72 U. S. DEPARTMENT OF AGRICULTURE. 



TURNIP: GRAY MOLD ROT; BOTRYTIS ROT. 



(See Gray Mold Rot). 

 TURNIP: SLIMY SOFT ROT; BACTERIAL ROT; SOFT ROT. 



(See Slimy Soft Rot). 



WATERMELON: ANTHRACNOSE. 



Cause: A fungus (Colletotrichum lagenarium). 



In its early stages, anthracnose is characterized by small 

 circular raised welts on the rind, dark green in color. As 

 these increase in size, the centers turn brown, become 

 sunken, and under moist conditions the pink acervuli of the 

 fungus are formed. As a lesion enlarges, the center becomes 

 more sunken, often turns black, and eventually the surface 

 cracks, exposing the rotted tissue or a cavity underneath. 

 The fungus causes a rather slowly advancing dry rot of the 

 rind tissue, and finally penetrates the edible pulp. Under 

 extremely dry, hot conditions, such as occur in California 

 during the melon harvest, the lesions may remain in the 

 blister or nail-head stage. 



Anthracnose is a serious disease of the vines and fruits in 

 the field. The fungus is spread with the seed, overwinters 

 in the soil, and spreads in the field during rainy weather. 

 This is the same fungus which causes cucumber and musk- 

 melon anthracnose. 



Many fruits are rendered worthless in the field. The dis- 

 ease is also present in almost every car of melons shipped 

 north as a result of field infection which may or may not 

 have been detectable at the time of loading. The lesions 

 enlarge during transit and not only seriously impair the 

 appearance of the fruit, but open the way for the entrance 

 of other rot-producing organisms. 



Anthracnose is prevalent throughout the southern melon 

 regions and the Ohio Valley. It is the source of great losses 

 in the field, in transit, and in the market. 



The disease can be controlled in the field by crop rotation, 

 use of disease-free seed, and spraying with Bordeaux mix- 

 ture. 



Ref. (58). 



WATERMELON: STEM-END ROT. 



Cause: A fungus (Diplodia). 



This is a rapidly progressing soft rot of the stem end of 

 the melon, marked externally by a brown discoloration and 

 shrivelling followed by the development of abundant black 

 pycnidia or a dark, gray, moldy outgrowth of the fungus. 

 Whitish spore masses are often discharged from the pycni- 

 dia. The disease usually affects the stem-end of fruit, but 

 occurs also at wounds and, in the field, as a blossom-end rot. 



While the rot is rather common in the field, diseased 

 fruits are not often shipped,, and it seems quite likely that 



