CHAPTER VIH 



FRIENDS AMONG THE BIRDS AS DESTROYERS 

 OF WEED SEEDS 



Harm done by weeds. Weeds constitute one of 

 the greatest enemies against which the farmer or 

 gardener must contend. During the growing season 

 he must wage a constant warfare against them. 

 Weeds may be injurious in the following ways: (1) 

 Weeds interfere with the growth of crops by depriv- 

 ing them of plant-food, moisture, and sunlight and 

 thus reduce the yield. (2) Another loss results from 

 the mixture of weed seeds with the seeds of farm 

 crops. It has been estimated that in the State of 

 Minnesota alone the damage due to weed seeds 

 amounts yearly to two and a half million dollars. 

 (3) Weeds interfere with the harvesting and curing 

 of crops. (4) Some weeds harbor insect pests and 

 fungus diseases, which may injure crops growing near. 

 (5) Some weeds are poisonous either to man or to live- 

 stock. A recent bulletin published by the Department 

 of Agriculture estimated that weeds cost the Amer- 

 ican farmer three hundred million dollars every year. 



The seed period of the weeds is one of the most 

 vital at which they may be attacked. It is the 

 migration stage during which they are spread from 



