3. More vigorous genetic stocks. During the summers of 1935 and 1936, a number of maize geneticists tested a group of inbred strains for disease resistance and general desirability. The two inbreds, U.S. #204 and West Branch Sweepstakes, seemed best suited to Ithaca conditions and have been selected for use in the Co-op. They have been designated as Inbred I and Inbred II, respectively, and are being used in crosses with weak genetic stocks to increase vigor and, by repeated backcrossing of the segregates to the inbreds, to obtain a more nearly homozygous chromosome complement. Later, the segregates from each inbred line may be crossed to get hybrid vigor.
Last summer 17 genetic stocks were crossed with both Inbred I and Inbred II.