gilbert in England, were the greatest of the pioneers who blazed the path subsequently followed by the experiment station. The organization of scientific experimentation with governmental aid dates from 1851. The American stations are an adaptation of those of Europe to the conditions and requirements of this country, but one of their characteristic features is extensive co-operation. Their establishment naturally followed that of the agricultural colleges. In 1875 the first station in the United States was established at Middletown, Conn., for which the credit is due to Orange Judd, then editor and proprietor of the American Agriculturist. Seventeen stations had been established by 1887, when Congress passed the Hatch act, the great boon for American stations. In 1894, 55 stations were in operation. At some of the stations, especially that of Minnesota, new varieties of wheat and other cereals have been originated which increase the yield several bushels per acre over old varieties under the same conditions, giving to the farmer a pure gain of millions of bushels.
Agricultural Institutions of Learning.—The American agricultural colleges were organized under the land grant act passed in 1862, supplemented by an act of 1890. Under the provisions of these acts 65 institutions are in operation in the several states and territories. The movement for farmers' institutes, originating in various farmers' societies, has now become national in scope, and during the year ended June 30, 1905, institutes were held in nearly all of the states and territories.
1 For a complete account of the department, state experiment stations and agricultural colleges, see Bulletin 112, Office of Experiment Stations, U. S. Department of Agriculture.
Economic Position of Wheat Growers.—The story of the agriculture of the wheat area in the middle west of our country is the oft repeated one of agriculture in a new country, a fact which bespeaks an economic justification. There was but one way in which the western pioneer could draw a draft that would be honored for the cost of buildings, machinery and live stock, and that was to draw it at the expense of the natural fertility of the soil. One-crop wheat farming and neglect of crop rotation and domestic animals resulted. For over half a century, "Uncle Sam is rich enough to give us all a farm," was a household phrase. The farm having been obtained, it was used and abused in every way that was supposed to yield the largest amount of immediate profit, regardless of all other considerations. In no other section was this so true as in the wheat raising areas. In the meantime, millions of acres of fresh land produced more grain than domestic consumption could utilize, and for years the very existence of the farmer was threatened by 40-cent wheat and 20-cent corn. Lack of capital and the hard conditions of frontier life soon resulted in debt. Often there was not the wherewithal to pay the high interest and to procure the necessaries of life. With the twentieth century came a change, a change of such moment and speed as to be without parallel in the economic history of agriculture. The prosperity of the middle west transformed a million agricultural debtors into financially independent farmers. Free land, free immigration, and free private enterprise in railroad construction were the chief factors that ultimately led, not only to financial independence, but also to a new dignity and to a higher standard of living. With the telephone, the daily mail and newspaper, and means for traveling, a new horizon of comfort surmounts the skyline of the farmers' economic strength. This recent era of rural prosperity augurs well for the nation's future.
Wheat Improvement Proper consists of artificially increasing the natural variations of the wheat plant and its environment. Historically, it is unknown whether the plant or the environment was first the subject of improvement. The subsequent
portion of this chapter is exclusively devoted to the plant, the treatment of which naturally comes first.
Variation.—It has been recognized for at least a century that wheat is capable of variations. These may be peculiar to the plant itself, and may occur although the environment remains constant. Variation in this sense became established only with the theory of evolution, and refers to those changes which tend to become permanent through inheritance. Such variations are assumed to be the manifestations of a natural tendency inherent to all organic life.
The theory of common descent for all living beings found its first great advocator in Lamark at the beginning of the nineteenth century. Fifty years later Darwin assembled enough evidence in support of the theory to enable it to gain general acceptation. Darwin assumed that the great variation involved in the theory proceeded in the main by slow and gradual changes. He recognized, however, that species may also originate in nature by leaps and sports. The theory that all variation occurs by sudden mutations has been held by a minority of scientists. Cope and De Vries1 are among those who have most recently increased the evidence in this direction. A defence of discontinuous evolution has also been made by various other scientists, such as the paleontologist Dollo, the zoologist Bateson, and the botanist Korshinsky. In general, it may be said that if the followers of Darwin have been open to the criticism of under-emphasizing sudden change, the supporters of the theory of mutations have certainly erred more widely in the opposite extreme.
Variations may also be induced. In this process two different methods may be used, hybridization and change of environment. Only those variations which may occur or be induced independently of environment are considered in this chapter. Others are treated in subsequent chapters. Variations may include differences in habit of growth, chemical composition, periods of development, appearance, form, yield, prolificacy, vigor, hardiness and stability of type. Whatever his concep
1 An able criticism of the theory of mutations has been made by Prof W. F. R. Weldon, "Professor De Vries on the origin of species," Biometrika, 1:365, 1902. A study of this theory is interesting in conjunction with the more elaborate theory of homotyposis developed by Prof Karl Pearson in his work at University College, England, but space forbids a discussion of the matter here.
tion of variation may be, the scientific wheat grower utilizes the process in two different ways, by the simple process of selection, or by the compound process of selection, hybridization and selection.
Selection is an unfailing means for the modification of form and tendency in organic life. It augments the power of variation by successively selecting the most marked variations in any direction. While conscious selection is a modern process which has attained commercial importance at a comparatively recent date, there is no doubt of selection having been one of the most powerful influences from the very first in developing wheat, although men were not aware of its operation. Whatever protection or cultivation early man bestowed upon the cereal plants was naturally bestowed upon the grasses and wheats which produced the most food in return, and not upon those comparatively less important as food. The very essence of the importance attached to wheat has always been its food yielding quality. It is a perfectly sound inference that those varieties of wheat which had this quality in the highest degree had an advantage which aided them to survive other varieties. This, however, is only the operation of the prime factor of selection, or, as Darwin calls it, the "law of the preservation of the favorable individual differences and variations, and the destruction of those which are injurious."
Selection and cultivation, in the ordinary sense, were the processes of domestication. After domestication, varieties continue to be propagated in a similar manner. The results have been attained none the less advantageously and certainly on account of the fact that man was unconsciously the selecting agent. To this force of artificial selection was added that of natural selection in early development, which was a result of the coincidence that the quality of wheat as a human food and the reproductive functions of the plant were both united in its seed. The plant producing the greatest number of seeds was most apt to survive, not only because man was most likely to give it his fostering care, but also because of the increased chances of reproduction. In wheat artificially sown, care must be exercised lest this force of natural selection operate disadvantageously, for fewer seeds are no longer a disadvantage in reproduction. If for any reason, such as being brought to a