282 



In Central Alabama, especially in the more sandy soils, 

 the disease commonly known as Rust often causes serious in- 

 jury to the cotton crop. This disease causes the spotting and 

 finally the premature falling of the leaves, thus bringing 

 the growing season to an end in August or early September 

 instead of in November. As a result the number of bolls that 

 mature is greatly reduced, and the fibre in those that do open 

 is often light and inferior. 



The name Rust is evidently a misnomer for this disease, 

 sinc3 it has nothing in common with the true rusts like those 

 that attack small grain. It is, however, thoroughly established 

 in popular usage, and that, after all, should be the guide in 

 selecting popular names for plant diseases. It is true that 

 other diseases are sometimes confused with this one under 

 the name of Cotton Rust ; but nineteen out of twenty cotton 

 growers have this disease in mind when they use this name. 



This disease has been fully discussed by Dr. Atkinson in 

 Bulletins 27, 36 and 41 of this Station, and later in the com- 

 prehensive work on the Cotton Plant, issued by the United 

 States Department of Agriculture as Bulletin 33 of the Office 

 of Experiment Stations. In these publications it has been 

 variously called " Rust," " Black Rust," "Yellow Leaf Blight," 

 and " Mosaic Disease." The simple term Rust is retained 

 here as being the one in general popular use. 



The officers of this Station have continued the study of 

 this disease and it seems opportune to record our more recent 

 experience with it in view of the heavy losses occasioned by 

 it during the past two years, and especially to call attention to 

 it in connection with the present serious crisis that confronts 

 our cotton industry. 



The following quotation is from Dr. Atkinson's article on 

 Cotton Diseases in Bulletin 33, pages 279-283, of the Office of 

 Experiment Stations, referred to above. 



It is reproduced here as expressing his latest published 

 views of this disease, and because the earlier bulletins of this 

 Station are now largely out of print. 



Mosaic Disease, or Yellow Leaf Blight. 

 " The later stages of this disease probably form the larger 

 part of the troubles which are termed " black rust." The name 



