200 Weeds. 



power of propagation is attributable to the 

 ease with which the winds send it tumbhng 

 over the prairie for miles in succession, the 

 number of seeds which it produces, and the 

 readiness with which the seeds germinate 

 under favorable conditions. Railways are 

 largely responsible for the conveyance of 

 the seed to new centers. It has also been 

 carried in flaxseed and in the seed of cereals. 



Modes of Eradication. 



The Russian thistle is not difficult of 

 eradication. Its great weakness lies in the 

 inability of the seeds to maintain vitality 

 under normal conditions for a longer 

 period than two years. Under a good sys- 

 tem of farming it may be eradicated with- 

 out great difficulty. Any system of farm- 

 ing that will prevent the plants from matur- 

 ing their seeds for two successive years 

 will accomplish this end. 



The following are the modes of eradica- 

 tion which have been found most success- 

 ful in dealing with the Russian thistle : 



7. Modifying the rotation. Cereal crops 

 and other crops which favor the maturing 

 of the seeds may be omitted for two suc- 

 cessive years, and other crops grown in 



