SPRAYING 



247 



4. Do not try to save expense by scanty spraying. This may 

 prove to be very shortsighted economy. 



5. A high pressure maintained constantly is essential to the best 

 results. It must be sufficient to drive the spray well into the inte- 

 rior of the trees. In the application just after the blossoms fall — 

 the most important in controlling the codling moth — it is neces- 

 sary that the pressure be sufficient to drive the spray through the 

 interfering stamens and down 

 into the calyx cup. 



6. The poison must not be 

 adulterated, and must be used 

 in sufficient quantity. Paris 

 green is often adulterated with 

 some other material, and should 

 be tested by dissolving a small 

 quantity in ammonia, in which 

 it is entirely soluble. The 

 failure of any part of the solid 

 to dissolve within a few minutes 

 indicates adulteration. 



7. The lime should not be 

 air-slaked. Fresh stone lime 

 that has not been exposed to 

 air or moisture should be used. 

 The work of the lime is to 

 take up the free copper in Bor- 

 deaux mixture and the free ar- 

 senic in the arsenious poisons. 

 If the lime is weak it fails to 



perform this function, and the caustic copper or other poison will 

 seriously injure the leaves and fruit. 



8. The spray material should be stirred well while being applied. 

 It is of the utmost importance that a good agitator be kept going 

 constantly. This will make the mixture of the same strength through- 

 out, avoiding the danger of a weak solution in the upper part of the 

 tank and a strong one, dangerous to foliage, in the bottom. 



9. The solids must be dissolved separately. This is especially 

 true in the case of Bordeaux mixture. When the copper sulphate 



Fig. 1 13. A small compressed-air sprayer 



Practical for the home gardener or for very 

 young trees 



