28 EDUCATION AND THRIFT 



of 150 trees each, one sprayed twice, the other unsprayed ? 

 What will be the difference in their value, firsts selling at 

 50$ per bushel, seconds at 25$ per bushel ? 



3. With lime at 1$ per pound, copper sulphate at 10$ per 

 pound, and arsenate of lead paste at 20$ per pound, aver- 

 aging 2 gal. of the mixture to a tree for a single spray, what 

 would be the cost of spraying 100 apple trees twice ? 



4. If the orchard in problem 1 is a square consisting 

 of 10 A., with the trees set in rows 30 ft. apart and the trees 

 in the row the same distance apart, what would be the cost 

 of the material for spraying the orchard twice ? What would 

 be the value of the increased yield when apples of the first 

 grade sell for 60$ per bushel, and of the second grade for 

 30$ per bushel ? 



5. What would be the cost of the material required to 

 spray an orchard of 50 trees twice ? 



6. To destroy blight, rot, and insects, a farmer sprayed 

 half of a 2-acre field of potatoes three times with Bordeaux 

 mixture containing Paris green. The expense was as follows : 

 24 Ib. of lime at 1^$ per pound ; 24 Ib. of copper sulphate at 

 24$ per pound ; 1^ Ib. of Paris green at 30$ per pound ; 

 $4.25 for labor. The sprayed acre yielded 165 bu. of potatoes, 

 for which the farmer received 60$ per bushel. The unsprayed 

 acre yielded 57 bu., for which he received 60$ per bushel. 

 What was the value to the farmer of the spraying of the 

 1A.? 



7. What is the cost of materials required for spraying a 

 10-acre field of potatoes three times for insects, if Paris 

 green is 30$ a pound and 300 gal. of the solution are used 

 to the acre ? What is the profit for spraying if the labor 

 cost $22.50 and the increased yield is worth $75 ? 



