388 THE CEREALS IN AMERICA 



come when the corn is tasseling. They cause the pollen to dry up, and the silk ts 

 not fertilized. Even with a sufficient rainfall, a few days of these withering blasts 

 from the southwest, in tasseling time, may reduce the yield of com fifty per cent- 

 Kafir corn is not affected in the same way. Fertilization takes place more readily 

 and the whole plaat is better adapted to stand dry weather. The leaves are tliicker 

 and coarser than corn leaves, and do not dry out so readily ; they are closer together 

 and partly protect each other, and the plant is not so tall and, therefore, not so 

 much exposed. WTien corn has once been stunted by drought or hot winds, it never 

 recovers. Not so with Kafir corn. It may remain stationary and curled for days 

 and even weeks, but when the hot winds cease and rain comes it will revive and, if 

 not too late in the season, will still produce a crop of grain."! 



It is necessary to distinguish between possible climatic range 

 and the economic climatic range of sorghum. While sorghum 

 can be grown in almost any climate in which maize can be 

 grown, its economic climatic range does not extend north of the 

 fortieth parallel 



545. Soil. — The soil requirements of sorghum are similar to 

 those of maize, although the Kafir varieties are believed to suc- 

 ceed on land too poor to raise the latter. The plant also seems 

 to be rather more resistant to alkali. For its best development, 

 broom corn requires rich soil. Ordinarily it would not be wise 

 to attempt to raise it on any but the best maize lands, although 

 river bottoms are usually not desirable on account of the weeds. 

 Dwarf broom corn succeeds best on dry, sandy soils, the brush 

 having a tendency to grow coarse on the richer soils. The 

 same principles apply in the use of fertilizers as in maize. 

 (285-294-) 



546. Rotation. — Ordinarily sorghum takes the same place in 

 the rotation as maize. It is a general experience that a crop fol- 

 lowing sorghum, particularly the Kafir varieties, is not so good 

 as one following maize. The reason for this appears to be that 

 the sorghum being more resistant to drouth continues to grow 

 and thus exhaust the soil of its moisture, and possibly its plant 

 food, when the maize would be prevented from doing so. The 

 land thus breaks up hard and lumpy after the sorghum. As 6 



1 U. S. DepL of Agr., Farmers' Bui. 37, p. 5. 



