476 
Journal of Agricultural Research 
Vol. I, No. 6 
place. Cladosporium gramineum was obtained from the leaves of oats 
at the same station. The Alteraaria species occurring with Helmintho- 
sporium or independently were isolated from wheat culms in the same 
manner as Helminfhosporium gramineum. Fusarium culmorum was iso¬ 
lated from wilted oat plants obtained from a io-acre field on the farm of 
Mr. Peter Hanson, Sandy, Utah, on May io, 1910. On this farm about 
10 acres of oats had been practically destroyed by disease a few weeks 
after the seed was planted. The plants sent to the cereal-disease labora¬ 
tory for examination and diagnosis were sterilized by immersing them 
in a 1 to 1,000 mercuric-chlorid solution for 10 minutes, followed by wash¬ 
ing in sterile water. They were then placed in a moist chamber at a 
temperature of about 75 0 F. for several days and were soon covered with 
a luxuriant fungous growth. This proved to be a pure culture of Fusa¬ 
rium culmorum . It was plated and grown on potato cylinders and corn 
meal and sporulated abundantly. 
After securing these fungi in pure cultures and inducing profuse 
sporulation, tests were made as to their pathogenicity on the leaves, 
seeds, and seedlings of wheat, oats, barley, and rye. 
INOCULATION OF LEAVES OF WHEAT, OATS, BARLEY, AND RYE WITH 
SPECIES OF IMPERFECT FUNGI 
* 
Seedling plants of wheat (Haynes Bluestem, Minn. No. 169), oats 
(Early Gothland, Minn. No. 26), barley (Manchuria, Minn. No. 105), and 
rye (winter) were grown in the greenhouse at Washington, D. C., in 6- 
inch pots under temperature and moisture conditions as nearly normal 
as possible. When the seedlings were 2 to 3 inches high, inoculations 
were made about an inch from the leaf tip, with spores transferred from 
pure cultures in test* tubes by means of a flattened inoculating needle, 
care being taken that little or none of the nutrient medium was trans¬ 
ferred to the leaves. If any of the medium accompanied the spores, 
control plants were similarly treated with the same medium minus the 
spores. Care was taken not to injure the leaves in any way. The 
inoculated plants were placed under bell jars standing in pans of sand 
and water, thus permitting the moisture transpired to condense on the 
leaves, making an ideal condition for spore germination. They were 
allowed to remain under the bell jars for 48 hours and were then removed 
and placed in the greenhouse at a temperature ranging from 55 0 to 65° F. 
Table I shows the results of these inoculations. 
