14 BULLETIN 1284, U. S. DEPARTMENT OF AGRICULTURE 
In many cases the number of plants was very much less than this, 
poor germination having resulted in thin stands. The plants, when 
necessary, were thinned so as to be approximately 4 to 6 inches apart. 
The investigations at Manhattan, Kans., and Amarillo, Tex., were 
begun in 1916. Potter and Melchers {92) reported briefly on the 
results of their experiments during 1916 and 1917 at these two stations. 
They state that milo and f eterita, a few durras, and a dwarf kaoliang 8 
proved highly resistant. Other varieties of durra, the kafirs, broom- 
corns, and sorgos were found to be generally susceptible. The varie- 
ties of kaoliang showed a moderate degree of resistance. Melchers 
(74) made a further brief report on this work. 
The seed used at Manhattan and Amarillo was obtained from the 
Office of Cereal Investigations and from Prof. John H. Parker, of 
the department of agronomy of the Kansas Agricultural Experiment 
Station, and consisted of lots bearing Cereal Investigations, Seed and 
Plant Introduction, and Kansas agronomy department numbers. In 
so far as possible, several heads of each variety were bagged each sea- 
son, and the seed from these was used the following year. 
The smut for inoculation was collected in the autumn and kept in a 
dry, cool place. Later it was ground and sifted through a fine screen 
so as to exclude all grain. Germination tests of the spores were made 
in order to be certain of their viability. The seed to be inoculated 
was placed in a small box and sufficient smut was added to give the 
seed a noticeable brown color after shaking. The seed then was 
sown l 1 ^ inches deep in rows 30 inches apart. The plants were 
thinned to one every 8 to 10 inches in the row. 
INOCULATION EXPERIMENTS WITH COVERED KERNEL SMUT 
The percentages of infection obtained in the inoculation experi- 
ments with covered kernel smut (SpJiacelotheca sorghi (Link) Clinton) 
are shown in Tables 1 to 7. These tables also include the varietal 
name and seed number of each strain and the station and year each 
was grown. If a strain was grown two oi more years the average 
percentage of infection, based on the total number of plants grown 
and total number infected, also is shown. 
RESULTS WITH SHALLU 
Shallu {102) belongs to a group of sorghums commonjy grown in 
some parts of India and central East Africa. The so-called rabi jowar, 
or winter sorghum, of India, which is sown in September and October 
and harvested in February and March, consists very largely of differ- 
ent strains of shallu. The crop is grown during the period of least 
rainfall, and smut seems to be less prevalent in it than in the kharif 
varieties which are grown during the summer season and spoken of 
as the monsoon crop. The kharif varieties are very largely durras. 
Shallu was imported from India about 1890 by officials of the 
Louisiana Agricultural Experiment Station. It was grown for several 
years under the name ''Egyptian wheat" and then discarded only to 
8 This so-called dwarf kaoliang, C. I. No. 293 and S. P. I. 22010, is different from the rest of the kaoliang 
group, according to C. R. Ball, and probably represents either a selection or a hybrid from one of the 
near durras from India. 
