12 



practically dead, the yield is usually considerably increased 

 over that on the unsprayed portion of the field, even during 

 those seasons when the blight is not very bad. The late blight 

 is likely, however, to be such a destructive disease that a 

 potato grower should by all means spray as a regular part of 

 his field operations. 



Cost of Spraying. 



For flea beetles and potato beetles use arsenate of lead 

 solution, as follows: — 



Approximate Cost 

 per Acre. 



Arsenate of lead, 3 pounds at 7 cents, $0 21 



Water, 50. gallons, - 



Labor, man and horse, spraying, 37 



Total, SO 58 



For blight use Bordeaux mixture, using the 4-4-50 formula, 

 as follows : — 



Approximate Cost 

 per Acre. 



Copper sulphate, 4 pounds at 6 cents, $0 24 



Lime, 4 pounds at f cents, 03 



Water, 50 gallons, 



Labor, spraying, 37 



Total, SO 64 



If 60 gallons of Bordeaux are used to the acre one spraying 

 costs about 70 cents, and if ten applications are made the total 

 cost is about 17 an acre. For thorough spraying late in the 

 season 100 to 150 gallons to the acre may be needed. 



It is a common practice to use poison in the Bordeaux 

 mixture when "bugs" are numerous. In such a case arsenate 

 of lead may be used five times, costing about as follows : — 



Approximate Cost 

 per Acre. 



Arsenate of lead, 5 applications at 21 cents, SI 05 



Bordeaux, 10 applications, 7 00 



Total, S8 05 



