14 



Eradication. The roots of this pest are very long-, thick, and much 

 branched. A good-sized plant will have a root over two feet long with 

 numerous deep rootstocks. A weed with such an underground root 

 system is necessarily hard to combat. Some means must be taken by 

 which the deep roots and rootstocks can be destroyed. Small patches 

 should be carefully dug out early enough in the season to prevent seed- 

 ing, taking pains to get every piece of the root and rootstocks. Badly 

 infested fields should be plowed deeply immediately after harvest ; and 

 then thoroughly cultivated and cross-cultivated with the broad-shared 

 cultivator in order to cut up and weaken the underground root system. 

 The following spring continue this deep cultivation at intervals of about 

 two weeks until it is time to put in a hoed crop, which must be kept 

 thoroughly clean in order to be effective. 



Fig. 12. Eoot of Bladder Campion. 



Fig. 13. Stinkweed or Penny Cress. 



( Thlaspi arvense. ) 



About I natural size. 



