376 
Journal of Agricultural Research 
Vol. XXX, No. 4 
Barney (8) recently has reported on 
some studies of the inheritance of 
resistance to loose smut of oats in 
crosses between Fulghum and Black 
Mesdag, Swedish Select and Burt, and 
Turkish Rustproof and Golden Rain. 
The first cross involved two very re¬ 
sistant varieties, the second a resistant 
and a susceptible variety, and the 
third two moderately susceptible varie¬ 
ties. Barney suggests that resistance 
in the first cross depended upon three 
different factors, in the second upon 
two, and in the third upon only one. 
He also has shown that, in the F 2 gen¬ 
eration, highly resistant as well as 
highly susceptible families which breed 
true can be isolated. 
The data here presented were ob¬ 
tained from a cross between Fulghum 
and Swedish Select. Reed (14) and 
Reed, Griffiths, and Briggs (15), who 
have made extensive studies on the 
resistance of oat varieties to loose smut, 
Ustilago avenae (Pers.) Jens., and 
covered smut, U. levis (K. and S.) 
Magn., found that various strains of 
Fulghum were highly resistant, while 
strains of Swedish Select were mod¬ 
erately susceptible. 
RELATIVE SUSCEPTIBILITY 
All of the tested strains of Fulghum 
and Swedish Select have been grown 
at one or more of the following sta¬ 
tions: Columbia, Mo.; Ames, Iowa; 
Aberdeen, Idaho; Manhattan, Kans.; 
Pullman, Wash.; and Brooklyn, N. Y. 
All have been grown two or more years 
in the series inoculated with Ustilago 
avenae. The same is true in the series 
inoculated with U. levis, except that 
two strains were grown in only one 
year at one place. 
FULGHUM 
Four different strains of Fulghum 
oats, including two of Kanota, have 
been grown. These strains, at every 
station in every year, have consistently 
shown a high degree of resistance to 
both Ustilago avenae and U. levis. The 
highest percentage of infection (2.4 per 
cent) by U. avenae was obtained at 
Aberdeen in 1920, and the highest 
percentage of infection (3.2 per cent) 
by U. levis occurred at Manhattan in 
1920. 
At all the different stations 10,803 
plants were grown in the Ustilago 
avenae series. These showed 0.6 per 
cent of infection. From seed inocu¬ 
lated with U. levis 10,200 plants were 
grown. These showed 0.4 per cent of 
infection. 
SWEDISH SELECT 
Six different strains of Swedish 
Select oats have been grown at the 
several stations in order to determine 
their susceptibility to Ustilago avenae 
and U. levis. 
Results from inoculation with Usti¬ 
lago avenae show that the highest 
percentage of infection (42.6 per cent) 
was obtained in strain No. 225 at 
Brooklyn, N. Y. The lowest per¬ 
centage of infection (1.1 per cent) 
occurred at Brooklyn in 1922, in 
strain No. 226 (C. I. No. 134) 4 and also 
No. 227. All of the strains at some 
locality have had percentages of in¬ 
fection above 32.3 per cent except 
strain No. 229 (C. I. No. 1743). Of all 
the strains at the different stations 
2,694 plants have been grown and 19.9 
per cent were infected. 
Results with Ustilago levis show that 
the highest percentage of infection 
(45.1 per cent) was obtained in strain 
No. 168 at Columbia. High infec¬ 
tions of 39.7 per cent and 40.2 per 
cent, respectively, were obtained in 
strains Nos. 226 (C. I. No. 134) and 
227. The lowest percentage of in¬ 
fection obtained was 3.4 per cent in 
strains No. 226 (C. I. No. 134) and 
229 (C. I. No. 1743) at Brooklyn. 
In the entire series, 2,172 plants were 
grown, and 17.6 per cent of these 
were infected. 
Where the data are sufficient for 
comparison there seems to be no ob¬ 
vious difference in the susceptibility 
of these strains to the two different 
smuts. Infections above 40 per cent 
are only occasional. 
PARENT VARIETIES 
Fulghum and Swedish Select are 
important varieties of oats in the United 
States. They are representative of 
the two groups of oats to which prac¬ 
tically all our cultivated varieties be¬ 
long, namely, Avena sativa L. and A. 
T>yzantina C. Koch. Panicles and 
spikelets of these varieties are shown 
in Plate 1. 
Fulghum is one of the leading varie¬ 
ties of so-called red oats grown in this 
country. As already noted, it has 
shown a high degree of resistance to 
smut. It is grown most extensively 
in the Southern States and in Kansas, 
where it has recently become popular 
under the name Kanota (16). 
Swedish Select is one of our princi¬ 
pal midseason white varieties, and 
is grown extensively throughout the 
northern United States. In the va- 
4 C. I. No. = Cereal Investigations accession number, here and throughout this report. 
