30 BULLETIN" 1284, IT. S. DEPARTMENT OF AGRICULTURE 
The durras now grown in the United States constitute a group of 
the grain sorghums closely related to feterita and the milos. They 
are characterized by slender to midstout dry, pithy sterns. The 
panicles are short, broadly ovate or oval, and compact. The glumes 
are greenish white, densely pubescent, and not transversely wrinkled. 
The seeds are very much flattened. 
Two varieties of durra are grown in the United States — White 
durra, with white seeds and awned lemmas, and Brown durra, with 
brown seeds and awnless lemmas. White durra was introduced into 
California about 1874, where it is commonly known as White Egyp- 
tian corn. A few years later this durra was grown to some extent in 
the southern Great Plains States under the name of Jerusalem corn. 
Brown durra has frequently been known as Brown Egyptian corn, 
but it has never been agronomically important. Data from the 
infection experiments with the durras are presented in Table 6. 
Two strains of Brown durra were grown at Columbia. One strain 
(Missouri No. 30), grown during three years, showed an average 
infection of 45 per cent. A second strain (Missouri No. 74), grown 
in 1918, gave negative results, but the same strain showed 10 per 
cent infection at Rosslyn and 50 per cent at Brooklyn. Brown durra 
(C. I. No. 183) was grown four years at Manhattan and Amarillo, 
the average at Manhattan being 12 percent and at Amarillo 15.5 per 
cent. Brown durra (C. I. No. 246) was also grown four years at both 
Manhattan and Amarillo, the average infection being 32.8 per cent and 
35.5 per cent, respectively. Brown durra (S. P. I. No. 17537) was 
grown four years at Manhattan and Amarillo, with an average infection 
at the former station of 11 per cent and of 11.3 per cent at the latter. 
Three strains of White durra were grown at Columbia. Negative 
results were obtained on one of them in 1915, while another showed 
8.6 per cent infection. The third had a 3-year average infection 
of 22.4 per cent. White durra (C. I. No. 81) was grown for five 
years at Manhattan with an average infection of 16.8 per cent and 
for four years at Amarillo with an average infection of 19 per cent. 
It also was grown at Rosslyn, where it showed 22.2 per cent infec- 
tion, and at Brooklyn with 82.8 per cent infection. Another strain 
(Missouri No. 200) at Brooklyn showed 41.9 per cent infection. 
In addition to these strains of the common Brown and White 
durras a number of other strains of White durra were grown at Man- 
hattan and Amarillo. 
White durra (S. P. I. No. 14518) received from the Bombay Presi- 
dency; India, showed 9.5 per cent infection at Amarillo during three 
seasons and no infection at Manhattan in two seasons. This is a 
very tall strain which appears to have little agronomic value. 
Another White durra (S. P. I. No. 14628) received from the Bom- 
bay Presidency has proved to be practically free from kernel smut, 
only one plant in 688 having been found to be infected at Amarillo 
during three seasons and has produced no smut in 369 plants at Man- 
hattan in three seasons. This strain seems to have no special agro- 
nomic value. 
On the other hand, White durra (S. P. I. No. 17535) from India 
has proved quite susceptible to the kernel smut. It was grown for 
four years at both Manhattan and Amarillo. At Manhattan 21.3 
per cent of the plants were infected and at Amarillo 18.3 per cent. 
