1 86 THE ESSENTIALS OF AGRICULTURE 



picking. The grower should study the characteristics of the 

 leading varieties, take up new ones cautiously, and try to keep 

 the adopted variety true to type and constantly improve it by 

 selection. 



The following are some of the points to keep in mind in 

 selection : short joints indicate a tendency to early maturity ; 

 bolls of five locks have more weight of seed cotton than bolls 

 of four locks ; locks that are liberated from the burs by exces- 

 sive opening are not resistant to storms, while some bolls may 

 not open sufficiently to make picking easy ; an intermediate 

 degree of storm resistance should be sought ; bolls that droop 

 on the stem are desirable ; earliness and long staple are to some 

 extent incompatible ; stalks with large bolls generally have fewer 

 bolls ; large seeds indicate a small percentage of lint ; resistance 

 to disease is more or less hereditary. 



235. Insect enemies. The insects most destructive to the 

 cotton crop are the boll weevil, the boll worm, and the cater- 

 pillar. Of these the boll weevil is the most destructive in the 

 territory now infested. (See Chapter XXVI, Insects on the 

 Farm.) The caterpillar eats the leaves of the cotton in the late 

 summer. Since the invasion of the boll weevil the caterpillar 

 often serves a good purpose in cutting off the food supply of 

 the weevil. Poisoning with Paris green serves well as a remedy 

 against the caterpillar. 



236. Diseases of cotton. The cotton plant is subject to attack 

 by a number of fungous and bacterial diseases that are some- 

 times quite destructive. Probably the worst fungous disease is 

 the cotton wilt. 



Anthracnose is a fungous disease that attacks both the bolls 

 and the stems, destroying the tissues and causing the infected 

 portion to rot. The disease is transmitted from one season to 

 another on the seeds of cotton. Seeds that are two years old 

 are free from the disease, since the fungus dies in that time. 

 Means of combating the disease, therefore, are either .to secure 

 clean seed from noninfected cotton or to plant seed that is 

 two years old. 



