Mar. a S , 1914 Imperfect Fungi from Wheat , Oats , and Barley 
483 
was not in a profusely sporulating stage and therefore not in as active a 
condition as the material which was used in the inoculations in the green¬ 
house. The seed which was inoculated also was still slightly damp after 
the treatment in the formalin solution and this trace of formalin might 
have reduced the effectiveness of the spores to some extent. The strain 
of H. gramineum from barley was more virulent than the strain from 
wheat, the percentage of germination being less where this strain was 
used for inoculation than where the strain from wheat was used. After 
inoculating with this strain, even the germination of the oats was con¬ 
siderably affected. The material used for inoculation, however, was in 
better condition than the material of the strain from wheat, as the fungus 
was sporulating abundantly when used. The plants of both wheat and 
oats which survived were less vigorous than the plants from clean seed, 
being slightly smaller than the plants in the control rows. 
Fusarium cultnorum also wasi virulent, particularly on oats, and its 
effect on wheat and barley was marked. The wheat plants which sur¬ 
vived after inoculation with this fungus were smaller than those in the 
control rows, the difference being measurable. Several of the plants 
were dying when counted. In the case of barley the difference in the 
plants from inoculated seed and control seed was not marked, while in 
the case of oats many plants from the inoculated seed were very weak 
when counted, the difference in vigor between them and plants from 
clean seed being very noticeable. There was a sufficient difference in 
stand between rows from inoculated and from clean seed in the case of 
wheat, oats, and barley to be noticeable even without counting the plants. 
That the reduction in germination and injury to seedlings was less 
marked in the field experiments than in the greenhouse experiments may 
be due to several causes. The temperatures in the field were consider¬ 
ably lower than under greenhouse conditions, and the fungi may have 
been less active for that reason. Again, the grain which had been treated 
with a formalin solution was not absolutely dry when inoculated and the 
trace of formalin present may have reduced the vitality of the spores. 
One other fact, however, which may have had a marked influence is that 
in the field the fungi used for inoculation would have to compete with 
other fungi and bacteria in the soil and many of the spores may have been 
injured before they could germinate and infect the grain. That such 
competition between fungi and bacteria in the soil may not be uncommon 
was indicated in a preliminary experiment in the greenhouse where wheat 
inoculated with Helminthosporium gramineum was planted in sterilized 
and unsterilized soil. It was found that the wheat planted in the ster¬ 
ilized soil was more severely injured by the fungus than the wheat planted 
in unsterilized soil, the percentage of germination being less in the ster¬ 
ilized soil than in the soil not sterilized. In a second experiment of this 
