992 BULLETIN 698, U. S. DEPARTMENT OF AGRICULTURE. 
tative period and covers the time elapsing between heading and 
ripening. 
The height of the plants is the average of measurements made at 
several, usually 10, points in the plats. 
The varieties are all harvested with a corn binder, leaving a stubble 
varying in height from 5 to about 8 inches (1 to 2 dm.), depending on 
the height of the standing plants. The bundles are shocked in the 
field and allowed to cure for four to six weeks before being thrashed. 
The shocks are then hauled to the scales and weighed. 
The heads are cut from the bundles by means of a large knife 
fastened to the edge of a box. Very dwarf strains are not headed, 
but are thrashed in the bundle unless the weight of the heads is 
desired. Since the stalks often are not of uniform height, the piece 
of the peduncle or stem left attached to the heads also varies in 
€ 
length. In general it averages about 10 to 12 inches (2.5 to 3 dm.) 
long. Where it is desired to determine the proportion of heads in 
the total crop, the heads are weighed before thrashing and the per- 
centage computed. 
Thrashing has been done with a small separator. The thrashed 
seed is weighed as it comes from the separator and the acre yield 
computed therefrom. 
The yields are based on 60 pounds to the bushel of kafir and 58 
pounds of all other varieties. After weighing, the thrashed seed is’ 
run through a fanning mill and the bushel weight then determined 
with the standard tester. 
ENVIRONING CONDITIONS. 
To aid in an understanding of the results optained during the 
9-year period from 1908 to 1916, inclusive, a brief summary of 
seasonal conditions is given and their effects on crop growth and 
production are noted. Figure 2 shows the annual and seasonal 
(April to September, inclusive) precipitation during the 10-year 
period from 1907 to 1916, inclusive. 
The season of 1908 was favorable to good yields. The precipita- 
tion in the last three months of 1907 was slightly above normal, but 
in the first three months of 1908 it was considerably below normal. 
This left little or no stored moisture at the end of March. However, 
the rainfall in April, May, and June was about normal and fully 
sufficient for plant growth. With arainfall of nearly 2 inches above 
normal in July and August, most of which fell in July, conditions 
were favorable for a heavy grain yield. Dwarf milo averaged over 
41 bushels and Blackhull kafir a little less than 34 bushels per acre. 
The season of 1909 was variable and unfavorable. It consisted of 
a dry spring and a dry summer with a wet June intervening. Pre- 
cipitation in the winter of 1908-9 was decidedly below normal. The 
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