I SOLUTIONS FOR SPRAYING 145 



lead. Other combinations can be used with equal facil- 

 ity, but these two are the most common. 



These combinations give quite as good results as 

 the same chemicals applied separately. In fact paris 

 green is better when mixed with bordeaux, as the lime 

 tends to neutralize the free acids, which sometimes 

 burn the foliage. Again, bordeaux mixture is im- 

 proved by the addition of arsenate of lead, as it sticks 

 to the foliage much better. Of course there is no more 

 labor required to put on both the insecticide and the 

 fungicide than there would be needed to put on either 

 one separately. The saving of labor is the chief item, 

 and it is a very large one. 



DUST SPRAYS 



A few years ago considerable interest was aroused 

 by the introduction of dust sprays^ but these have now 

 been almost abandoned. The chemicals are simply 

 made up in dry form, very finely pulverized, and are 

 thrown upon the trees from a powerful blower. Paris 

 green is mixed with a little lime or with fine road 

 dust or other practicable dry powder. 



Dust spraying -is easier and cheaper than liquid 

 spraying; but experience everywhere shows that it is 

 very much less efficient. It cannot be depended on to 

 control fungous diseases to any extent. In fact, the 

 only service which it can perform with any degree of 

 efficiency is the control of the codling moth. Even in 

 this it is less successful than equally careful applica- 

 tions of liquid insecticides. 



On account of their lightness and portability the dust 

 blowers can be handled in some orchards which are 

 so stony and rough that ordinary spray pumps can- 

 not be used. On such land the dust method of spray- 



