WHEN TO CULTIVATE 



165 



at the proper time the farmer must observe closely and often the 

 condition of the different fields. Growing weeds may be killed 



FIG. 108. Other types of riding cultivators. A, four-shovel, spring-tooth gang; B, disk 

 cultivator; C, surface cultivator; D, single row lister cultivator. 



through cultivation in three ways: (a) They may be loosened 

 and exposed to the drying sun; (b) they may be covered and 



FIG. 109. Two types of walking cultivators. 4. seven-shovel one-horse cultivator; 

 B, fourteen- tooth cultivator. 



smothered with soil, and (c) they may be cut off or covered with 

 soil to prevent their manufacturing any food. In the last one, 

 much diligence and close watching is required. Some prefer to 



