272 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 6 



successful in controlling the Pernicious Scale. The directions accom- 

 panying the commercial productions usually give the dilution one part 

 of lime-sulphur to thirteen parts of water. The resultant spray is 

 satisfactory and efficient if all conditions are right, but usually they 

 are not. In our work we are inclined to recommend that the dilution 

 be one to nine, while some growers go farther and say that one to six 

 is not too strong. Naturally we find some difference in the commercial 

 products, but it is safe to say that most of the reputable houses aim 

 to make them all about the same strength; and so we find Rex as good 

 as Ortho, these being practically the only commercial sprays now used 

 in California. 



3. The methods of application: To my mind the right application of a 

 spray is often more important than any other factor. A poorly made 

 product is often efficient if plentifully and thoroughly applied. 



Pumps. Always the first consideration is a good pump. The best, 

 of course, is a power machine. Some hand pumps give fairly good 

 results but for the best work the growers, even those owning ten and 

 twenty-acre orchards, are coming to see the efficiency behind the power 

 sprayer. Many are clubbing together and securing jointly such a 

 machine, which is capable of spraying all their orchards thoroughly 

 several times a year. 



Pressure. In application, pressure is the greatest consideration. It 

 must be sufficiently and evenly maintained in order to drive either a 

 fine or coarse spray with force enough to drench the most secluded 

 and protected spots. It should not fall below one hundred and fifty 

 pounds to the square inch, while two hundred pounds is much to be 

 desired, and should be insisted upon. 



Nozzles. The spray for the particular pest in question should be 

 fairly coarse and driving and applied with some such nozzle as the 

 "Whirlpool," "Jumbo," "Mistry, Jr.," "Friend," etc., using a large- 

 holed disc. The angle nozzle or a straight nozzle on an angle nipple 

 is certainly an improvement over the old straight form, making it 

 possible to easily and quickly reach any portion of the tree from any 

 position. In our work we use two nozzles to a hose, employing a 

 straight "Y" with angle nozzles, or an angle "Y" with straight 

 nozzles. 



Thoroughness. One good application is worth many poor ones. 

 It has been found that one thorough spraying accomplishes as much in 

 controlling the codling moth as three poor ones did under older and 

 more careless methods. The same is true of the Pernicious Scale. 

 Every part of the tree should be drenched. The tops are never exempt, 

 even though some of the material gels into your eyes. It seems to be 

 a common practice to omit the upper third of the tree. Last year I 



