A test of some three hundred oat varieties showed some susceptible and some resistant to Puccinia graminis avenae. A study of the inheritance of resistance has been made by determining the response of hybrids of resistant x susceptible varieties. In this study, Iowa 105 was found to possess a marked resistance in addition to maturing early and thus escaping stem rust. Green Russian and Raukura were both resistant. The F1 generation of Iowa 105 x Green Russian was resistant. The F2 generation gave a wide ratio of several hundred resistant plants to one susceptible. In the F1 progeny test the susceptible F2 plants bred true for susceptibility, while numerous progenies from the resistant F2 plants, segregated into resistant and susceptible plants. Such a wide ratio exists in the F2 generation it is impossible to determine the true factorial basis of inheritance without further work. It is probable, however, that several factors are responsible for the inheritance of resistance to stem rust of oats. These data were further confirmed by the Raukura x Green Russian crosses
