192 
Journal of Agricultural Research 
Vol. V, No. s 
days at average temperatures of 19.7 0 and 20.4 0 , respectively. Seven 
reisolations were identified. 
F. hyperoxysporum 3399; isolated from Ipomoea batatas from Lincoln, 
Ark., by Mr. E. E. Harter. Determined by Miss Ethel C. Field and the 
author. Culture used for inoculation, 20-day-old cotton stem. As 
given in Table II, after 51 days' incubation at an average temperature 
of 21.5 0 , the results were as follows: Of the four inoculated tubers of 
each of the varieties Idaho Rural, Netted Gem, Burbank, and Pearl 
o, 1, 1, and 4 tubers were rotting, respectively. The organism was 
recovered by four isolations. 
F. hyperoxysporum 3489; reisolation of strain 3399. Culture used for 
inoculation, 8-day-old potato cylinder and rice culture. This strain was 
considerably more active than the parent strain 3399. All tubers were 
rotted after an incubation of 25 days at 23.5 0 . Six reisolations were 
made. 
Table II gives the results of the inoculations with F. hyperoxysporum . 
Table II. —Results of the inoculation of different varieties of potatoes with original and 
reisolated strains of Fusarium hyperoxysporum 
Strain No. 
3*73 
3343>3 2 73 
3399. 
34&)>3399 
Variety of potato. 
Number of 
tubers. 
Incubation 
period. 
Average 
temperature. 
Percentage 
of tubers 
rotting. 
4 
Days . 
51 
°C. 
16.3 
IOO 
4 
51 
17 . O 
100 
Green Mountain.... 
< 4 
5 1 
17.8 
IOO 
4 
Si 
18. 4 
IOO 
. 10 
*4 
25 - 7 
IOO 
[Idaho Rural. 
4 
28 
19. 7 
IOO 
Netted Gem. 
4 
28 
19. 7 
IOO 
Burbank. 
4 
37 
20. 4 
IOO 
Pearl. 
4 
37 
20. 4 
IOO 
f Idaho Rural. 
4 
51 
21. 5 
0 
J Netted Gem. 
4 
51 
21. 5 
2$ 
I Burbank. 
4 
5 1 
2 i- 5 
25 
[Pearl. 
4 
5 i 
21. 5 
IOO 
[Burbank. 
9 
25 
23- S 
IOO 
{Netted Gem. 
25 
25 
23- 5 
IOO 
[Pearl. 
22 
25 
2 3 * 5 
IOO 
>“reisolation of. 
Fusarium vasinfectum Atk.—Inoculations were made with F. msin- 
fectum isolated from cotton and a similar organism from okra to determine 
whether this species, which is closely related to F. hyperoxysporum , 
would cause a decay of potatoes. Although considerable decomposition 
occurred in the inoculated tubers, a scrutiny of the data summarized 
below reveals the nonconclusive nature of the results obtained. 
F. vasinfectum 1855; reisolated by Dr. Wollenweber, in December, 
1912, from the vascular system of a cotton plant wilting as a result of 
