HOW TO GET RID OF WEEDS 



293 



season. If, however, a farmer wishes to destroy them 

 earlier than their flowering time, he uses the same methods 

 that are necessary for biennials. It is possible to get rid 

 of annuals or biennials (1) by thorough tillage; (2) by 

 cutting and pulling; (3) by using chemicals; (4) by 

 rotation of crops ; or by combining two or more of these 

 methods. 



To rid the farm of perennial weeds, the most ap- 

 proved methods are : 

 (1) thorough tillage; (2) 

 rotation of crops ; (3) us- 

 ing chemicals; (4) sum- 

 mer fallowing ; (5) using 

 a smothering crop, 



Tillage and crop rota- 

 tion were mentioned in 

 Chapter V as means of 

 destroying weeds. The 

 cutting and pulling 

 methods are used when 

 weeds are few in number, 

 or are scattered here and 

 there along fences and 

 roadsides. If the flowers are mature, however, there is 

 often sufficient vitality left to ripen the seeds, even after 

 the plant has been cut or pulled. Therefore weeds in 

 flower had better be burned. 



If annuals and biennials have spread thickly and widely 

 over an entire field, tillage and crop rotation are the best 

 means of eradicating them. 



Some plants, like wild mustard, when growing among 

 oats or potatoes, may be killed by an iron sulphate spray. 

 The chemical kills the weed but does not harm the oats 

 or potatoes. The 100-12-50 formula is used ; that is, 



WILD CARROT. 



