934 
Journal of Agricultural Research voi. xxvii, no. 12 
galls in the heads as were used in inoculating the seed. Only one barley 
plant was found showing symptoms of nematode injury in the seedling 
stage, while oats seemed to be entirely immune. Rye, barley, and oats, 
Marcinowski concludes, are not to be considered congenial hosts for the 
wheat nematode. Henslow ( 12 ) claims to have secured slight infection 
in oats, barley, and rye. 
In experiments extending over two years, Byars, Johnson, and Leukel 
(7) found rye to be fully as susceptible to the nematode disease as wheat 
and in some cases even more severely affected. The resulting galls 
usually are smaller than those in wheat and also lighter in color (PI. 5, H), 
but, contrary to Marcinowski’s findings, the larvae are as fully developed 
in the rye galls as are those found in wheat galls. Galls obtained from 
rye heads were used for inoculating both wheat and rye, and abundant 
infection was obtained in both cases. The infection percentages obtained 
by inoculating four varieties of rye with nematode galls at the time of 
seeding are given in Table II. 
Two varieties of emmer (Triticum dicoccum Schr.), Black Winter and 
White Winter, also were found to be extremely susceptible and were 
characterized by an unusually large number of leaf galls (PI. 1, B and C). 
The number of galls obtained upon threshing constituted over 25 per 
cent of the grain. 
Spelt {Triticum spelta L.), while more resistant than most of the varie¬ 
ties of wheat, rye, and emmer used in the experiment, nevertheless is to 
be classed as a susceptible host. It showed abundant symptoms of 
nematode injury in the seedling stage, and 6 per cent of the volume of 
the hand-threshed grain consisted of galls. The varieties grown were 
Alstroum, Bearded Winter, and Red Winter. 
The following varieties of oats were sown at the Arlington Experiment 
Farm in 1920 and galls sown with the seed : Aurora, Culberson, Fulghum, 
Red Rustproof, and Winter Turf. Red Rustproof was found to be 
slightly injured in the seedling stage (PI. 2, D and E), and in a few cases 
small galls formed while the heads were still in the boot, but up to 
the present time no galls have been found in the ripened grain. In order 
to determine whether the yield of spring oats can be reduced appreciably 
by the wheat nematode {Tylenchus tritici ), seed of two varieties was 
sown with an equal volume of galls at Madison, Wis., in April, 1922. 
An equal quantity of uninoculated seed was used as a control. Obser¬ 
vations were made at intervals during the growing period, and at 
maturity each row was threshed separately and the yield recorded 
(Table IX). In no case was there any perceptible difference in stand, 
vigor, or appearance between the inoculated oats and the control. 
Sparrow injury made exact yield data impossible, but such results as 
were obtained seemed to indicate that nematode injury did not affect 
the yield. 
The following five varieties of barley were used in infection experi¬ 
ments at the Arlington Experiment Farm (1919—1920) : Hansee Hull- 
less, Squarehead Winter, Tennessee Winter, Texas Winter, and Wis¬ 
consin Winter. Hansee Hull-less was the only one which showed any 
symptoms of nematode injury (PI. 3, A and B) although the others 
often were found to contain larvae between the leaf sheaths. Of 186 
ripe heads of Hansee Hull-less barley, only 3 contained galls (PI. 3 > 
These were small and shriveled, but contained larvae similar to those in 
galls from wheat. Wheat and barley, similarly inoculated, are shown in 
