10 



The cost of spraying varies under different conditions and is here 

 only estimated. The difficulty of hauling water up steep slopes is 

 sometimes so great as to make spraying almost prohibitive. After 

 the materials are hauled to the field, the work of spraying proceeds 

 faster than cutting. With ferns of an average degree of thickness 

 a man with a knapsack sprayer ought to cover about 5 acres a day. 

 Assuming that 150 pounds of salt are used to the acre at a cost of 

 one-half cent a pound and that 5 acres are covered in a day with 

 labor worth $1.50, the cost of spraying with salt is $1.05 per acre for 

 each application, not including the cost of hauling the materials. As 

 the first spraying is the most expensive in labor and materials, this 

 treatment may cost a little more than the amount mentioned, while 

 the subsequent treatments will probably cost less. 



One disadvantage of spraying is that it is a detriment to the growth 

 of young clover. This means that the measures for encouraging the 

 clover to work into the patches occupied by fern should be deferred 

 until after tlie last spraying has been made. It is probable that the 

 spray does not injure young grass to any great extent. 



An advantage of spraying is that it may be employed in situations 

 that arc too stony for the efficient use of the scythe (fig. 8). There 

 arc also certain other situations where large spraying outfits may be 

 satisfactorily used. Spraying with a barrel pump on a low wagon can 

 sometimes be made more cheaply than with a knapsack outfit. 



NUMBER OF TREATMENTS NECESSARY. 



Two treatments a year, either spraying or cutting, seem to be 

 about as effective as four, and are to be recommended. Undoubtedly 

 the best time to treat the ferns is just previous to sporing, or about the 

 middle of June and the middle of August. 



BURNING. 



Following a treatment of either spraying or cutting, fire may be 

 started when, the vegetation on the surface of the patches is dry. 

 The burning not only kills the shoots that have recently started, but 

 probably affects the vitality of the rootstocks as well. The subse- 

 quent growth of young shoots is usually not as vigorous as when the 

 patches are not burned. The burning should be done, of course, 

 before seeding to grass and clover. 



HOW LONG SHOULD THE MEASURES OF ERADICATION BE CONTINUED? 



It is probably not practicable absolutely to eradicate ferns. After 

 they have been reduced to a minimum the specific methods of de- 

 struction may be discontinued, at least until the weeds again become 

 troublesome. The reduction of the number of ferns will give the 

 grass and clover ample opportunity to work in, and this in itself will 

 tend to hold the ferns in check. 



