Minnesota Plant Diseases. 



313 



long spindle-shaped, consisting of a string of cells. Thick- 

 walled spores are also produced, consisting of several cells, and 

 are capable of resting over in the soil for some time before ger- 

 minating. The chief method of distribution of the fungus is by 

 means of the spores which cling to the seeds of the flax. 



Flax seed should therefore be treated before seeding to de- 

 stroy the fungus spores clinging to the coats. 



Professor Bolley has recommended the following treatment 

 and preventive measures : 



"Use formaldehyde at the rate of one pound of the standard 

 strength to forty or forty-five gallons of water (the same 

 strength used for wheat and oats). Spread the seed upon a 

 tight floor or upon a canvas and sprinkle or spray on a small 

 amount of liquid (a fine spray is best). Shovel, hoe, or rake the 

 grain over rapidly. Repeat this spraying, shoveling, hoeing or 

 raking until the surfaces of all of the seeds are just evenly moist, 



not wet enough to mat or gum, 

 but evenly damp. (This can be 

 done without matting if the grain 

 is well hoed or shoveled over 

 while the solution is slowly and 

 evenly sprayed upon it.) When 

 the seeds are just evenly moist, 

 cease applying the solution, but 

 continue to shovel the grain over 

 so as to get it dry as soon as 

 possible. Avoid any excess of 

 moisture. If flax seeds are dip- 

 ped in the solution or are al- 

 lowed to get enough to soften 

 the seed coats so that they will stick together, they will be con- 

 siderably injured or even killed. 



"It takes less than one-half gallon of the solution to properly 

 moisten one bushel of flax seed. 



"Caution: One must treat flax with much more care than 

 that usually taken in treating wheat or oats for smut. The 

 solution recommended is strong enough to kill all seeds, if they 

 are made thoroughly wet, or if they are allowed to stay quite 

 damp for some hours. 



Fie. 159. Flax wilt. A section of a flax 

 root with fungus threads and spores 

 at the surface. Magnified. After 

 Bolley. 



