408 DISEASES OF ECONOMIC PLANTS 



in the solution or are allowed to become wet enough to 

 soften the coats so that they stick together, they will be 

 considerably injured or even killed. 



The solution recommended is strong enough to kill all 

 seeds if they are made thoroughly wet or are allowed to stay 

 quite damp for some hours. Less than one half gallon of 

 solution is required to treat one bushel of seed. It is well 

 also to burn all the infected straw and to avoid planting 

 too deep. 



By continued selection of seed from resistant plants 

 Bolley ' has developed a variety which is resistant to 

 the wilt. 



Altemariose {Alternaria sp.). — This is said by Bolley 

 to cause destruction of young plants in damp soil. 



Colletotrichose (Colleiotrichum sp.). — This has been 

 mentioned by Bolley as very destructive to young plants. 



Rust (Melampsora lini (DC.) Tul.). — This rust shows 

 sori characteristic of the rusts. Upon the leaves in early 

 season they are yellow or orange. Later black sori appear, 

 chiefly upon the stems. Badly affected plants turn 

 brown and die earlier than plants not rusted. Large 

 injury is not usual, though in 1904 and 1905 considerable 

 damage was reported from North Dakota. 



' BoUey, H. L., N.Dak. Agr. Exp. Sta. Bui. 50, December, 1901. 



