REPORT OP COMMITTEE ON PUBLICATION 171 



soluble and if accumulated in sufficient quantity would be an undesirable soil 

 constituent. The quantity is smdll, however, and would be washed away by 

 drainage water. 



THE HOME PREPARATION OF SOME SULPHUR FUNGICIDES. 



Pottassium Polysulphide: In discussing the control of the red spider 

 which in this State is a serious menace to many varieties of fruit trees, 

 Volcki gives the following directions for the preparation of a stock solution 

 of sulphide of potash: 



"Granulated, or powdered concentrated lye, 15 pounds; sulphur, 18 

 pounds; water to make 20 gallons. Stir the sulphur and lye together in a 

 vessel which will allow plenty of room for boiling. When well mixed, add 

 about one pint of water, placing it in a slight hollow in the mixture, and stir 

 in slowly. The mixture will soon begin to melt and boil, forming a red 

 fluid; stir until the boiling ceases, and then add water to make 20 gallons. 

 This stock solution will keep for awhile, or indefinitely when protected from 

 the air." 



The finished spray was made up as follows: 



"Place 10 to 15 pounds of sublimed sulphur, or 14 to 20 pounds of ground 

 sulphur in the spray tank with 4 gallons of flour paste and 1 to 2 gallons of 

 the sulphid of potash stock solution; add water to make 100 gallons. For 

 summer or spring spraying after the danger of rains is over, the minimum 

 amount of sulphur is sufficient." 



Excellent results were obtained by the use of this spray against the red 

 spider on almond trees in full leaf. It was found that "dry sulphur is usually 

 successful as a partial control. Sulphur spraying has been found many times 

 more efficient than other methods of application and is perfectly successful 

 where dry sulphuring has failed." The sulphide of potash stock solution of 

 Volck would contain potassium polysulphides and pottasium thiosulphate as 

 the chief ingredients of fungicidal value. The solids would contain about 

 54 per cent, of sulphur and each gallon would carry nine-tenths of a pound of 

 sulphur in all forms. 



Sodium Polysulphide: In 1907, Haywoodi proposed a substitute for the 

 lime-sulphur-salt wash and gave the following directions for its preparation. 



"Water gallons 50 



"Powdered Sulphur pounds 19 



"Caustic soda pounds 10 



"The wash is mixed as follows: Make a paste of the sulphur with not 

 more than 5% gallons of boiling water; at once add all the caustic soda, 

 which has previously been broken up into pieces the size of a hickory nut or 

 smaller, and stir occasionally for one-half hour. At the end of this time add 

 44% gallons of water, stir, and the wash is ready for use. 



""An analysis of the liquid portion of this wash for sulphur compound 

 shows the following composition: 



Grams per 100 c.c. 



"Sulphur as thiosulphates 0.63 



"Sulphur as polysulphids and sulphids 2.85 



"Sulphur as sulphates and sulphites 01 



"Total sulphur 3.49" 



i Volck, W. H., "Sulphur Sprays for Red Spiders," Calif. Agr. Expt. Sta. 

 Bui. 154, page 10 (1903). 



i Haywood, J. K., "The Lime-sulphur-salt Wash and Its Substitutes." U. 

 S. D. A. Bur. Chem. Bui. 101, page 28 (1907). 



