06 
New races of oat smuts 
Additional experiments were carried on to determine more def- 
initely the characteristics of certain new races of both loose and 
covered smut. Several different varieties of oats were inoculated 
with these races and their resistance or susceptibility determined. 
It is quite clear that both of these smuts are sharply differentiated 
into distinct races which may be recognized by their reaction on 
different varieties. 
Bunt of wheat investigations 
During the past year a large amount of data establishing the 
existence of races in the two species of bunt, or stinking smut 
of wheat, was published. Four races of Tilletia laevis and six 
races of T. tritici were clearly differentiated by their behavior 
on varieties of winter wheat. Such varieties as Hussar, Martin, 
Turkey and Kanred proved to be particularly valuable in differen- 
tiating the specialized races. Further tests during the past year 
were made with these races of bunt and the earlier conclusions 
substantiated. 
Several varieties of spring wheat were also tested with these 
different races. All the specialized races of T. laevis and T. tritici 
already distinguished were used. Most of these races behaved in 
a more or less similar fashion on all the spring wheats grown. 
One race, however, already distinguished as T. tritici, Race Six, 
stood out conspicuously with reference to its behavior on the va- 
rieties. With this race several varieties, including Garnet, Hope, 
Kitchener, Ruby, Kota, Marquis and Florence, gave negative re- 
sults. Only a few varieties gave relatively high percentages of 
infection, the highest being obtained with Red Sask, namely, 70.8 
per cent. infection. 
With the remaining nine races, most of the varieties, such as 
Preston, Karly Red Fife, Power, Prelude, Pioneer, Ceres, Garnet, 
Kitchener Ruby and Kota, gave very high percentages of infection. 
Occasionally 100 per cent. infection was obtained ; in several cases 
go to 99g per cent. of the plants were infected while in a large 
number of cases the percentage of infection was between 80 and 
89 per cent. Only occasionally did the percentage of infection 
fall below 50 per cent. 
