favorable and dry weather unfavorable, to the disease, weather con- 

 ditions such as heat or cold have never been known to exterminate the 

 fungus. 



"As the fungus causing the black root disease of cotton only attacks 

 cotton and okm, it follows that planting the land in other crops will 

 slowly starve out the fungus. Thus far though all attempts have failed 

 to completely eradicate the fungus from the soil of infected fields, 

 even with a rotation of ten years. Rotation of crops is important, 

 however, in the control of the black root disease on account of the 

 nematode worms. 



"Our experiments and those conducted by Prof. W. A. Orton 

 show that fungicides, such as Bordeaux mixture, copper sulphate, copper 

 carbonate, liver of sulphur, formalin, sulphur, sulphur and lime, are of 

 no value in controlling the black root disease of cotton. 



"In variety tests made in 1900 by Prof. W. A. Orton, the Jackson 

 Limbless was found to be the most resistant to the disease of the varie- 

 ties tested. By continued selection of the most resistant plants from 

 this variety, he has secured a strain of this type of cotton which is 

 very resistant to the black root disease of cotton. This restraint 

 strain he has named the Dillon. The Dixie originated from a selection 

 made by Prof. W. A. Orton, in Alabama, in 1901. In 1905 Prof. Orton 

 kindly furnished us some seed of both of these varieties. Each year in 

 our tests they have proven to be quite resistant to the disease, only 

 ten per cent to fifty per cent dying, where seventy-five per cent to 

 ninety-five per cent of the ordinary varieties died." 



Other Diseases 



We will not attempt to enter into a discussion of other diseases of 

 cotton, but will simply refer to them. 



Anthracnose 



A disease known as Anthracnose attacks bolls, stems, and leaves. 

 It appears in the form of a fungus parasite in all stages of the growth 

 of the plant. 



Leaf Blight 



Leaf blight is a fungus that attacks mainly the older leaves of the 

 plant. 



Mildew 

 This is also a fungus disease that affects the leaves. 



Mosaic Disease, or Yellow Blight 



is a disease due to the poor condition of the soil and surroundings. 

 If the plant is kept healthy, clean and growing, it is not usually attacked 

 by this disease. 



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