THE LIMA BEAN MILDEW 



133 



teria were always present. In later stages saprophytic 

 fungi gained entrance througli the diseased places and 

 hastened the destruction which the bacteria had inau- 

 gurated." The beans within the pods are also affected, 

 many of them being more or less discolored and disfig- 

 ured by the blight. Lima beans are also attacked by 

 what is supposed to be the same disease. So little is 

 known of this disease that the onlv remedial measures 

 at present to be suggested are the burning of diseased 

 vines, the selection of healthy seed, and crop rotation. 



The Lima Bean Mildew 



Phytophora phaseoli 



This fungus first attracted attention two or three 

 vears asfo. in the vicinity of Xew Haven, Connecticut, 

 wiiere it was carefully studied 

 by Dr. Roland Thaxter, who 

 has published an excellent 

 account of it. It does not, 

 as yet, seem to have spread 

 over a wide area, but it is 

 likely to do so within a few 

 years. 



This mildew generally 

 first appears on the sides of 

 the immature pods as a whit- 

 ish, woolly spot, which, dur- 

 ing damp weather, increases 

 rapidly in size. The threads 

 of the fungus penetrate the 

 pod, and may develop on its 

 outer surface until it forms a thick white coating, which 

 often completely envelops the pod. The tissues of pods 

 so affected are, of course, ruined ; they shrivel, blacken 

 and decay. A similar injury to the young shoots is 

 often produced, and sometimes the leaves also are 

 affected. 



a 



P IG. 56. 



LIMA BEAN MILDKW. 



rt, Spore and zoospores; 6, fruiting 

 tuft. Magnified. 



