6 BULLETIN 1347, U. S. DEPARTMENT OF AGRICULTURE 
to seasonal conditions the severity of the disease has increased or 
decreased from one season to another. It has been found, however, 
that where wheat follows wheat repeatedly on infested land, the 
take-ail spots increase in size slowly but steadily, and newly in- 
fested areas become evident. 
In Australia McAlpine (42) states that take-all is more dreaded by 
farmers than rust, and Brittlebank (//) says: “ Of all fungous dis- 
eases affecting wheat ‘take-all’ is the most destructive, and the ac- 
tual loss caused by it is far greater than by any other single dis- 
ease, rust included, or perhaps by a combination of all known fun- 
gous diseases affecting wheat in Victoria.” Darnell-Smith (/6, pp. 
25-27) states that i New South Wales take-all reduces the wheat 
yield as much as 50 per cent in the affected fields. According to E. 
Foéx’ take-all is of considerable economic importance in France, 
and it was especially severe in 1912, 1913, and 1914. Hori (37) 
states that take-all appeared in Japan about 1891, extending its 
range from year to year. In 1901 the disease had spread widely 
from Kanto, the original center of infestation, and in many lo-. 
calities had become a limiting factor in successful barley and wheat 
production. 
Many other accounts could be cited regarding the importance of 
take-all abroad, but the ones given will suffice. In this country the 
strictly economic importance of the disease from the national point 
of view is potential. Apparently Ophiobolus graminis has not oc- 
curred in the United States long enough to cause such large losses 
as it does in foreign countries. However, it apparently is a subtle 
type of parasite which when once established probably can not be 
totally eradicated. It may increase steadily and eventually cause 
as great losses in this country as it does abroad if adequate control 
measures are not developed. 
DESCRIPTION OF THE DISEASE 
In describing the symptoms manifested by the foot-rots, the 
writer wishes to emphasize that under certain conditions some of 
these diseases are difficult to distinguish from each other. This is 
especially true in certain cases regarding general field appearances, 
such as spotting, and it is becoming more evident as our studies pro- 
gress that gross plant symptoms, such as stunting, yellowing, bronz- 
ing, bleaching, and white-heads, are of much less value as diagnostic 
characters of the specific foot-rots than has been thought heretofore. 
The fungus causing the take-all disease attacks all of the under- 
ground parts of the plant and parts near the soil line, but there is no 
evidence which indicates that Ophiobolus graminis attacks the leaves, 
heads, or parts of the stem which are some distance above the soil 
line. The symptoms manifested by these parts of diseased plants 
appear to be brought about wholly as a result of the destruction of 
the root system and basal portion of the affected plants. 
FIELD APPEARANCE 
The writer has never noted any conspicuous indication of take-all 
during the fall in fields of winter wheat. Occasionally a plant will 
7 While on a visit to this country in 1920 Doctor Foéx very kindly gave the writer 
considerable information concerning the occurrence to foot-rots in France. 
