10 Xebraska Experiment Station Research Bulletin 22 
Table 1. — Viability of the uredinios pores of Puccinia graminis 
tritici Form III. 
Approximate 
relative 
humidity 
After 1 week 
After 2 weeks 
After 3 weeks 
After 4 weeks 
After 5 weeks 
After 6 weeks 
After 7 weeks 
After 8 woeks 
After 9 weeks 
After 10 weeks 
After 1 1 weeks 
After 12 weeks 
After 13 weeks 
After 14 weeks 
After 15 weeks 
CO 
0) 
1 
co 
■u 
< 
Per cent 
25° 
C. 
100.0 
1 0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
89.9 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
80.5 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
70.4 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
o i 
0 
0 
0 
60.7 
+ 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
49.0 
+ 
+ 
— 
— 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
38.0 
0 
— 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
29.5 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
21.5 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
10.5 
0 
0 
0 
1 0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0.0 
0 
0 
0 
! o 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
Per cent 20° C. 
100.0 
— 
0 
1 0 
0 
1 0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 I 
0 
89.9 
0 
1 — 
0 
! o 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
80.5 
— 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
70.4 
+ + 
0 
+ 
0 
— 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
60.7 
+ + 
+ 
+ 4- 
+ + 
4“ 
it 
— 
— 
— 
0 
0 
0 
0 
0 
0 
0 
49.0 
+ + 
+ 
+ + 
+ + 
+ + 
+ 
4- 
db 
— 
— 
— 
— 
0 
0 
0 
0 
38.0 
+ + 
+ 
+ 
+ 
+ 
— 
— 
— 
0 
0 
0 
0 
0 
0 
0 
29.5 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
21.5 
+ + 
0 
— 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
10.5 
— 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0.0 
+ + 
4- 
1 + 
0 
0 
ifc 
— 
— 
0 
0 
0 
0 
0 
0 
o ! 
0 
Per cent i 5° C. 
100.0 
± ] 
i + 
0 
0 
1 0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
89.9 
— 
1 0 
0 
+ 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
80.5 
+ + 
0 
— 
— 
— 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
70.4 
— 
! 0 
— 
— 
— 
it 
0 
0 
0 
0 
0 
0 
0 
(1 
0 
0 
60.7 
+ + 
+ 
4- + 
+ + 
0 
4“ 
+ 4- 
+ 
+ 
— 
it 
— 
— 
it 
— 
0 
49.0 
+ + 
+ 
+ + 
+ + 
+ + 
4-4- 
+ + 
+ 4 - 
+ + 
4- 
— 
— 
— 
0 
4 - 
— 
38.0 
+ + 
+ 
+ 4 - 
+ + 
+ 
+ 
4 - 4 - 
+ + 
0 
+ 
— 
— 
— 
0 
— 
— 
29.5 
++; 
+ 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
21.5 
0 
0 
— 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
10.5 
++I 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0.0 
1 - 
+ 
+ 
4- 
_+_ 
it 
— 
0 
0 
0 
0 
0 
0 
0 
0 
Per cent 
10 ° 
c. 
100.0 
=±= 
— 
0 
— 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 I 
0 
0 
89.9 
— 
0 
± 
0 
+ 
it 
— 
0 
— 
— 
0 
0 
0 
0 
0 
80.5 
4 " 
+ + 
4 - + 
4 - 4 - 
+ 
+ 
+ 
— 
it 
— 
0 
0 
0 
0 
0 
70.4 
+ + 
+ 4 - 
+ 
+ 
4 - + 
4 - 
4 - 
4 - 
4 - 
4 - 
it 
— 
0 
db 
0 
— 
60.7 
4 - 
— 
4 - 
+ 
4 “ 
+ + 
+ + 
+ + 
+ 4 - 
+ + 
4 - 
+ 
+ 
4 - 4 - 
— 
49.0 
+ + 
+ 
4 - 4 - 
+ + 
+ + 
4 " 
4 - 4 - 
+ + 
+ + 
4 - 4 - 
+ + 
— 
4 - 
+ 
+ 
+ 
38.0 
+ 
+ 
+ + 
+ + 
4 - 4 - 
4 - 4 - 
4 - 4 - 
it 
+ 
+ 
— 
4 - 4 - 
It 
29.5 
+ 
+ 
+ + 
+ 
0 
— 
— 
— 
0 
— 
0 
— 
0 
0 
o 
0 
21.5 
+ 
t 
+ + 
it 
0 
— 
0 
0 
0 
it 
0 
0 
0 
0 
0 
0 
10.5 
— 
— 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0.0 
+ 
+ 
+ 
+ 
+ 
it 
0 
— 
— 
0 
o 1 
1 0 | 
0 
0 
Per cent 5° C. 
100.0 
— 
— 
0 
it 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
0 
89.9 
— 
— 
— 
0 
0 
0 
0 
0 
0 
0 
0 
1 o 
0 
II 
0 
80.5 
+ + 
it 
+ + 
+ + 
+ + 
— 
+ + 
+ 
+ 
— 
db 
0 
— 
0 
0 
0 
70.4 
+ + 
+ + 
+ + 
+ + 
+ + 
+ + 
+ + 
+ + 
+ 
+ + 
+ + 
+ 
+ 
+ + 
+ + 
— 
60.7 
+ + 
+ + 
+ + 
+ 4- 
+ + 
+ + 
+ + 
+ + 
+ + 
+ + 
+ + 
— 
+ + 
+ 
4- + 
4- 
49.0 
+ 
t 
+ + 
— 
+ 
it 
+ + 
+ + 
— 
+ + 
— 
— 
+ 
+ + 
4 - 4 - 
— 
38.0 
+ + 
+ 
+ + 
+ + 
+ + 
+ + 
+ + 
+ 
+ 
+ + 
+ + 
+ 
+ 
dl 
t 
29.5 
+ + 
+ 
+ 
— 
+ 
+ 
it 
+ 
— 
1 0 
— 
II 
0 
0 
0 
0 
21.5 
+ 
+ + 
+ 
+ 
+ 
dt 
— 
— 
0 
II 
0 
0 
0 
o 
10.5 
<i 
0 
o 
0 
0 
0 
0 
0 
0 
0 
0 
1) 
0 
0 
0 
0 
0.0 
0 
0 
o 1 
0 
0 
0 
0 
0 
0 
0 
0 
0 
o 
0 ~ No germination. + = 10 to 40 per cent germination. 
= 1 to 5 per cent germination. -j- 4- = above 50 percent germination. 
=*= = 5 to 10 per cent germination. 
