266 Diseases of Truck Crops 



with spores of the fungus. This will make sure that 

 the parasite has been placed on the host. If there 

 is any difference in resistance, it will be evidenced by 

 the amount of infection developing on each variety 

 tested. In this connection it should be remanbered 

 that there are ntimerous strains of C. Undemuthianum, 

 some of which are very virulent while others are less 

 so. In inoculating for resistant varieties, an attempt 

 should be made to secure pure culture strains from 

 various localities. 



Stem Anthracnose 

 Caused by Colletotrichum caulicolum H. and W. 



A serious stem rot attacks the Kentucky Wonder 

 bean. The disease differs from anthracnose described 

 above in that the former destroys the stems of the 

 plant. Observations made by Heald and Wolf' 

 show that the disease girdles the stem, and also 

 causes deep fissured cankers on one side of it. The 

 trouble has been found in only one locality in Texas, 

 and it is doubtful if it is prevalent elsewhere. Little 

 is known of the control of this disease. 



Angxjlar Leaf Spot (fig. 47 g) , see Cowpea., p. 271 . 



Southern Blight, see Pepper, p. 305. 



Root Rot (fig. 49 a), see Rhizoctonia, p. 45. 



Texas Root, see Sweet Potato, p. 175. 



Root Knot, see Nematode, p. 49. 



• Heald, F. D., and Wolf, F. A., U. S. Dept. of Agr. Bur. PL Ind. 

 Btil. 226 : 35-36, 1912. 



