72 
Journal of Agricultural Research voi. xxiv, no. n 
TablB VIII. —Influence of age of cabbage seedlings upon the occurrence of yellows 
Date planted. 
Condition of soil. 
Wisconsin Hollander. 
Grown in 
“sick" soil 
20 days 
from seed, 
at 26° C. 
li 
(S 
Grown in 
“sick" soil 
20 days at 
14® C., then 
transferred 
to 26 ° for 
10 days. 
r- 
I" 
§1 
8 ^ 
Commercial Hollander. 
Grown in 
“sick" soil 
20 days 
from seed, 
at 26® C. 
S .1 
illl 
FF 
Grown in 
“sick" soil 
20 days at 
14° C., then 
transferred 
to 26° for 
10 days. 
^ . 
3 “ 
Feb. 1,1918. 
Mar. 29, X918. 
Averacre results of two 
experiments. 
Mar. 29.1918,. . . 
May 5,1919. 
Naturally infested. 
_do. 
Naturally infested soil... 
Artificially inoculated... 
_do. 
19 I 78 
10 xoo 
29 89 
89 
100 
94 
zoo 
72 
,18 :100 
18 
TablF IX. —Number of cabbage plants which showed yellows at the end of jo days after 
transplantation to *'sick soil*' 
Temixera- 
ture. 
Number of 
plants. 
Wisconsin Hollander. 
Commercial Hollander. 
Number 
healthy. 
Number 
yellow. 
Number 
dead. 
Number 
healthy. 
Number 
yellow. 
Number 
dead. 
"C. 
14 
3 
3 
0 
0 
3 
0 
0 
17 
3 
3 
0 
0 
0 
3 
2 
26 
3 
3 
0 
0 
0 
3 
3 
All of the Wisconsin Hollander plants remained healthy throughout 
this experiment, whereas all of the susceptible commercial plants at 17® 
*and 26° C. developed typical yellows symptoms. At 26° yellows began 
to appear after ii days and at 17° after 17 days. All three plants at 
26° were dead after 17 days. 
In the second experiment, plants were grown in sterilized soil 36 days 
from seed before they were transplanted into ‘‘sick'* soil on May 24, 
1919. The air temperature ranged from 22° to 25*^ C. during this period, 
but the subsequent treatment was similar to that in the preliminary 
experiment. The final results, recorded on June 13, are shown in Table X. 
Tabli® X. —Number of cabbage plants which showed yellows at the end of 20 days after 
transplantation to sick** soil 
Tempera¬ 
Wisconsin Hollander. 
Commercial Hollander. i 
Number 
ture. 
Number 
Number 
Number 
Number 
Number 
healthy. 
yellow. 
dead. 
healthy. 
yellow. 
dead. 
14 
3 
0 
0 
3 
0 
0 
17 
3 
0 
0 
2 
I 
0 
20 
3 
0 
0 
0 
3 
0 
23 
2 
« I 
0 
0 
3 
2 
26 
I 
0 2 
0 
0 
3 
3 
29 
1 
a 2 
0 
0 
3 
3 
32 
2 
I 
0 
I 
2 
0 
3 S 
3 
0 
0 
0 
3 
0 
a The Wisconsin Hollander plants showed yellows in none but the lower leaves, and there only in incip¬ 
ient form. 
