CEREAL PESTS WEEDS 463 



by the hedge bindweed, the reproduction is from under- 

 ground stems. The new shoots may start from new stems 

 developed the preceding year, or from portions of old 

 stems which retain their vitality 2 or more years. By the 

 second method exhibited in the field bindweed new shoots 

 arise from horizontal roots, lying from several inches to 

 several feet below the surface. 



506. Eradication of bindweed. A number of methods 

 of eradicating bindweed have been proposed, of which 

 three appear to be the most practicable. 



Clean cultivation, if thoroughly done, will destroy the 

 weed usually in two years and occasionally in one year, 

 if the underground parts do not lie too deep. The land 

 must be cultivated every week or ten days throughout the 

 growing season of the weed, or from spring frost to fall 

 frost. The eradication may be effected in a bare fallow 

 or in connection with an intertilled crop, the latter of 

 course being the more profitable. After the crop is 

 " laid by," the hoe must be used still, until every individ- 

 ual plant is cut off. On fallow land a large V-shaped 

 knife is sometimes used. It runs 3 to 6 inches under the 

 surface, and is attached to a frame like that of a 2-horse 

 cultivator. 



A second method is to seed the infested field with alfalfa. 

 The frequent cutting, followed later by the smothering 

 effect of the crop, will greatly lessen or entirely eliminate 

 the bindweed. The cutting keeps down the tops about as 

 effectively as clean cultivation. The alfalfa grows more 

 rapidly after each cutting than the weed, which is shaded 

 by the former. 



Pasturing infested land with sheep or hogs has proven 

 to be a good method of eradication. Three years of pas- 

 turing with sheep will nearly or entirely destroy the pest. 



