202 



DISEASES OF ECONOMIC PLANTS 



It is reported upon many species of true beans (Phaseolus) 

 and upon related genera a Visgna, Falcata, Strophostyles. 

 If the disease proves destructive, clean culture, the de- 

 struction of all wintering forms, is advisable. 



Blight (Pseudomonas phaseoli E. F. Smith). — Beans of 

 various kinds are subject to a blight which manifests 



Fic3. 90. — Bacteriowis of bean leaves. After Fulton. 



itself upon the pod, leaf, or stem. It has been reported 

 from various states, from Canada, is widely distributed, 

 and often quite destructive. It was first observed by 

 Beach ^ in New York. 



Usually the leaves are the parts first attacked. Here 

 large watery patches, brown in color, are produced. 

 These spots later dry, become papery in texture, and 

 rupture, leaving the foliage ragged and torn. After 



1 Beach, S. A., N.Y. (Geneva) Agr. Exp. Sta. Bui. 48, December, 

 1892. 



