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ing. The first hybrid produced in the United States was probably a pear (1806). The importance of hybridization in relation to variation was demonstrated by Naudin and Nageli (1865).

The pioneer producer of wheat hybrids in America was C. G. Pringle of Charlotte, Vt. He began his work in 1877, and several varieties have received his name, some of which have become standard. Pringle's Defiance has been a rust resistant variety of California since 1878. During his connection with the Colorado agricultural college A. E. Blount produced quite a large number of hybrids, some of which are now well known in the United States and are also among the most valuable varieties in Australia, both as field wheats and as parents of native hybrids. The most important are Amethyst, Improved Fife, Hornblende, Gypsum, Blount's No. 10, Felspar, Ruby and Granite.

The director of the experimental farm at Ottawa, Canada, Dr. William Saunders, began hybridizing wheats in 1888. His main object has been to procure early ripening varieties, and he has attained success by hybridizing American and Russian races. Preston and Stanley are two of his best productions. In the main these hybrids have been produced in the most simple way. A. N. Jones of Newark, N. Y., practicing composite crossing, though always with quite closely allied parents, has done the most important work in wheat hybridization in this country, and his varieties are now the most widely used of all recent American wheat hybrids. The two features characteristic of his work have been composite methods, and high gluten content as an ideal. The nature of the soil and climate of eastern United States is such as to produce soft and starchy wheats. His efforts have been to raise the standard of eastern varieties as to gluten, and he has largely succeeded. Winter Fife and Early Red Clawson were the two most popular of his first varieties. Early Genesee Giant, another well-known variety which he originated, is widely grown in New York and Pennsylvania. It has no ancestors outside of the common bread-wheat group. This seems to be a weak point in Jones' method of procedure, for the most advantageous composite crossing is supposed to be with varieties of entirely different wheat groups.

This gives by far the greatest variations in degree and number, and gives qualities not otherwise obtainable. For example, the highest degree of non-shattering must be obtained from spelt or emmer, while the quality of resistance to leaf rust is best acquired by crossing with the durums. Jones' Winter Fife could not be grown in the Palouse country on account of its shattering, though it yielded 60 to 65 bushels per acre.

The Garton Brothers of England and William Farrer of New South Wales have extensively practiced crossing the different wheat groups. Every variety and every intergradation results from such crossing. A local variety may acquire, not only rust resistance and tenacity of chaff by intercrossing with a spelt and a durum, but also greater fertility of the head drawn from the spelt, and increased vigor of the seed, which produce a higher yield. These, and increased hardiness and gluten content, are practical results attained by the Garton Brothers. William Farrer has done an immense amount of excellent work in improving Australian wheats, especially as to rust resistance. The most important work in breeding cereals on the continent has probably been done by W. Rimpau of Schlanstedt, Germany, though his work is not generally characterized by composite methods. The Vilmorins have also done work in this line. The Dattel, one of the most widely distributed varieties of wheat around Paris, was originated by them.

Breeding Experiments have been carried on in the Kansas wheat belt for some years, and extensive co-operative work in this line has been taken up with the experiment stations in different wheat growing states, particularly in Texas, Kansas, South Dakota, Minnesota and Maryland. Efforts are being made to secure a variety that will ripen a few days earlier, so that by sowing two varieties the harvest period can be lengthened, and the danger of green cutting and shattering be avoided. Wheat and rye have been successfully hybridized by a number of experimenters, but as yet with no valuable results.

Experience has taught that the most successful and practical way to fight disease is to aid natural selection in producing disease-resistant or immune plants, rather than to attempt to cure the disease. "As a foundation for rational wheat improvement, a knowledge is required of the characteristics and needs of different wheat districts, and the characteristic qualities of the natural groups of wheats." A century ago wheat was wheat, but now thousands of varieties have been bred up which thrive best under the local conditions for which they were bred, and often they satisfy conditions, uses and tastes not in existence a century ago. The entire wheat harvest of the world is being improved. The value of this work in proportion to its cost must appeal to everyone, and indicates its permanency. Luther Burbank made the statement that if a new wheat were bred that would yield only one grain more to each head, Nature would produce annually, without effort or cost for man, 15,000,000 extra bushels of wheat in the United States alone.

The conclusions of scientists seem to be that varieties will hot wear out or materially change if the same conditions which made them excellent are kept up. If special care was exercised to produce an artificial variety, this care must be continued, or it will deteriorate. The improvement of wheat by breeding is no longer a theory, as in the time of Darwin, but an established fact.

CHAPTER IIL

NATURAL ENVIRONMENT.

The individual plant is the complex resultant of two forces, heredity and environment. Those characteristics of wheat which are acquired from environmental influences and which are transmissible from generation to generation of plants may be considered as belonging to heredity, a subject fully treated in the preceding chapter. The natural environment, consisting of soil and climate, is a pronounced factor in the growth of wheat, independent of the artificial modifications known as cultivation. The latter subject is treated in a later chapter.

ENVIRONMENTAL INFLUENCES.

Soil.—There are mechanical and chemical differences in soil that exert a varying influence upon the quantity and quality of wheat. The effect upon yield is more pronounced than that upon quality. In North Dakota 39 different samples of Blue Stem and Scotch Fife wheats of known history were obtained from farms representing the varied soils of the state. Sown upon the same soil, all gave approximately the same results in yield and quality of grain and straw. They also matured at the same date, and had like periods of development. Another experiment was made in which seed raised from one soil was hand picked to uniformity, and then grown upon various types of North Dakota soil in different portions of the state. The resulting grain and straw showed great variation.1 Similar experiments were made in Indiana* and Maryland* with practically the same results.

The soil has been a great factor in determining the distribution of wheat. Much of the wheat of the United States is grown upon glacial drift soil. There are two general types of this soil: The uplands, which are usually of a light-colored, tenacious clay; and the lowlands and prairies, which have a dark, loamy, organic, friable soil. Common bread wheats are usually grown on black soils. These soils are not well adapted to fall wheat, however, for it is apt to winterkill. Durum wheats thrive best in alkaline soils rich in nitrogenous matter. Sandy bottom land is best adapted to the production of soft wheat. Richardson attributed the low protein content of some American wheat to a deficiency in soil nitrogen. The ash of wheat stands next to the gluten in variability, and the factor most concerned in its variation is the soil.

1 N. D. Bui. 17, pp. 89-95. » Ind. Bui. 41. > Md. Bul. 14.

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DURUM WHEAT DISTRICTS OF THE UNITED STATES (By Carletou)

The lined districts show where durum wheat will succeed best and the dotted districts where it may be grown with grain of less quality.

Climate.—Seasonal differences are included under this subject, because their effects are the same in kind as those of climatic differences. Certain climates produce certain corresponding characteristics in wheat, regardless of what the soil conditions are. The protein content of wheat, and correspondingly its moist and dry gluten, is extremely sensitive to environment of a meteorological nature. The starch content is also sensitive, but in an inverse ratio. Climate varies from

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