Family Cucurbitaceae 241 



States, although it has not as yet been found to be 

 serious in Texas. 



Symptoms. It attacks all parts of the plant except 

 the root. On the stems it causes watersoaked 

 spots, which in time turn brownish and become 

 depressed and cracked. On the leaves, somewhat 

 circular dark spots become so numerous as to involve 

 the entire area (fig. 42 b), resulting in the death of the 

 leaf. Diseased leaves soon crinkle, turn black, and 

 have the appearance of being burned by fire. On the 

 fruit, anthracnose is manifested on the rind as cir- 

 cular deep depressions (fig. 42 c) which soon become 

 covered with a salmon-colored coat made up of the 

 spores of the fungus. Ordinarily the spots do not 

 go deeper than the rind. Under improper methods 

 of shipping, the fungus eats into and penetrates the 

 flesh of the melon which decays rapidly. Anthrac- 

 nose reduces the market value of the melons, and 

 makes shipping a very risky affair, since the disease 

 readily spreads in the car. This is especially true 

 when the cars are sidetracked and held too long in 

 transit. In the field, anthracnose may ruin the 

 entire stand (fig. 43 a-b). 



Besides attacking watermelons, anthracnose also 

 attacks cucumbers, cantaloupes, citrons, and gourds. 

 The disease is not usually serious on new land; but 

 on land where watermelons have been grown in suc- 

 cession for a period of years, or where melons fol- 

 lowed cantaloupes or cucumbers, the disease may 

 become serious. 



The Organism. In structure, Colletotrichum lage- 



16 



