Nov. io, 1923 Varietal Resistance in Wheat to Rosette Disease 
269 
apparently has all of the good qualities of the Harvest Queen variety, 
which has always been looked upon with favor by farmers, especially 
in the Granite City area. Harvest Queen is awnless, is a good yielder, 
stands the winter well, has a tall, strong straw, and produces a good, 
marketable quality of grain, of the soft red winter class. This resistant 
selection has shown 100 per cent freedom from the rosette disease when 
resown on badly infested soil in each of the three years since the original 
mass selection was made. Heads taken from this selection in 1922 are 
being grown in head rows in connection with flag smut experiments. 
It is hoped that a highly desirable strain, resistant to both diseases, 
may be obtained in this way. 
In the list of varieties that have shown no infection are many of the 
important wheats of the United States. Five important classes, hard 
red spring, hard red winter, soft red winter, common white, and club, are 
represented. These five classes comprise more than 90 per cent of the 
wheat grown in the country, the two classes, hard red winter and soft 
red winter, being of nearly equal importance and making up more than 
60 per cent of the annual acreage of the wheat crop. The resistant 
varieties listed in Table II are those used for sowing about one-eighth of 
the hard red spring wheat acreage, nearly all of the hard red winter 
wheat acreage, by far the larger part of the soft red winter wheat acreage, 
about a third of the common white wheat acreage, and about one-fifth 
of the club wheat acreage. 
The only widely grown variety that has been found to be highly sus¬ 
ceptible is the Harvest Queen. Several other important wheats have 
shown a slight percentage or a trace of infection (Table I), but in some 
cases the strain showing infection represents only a selection developed 
in connection with wheat breeding, and not the commercial variety. 
CONTROL OF ROSETTE 
The rosette disease has been controlled in the localities where 
it has been found by the use of varieties that are immune from the 
disease. In the Illinois area near Granite City, the Harvest Queen 
variety (known locally as Salzer’s Prizetaker) was the principal one being 
grown when the disease was discovered in 1919. This variety is very 
susceptible to the disease. Conditions, therefore, were very favorable 
for the appearance of the disease, and it was widely distributed in 
this area in the year of discovery. Losses were heavy that year in the 
fields most severely infected. In later years Red Wave, which appears 
among the immune varieties, was largely substituted for the Harvest 
Queen variety. Fultz, many strains of which are immune or highly 
resistant, also was used to some extent. In addition to these soft red 
winter varieties, a number of hard red winter wheats of the Turkey type, 
such as Illinois 10-110 and Kanred, have been sown. These hard wheats 
also are immune. 
On account of the large number of varieties immune to the rosette dis¬ 
ease it is not difficult to control it in farm practice. However, the pres¬ 
ence of flag smut in southern Illinois in the same locality with rosette is 
a complicating factor. As shown by Tisdale, Dungan, and Leighty 8 
there are several varieties that are immune or highly resistant to flag 
smut, but not so many as are resistant to rosette. The varieties resistant 
to both diseases are still fewer in number. 
8 Tisdale, W. H., Dungan, G. H., and Leighty, C. E. op cit. 
