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ing. The consequent weakening of the vital forces of the 

 plant, the stoppage of growth, and the partial ripening of the 

 leaves left them in a state unable to resist the attacks of the 

 various species of fungi connected with this disease that de- 

 veloped rapidly during a period of warm rains early in 

 August. 



The fence row land on the other hand had for years been 

 allowed to grow up in weeds and bushes that had shaded it 

 and caught the wash from the cultivated portions. It was 

 black with humus formed from the annual decay of the weeds, 

 leaves and grass. In other words, its fertility had been con- 

 served and built up while that of the cultivated portion had 

 been wasted. As a consequence its chemical and mechanical 

 composition, in other words its tilth, was such as to retain 

 sufficient moisture and furnish appropriate food to keep the 

 cotton plant in a constant condition of vigorous growth and 

 thus to enable it to repel its fungous foes. 



This observation repeated again and again by the road- 

 sides was more convincing than any single experiment could 

 have been, no matter how carefully planned or elaborate. It 

 seemed to teach the plain lesson that to prevent Cotton Rust 

 it was first necessary to restore the lost fertility of our worn 

 out lands, not only by supplying lacking chemical elements 

 like potash, but above all by supplying the needed vegetable 

 matter for the formation of an abundant supply of humus, so 

 necessary for preserving a uniform water supply. 



In order to test this view more fully and to bring the 

 matter somewhat widely to the attention of representative 

 farmers, a simple co-operative experiment was planned, and 

 the following circular letter was sent to numerous addresses 

 in this and other of the cotton States : 



Auburn, Ala., Dec. 29, 1897. 

 " Dear Sir — The loss caused by Cotton Rust in many parts 

 of the State during the past season serves to forcibly call at- 

 tention to the need for further study of this obscure disease. 

 The rust referred to is the one that has been variously called 

 " Black Rust," « Yellow Leaf Blight," and « Mosaic Disease" 

 in the publications of this Station. The exact symptoms vary 



