502 THE HANDBOOK FOR PRACTICAL FARMERS 



farmers should follow in destroying weeds, but these laws have 

 been very ineffective. If the farmers would cooperate in the 

 control of such w^eeds as the Canadian thistle, milkweed, and 

 others, they might in a short time free the community of them. 

 The man who has a weedy farm not only loses a large per cent 

 of his own crops because of the loss of moisture, plant food, 

 crowding, shading, etc., but he allows the seed to ripen and thus 

 the adjacent fields of his neighbors become infested and so this 

 menace spreads. 



Fig, 236. — Bull thistle, showing floweiing top of plant, separate leaf and roots ( X 3) ■ 



