Mar. i2 t 1917 
Fusarium-Blight of the Soybean 
43i 
Table I. —Characters which separate a number of the wilt-producing specie9 of Fusarium 
from F. tracheiphilum and the soybean fungus — Continued 
Species. 
Macroconidia. 
Odor. 
Size of 3-septate. 
Type. 
F. din mint . 
No data. 
Discolor; mostly 5-septate. 
Elegans; mostly 3-septate. 
.do. 
None. 
Strong lilac on rice. 
Often none, some- 
times scant lilac. 
None. 
Do. 
Do. 
Do. 
F. vasinfectum . 
F. nrysparum. . 
Same as in F, oxysporum .. 
28.7 to *s.6 by 3.6 toa.i u 
F . lycopersicA. . 
1 vv yJ * v Q * v T* ■ * r 
Abnormal.. 
.do. 
P . 
Abnormal; (original de* 
scription gives larger 
than in F. Oxysporum). 
23.6 to 41.0 by 3.9 to 4.1 u,. 
do... 
P‘, f.-rn.rhfi.iphil'Um . 
.do. 
Fusarium sp. on soybean... 
24.6 to 358 by 2.89 to 4.1 n. 
From the data in Table I it is important to observe that F. trachei¬ 
philum and the species of Fusarium on soybean belong to the section 
Elegans, as established by Appel and Wollenweber (1) and modified by 
Wollenweber (25) in a subsequent study. They are themselves very 
similar in cultural characters, but can be quite sharply separated from 
the other species included in the tabulation. When the characters of 
the species of Fusarium on the cowpea and soybean noted in this table 
are compared with those in the original descriptions of certain other 
members of the section Elegans—namely, F. redolens , F. orthoceras , and 
F. conglutinans , there is plainly no chance of their confusion. F. redolens 
(25) produces no blue sclerotia, and its conidial masses are brownish 
white; F. orthoceras (25) possesses neither sclerotia, sporodochia, nor 
pionnotes; and F. conglutinans (25) is distinguished because of the 
absence of the typical wine-red to purple colors of the section. 
MORPHOLOGICAL AND CULTURAL COMPARISON OF THE FUSARIUM 
SP. ON SOYBEAN WITH F. TRACHEIPHILUM 
Since the studies summarized in Table I do not succeed in distinguish¬ 
ing the species of Fusarium on soybean and cowpea, a more extensive 
cultural study of these two fungi was made. For this purpose three 
series of cultures were grown, and the results have been summarized in 
Table II. Each series contained 10 cultures of each fungus on stem 
plugs, potato plugs, steamed rice, standard nutrient agar (1.8 per cent 
agar and 1.0 per cent acid), string-bean hard glucose agar (3 per cent 
agar, 1.0 per cent acid, and 10 per cent glucose), and oat hard agar (3 
per cent agar and 1.0 per cent acid). The cultures were examined 
when they were 8, 15, 30, 50, and 75 days old. 
