Alfalfa in Kansas. 



347 



This disease is often most prevalent in fields where inadequate drain- 

 age exists. Unfavorable soil conditions for alfalfa make conditions 

 favorable for the development of the fungus. 



Since this disease may live over in the soil for a number of years, it 

 will not do to replant these vacant spots until the disease has been 

 killed out. Generally this disease is worse in fields which are eight years 

 old or older. If a field contains a number of patches in which the plants 

 have been killed, the entire field should be plowed up and not replanted 



FIG. 292. Downy mildew of alfalfa. 

 Note the mold-like growth at the tip of 

 the plant. 



FIG. 293. Red or violet root rot. 

 Note the fungus threads creeping over 

 the surface of the root. 



to alfalfa or clover for at least three years. As soon as the disease is 

 observed, and before it has advanced very far, it may be checked by 

 digging up all the diseased plants and burning them. A trench should 

 be dug around the entire patch, beginning at least five feet beyond the 

 outer limits of the area where the plants show wilting or yellowing. All 

 plants and soil should be thrown toward the center of the patch, other- 

 wise the disease will be disseminated. Later the diseased plants should 



