A PRACTICAL METHOD OF FIGHTING WHEAT RUST 



By D. B. Swingle 



Botanist and Bacteriologist, Montana Experiment Station. 



Of all the diseases of crops the stem rust of wheat has long held 

 a place of first importance. No other disease has caused so much 

 loss to the human race. Much time and money have been spent 

 studying the disease and many important facts' about it have been 

 discovered, but owing to lack of concerted action on the part of 

 farmers none of the possible remedies have been put into general 

 operation. 



The Original Discovery 



Many years ago European botanists discovered that the disease 

 was caused by the attack of a fungus" — a reddish mould-like growth. 

 They made the further interesting discovery that this fungus cannot 

 pass through its complicated life cycle on any one plant, but requires 

 two: either wheat or some other cereal or grass and the barberry. 

 Commonly wheat and barberry are the two hosts used by this' rust. 



Figure 1. Map of the United States showing Barberry Eradication District. 

 In the shaded states the barberry is known to be of importance in the dissemina- 

 tion of wheat rust, and its eraxlication is being carried on. 



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