Orchard Pests and their Control 385 



By this we do not mean that the spray should be com- 

 posed mostly of large drops produced by the breaking up 

 of a solid stream thrown forcibly into the air, or that it 

 should not be a fine mist or fog. A rather coarse ver- 

 morel, or a good bordeaux nozzle with a pressure of 100 

 or 125 pounds, will furnish such a spray. When spraying 

 is being done to destroy leaf -eating insects, care should be 

 taken not to spray too long in one place, as this will result 

 in the little drops that collect on the leaves uniting and 

 running off, carrying the poison with them. Here, again, 

 this rule does not apply to the first treatment for the 

 codlin-moth. In that application there should be but 

 one end in view, and that to fill every blossom-end or 

 calyx-cup with the spray. 



Two types of nozzles are used almost exclusively for 

 the distribution of liquids. Perhaps the most popular 

 are the bordeaux and the clipper nozzles, which throw a 

 flat spray or a solid stream, and the vermorel nozzles 

 which throw a cone-shaped spray which may be graded 

 from medium coarse to extremely fine, depending upon 

 the pressure and the tip that is used upon the nozzle. 

 It is a big advantage in nozzles of this class to have them 

 joined to the connecting end so they may be turned at 

 any angle to the rod that is desired. 



Any of these nozzles may be used singly or in batteries 

 of two or more. 



FORMULAS 



Arsenate of Lead. This compound contains only about 20 

 to 25 per cent of arsenious acid, but has some important ad- 

 vantages over the other arsenical compounds. It is so slightly 

 soluble in water that it may be used in almost any strength with- 

 out injuring foliage, and consequently is least likely to injure 

 2c 



