APPLE GROWING 



turn Is looked for. To be sure, it is only one 

 of the operations necessary to success, but it 

 enables us to grow a quality of fruit which we 

 could not obtain without it. 



Spray Materials are conveniently divided 

 into two classes, insecticides and fungicides. iVn 

 insecticide is a poison by which the insect is 

 killed either directly by eating it, or indirectly 

 by the caustic, smothering, or stifling effects re- 

 sulting from closing its breathing pores. Direct 

 poisons are used for Insects which eat some 

 part of the tree or fruit and are called stomach 

 poisons. Sprays which kill indirectly are used 

 for insects which suck the sap or juice from the 

 tree or fruit and are called contact sprays. 

 Arsenical compounds have supplanted practi- 

 cally all other substances used to combat ex- 

 ternal biting insects. Two stomach poisons are 

 commonly used, namely, arsenate of lead and 

 parls green, but the former is rapidly replacing 

 the latter. 



Arsenate of Lead Is prepared by mixing 

 three parts of crystallized arsenate of soda with 

 seven parts of crystallized white sugar (acetate) 

 of lead in water, but It will not as a rule pay 

 the grower to mix his own material, as arsenate 

 of lead can be purchased In convenient commer- 



IIO 



