Alfalfa in Kansas. 



345 



acreage of alfalfa has increased materially since that time, and the 

 disease has consequently spread. It has been known in Europe for many 

 years, and not infrequently has caused the death of half the crop. It is 

 certain to become more serious in this state every year, and since the 

 entire plant is at the mercy of this fungus its damage is lasting. 



The first external symptom which attracts one's attention is the yellow- 

 ing of the entire plant, which soon begins to wither, and eventually dies. 

 If the roots of such a plant are carefully examined one will notice a mat 

 of brownish-red or violet fungus threads covering them. (See Fig. 293.) 



FIG. 290. Downy mildew of alfalfa, showing the mold-like growth, on the under side 



of the leaf. 



