20 BULLETIN 1281, U. S. DEPARTMENT OF AGRICULTURE 
The Orange group of sorgos has proved extremely susceptible to 
the kernel smut. Seventeen varieties and strains have been grown, 
and usually very high percentages of infection have been obtained. 
This is notably the case with one strain at Columbia and with prac- 
tically all the strains grown at Brooklyn. Certain strains grown at 
Columbia in 1918 usually gave negative results, but the same strains 
at Rosslyn and Brooklyn later proved to be very susceptible. Rela- 
tively high percentages of infection were obtained with the strains 
grown at Amarillo and Manhattan. 
A fourth group of sorgos includes the Sumac sorgo, also one ot 
Wray's original varieties. It is sometimes called Redtop, Redtop 
African, Redhead, Red Liberian, or Red Imphee. It has remained 
true to type, while many of the other African varieties proved to 
be exceedingly variable. 
Five strains of Sumac sorgo were used in the experiments. One 
strain of Dwarf Ashburn, a form similar to Sumac but with a shorter 
stalk, also was grown. Relatively high percentages of infection were- 
qbtained on nearly all strains grown at Columbia and Rosslyn, and 
especially at Brooklyn. Sumac must be classed among the more 
susceptible varieties of sorgo. 
Other varieties which do not belong to any of these groups are 
Denton, Gooseneck, Honey, White African, and two importations 
from Java. One strain of Gooseneck showed no infection on a 
limited number of plants at Columbia in 1918 and Rosslyn in 1920, 
and another strain showed no infection at Brooklyn in 1921, although 
heavily infected at Manhattan that year. With the exception of one 
strain at Columbia in 1917, Honey sorgo has shown little or no 
infection. The two varieties from Java and the White African have 
been heavily infected in every case. 
Sudan grass has proved somewhat susceptible to the covered kernel 
smut. Three lots were grown at Columbia ; two of them gave slightly 
less than 10 per cent infection and the third gave negative results. The 
latter, however, was grown only during the season of 1918. At 
Amarillo, Tex., two lots were grown, and only three heads were 
smutted. At Manhattan, Kans., two lots were grown, and 18 out 
of 852 heads were infected. These results are based upon head 
counts rather than upon plant counts. 
RESULTS WITH BROOMCORN 
• Three distinct varieties of broomcorn are grown in the United 
States, the principal differences being in the height of the plant, 
in the tenacity of the attachment of the peduncle to the upper node, 
and in the length and texture of the brush. One of these varieties, 
best known as Standard broomcorn, is grown under various names, 
such as Australian, California Golden, Chinese Evergreen, Early 
Longbrush Evergreen, Evergreen, Imperial Evergreen, Improved 
Evergreen, Missouri Evergreen, Tennessee Evergreen, and Wisconsin 
Evergreen. During the early period of broomcorn culture in the 
United States the Standard variety was the one grown. In recent 
years, as the center of production has been moved westward the 
Standard variety has boon replaced largely by the dwarf broomcorns. 
There are two varieties ol dwarf broomcorn. Acme broomcorn, 
sometimes known as Dwarf Standard, was developed recently from a 
