RUST RESISTANCE OF OAT VARIETIES. 9 
majority of cases all leaves or culms inoculated showed infection 
(normal uredinia) except in certain varieties where there were very 
evident signs of resistance and to which attention is directed in the 
footnotes to Table I. 
Table I. — Summary of notes on the rust resistance of oat varieties tested in the 
greenhouse at Cornell University, Ithaca, N. Y., 1915-16. 
[R.= resistant; S.= susceptible.] 
Identification numbers. 
Crown rust. 
Stem rust. 
Variety. 
V. 
s 
o 
1 
© 

o 
03 
Op' 
53 .53 
OT 
03 
5 
|| 
"oltf 
as suj 
<v 
O 
cd 
cd 
< 
d 
a 
03 
03 
CO 
1° 
o3^3 
^ 60 
3 S 
a 
03 
03 
CO 
o3 
03 • 
r- 03 
Si 
is- 
o3— ' 
s 
Remarks. 
1 
2 
3 
4 
5 
6 
7 
8 
9 
10 
Common (sativa) varieties: 
7 
94 
9 
11 
?3 
272 
S. 
S. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
f^oR. 
\(+S.) 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
S. 
S. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
12 s.? 
s. 
is.? 
s. 
s. 
s. 
s. 
2R.? 
s. 
s. 
s. 
------ 
s. 
s. 
3S.? 
s. 
s. 
s. 
s. 
5R. + S. 
7R.? 
s. 
S. 
s. 
s. 
s. 
8R. + S. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
/13R. 
i +s. 
1797 
275 
280 
305 
348 
Archangel X Early Goth- 
land 
39 
51 
42 
102 
37 
108 
29 
91 
8 
89 
33 
96 
Bicknell 
206 
354 
Black Anthony 
Black Beauty 
1804 
342 
1814 
Black Tartarian 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
*R.? 
6S.? 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
s. 
}nR.+ 
1791 
273 
'""336 
1729 
Colorado No. 9 

1798 
68 1 
fi'il 
69 1 672 
Early Champion 
Early Gothland 
4 
2 
104 
! 
26 
English Wonder 
1807 
83 
7-W 
GartonNo.396 
46 
103 
405 
1805 
97 1799' 
41 
106 
98 
36 
350 
Do. 
1808 
1800 
341 
6 
340 
1 
34 
88 
43 
79 
Pickett.. .. 
1728 
391 
Ruakura Rustproof » 
701 
} Do. 
i Normal infection on one plant; on the other, only a few uredinia surrounded by purple blotches. 
2 Only a few abnormally small uredinia in 14 days after inoculation. 
s No uredinia in 10 days after inoculation, and finally only one on each culm, accompanied by purple 
color of host tissue. 
4 Only a few tiny uredinia on each leaf. 
6 Normal uredinia on one culm; only a few on the other. 
6 Infection only fairly vigorous. 
7 Unusually small uredinia first appeared 14 days after inoculation. 
8 Normal infection on one culm; no uredinia on the other. 
9 The results with this variety probably were more interesting and valuable than those from any other 
included in the test, for there were signs of resistance to both rusts at both stages of growth. This variety 
is of undoubted value as a source of the character of rust resistance, the more so because of its resemblance 
to yellow and white oat varieties of the A vena sativa group. 
'" Six leaves severely rusted; on four only extremely small uredinia. In two pots of seedlings later 
inoculated no normal infection resulted. 
u Flecks only; no uredinia. Within two weeks the small dark telia, characteristic of resistant varieties, 
were formed. 
i 2 Uredinia moderately abundant, somewhat small and surrounded by yellow flecks. 
1 3 On one plant uredinia were abundant and of normal size. On the other plant they were small and 
tardy in breaking through the epidermis. 
