64 BULLETIN 1175, U. S. DEPARTMENT OF AGRICULTURE. 
44-inch rows has averaged but 1.2 bushels per acre annually for the 
5-year period, while the extreme difference in yield between the 
various plant spacings in 88-inch rows has been only 1.6 bushels. 
SUMMARY. 
Cooperative experiments with gram sorghums have been conducted 
at the Woodward Field Station since 1914. Results obtained during 
the 8-year period from 1914 to 1921. inclusive, are reported in this 
bulletin. 
The average annual precipitation at Woodward, Okla.. is approxi- 
mately 24 inches. During the 8-year period under consideration the 
extremes in annual rainfall were 13.68 inches in 1914 and 35.78 
inches in 1915. On the average. 70 per cent of the annual precipita- 
tion occurs during the six months from April to September, inclusive. 
This distribution of rainfall is favorable for the production of annual 
summer-growing crops, such as the sorghums. 
Low yields of sorghums are due to periods of drought in July and 
August rather than to an annual or seasonal deficiency of rainfall. 
Varietal experiments with representative varieties of grain sorghums 
have been conducted during the eight year-. Results for this full 
period are reported for 15 varieties or selections of gram sorghums. 
A number of other varieties have been grown for shorter periods. 
Five varieties or strains of the durra-milo group have been grown 
during the 8-year period. The average acre yields of these strains 
are: Standard Yellow milo. 22.8 bushels: Standard White milo, 19.7 
bushels; two selections of Dwarf Yellow milo (C. I. Xos. 332 and 
359), 21.2 and 21.8 bushels, respectively: and feterita. 21.6 bushels. 
Though the Standard Yellow milo produced an average of 1.6 bushels 
and 1 bushel per acre more than the two Dwarf Yellow milos, the 
latter are to be preferred for grain production, as their shorter stalks 
permit easier and more economical harvesting. 
Of the kafir group, six varieties or strains have been continued 
during the entire eight years. These varieties, with their 8-year 
average vields, are: Blackhull kafir. 16.8 bushels; Dawn kafir, 23.8 
bushels; Sunrise kafir. 26.3 bushels: White kafir (€. I. Xo. 370), 17.5 
bushels; White African kafir. 19.9 bushels; and Red kafir, 20.8 
bushels. Sunrise is a midearlv. tall, blackhulled kafir, and in the 
varietal experiments has produced higher average yields of grain and 
total crop than any other variety. In grain yield Dawn kafir ranks 
second to Sunrise. 
Three varieties of kaoliang have been grown during the eight years. 
Their average grain yields are: Blackhull. 18.7 bushels: Manchu, 
13.4 bushels; and Valley. 15.9 bushels. The Blackhull kaoliang is the 
only grain sorghum tested in these experiments that has yielded 
more than 10 bushels of grain in each of the eight years. 
Shallu during the eight years has averaged 15.4 bushels of grain 
to the acre. 
Darso, Schrock sorghum, and Dwarf hegari have been grown in 
the varietal experiments for less than eight years. 
In the varietal experiments, which have been seeded as near the 
middle of May as conditions permitted. Sunrise and Dawn kafirs have 
produced the highest yields of grain. 
