Some Possible Modifications and Uses of the Sedimentation Test in a Wheat Breeding Program 1

in a Wheat Breeding Program Wade G. Dewey THE application, and to some extent the interpretation, of the wheat sedimentation test by plant breeders and by those engaged in the buying, selling, storing, and processing of wheat differ considerably. At least part of the present controversy over the merits of the test can be attributed to the rather free substitution of the methods and objectives of the plant breeder, the commercial trade and the U. S. Department of Agriculture, when in many instances these methods and objectives are not readily interchangeable. The plant breeder is primarily concerned with the classification of breeding lines into broad sedimentation categories; consequently, his interest is in relative sedimentation values and large differences. Under the present price support system, in which premium payments are based on sedimentation, the USDA and commercial millers are very much interested in absolute sedimentation values and small differences. The breeder works with segregrating material, often of wide genetic diversity. Numbers of individual selections are large and the seed supply of each is usually small. By contrast, the milling industry and USDA