Sudan Grass. 5
CLIMATIC REQUIREMENTS.
Sudan grass, like sorghums, does best in a warm climate. In favor- able seasons, where the growing period is long, as many as four cut- tings can be obtained in one year. As in the case of all other crops, in determining the regions of greatest importance, climatic and soil conditions are linked with the acuteness of the need for such a crop. The principal regions of production in the United States are shown on the map (Fig. 3), as follows:
Region i.—Two or three good cuttings of hay are secured without irrigation in this region, the yields varying from 2 to 4 tons to the acre. This is the region of its greatest importance because of the need for a better hay grass in these States. Profitable seed yields are secured west of the ninety-eighth meridian only, the sorghum midge usually preventing seed formation in the more humid district east of this meridian.
Region 2.—Sudan grass thrives here almost as well as in region 1, making good yields both of hay and of seed. Timothy, clover, and alfalfa, however, meet the hay requirements of this region so fully that Sudan grass is valued chiefly as a pasture and catch crop or for limited culture on soils not suited to these forage crops.
Region 3.—This comprises the region west of region 2, where the rainfall is too low for the successful cultivation of timothy and clover. Sudan grass commonly makes 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 irri- gated 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 di- gestive 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 short growing season.
Since its introduction in 1909 Sudan grass has become known in nearly every part of the United States, and is now being gro^n where it was at first thought to» be wholly unadapted. Its short
growing period permits it to thrive and make good crops of hay as far north as southern Michigan and New York. Throughout the