THE MUSTARD FAMILY 89 



the small seeds are common in threshed grain, frequently neces- 

 sitating dockage and recleaning at points of inspection and 

 storage. 



Remedy: Sow clean seed. This weed will not long give 

 serious trouble where crop rotation is practiced. Where cereal 

 grains follow cereal grains, plowing or discing in the fall and 

 clean cultivation in the spring, with a disc or broad-shared 

 cultivator, is recommended. Harrow the crop before the 

 plants emerge from the ground, and again when they are three 

 inches high, to destroy seedling weeds. Badly infested areas 

 should be summer-fallowed; disc and harrow early in the spring 

 and plow early in June. Seeding to grass for three or four years 

 will greatly reduce this pest. The edges of prairie grain fields 

 should be trimmed with the mower before these weeds have 

 passed the flowering stage. 



In some of the more northerly districts of the Prairie Prov- 

 inces, where summer -fallowing is not expedient, growing 

 grain for fodder gives an opportunity to clean the land of this 

 pest. As with summer-fallow, begin with discing or early 

 plowing immediately behind the binder in the fall. This should 

 be followed by cultivation with disc or harrow early in the 

 spring. The land should be plowed in June, thoroughly worked 

 up, and seeded with oats, barley or timothy. Be sure to cut 

 the crop before any of the mustard seeds mature. 



Ball Mustard seeds are usually present in western oats 

 sold for seed in Ontario, Quebec and the Maritime Provinces. 

 Where clean seed can not be obtained, the fanning mill will 

 eliminate these seeds by screening. The alternation of crops 

 commonly practiced in mixed farming will usually keep this 

 weed in check in eastern Canada. Sheep will feed on the young 

 and tender plants of this weed and of most others of the Mustard 

 family. 



