COST OF GROWING CORN 307 



data submitted it appears that the average investment 

 required to furnish implements for a 40-acre corn 

 field was $83.59, or $2.09 per acre, ranging from 87 



Pig 88— Work of the Larger Cornstalk Borer 



a. ireneral appearance of stalk infested by the early generation of borers ; b, same, 



cut open to show pupa and larva burrow (after Howard; 



cents per acre in Virginia to $2.62 in Iowa. The aver- 

 age effective life of such implements was a fraction 

 over ID years, thus fixing the allowance for deprecia- 

 tion of implements at 20.9 cents per acre. This allow- 



