22 BULLETIN 981, U. S. DEPARTMENT OF AGRICULTURE. 
one cutting under such conditions, and in favorable seasons two, yielding 1 to 3 tons 
of hay tothe acre. Its chief competitors in this region are alfalfa, sorghum, and millet. 
Alfalfa is preferred to Sudan grass only in the more favored locations, such as river and 
creek valleys or where irrigation is possible. The better varieties of sorghum, such 
as Red Amber and Orange, will outyield Sudan grass, but the latter is better suited 
for pasture purposes, produces a better quality of hay, and is easier to handle with 
haying machinery. Seed production, though possible in most of this region, is 
profitable only in the southern part. 
Region 4.—Sudan grass yields abundantly both in hay and in seed in all irrigated 
localities in this region; yields of 4 tons of hay to the acre are not uncommon on good 
soils. Itis used chiefly to supplement alfalfa in the rations of horses and dairy cattle, 
as a pure alfalfa hay ration seems to result in digestive disturbances, especially in 
dairy cows. 
Region 5.—In this part of the United States Sudan grass is successful only in limited 
areas. Its failure except in these localities is due either to low temperatures caused 
by high altitudes or to insufficient rainfall. 
Region 6.—In this region, including Florida and the Coastal Plain along both 
the Atlantic and Gulf coasts, Sudan grass is usually a failure, largely on account of 
the injury to the foliage caused by red-spot, or sorghum blight. 
Region 7.—This is a region 100 to 200 miles wide along the northern border of the 
United States. Sudan grass is not profitable here, because of the cool summers and 
the short growing season. 
The Office of Forage-Crop Investigations of the Bureau of Plant 
Industry, United States Department of Agriculture, sent seed to 
numerous State agricultural experiment stations in 1912 and succeed- 
ing years. In 1914 the Office of Congressional Seed Distribution 
sent out 1-pound packets of Sudan grass seed to 2,800 farmers, in 
1915 to 75,751, and in 1916 to 97,392. Reports as to the success of 
Sudan grass and its probable value, as compared with other forage 
crops, were called for from several thousand of these farmers in 
1915 and 1916. Their answers have been examined and their 
opinion of the crop, expressed in the percentage of favorable reports 
for each section of the United States, is shown on the map, figure 14, 
which indicates in more detail than figure 13, the relation of Sudan 
grass to climatic factors. 
This map (fig. 14) is based upon Weather Bureau Bulletin W 
and shows for each section of the United States (1) the average 
length of the growing season, 1. e., the time elapsing between the 
last killing frost in spring and the first killing frost in the fall; (2) 
the mean temperature for the growing season; (3) the normal rainfall 
for the entire year; and (4) the adaptation of Sudan grass to these 
conditions, as shown by the percentage of favorable reports from 
farmers who received seed through the Office of Congressional Seed 
Distribution. 
The rather complete agreement between this map and the outline 
map, which was prepared largely from reports secured through State 
agricultural experiment stations, is worthy of note. There are 
several slight inconsistencies in the results, but on the whole the 
