Muskmelon Diseases 157 



the way to this disease. A characteristic of the 

 trouble is that the edges of the infected areas are 

 covered with an oily, green to raisin-colored gum. 

 The older parts of the spots are either dark and 

 gummy or gray and dry, bearing numerous brown 

 pycnidia. 



The Organism. The perithecia are roundish, 

 rough, dark brown to black, and almost superficial 

 on the surface of the spots. The necks of the peri- 

 thecia are hairy, the ascospores are cylindrical, two- 

 celled, hyaline, and slightly constricted at the center. 



Control. Spraying with Bordeaux mixtures when 

 the plants are about half grown and before the dis- 

 ease appears is recommended. Spraying should be 

 continued so that the growing parts are kept cov- 

 ered with the fungicide. 



Anthracnose, see Cucumber, p. 141. 



Leaf Blight 



Caused by Alternaria brassica var. nigrescens 

 Pegl. 



Symptoms. The disease begins as small round 

 spots which gradually enlarge. These spots are dry, 

 brown in color and made up of concentric rings or 

 zones (fig. 30, a and b.). Usually the spots are very 

 numerous and their presence causes the leaves to curl 

 and dry up prematurely, leaving bare vines and un- 

 protected fruit. As a result, the melons ripen early 

 and have an insipid taste, and are very poor shippers. 

 Leaf blight is most serious under field conditions. 



