30 
BULLETIN 1275, U. S. DEPARTMENT OF AGRICULTURE 
RESULTS FROM AVENA LUDOVICIANA 
Five strains of Avena ludoviciana Dur. have been grown. Three 
of these strains (S. N. 80, 176, and 180) are moderately susceptible, 
especially to Ustilago levis. The results, however, have been quite 
variable at the different stations in different years. Strain S. N. 291 
has proved to be somewhat more susceptible than the other three, 
showing higher percentages of infection. The fifth strain, S. N. 
72, proved to be highly resistant. It is characterized by a prostrate 
habit in early growth. It was received under the name of Avena 
sulcata F. Gay. 
RESULTS FROM AVENA NUDA 
Two strains (S. N. 181 and 293) of the awned type of naked oats 
(Avena nuda L.) were grown and both proved to be highly susceptible. 
With rare exceptions the infection was always above 80 per cent 
and occasionally percentages of 90 to 100 were recorded. 
Five additional strains of Avena nuda were grown, namely, inermis 
(S. N. 26, 30, 144, and 294) and Liberty (S. N. 292). These varieties 
also proved highly susceptible, commonly showing 80 per cent or 
more of infection. The results from Liberty, a cross between a 
naked oat and Swedish Select, were slightly lower than from the 
other varieties. The Liberty variety, while quite susceptible to 
both smuts, usually does not show percentages of infection as high 
as those obtained on the other naked oats. 
The results clearly indicate that all strains and varieties of Avena 
nuda are extremely susceptible to both loose and covered smut. 
RESULTS FROM AVENA SATIVA 
In the course of the experiments more than 90 varieties of Avena 
sativa, represented by 182 strains, were grown. Based upon the 
percentages of infection these different strains and varieties fall into 
several groups. The first group includes the varieties which may 
be described as immune from or highly resistant to both smuts. 
The number of varieties included in this group is comparatively 
small. The list is given in Table 3. 
Table 3. 
-List of varieties and strains of Avena sativa found to be highly resistant 
to both loose and covered smuts of oats 
Variety or strain 
Seed No. 
Variety or strain 
Seed No. 
Bclyak 
306 
70, 117, and 188 
279 
295 
311 
187 
Black Mesdag 
215 
Caucasus 
45 
Culberson 
218 
Danish Island 
323 
Black Mesdag, represented by three strains (S. N. 70, 117, and 188), 
has proved to be practically free from infection. A total of 7,237 
plants in the experiments with Ustilago avenue and G,435 plants in 
the experiments with U. levis has been grown at all the different sta- 
tions. At Manhattan and Ames a doubtful infection of this variety 
has been recorded. Unfortunately, plants wero not preserved for 
final identification. Out of a total of 2,288 plants in the series in- 
oculated with U. avenae grown at Brooklyn 4 were found infected. 
