Feb. 3,1923 
Cotton-Witty a Seed-Borne Disease 
39i 
after the others had died, as in the case of the culture D 9. The pot 
was inoculated on November 28, the first reisolation of the wilt fungus 
from a wilted plant was made February 5, and the last plant shed all its 
leaves on March 18. This plant had a blackened xylem from the roots 
to the growing point of the plant (PI. 1, B). Some of the other cultures 
produced rather mild cases of wilt in plants which grew for several 
months. 
Table II. —Inoculation experiments with Fusarium vasinfectum isolated from cotton 
seed. 
Date planted. 
Nov. 28,1921 
Do. 
Do. 
Do... 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do. 
Do... 
Do. 
Do. 
Do. 
-dar. 13,1922 
Do. 
Series No. 
A 9. 
B 1 . 
B 2 . 
B 4. 
B 9. 
C 2. 
C 4 . 
Cs. 
C 10.... 
Cm.... 
I>7. 
g9. 
F 1 . 
P2. 
£5 . 
F 6. 
P7. 
X 1. 
X 3 . 
x 4 . 
Xs. 
H 6. 
H 8. 
Wilt reisolated. 
Feb. 
Dec. 
Dec. 
Feb. 
Apr. 
Jan. 
Feb. 
Dec. 
Dec. 
Feb. 
Mar. 
Feb. 
Feb. 
Dec. 
Dec. 
May 
Dec. 
Dec. 
Dec. 
... .do 
Dec. 
June 
Apr. 
21,1922 
23.1921 
23.1922 
18.1922 
23.1922 
5,1922 
I 5 > 1921 
17.1921 
13.1922 
23.1922 
5,1922 
13.1922 
17.1921 
15.1921 
18.1922 
30.1921 
23.1921 
15.1921 
17.1921 
3,1922 
27.1922 
Date planted. 
,1922 
Mar. 13, 
.do. 
Mar. 29,1922 
.do. 
.do. 
Apr. 24,1922 
May 22,1922 
do. 
_do. 
_do. 
_do. 
_do. 
_do. 
_do. 
_do. 
_do. 
_do. 
_do. 
_do. 
_do. 
_do. 
_do. 
_do. 
Series No. 
hi 3 
K 1. 
J 3 * * • 
Yi. 
A 10, 
B 6., 
B ii. 
D 4.. 
D 6.. 
g is 
F 3 - 
F 4 .. 
F 8.. 
F 9 .. 
F 10. 
F 11. 
F 12. 
F13. 
Xj., 
t 4 *:: 
Wilt reisolated. 
Apr. 
Apr. 
June 
June 
June 
June 
June 
June 
May 
27.1922 
22.1922 
1.1922 
3.1922 
1.1922 
3.1922 
1.1922 
3.1922 
10.1922 
June 10,1922 
o 
June 10,1922 
Do. 
June 16,1922 
e) 
June 5,1922 
June 7,1922 
June 12,1922 
( 2 ) 
May 31,1922 
June 5,1922 
1 Pot destroyed. 
* These cultures had not produced wilt up to Oct., 1922. 
LONGEVITY OF THE WILT FUNGUS BORNE EXTERNALLY ON COTTON 
SEED 
The isolation of the wilt fungus from surface-sterilized seed plated 
April 17 and its successful inoculation on cotton seedlings proved quite 
definitely that the cotton-wilt fungus can live over from one season 
to the next within the cotton seed. Another point of interest was the 
length of time the fungus spores would remain viable on the outside of 
the seed. In an effort to determine this point, on January 2 a con¬ 
siderable quantity of undelinted seed was quite thoroughly infected by 
mixing it with a large culture of the known wilt organism growing on 
inoculated cotton stem fragments. After thorough mixing to secure a 
good distribution of the spores the stem fragments were picked out. 
This seed was first air dried, then put away in a covered battery jar. 
From 50 to 100 of these seeds were plated out each month up to May 
23. At every plating from 80 to 100 per cent of the seed yielded 
viable spores of the wilt organism. The identity of the organism iso¬ 
lated from this seed was determined by its morphology and color reaction 
and in no case by inoculations. The later platings have been made 
