COTTON 



111 



Anthracnose of the Boll. 1 This disease is due to the 

 fungus Glomerella gossypii (Fig. 49), which has been 

 previously mentioned. It attacks various parts of the 

 plant throughout its entire life, from seedling to 

 maturity. When it attacks the bolls, they usually 

 lose their green colour, and frequently become a dull 

 red or bronze. In case the boll is near maturity it may 





r 



FIG. 49. Cotton balls affected with anthracnose. (Photo by C. W. Edgerton.) 



be able to complete its growth, ripen and open in the 

 normal manner without much injury. However, if the 

 fungus attacks the boll early it causes a premature 

 dying of the diseased parts of the carpels, and therefore 

 an unequal growth which causes them to crack open 

 and expose the immature lint to the weather. Of 

 course this immature lint is a poor grade, and the 

 greater part of it decays. In case it is sufficiently 



1 Syn. Collctotriclmm gossypii, South worth. This fungus is well known in 

 the United States, and has been reported from South Africa. 



