10 
existence of physiologic races of the pathogens. In recent vears 
the Victoria oat variety, introduced from South America, has 
been used extensively in oat-breeding work and has proved par- 
ticularly valuable because of its high degree of resistance to known 
races of both loose and covered smuts. Victoria has been crossed 
with other varieties and, from the hybrids, selections have been 
made, some of which are well adapted to the Northern oat-growing 
region, while others are suitable as winter oats in the South. 
However, new races of smut have been discovered which attack 
Victoria and many of the most desirable selections derived from 
the crosses in which it was one of the parents. In most of these 
cases both of the original varieties used in crossing were suscept- 
ible to the new races. In some cases, however, resistant selec- 
tions have been obtained from hybrids in which Victoria has been 
crossed with a variety resistant to the new races, and among the 
latter are some of the outstanding recently introduced varieties 
of oats for the North, such as Vicland in Wisconsin and adjacent 
States. 
Investigations on the resistance of newly developed varieties of 
oats and the discovery of new races of oat smuts have resulted 
from cooperation with Mr. T. R. Stanton, Senior Agronomist, 
Division of Cereal Crops and Diseases, Bureau of Plant Industry, 
Beltsville, Md., and oe George J. Wilds, Coker’s Pedigreed 
Seed Co., Hartsville, S. 
Studies on the ee of Oat Smut Reststance.—As reported 
last year, experiments were conducted with second generation 
plants of hvbrids involving Victoria and Monarch, inoculated 
with Race 1 of the covered smut, to which Victoria is resistant 
and Monarch is susceptible, the data secured indicating a single 
factor for,resistance. During the past year 200 third generation 
progenies were grown and the data obtained confirm the conclu- 
sion that one resistant factor differentiates the two parental 
varieties, 
The second generation plants of 32 additional crosses were 
tested with definite physiologic races of smut. The parental 
varieties of these hybrids varied in their reaction to the races used. 
In some cases the data indicate a single factor difference while in 
others two or more factors seem to be involved. 

