260 



NATURAL HISTORY OP THE FARM 



Successful weeds must be able to thrive on the treatment 

 accorded to the crop with which they grow. In our study of 

 pasture plants (Study 6, p. 56), we found that the weeds of 



pasture, like the forage 

 plants there, are chiefly 

 perennials that are able 

 to withstand browsing 

 and trampling. So, in 

 the fields, they must be 

 able to mature a crop 

 within the lifetime of the 

 cultivated species with 

 which they are associated. 

 Since good plowing puts 

 an end to both alike, a 

 new start must be made 

 from seed. B etween plow- 

 ing and plowing, there- 

 fore, a new crop of seed 

 must be matured. Hence, 

 the important weeds of 

 the cornfield are annuals. 

 Perennials are of little 

 consequence in tilled fields. 

 The weeds that in season 

 and habits and require- 

 ments are most like the 



FIG. 99. Sun prints of camomile and carrot. CrO P S With which they 



grow, are the ones that 



give the farmer the most trouble. They are natural com- 

 petitors. 



The farmer gives them as bad a handicap as possible at 

 planting time. He buries their seed deeply by plowing 

 the soil, and at once he plants seed of his own crop at the 



