22 BULLETIN 981, t T . S. DEPARTMENT OF AGRICULTURE. 



one cutting under such conditions, and in favorable seasons two, yielding 1 to 3 tons 

 of hay to the 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. It is 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, i. 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 



