14 BULLETIN 1347, U. §. DEPARTMENT OF AGRICULTURE 
reports of foreign workers and from observations made in this coun- 
try that there are other factors which exert greater influence on the 
development of the disease than these. Hori (37) states that the 
disease seems to be more prevalent in Japan on clay, clay loam, and 
gritty clay land, and he has found the disease less prevalent on sandy 
soil. McAlpine (4/7) and Sutton (68) in Australia find that the 
disease occurs on all kinds of soils and in all locations. It is stated 
also that take-ail is serious on the best soils. In this country take- 
all is not restricted to any particular soil type or to soils showing 
any particular degree of fertility. The writer has observed fields in 
Kansas, Oregon, and New York where the disease occurred on the 
best of soil. However, in other localities, as in Knox County, Ind.., 
and in Arkansas, the disease appeared on soils poor in texture and 
fertility. Rosen and Elhott (67) reported that take-all was as- 
sociated primarily with poor infertile soils. -This is true for the 
known locations of take-all in Arkansas, but more extensive ob- 
servations in other parts of the country show distinctly that this 
correlation does not always exist. 
The effects of fertilizers and amendments and tillage methods on 
take-all will be considered later in connection with control measures. 
CONTROL OF TAKE-ALL 
It has been pointed out elsewhere in this bulletin that there is no 
evidence that Ophiobolus graminis infects the heads or seed of plants, 
and therefore seed-treatment methods have little bearing on the 
control of take-all. However, as bits of straw bearing the perithecia 
and mycelium of the fungus may get into the grain at threshing time, 
care must be exercised in connection with the use of seed from fields 
infested with take-all. Such seed should be very thoroughly cleaned 
before sowing, in order to prevent the introduction of the fungus 
into the soil through the seed, or, better still, avoided entirely. 
Take-all is caused by a soil-borne parasite; hence the problem of 
its control becomes immediately centered on the soil and on cropping 
methods. As in the case of observations dealing with the influence 
of seasonal conditions on the development of the disease, many 
of the control measures which have been recommended have had to 
do with more than one foot-rot or with a foot-rot of uncertain 
cause. In most cases field experiments dealing with soil treat- 
ments and cropping and tillage systems have been carried out in 
plats which were not uniformly infested with the parasite, and in 
other cases the experiments have not been conducted over sufficiently 
long periods to enable the drawing of reliable conclusions. The 
writer’s experience with take-all in this country indicates that it is 
rather difficult to find uniformly infested areas which are sufficiently 
large for plat treatment and cropping experiments, and no doubt 
foreign workers have encountered the same difficulty. This con- 
dition makes it necessary to use relatively small plats of uniformly 
infested soil in conjunction with larger field plats, and in addition it 
is essential that experiments be carried on over a period of years 
before arriving at definite conclusions. 
The control influence of various fertilizers has been studied by 
several workers, but there is not full agreement as to the influence 
of these treatments on the disease. Reuther (60) claims that ex- 
cessive nitrogen favors take-all and other foot-rots, but he thinks 
