1 64 Weeds. 



which it grows is ripe. It is manifest that 

 where spring grains are chiefly grown the 

 contest with this weed will be a difficult 

 one. It has been argued by some persons 

 that wild mustard does not interfere to any 

 serious extent with the yields of the crops 

 amid which it grows, but it must be evident 

 to any one who understands the way in 

 which plants feed that a soil cannot produce 

 a crop of mustaid and one of grain at the 

 same time, with the result that the grain 

 will yield as well as if the mustard had not 

 been there. 



Wild mustard is distributed by means of 

 various agencies. Some seeds are carried 

 from place to place by birds, but usually 

 this weed finds its way to new centers by 

 the seed being carried in grain. The thrash- 

 ing machine is also a potent means of car- 

 rying it from farm to farm. It is further 

 distributed over farms on which it grows 

 by means of the droppings of cattle, and by 

 the manure. It is also very frequently dis- 

 tributed by spring floods; when this is the 

 case the farmer has great difficulty in deal- 

 ing with it. 



