23. 



by seeding the land to alfalfa. The frequent cutting and the 

 shading effect of this crop are the determining factors. Alfalfa 

 should be followed by a cultivated crop to complete the work of 

 destruction. 



"Pasturing with hogs has been successful in killing bindweed, 

 since hogs are quite fond of the underground parts. This me- 

 thod can be used with both ordinary pasture and fallow land. 

 Results can probably be obtained in less time in the latter case." 



Indian Mallow. This weed is an annual. It is not difficult to 

 exterminate, cultivation will destroy it. The great difficulty 

 with this weed and the Shoo fly is that the seeds retain their 

 vitality for many years. There are cases on record where a per- 

 centage of the seeds of Indian mallow germinated after the lapse 



Greater Ragweed or King Head (Ambrosia triflda). Sometimes called 

 Horseweed. Upper p:irt of a branch, staminate flowers above, pistillate 

 flowers just above the leaves, n a so-called seed more properly an Involucre 



with a bract on the right hand 

 Agr.) 



Ida, 



-with bracts removed. U. S. Dept. 



