276 SUCCESSFUL FARMING 



must always be used. Even the sulphur alone thickly strewn over leaves 

 is a fairly good remedy for mildew. A very small quantity of the sulphur 

 dissolved in the presence of lime renders it more effective both as an insect- 

 icide and as a fungicide. 



COMBINED INSECTICIDES AND FUNGICIDES 



The cost of treatment for pests is greatly increased by the necessity 

 for frequent spraying when insecticides and fungicides are used separately. 

 They have been combined in some cases with no loss in the effectiveness of 

 either, and one of the important problems of both entomologists and plant 

 pathologists at the present time is the finding of ways and means of reducing 

 the number of sprayings still further. 



Some work in determining the compatibility of different mixtures has 

 already been done, and it may be said that the following mix without loss 

 and in some cases with a gain in effectiveness: 



Arsenate of lead (acid) and Bordeaux mixture. 



Arsenate of lead and tobacco. 



Arsenate of lead and acids. 



Arsenate of lead (neutral) and Bordeaux mixture. 



Arsenate of lead (neutral) and lime-sulphur. 



Arsenate of lead (neutral) and tobacco. 



Paris green and Bordeaux mixture. 



Arsenite of lime and Bordeaux mixture. 



Arsenite of lime and tobacco. 



Lime-sulphur and tobacco. 



Soaps and Bordeaux mixture. 



Soaps and tobacco. 



Soaps and emulsions. 



Tobacco and lime-sulphur. 



Tobacco and soaps. 



Tobacco and emulsions. 



Tobacco and alkalies. 



Some dangerous combinations are the following: 



Arsenate of lead (acid) and soaps. 



Arsenate of lead (acid) and emulsions. 



Arsenate of lead (acid) and alkalies. 



Arsenate of lead (neutral) and acids. 



Arsenite of zinc and lime-sulphur. 



Arsenite of zinc and soaps. 



Arsenite of zinc and emulsions. 



Arsenite of zinc and alkalies. 



Arsenite of zinc and acids. 



Hydrocyanic acid gas and Bordeaux mixture. 



