430 CONTROLLING INSECTS AND PLANT DISEASES 



FIELD AND LABORATORY EXERCISES 



1. Potato Scab. Make up a solution of formalin, using one ounce to two 

 gallons of water. Use this for treating a small quantity of seed potatoes to 

 kill spores of the scab disease. 



2. Copper Sulfate Solution. Dissolve two pounds of copper sulfate in 

 two gallons of water by hanging the sulfate in a piece of cheesecloth tied to a 



FIG. 300. Types of spray pumps. 1, bucket pump, in which the agitation is by a jet 

 at base of pump; 2, knapsack sprayer, carried on back of the operator; 3, barrel sprayer with 

 wooden agitator and two lines of hose. (Fights of the Farmer.) 



stick across the top of the vessel which should be of earthenware, wood or 

 glass, (not metal). As the sulfate dissolves, the solution settles to the bottom 

 and a circulation is thereby kept up during the dissolving process. Keep this 

 as a stock solution and label its strength "One pound to one gallon." 



3. Lime Solution. Slake two pounds of lime by moistening with a little 



