8 COTTON CULTURE 



ture fiber. In making thread, these "twists" interlace 

 with one another, which action assists in the formation of 

 a strong thread from comparatively so weak a fiber as 

 cotton. The average length of an ordinary cotton fiber in 

 the United States is one and one-tenth inches. Sea- Inland 

 cotton has a much longer fiber. 



THE COTTON CLIMATE 



In the United States , the thirty-seventh parallel of 

 latitude seems to mark the limits of economical cotton 

 culture, though in many places the line curves below that 

 latitude. A line drawn from Old Point Comfort, Vir- 

 ginia, through Cairo, Illinois, would cover practically the 

 same limits. Cotton is a plant which thrives in a very 

 warm or even hot atmosphere, providing the latter is 

 moist, and that severe drying winds are not prevalent. 

 Conditions are regarded unfavorable to cotton culture 

 where the winter and spring temperatures are low, as the 

 growing season is then liable to be too short. The time 

 from the planting of the seed to the bursting of the first 

 boll averages 130 days. 



The first killing frost of autumn checks further growth 

 or development, and, according to its severity, destroys 

 the plant and all immature bolls. For economical culture, 

 the crop requires six or seven months of favorable grow- 

 ing weather. In the typical cotton climate, the mean 

 daily temperature increases from the time of seeding, 



