SPRAYING FOR SCALES 217 



crops. What is saved yearly, per acre, on this basis 

 from rotation of crops? 



8. What is the vaiue of one acre of tobacco, 1,500 

 pounds, at 8 cents per pound ? 



9. What is the value of one acre of oats, sixty bush- 

 els, at 30 cents per bushel? 



10. What is the value of one acre of clover, three 

 tons, at $6 per ton? 



11. What is the value of one acre of corn, fifty 

 bushels, at 40 cents per bushel? 



12. What is the value of one acre of peas, twenty 

 bushels, at $1.50 per bushel? 



LESSON LXIV 



SPRAYING FOR SCALES 



During this month we must spray our peach and apple 

 trees to rid them of San Jose and other scale insects, 

 or to insure against them should there be none present. 

 The reason for doing this work in March is because 

 the insecticides we must use against the scale would be 

 injurious to the foliage of the trees. 



San Jose scale. The San Jose scale is one of the 

 most dreaded enemies of the fruit trees. In most states 

 it is an illegal act to sell fruit trees infested with it. 

 This insect is very minute, yet it spreads rapidly and 

 soon covers the branches of the trees with a grayish 

 scale, beneath which is the living pest, sucking the life 

 from the tree. Probably the best thing to do when one 



