THE FIBER CEOPS 347 



limited by temperature, rainfall, and the character of the 

 soil. Cotton is extremely sensitive to temperature, 

 requiring for its best growth a long, hot growing season 

 without marked changes in the temperature. The 

 length of the growing season for cotton from the time it is 

 planted until the crop is harvested is approximately 6 to 

 7 months, during which time, for most favorable growth, 

 the mean daily temperature should increase until the 

 vegetative growth is made, after which time it should 

 decrease, which is favorable to the production of the fruit. 

 Cotton cannot be profitably grown in the northern part 

 of the United States because of the short growing season 

 and frequent changes of temperature. Cotton for its 

 best growth requires frequent rains during the period of 

 vegetative growth, and little or none during the fruiting 

 and harvesting season, although if too much rain falls 

 during the period of early growth, the plants quite fre- 

 quently grow large and rank without a corresponding 

 growth of fiber and seed. 



366. Probably no important crop can be grown with 

 favorable results on such a large variety of soils. In 

 the cotton belt it is grown on sandy clay, sandy loam, 

 limestone, and black alluvial soils, and with good cultural 

 methods profitable crops may be secured on any of them. 

 It grows best, however, on a clay or sandy loam soil, 

 rich bottom lands often producing an excess of stalk, while 

 sandy types are often too greatly lacking in fertility for 

 the production of a good crop. Sandy and other types 

 of poor soils may be made by proper fertilization to yield a 

 very profitable crop. So completely has the growing 

 of the cotton absorbed the attention of the grower that 

 little else has been grown. Within recent years, how- 

 ever, injury to the soil resulting from continuous cropping 



