CHAPTER IX 



INSECTICIDES, FUNGICIDES AND SPRAY 

 MACHINERY 



The successfiil grower of sweet potatoes will be 

 called on to administer preventatives and remedies 

 for insect depredations and attacks of plant diseases. 

 It is, therefore, necessary that he should be familiar 

 with different chemicals used as poisons for insects and 

 as remedies for" plant diseases, and he should in addition 

 have a general knowledge of the kinds of spray machin- 

 ery and pumps with which to apply them. 



Of course, there are many areas in many localities 

 where remedies will not often be needed, but at certain 

 times the grower will probably have to resort to spraying 

 in order to control these pests and diseases. It is, 

 therefore, thought" necessary to give some information 

 concerning the more important sprays, and the differ- 

 ent forms of sprayers. 



INSECTICIDES- AND FUNGICIDES 



Arsenate of lead is one of the commonest insecticides 

 and the spray may be made as follows : 



3 to 5 pounds of arsenate of lead. 

 1 pound of fish-oil soap. 

 50 gallons of water. 



This makes an average solution that is commonly used 



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