Mar. 22, 1924 
Nematode Disease Caused by Tylenchus tritici 
933 
Table VII. —Comparative seedling injury and injection percentages and yields of Wis¬ 
consin spring rye grown on soil uninoculated and inoculated with galls in the fall and 
m the spring, respectively, at Madison, Wis., in IQ22 
Plat. 
Seedling 
Volume 
of 
yield. 
Reduc¬ 
tion in 
volume. 
Weight 
of 
yield. 
Reduc¬ 
tion in 
weight. 
Volume. 
injury. 
Kernels. 
Galls. 
Galls. 
Control uninoculated. 
Fall inoculated. 
Per cent. 
0 
2 
Cc. 
350 
1 CO 
Per cent. 
0 
Grams. 
262 
253 
172 
Per cent. 
0 
Cc. 
350 
348 
220 
Cc. 
0 
Per cent. 
0 
Trace. 
12 
Spring inoculated.... 
l 6 
250 
29 
3 
34 
2 
30 
Winter wheat and rye also were sown at Madison in the fall of 1920, 
and the soil was inoculated with galls at the time of sowing. The results 
were very similar to those obtained in the southeastern United States. 
The symptoms of the disease appeared in the fall, the organisms were 
found between the leaf sheaths of the plants throughout the winter, 
and at harvest time an abundance of galls was found in the heads. On 
account of injury caused by sparrows, complete data on the wheat were 
not obtained. The rye, however, was not injured by the birds and pro¬ 
duced the results shown in Table VIII. 
Table VIII .—Percentage of seedling injury, volume and weight of grain from inoculated 
and uninoculated plats of Wisconsin winter rye, volume and percentage by volume 
of galls, and percentage reduction in yield in the threshed grain from the inoculated 
plats at Madison, Wis., in IQ22 
Row. 
Seedling 
injury. 
Volume 
of total 
yield. 
Reduc¬ 
tion. 
Weight 
of total 
yield. 
Reduc¬ 
tion. 
Volume. 
Kernels. 
Galls. 
Galls. 
Uninoculated control. 
Per cent. 
Cc. 
560 
325 
320 
Per cent. 
/ 
Grams. 
407 
215 
202 
Per cent. 
Cc. 
560 
275 
250 
Cc. 
0 
30 
40 
Per cent. 
Inoculated. 
60 
60 
42 
43 
47 
50 
10 
14 
Inoculated. 
From these experiments we may conclude that the nematode disease 
could cause serious losses in the spring-wheat region if, unfortunately, it 
were introduced there. Gall-infested seed when sown in spring insures 
the presence of enormous numbers of active larvae which are not sub¬ 
jected in the free-living state to the unfavorable conditions obtaining in 
the winter and thus are able to bring about severe infection. 
HOSTS 
Considerable disagreement exists among investigators as to the host 
range of the wheat nematode, although all have secured abundant infec¬ 
tion in wheat. 
Roffredi {21, 22) states that he obtained infection in rye, barley, and 
spelt. 
Marcinowski (17, p. 67-11 7) tried to infect rye, spelt, barley, and oats. 
Galls were found in the first two only, although larvae in abundance 
were found between the leaf sheaths of all four. She states that the rye 
galls were small and that the larvae in them were not so far developed 
as those found in the galls in wheat. Spelt did not produce as many 
