Page:Farmers' Bulletin, No. 1280.djvu/4

2 are grown in all other parts of the United States except the South-eastern States, the Atlantic Coast States, and the New England States. More than 18,000,000 acres, or nearly one-third of the wheat grown annually in the United States, is of the hard red winter class. The distribution of hard winter wheat in 1919 is shown on the accompanying map (Fig. 1).

The hard red winter wheats are best adapted to a section comprising portions of Kansas, Nebraska, Oklahoma, and Colorado, having an annual rainfall of less than 35 inches. In this section there is

little competition with other classes of wheat. As the annual rainfall increases eastward the hard red winter wheats come into competition with the soft red winter wheats. In eastern Kansas and Oklahoma, northern Missouri, southern Iowa, and central Illinois, where the annual rainfall varies from 35 to 40 inches, the hard red winter wheats are adapted only to the higher, drier, and less fertile soils. In some of the drier sections of Oregon, Washington, and Idaho, where the annual rainfall is around 15 inches, hard red winter wheat is well adapted also and successfully competes with several other classes of wheat. The hard winter wheats also are quite important in Minnesota, South Dakota, Wyoming, and Montana and are practically the only winter wheats which will survive the extreme