280 



ARID AGRICULTURE. 



SOME NEW 



ALFALFA 



DISEASES 



and then burn it to destroy the fungus spores. 

 The third remedy is the production of a disease . 

 resistant variety. 



In Colorado a bacterial blight of alfalfa lias 

 made its appearance. When this disease has in- 

 fested a field the results are bad. It is usually 

 indicated by a poor first cutting of hay. When 

 the blight gets down to the tap root it kills out 

 the entire plant. ~No remedy is yet known for 

 it. In Kansas a red root rot is reported on al- 

 falfa, that works in circles, killing the plant as it 

 travels through the soil. This again seems to be 

 due to Rhyzoctonia. Another root rot which 

 works on cotton is reported from the Southwest 

 on alfalfa. There is a rust affecting alfalfa, but 

 it does not seem to cause serious loss. The 

 downy mildew which is noticed as large yellow 

 or white areas on the upper sides of the leaves, 

 occurs during wet weather, but the damage from 

 it is not great. No doubt other diseases mav 

 appear from time to time. In nearly all these 

 diseases of alfalfa the plowing of the field and 

 planting some other crop is a general recommen- 

 dation to be carried 'out, or checking the disease 

 bv cultivation to aerate the soil. 



BORDEAUX 

 MIXTURE 



Bordeaux mixture is a fungicide which is 

 more commonly used than any other for the 

 treatment of all those plant diseases which are 

 caused by fungi that grow on the exposed parts 



