ever, under normal climatic conditions, especially if the 

 plants are too thick, or if, as occurs in some varieties, a 

 large amount of fruit is produced in proportion to the leaf 

 surface. 



ATKINSON : "Diseases of the Cotton Plant," U.S. Dept, 

 Agric. Bull, No. 33, 1896. 



ANGULAR LEAF SPOT OF COTTON. 



In this disease definite spots of the leaf present a 

 watery appearance ; the spots are bounded by the veinlets 

 of the leaf. Later, the spots become blackish and then 

 brown, and are frequently bordered by a blackish area. 

 The disease was at first thought to be caused by bacteria, 

 but has since then been attributed to physiological causes. 



MELANOSE. 

 (Disease of Citrus spp.) 



The disease appears in the form of small, dark- brown 

 spots on the leaves, stems and fruits of various citrus trees 

 in the United States ; it has also been found in Montserrat. 

 It has been attributed to physiological causes. 



The spots increase in size and may split in the centres. 

 Many of the leaves fall and, in severe attacks, the branches 

 become twisted and contorted, while the fruit is rendered 

 unsaleable. 



Swingle and Webber : U. S. Dept. Agric. Bull. 8, 

 Division of Vegetable Physiology and Pathology. 



B. Diseases caused by Bacteria. 



There are a few diseases which have been ascribed to 

 bacteria, but none of them can be said to have been 

 thoroughly investigated. 



BACILLUS GOSSYP1NUS, Atk. 

 (Rot of Cotton Boils.) 



This commences as a small, brown area within the boll, 

 usually at a point near the attachment of the boll to the 

 stalk. The rot spreads through the contents of the boll, 

 and the exterior then shows signs of disease. 



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