2, BULLETIN 734, U. S. DEPARTMENT OF AGRICULTURE. 
smut, live insects, and odors. The list of foreign material other than 
dockage now is quite large, and any further addition must be viewed 
with some concern on the part of the merchant or miller. 
A comparatively new source of foreign material not previously en- 
countered in marketed wheat has lately come to the attention of the 
Department of Agriculture; this, if not controlled, will figure con- 
spicuously both as dockage and foreign material other than dockage 
in grain. This isa black, misshapen gall resulting from the infection 
of wheat heads by the nematode 7 ylenchus tritici (Steinbuch) Bastian. 
This foreign material, as far as known, has not been recognized by 
grain inspectors in the commercial grading of wheat. Investiga- 
tions up to the present time indicate that the disease has a rather 
limited distribution and there is as yet little evidence to indicate 
whether it will prove to be a serious factor in wheat growing in other 
parts of the country. 
On account of the number of places where this disease seems to be 
established, it was thought necessary to bring the disease to the atten- 
tion of merchants, millers, and wheat growers in order that they 
might easily recognize it, have some knowledge of its present dis- 
tribution, its importance as a factor in affecting market grades and 
milling quality; also to give some information concerning its control 
in order that it may be eliminated efficiently and quickly as a serious 
pest in wheat. : 
PREVIOUS OCCURRENCE OF THE DISEASE. 
This disease has been known as a serious pest in Europe since 
1745. Has been found in Australia, Austria-Hungary, Ger- 
many, Holland, Sweden, Switzerland, and very recently in China. 
Previous citations as to its occurrence in this country are few. 
Bessey + has noted related forms in various grasses, but did not ob- 
serve any form attacking wheat. Johnson? seems to have first noted 
its distribution in this country, having found it near Modesto, Cal., 
in May, 1909. He also reported finding it established in the States 
of West Virginia, New York, and Georgia. Byars? and Fromme* 
have reported it from China and Virginia, respectively. 
PRESENT DISTRIBUTION. 
The importance of this disease as a factor in the marketing and 
milling of wheat first came to the attention of the Bureau of Mar- 
kets by a request for identification as a troublesome foreign material 
1 Bessey, Ernst, A. A nematode disease of grasses. Science N. S. 21, 391, 1905. 
2 Johnson, Edward C. Notes on a nematode disease in wheat. Science N. S. 30, 576, 
1909. 
3 Byars, L. P. Tylenchus tritici on wheat. Phytopathology, vol. VII, 56-57, Feb., 191T. 
*Fromme, F. D. Tylenchus tritici on wheat in Virginia. Phytopathology, vol. VII, 
452-453, Dec., 1917. : 
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