Pomona College Journal of Economic Botany 



51 



The mixture should be strained through a sieve of 20 meshes to the inch 

 in order to remove the coarse particles of the lime, but all of the sulphur 

 should be worked through the strainer. 



The amount of water required to make the best mixture depends largely 

 upon the lime. Some grades of lime respond quickly and take a large 

 quantity of water, while others heat up slowly and are easily "drowned" 

 if too much water is added at once. Hot water may be used to good ad- 

 vantage in preparing the mixture with sluggish lime, but with quick acting lime 

 hot water is not necessary and is more likely to bring too much of the 

 sulphur into solution. If desired, the mixture may be kept for a week 

 without deterioration, but should be thoroughly stirred before using. 



In applying the self-boiled lime-sulphur mixture the spraying outfit should 

 be equipped with a good agitator. The mixture settles to the bottom of 

 the tank, and unless kept thoroughly agitated cannot be evenly applied. For 

 a power sprayer the propeller type of agitator is most suitable. The agitator 

 of the ordinary barrel sprayer is not unusually adequate and when used 

 should be supplemented with frequent hand agitation." — U. S. Dept. of Agrcl. 

 Circ. No. 2"/, pp. 5-6, 1909. W. M. Scott. 



Regarding this mixture Dr. Woods wrote Mr. Culbertson : 



"Of course, we have not tried these mixtures on oranges and lemons, but 

 Mr. Scott suggests that the mixture made of 8 pounds of sulphur, 8 pounds 

 of lime, and 50 gallons of water would be the best for this purpose. This 

 would probably control the wither-tip and to a considerable extent prevent 

 the development of the sooty mould following aphis and scale." 



POTASSIUM OR SODIUM SULPHID SPRAY 



As recommended by Prof. Rolfs in Bull. 52: 



FORMULA 



Dilute four quarts of above mixture to 50 gallons of water. 



Place 30 pounds of flowers of sulphur in a wooden tub large enough to 

 hold 25 gallons. Wet the sulphur with 3 gallons of water; stir it into a 

 paste. Then add 20 pounds of 98% caustic soda (28 pounds should be 

 used if the caustic soda is 70%) and mix it with the sulphur paste. In a 

 few minutes it becomes very hot, turns brown and becomes a liquid. Stir 

 thoroughly and add enough water to make 20 gallons. Pour off from the 

 sediment and keep the liquid as a stock solution in a tight barrel or keg. 

 Of this solution use 4 quarts to 50 gallons of water. 



Important. — (In regard to the use of this spray in California see the 

 letter from Mr. R. C. Allen of San Diego County, in Mr. Culbertson's paper. 

 Also see what Mr. Culbertson says about this.) 



The potassium sulphid is made as above only when diluted for use add 

 1 ounce of stock solution to 2 gallons of water. 



Flowers of sulphur 

 Caustic soda (98%) 

 Water to mix 



...30 lbs. 

 ....20 lbs. 

 .20 gals. 



