Fusarium Blight of the Soy Bean 35 
From an examination of the table as a whole it is evident in 
the case of both strains of the organism that there was better 
growth in the presence of various amounts of acid than in the 
presence of alkali, but that even on a strongly alkaline sub- 
stratum the colonies required only 2 or 3 days longer in which 
to extend themselves over the entire surface of the medium in a 
petri dish. 
Edgerton (7, p. 12) reports field tests with F. ly coper siei in 
which tomato wilt was only temporarily checked by the applica- 
tion of lime. He says, “The hea^y application of lime (10 tons 
per acre) decreased the wilt and the plants produced a larger 
yield of tomatoes. * * As the season advanced, however, 
most of the plants in the treated plot also died with the disease.” 
THE INFLUENCE OF THE NEMATODE (HETERODERA RADICICOLA) 
As noted in the above experiment with the eleven types of 
the Xorfolk series of soils, nematodes had been introduced with the 
Fusarium cultures into each flat. This experiment differed from 
others in which nematodes were iDresent in that the conditions 
were those of the field under slight modification. The plants 
were grown to maturity and only a few nematodes were present 
on the plants indicated as affected with nematodes. Twenty-three 
]3er cent of the total number developed galls, however, but none 
showed symjDtoms of the blight, altho the cultures were knoAvn to 
be Aurulent for the reason already stated. 
Table 8. — Influence of nematodes on the percentage of infection 
loy F. tracheiphilum. 
Organism 
1 
Total 
number 
plants 
No. with 
nematode 
galls 
No. with 
Fusarium 
sp. 
F . tracheiphilum from cowpea and nematodes . . 
10 
10 
2 
F. tracheiphilum from cowpea without 
nematodes 
10 
0 
0 
F. tracheiphilum from soy bean and nematodes . 
10 
10 
3 
F. tracheiphilum from soy bean without 
nematodes 
10 
0 
2 
Nematodes only 
10 
10 
0 
None (control) 
20 
0 
0 
