ERADICATING TALL LARKSPUR ON CATTLE RANGES. 17 



the Sevier National Forest. Approximately 63 acres of larkspur 

 was responsible for this loss. It was estimated that this can be 

 crabbed out for about $400. This range supports 1,600 head of cattle. 

 The eradication work, therefore, can be done for about 25 cents per 

 head, or a total cost amounting to less than one-seventh the value 

 of the cattle lost in 1916. 



On the Grand Canyon cattle range of the Palisade National For- 

 est, during the season of 1915, about 65 head were lost out of the 660 

 cattle grazed. In 1916 only 320 animals were grazed on the allot- 

 ment, principally on account of previous excessive losses, which 

 caused several users to sell their stock rather than have them go back 

 on the range. The larkspur grows in scattered stands in isolated 

 areas, and the entire range can be grubbed for about $1,200. If this 

 is done, it will make possible the grazing of at least 1,000 head of 

 cattle on this range without loss from poisoning. In addition, con- 

 siderable money which is now expended for employing riders to keep 

 the stock off the dangerous areas would be saved. On the basis of 

 the carrying capacity of the range, the grubbing work can be done 

 for $1.20 per head. 



METHOD OF GRUBBING. 



DEPTH. 



To grub tall larkspur effectively, the main part of the root sys- 

 tem, including all of the main roots before they divide into small 

 lateral roots, should be removed. The depth of grubbing necessary 

 to accomplish this depends upon the size of the root. Where the 

 roots average about 2 feet in length, grubbing should be done to a 

 depth of 8 inches. Where the roots do not average more than 1J 

 feet in length, grubbing to a depth of 6 inches is usually sufficient. 

 The very large bunches frequently have large shallow lateral roots. 

 Care should be taken to remove these to at least 4 inches from where 

 they leave the main root. A great number of the plants which sur- 

 vive the first grubbing sprout from these lateral roots that have not 

 been grubbed far enough from the main root. (See fig. 7.) 



TOOLS. 



A pick with one end drawn out to a chisel form about 2 inches 

 wide is probably the best tool for use in all kinds of soil. A shovel 

 is unsatisfactory. A mattock is good in sandy soil, but can not be 

 used advantageously in rocky soil. Grubbing hoes are not satisfac- 

 tory because the blade is too short to remove enough of the roots to 

 kill the plants unless extra care and time are taken. 



