12 BULLETIN 712, U. S. DEPARTMENT OF AGRICULTURE. 



uing, add li gallons of commercial lime-sulphur solution ; then add commercial 

 sulphuric acid until the yellow color is almost but not entirely replaced by 

 white. It usually requires about 0.9 pint of sulphuric acid for 1^ gallons of lime- 

 sulphur solution. When arsenate of lead is to be used in combination with this 

 material it should be added after the acid. Colloidal sulphur spray made up 

 in this manner analyzes approximately as follows, depending upon the composi- 

 tion of the lime-sulphur used: Polysulphid sulphur (calcium as sulphur), 0.09 

 per cent; thiosulphate sulphur (calcium as sulphur), 0.08 per cent; sulphate 

 sulphur (calcium as sulphur), 0.08 per cent; free sulphur, 0.41 per cent; 

 insoluble matter other than sulphur, 0.009 per cent. 



Formula 9. — Finely ground sulphur material of the following composition: 

 "Water, 41.44 per cent; sulphur, 55.15 per cent; organic matter (in the form of 

 glue), 1.94 per cent; ash, 1.47 per cent. Dilute to 7. pounds to 50 gallons of 

 water. 



Formula 10. — Finely ground sulphur material of the following composition: 

 Water, 14.82 per cent ; sulphur, 76.72 per cent ; organic matter, 1.80 per cent ; 

 ash, 6.66 per cent, Dilute to 6 pounds to 200 gallons of water. 



Formula 11. — Sodium-sulphur material of the following composition : Sodium 

 polysulphid, 56.84 per cent; sodium thiosulphate, 36.56 per cent; sodium sul- 

 phate, 0.66 per cent ; free sulphur, 3.38 per cent ; iron and aluminum oxids, 0.14 

 per cent ; water, 2.42 per cent. Dilute to three-quarters pound to 50 gallons 

 of water. 



Formula 11a. — Same as formula 11, but diluted to li pounds to 50 gallons of 

 water. 



Formula 12. — Sodium-sulphur material of the following composition : Sodium 

 polysulphid, 55.06 per cent ; sodium thiosulphate, 40.80 per cent ; sodium sul- 

 phate, 2.17 per cent ; free sulphur, 1.56 per cent ; water, 0.41 per cent. Dilute 

 to 1 pound to 50 gallons of water. 



Formula 12a. — Same as formula 12, but diluted to 1* pounds to 50 gallons of 

 water. 



Formula 13. — Barium-sulphur material of the following composition: Barium 

 polysulphid, 67.44 per cent ; barium thiosulphate, 8.67 per cent ; barium sulphate, 

 5.15 per cent ; free sulphur, 17.28 per cent ; water, 1.46 per cent. Dilute to 



4 pounds to 50 gallons of water. 

 Formula 14- — Bordeaux mixture, 4-4-50. 



Formula 15. — Ammoniacal copper carbonate prepared as follows : Dissolve 



5 ounces of copper carbonate in 3 pints of ammonia (25 per cent solution, 

 which should be diluted before using). Dilute to 50 gallons in spray tank. 



Formula L. — Lead-arsenate paste, 2 pounds to 50 gallons of water, or pow- 

 dered lead arsenate, 1 pound to 50 gallons. Where used in combination with 

 fungicides, this designation appears in the spraying schedule, together with the 

 number of the fungicidal formula. 



Formula S. — Soap. The addition of 2 pounds of potash-fishoil soap to 50 

 gallons of spray for a spreader is indicated where this designation appears, 

 together with the number of the fungicidal formula in the spray schedule. 



SPRAYING EXPERIMENTS IN 1915. 



The results of the spraying experiments conducted in 1915, together 

 with the resulting spray injury and the control established, are 

 shown in Table I. 



Aside from the foliage injury shown in Table I, very severe burn- 

 ing of exposed fruits was noted on June 9 on the south and south- 

 west sides of the trees. An estimate of this burning in the various 

 plats was not attempted because of the almost entire absence of a 



