INSECTICIDES 485 



hot water gradually in sufficient quantity to produce the most 

 rapid slaking of the lime. If too much water is added at first, 

 it ''drowns" the lime and slaking takes place very slowly. 

 When the lime begins to slake add the sulfur and stir it in thor- 

 oughly. When the slaking is completed add more water and 

 boil the mixture about one hour. As the lime and sulfur go 

 into solution a rich orange-red or olive-green color will appear, 

 depending on the kind of lime used. After boiling one hour 

 add water to the required amount and strain into the spray 

 tank. This wash is most effective when applied warm, but may 

 be used cold. 



Owing to the excess of lime used a solution made by the above 

 method will contain a large quantity of sediment. As this sedi- 

 ment is liable to clog the nozzles and interfere with the appli- 

 cation of the wash, and as it has little insecticidal value, this 

 method of preparation has been abandoned by most commercial 

 growers, who now use the concentrated solution. 



Concentrated commercial lime-sulfur. — There are on the mar- 

 ket many brands of the concentrated lime-sulfur solution. 

 They usually test from 30 to 33 degrees Beaume and should 

 for use be diluted according to the table given above. 



Self -boiled lime-sulfur. — This preparation is used primarily 

 as a fungicide for the prevention of brown rot on stone fruits. 

 This is not a boiled solution, as might be inferred from the name. 

 It is prepared by placing in a barrel 8 pounds of the best stone 

 lime, to which is added a small quantity of cold water in order 

 to start it slaking. Eight pounds of sulfur worked through a 

 sieve to break up the lumps is then added slowly to the slaking 

 lime, which is kept from burning by the addition of just enough 

 cold water so as not to drown it. The slaking mixture must 

 be stirred constantly. Just as soon as the slaking is completed 

 (which should be in five to fifteen minutes) , fill the barrel with 

 cold water (50 gallons). The mixture is strained into the 

 sprayer tank through a sieve of 20 meshes to the inch. It must 



