

Alfalfa in Kansas. 361 



the machine must be constantly on the lookout for the mounds, so that 

 he may raise the sickle-bar until the obstruction is passed. Thus much 

 extra work is entailed and a portion of the crop is lost by running the 

 sickle too high. If the operator does not see the mound in time it is very 

 likely to clog the machine, or at least one or more sections of the sickle 

 may be dulled or nicked by encountering gravel or pebbles. If the ground 

 is reasonably mellow the horses drawing the mower stumble frequently, 

 their feet breaking through into the runways of the gopher. Sometimes 

 the holes thus formed are not filled again from below, and the rains 

 washing in enlarge the openings to a pit a foot or more in diameter. 



JT 



FIG. 307. A prod for locating runways of the pocket gopher and making openings 

 for the introduction of poisoned bait. [Courtesy Kansas Experiment Station.] 



Methods of Combating. 



POISONING. Gophers do not possess the shrewdness and cunning that 

 have become instinctive in many other wild creatures because of the con- 

 stant necessity imposed upon the latter of avoiding and escaping enemies. 

 Later experience in the wiles of man has evidently taught them nothing, 

 for they seldom reject any kind of poisoned food offered them. 



As stated before, poisoning is the more thorough and easily applied 

 method of ridding a badly infested farm of the pest. It is also the best 

 method if the territory to be freed from gophers is of considerable ex- 

 tent. In either of the above cases one man can accomplish as much with 

 poisoned bait as a half dozen could in the same time with traps. The 

 danger of killing stock or useful birds and animals, attending the use of 

 poison for prairie dogs, English sparrows and the like, is entirely 

 eliminated by the plan of introducing the bait through small openings 

 into the gophers' burrows. 



Since the pocket gopher lives naturally on the roots and tubers of 

 native plants, or on succulent vegetation drawn down into the burrow 



from the surface, it follows that a 

 close substitute for these articles 

 will make the best bait for poison- 

 ing. Knowledge gained by per- 

 sonal experiments and by careful 

 FIG. 308. A handy^tool for use in inquiry among farmers and fruit 



[Courtesy Kansas Experiment Station.] growers goes to show that pieces 



of potato, apple or sweet potato, 



poisoned by inserting a few crystals of strychnine into slits made with the 

 point of a knife, answer the purpose very well. Some correspondents 

 have reported good results from soaking the baits in a solution of arsenic 

 or strychnine. Only a mechanical mixture of the former substance can be 

 obtained in water, however, and the presence of particles of the free poison 

 on the surface of the bait would be more likely to cause its rejection than 

 if they were concealed in small slits. Raisins and prunes, treated like the 

 pieces of potato or apple, seem to be very effective baits also. Our ex- 



