THE SORGHUM PLANT 289 



humidity such as prevail in the Mississippi valley, and 

 sorghum preferring regions of dry air such as prevail in 

 the Great Plains region of the upper Missouri River 

 valley and southward. 



The above general difference may be due in part to 

 selection of varieties. Sorghum being of tropical origin 

 and widely distributed, certain varieties flourish in very 

 humid regions of Africa. Certain varieties of the sweet 

 sorghums grow well in the Carohnas and Gulf States, 

 where both rainfall and humidity are high. 



While certain sorghums do well under humid conditions, 

 the ability of all sorghums to remain more or less dormant 

 during periods of drought, and to renew growth with the 

 return of rain, has qualified the crop for adaptation to dry 

 climates. For centuries sorghums have been grown and 

 adapted to dry conditions in the Old World as they are 

 being further adapted in the United States. The result 

 is that the principal varieties of sorghum under cultivation 

 prefer a drier and warmer climate than is required by the 

 corn crop, although no doubt varieties of sorghum could 

 be found equally adapted to humid regions. The above 

 conclusion applies with more truth to the grain sorghums 

 (Kafirs and Durras) than to the sweet sorghums or broom- 

 corns. 



Soil requirements 



218. The sorghums are adapted to a wide range of soils, 

 but they prefer a medium-weight loam to very light or very 

 heavy soils. The grain sorghums are apparently more 

 sensitive in this respect than the sweet sorghums. Sor- 

 ghums for forage are often grown on poor land, not only 

 because they produce more forage than any other crop 

 under such conditions, but also because the stems are 

 finer than when grown on heavy land. 



