VARIETAL SUSCEPTIBILITY OF OATS TO SMUTS 
35 
Table 8. — Results of inoculating seed of several of the most resistant and extremely 
susceptible varieties and strains of different species of Avena with spores of Ustilago 
avenae and U. levis in the greenhouse in the years indicated 
S.N. 
Year 
Ustilago avenae 
Ustilago levis 
Species and variety 
Num- 
ber of 
plants 
Infected 
Num- 
ber of 
plants 
Infected 
Num- 
ber 
Per 
cent 
Num- 
ber 
Per 
cent 
77 
I 134 
/ 143 
\ 290 
[ 72 
\ 180 
I 291 
j 181 
j 293 
j 30 
1 144 
292 
306 
116 
70 
117 
119 
120 
311 
f 150 
\ 197 
f 121 
\ 316 
158 
266 
164 
168 
126 
108 
110 
175 
129 
257 
262 
133 
1919 
/ 1920 
\ 1921 
1919 
1920 
1921 
1919 
1920 
1919 
J 1920 
\ 1921 
/ 1920 
\ 1921 
1919 
1920 
1921 
1919 
f 1919 
\ 1920 
[ 1921 
f 1919 
\ 1920 
I 1921 
/ 1920 
\ 1921 
1919 
1921 
1920 
1921 
1920 
1921 
1920 
1919 
1920 
1920 
/ 1920 
\ 1921 
/ 1919 
\ 1921 
1920 
f 1919 
\ 1920 
1 1921 
1919 
< 1920 
I 1921 
( 1919 
\ 1920 
I 1921 
1920 
f 1920 
\ 1921 
122 
52 
52 
14 
38 
36 
33 
58 
76 
40 
41 
50 
60 
70 
48 
58 
29 
59 
'55 
56 
63 
49 
60 
53 
60 
84 
54 
30 
49 
42 
56 
28 
57 
7 
10 
23 
49 
42 
37 
54 
60 
59 
56 
61 
55 
52 
49 
42 
48 
22 
48 
52 



9 
31 
1 

8 
76 
39 
41 
46 
60 
50 
46 
4 
2 






47 
50 
7 
13 
24 
42 
26 
11 
11 
2 
3 
5 
14 
38 
18 
22 
27 


1 

3 



1 






64.2 
81.5 
2.7 

13.7 
100 
97.5 
100 
92.0 
100 
71.4 
95.8 
6.8 
3.4 






88.6 
83.3 
8.3 
24.0 
80.0 
81.6 
61.9 
19.6 
39.2 
3.5 
42.8 
50.0 
60.8 
77.5 
42.8 
59.4 
50.0 


1.7 

5.4 



2.1 



103 
47 
44 
50 
26 
1 


30 
25 
0.9 


60.0 
96.1 
Avena nuda: 
44 
30 
68.1 
36 
36 
48 
58 
40 
40 
64 
49 
36 
36 
48 
53 
35 
40 
2 
2 
100 
100 
100 
91.3 
87.5 
100 
Avena sativa: 
Belyak .. -.- 
3.1 
4.0 
54 
53 
85 
54 
55 
55 
54 
70 
65 





54 
35 
3 
5 




98.1 
64. 8 
4.2 
7.6 
52 
27 
51. 9 
49 


49 
42 
33 
49 
36 
14 
16 
42 
Avena sativa orientalis: 
Black Tartar 
73.4 
33.3 
Green Mountain 
48.4 
85.7 
Avena sterilis: 
Burt 
48 
54 
48 
46 
54 
1 


2 

2.0 
Fulghum 


4.3 

Red Rustproof 
43 
51 
1 
4 
2.3 
7.8 
35 
47 




The varieties that were extremely susceptible Tinder field conditions 
also were severely attacked in the greenhouse cultures. These varie- 
ties were Avena fatua (S. N. 143 and S. N. 290) ; A. nvda var. biaristata 
(S. N. 181 and S. N. 293), var. inermis (S. N. 30 and S. N. 144), and 
var. Liberty (S. N. 292); A. sativa var. Canadian (S. N. 119), var. 
Early Champion (S. N. 150 and S. N. 197), var. Green Russian (S. N. 
121), var. Silvermine (S. N. 164), var. Swedish Select (S. N. 168), and 
var. Victor (S. N. 126) ; A. sativa orientalis var. Black Tartar (S. N. 108) 
