164 ELEMENTS OF FARM PRACTICE 



2. Why is a farmer interested in knowing whether an insect 

 gets its food by biting or sucking? 



3. What can you say of the cotton boll weevil? 

 Arithmetic: 



1. If corn on fall-plowed land yields 50 bus. per acre and on 

 spring plowed land 25% less on account of the damage done by cut- 

 worms, how much is gained per acre by fall-plowing, if corn is worth 

 50c. per bushel? 



2. A sprayed his cabbage with Paris green to kill cabbage worms, 

 and raised 15 tons of cabbage per acre; B did not spray his cabbage 

 and raised only 12 tons per acre. How much did A make by spray- 

 ing, if cabbage is worth 3^c. per pound? 



Exercises: 



1. Gather some specimens of wheat, oats, and corn that are 

 afflicted with smut. What has the disease done to the grain? 



2. If you can find a crop that is afflicted with smut, estimate 

 the loss. Show how it might have been prevented and at what expense. 



3. Make a comparative study of apple blight and potato blight 

 and apple scab and potato scab. How are they alike and how unlike? 



4. Make a collection of a few insects in their various stages of 

 development. 



5. Get specimens of insects that eat and that suck and parts 

 of plants attacked. Also spray against each kind and note results. 



6. Try to estimate the loss that insects may cause to crops either 

 on your own farm or in the community. 



