PLANT DISEASES. 
63 
the present time the rust of wheat is probably attracting more 
attention in Australia than any other country. The whole colony 
is alarmed at the ravages of the rust pest, which it is estimated 
causes a loss of over 10,000,000 dollars annually. At a recent 
rust conference held in Sydney delegates were present from 
Victoria, South Australia, Queensland, and New South Wales. 
Some knowledge of what was done at this gathering may be gained 
when it is stated that it lasted five days, and that the report of its 
proceedings embodies over fifty thousand words. The delegates 
were a representative body of men, and the report shows them to 
be thoroughly conversant with nearly all known facts bearing upon 
this important subject. In this country rust has of late attracted 
no great amount of attention. This is not due to a diminution in 
the amount of damage it occasions, but is owing to the fact that the 
annual drain upon the farmer’s income, which it causes, has come 
to be regarded as a matter of course. Year after year the crop in 
nearly every field is cut short by rust, so that it is difficult to say 
just how much damage results simply because there are no figures 
for comparison. 
The average yield of wheat in the United States in 1891 was 
only 15’3 bushels per acre,* an amount insignificant when compared 
with some countries that do not have half the natural advantages. 
This abormally low yield is, of course, due to several causes, rust 
being one of them. By better methods of farming, such as the 
improvement of varieties, crop rotation, the prevention of rust and 
smut, proper use of plant foods, etc., the average yield could in all 
probability be raised to 20 bushels per acre at comparatively little 
additional expense. Such an increase would mean to our farmers 
more than 170,000,000 dollars annually. The rust problem, so 
far as it concerns the yield of grain, probably exerts as great an 
influence as any one thing over which there is a possibility of 
control. It is important, therefore, that all phases of the subject 
be fully investigated, as it is by this means only that proper con- 
clusions in regard to prevention can be reached. 
Plan of the Work. 
In planning the work on rust it seemed desirable at first to limit 
the investigations to two lines of research. These may be briefly 
summarized as follows : — 
(1.) Experiments in spraying with various chemicals and in 
treating the soil and seed in various ways in the hope of prevent- 
ing the disease. 
(2.) Comparative studies of several so-called rust-resisting and 
non-rust-resisting varieties, to determine whether they possess 
more or less constant anatomical or physiological characteristics 
which may explain susceptibility or non-susceptibility to the 
disease. 
This paper, as the title indicates, will deal with the first problem, 
i.e., experiments in spraying and in soil and seed treatments to 
* “ Report U.S. Department of Agriculture,” 1891, p. 29. 
