154 Weeds. 



ure conditions are right. Occasional har- 

 rowings will then kill the small weeds, and 

 encourage germination of more seed, which 

 in turn can be destroyed. This method is 

 particularly good when it can be followed 

 by the growing of a cultivated crop in the 

 spring, as outlined below. If it is neces- 

 sary to grow small grain on the field on 

 which autumn cultivation is practiced, har- 

 rowing in the spring after the grain is up, 

 as outlined in the preceding section, is 

 strongly to he recommended. 



5. Fall cultivation, foUozved by a cidti- 

 vated crop in the spring. Fields which are 

 pretty thoroughly infested with mustard 

 can be cleared of this weed, except as the 

 seed remains in the ground, by the autumn 

 cultivation advised in the foregoing para- 

 graph, if it is followed by a cultivated crop 

 in the spring. As previously noted, the 

 weeds of the mustard family do not give 

 serious trouble where thorough cultivation 

 is practiced. Growing a quick-maturing, 

 vigorous soiling crop which will tend to 

 smother the weeds and at the same time be 

 removed early enough to prevent the ripen- 

 ing of seeds in any quantity is also a good 

 method of fighting annual weeds in con- 



