166 COTTON 



ingly, or grown under some plan involving a con- 

 stant change of crops in which cotton appears only 

 once in four or five years, there would be consider- 

 ably less trouble from disease; for it is only in those 

 cases where a disease gains a foothold that it causes 

 appreciable loss to the cotton farm, and to gain 

 such a foothold permanently cotton must be 

 grown on the same land in fairly quick succession. 



The same principle of disease as it applies to the 

 cotton plant, or in fact to any plant, applies also 

 in animal life. Texas fever, for instance, affects 

 cattle only where they graze upon the same land 

 year after year and thus give the tick time to put 

 a new generation through the full cycle of changes 

 each season. But if, on the other hand, cattle are 

 withdrawn from the affected territory, and kept 

 from it a year or two, the tick disappears as soon as 

 the process involved in the completion of its life- 

 history is disturbed, and it perishes, leaving the land 

 entirely free from that time on. Perhaps there 

 would be no eradication of the disease were the 

 lands continually grazed without any period of 

 intermission. 



It is so with our cotton diseases where the crop 

 is grown continually, as cotton usually is. There 

 is no disturbance of the life process involved in the 

 disease and so it comes on year after year, com- 

 pleting its full cycle of development. 



The treatment of disease in general then should 

 involve preventive methods rather than specific; a 

 wise system of farming that will improve the land 

 and make it stronger this will mean interference 

 in the development of the disease; this will lessen 

 its ability to do harm, until it perishes altogether 

 for want of necessary surroundings and satisfac- 

 tory environments. 



