Hostname: page-component-8448b6f56d-wq2xx Total loading time: 0 Render date: 2024-04-19T23:20:56.261Z Has data issue: false hasContentIssue false
  • English
  • Français

An investigation of the chemical changes taking place in the mixed lime sulphur-lead arsenate spray

Published online by Cambridge University Press:  27 March 2009

WM. Goodwin  and
H. Martin
WM. Goodwin
Affiliation:
(Research Dept. South-Eastern Agricultural College, Wye, Kent.)
H. Martin
Affiliation:
(Research Dept. South-Eastern Agricultural College, Wye, Kent.)
Get access Rights & Permissions [Opens in a new window]

Extract

1. The reaction between lime sulphur and acid lead arsenate is shown to be small and to have little effect on the chemical properties of either material as a spray.

2. It is shown that the oxidation of lime sulphur proceeds according to the empirical formula:

CaS.Sx + 30 = CaS2O3 + Sx-1

and that the calcium sulphides are hydrolysed in aqueous solution.

3. The addition of lead arsenate has no effect on the amount of sulphur precipitated from the lime sulphur by oxidation or by the action of carbondioxide.

4. Lead arsenate is only slightly decomposed by lime sulphur or by the oxidation products of lime sulphur, the main decomposition being due to the action of sulphuretted hydrogen formed by the hydrolysis of the calcium sulphides. This decomposition becomes marked in the presence of carbon dioxide which reacts on the calcium sulphide to form sulphuretted hydrogen.

5. The fungicidal value of the mixed spray—as judged by the mildew killing properties of the polysulphides—is not less than that of lime sulphur alone. Additional fungicidal properties may be expected from the presence in the spray of soluble arsenates and thioarsenates.

6. Judging by the chemical changes which take place in the mixed spray the insecticidal value of the lead arsenate would not appear to be greatly affected by the addition of lime sulphur.

7. There is an increased amount of soluble arsenic formed by the action of carbon dioxide on the mixed spray which may prove sufficient in amount to cause spray injury.

8. The A.O.A.C. method for the determination of sulphate sulphur in lime sulphur solutions is shown to be inaccurate. A method yielding more concordant results is proposed.

Type
Research Article
Information
The Journal of Agricultural Science , Volume 15 , Issue 3 , July 1925 , pp. 307 - 326
Copyright
Copyright © Cambridge University Press 1925

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

(1)Bradley, C. E. (1909). Jour. Ind. & Eng. Chem. 1, 8, p. 606.Google Scholar
(2)Bradley, C. E. and Tartar, H. V. (1910). Jour. Ind. & Eng. Chem. 2, 7, p. 328.Google Scholar
(3)Ruth, W. E. (1913). Iowa Expt. Sta. Bull. 12, p. 409.Google Scholar
(4)Robinson, R. H. and Tartar, H. V. (1915). Oregon Expt. Sta. Bull. 128, p. 32.Google Scholar
(5)Ellett, W. B. and Grissom, J. T. (1915). Virginia Expl. Sta. Tech. Bull. 8, p. 160.Google Scholar
(6)Robinson, R. H. (1919). Jour. Econ. Ent. 12, p. 429.CrossRefGoogle Scholar
(7)Thatcher, R. W. and Streeter, L. R. (1924). New York Expt. Sta. Bull. 521, p. 8.Google Scholar
(8)Eyre, J. V., Salmon, E. S. and Wormald, L. K. (1919). Jour. Agric. Science, 9, p. 283.CrossRefGoogle Scholar
(9)Horton, E. and Salmon, E. S. (1922). Jour. Agric. Science, 12, p. 269.CrossRefGoogle Scholar
(10)Waite, M. B. (1910). U.S. Dept. Agr. Bur. Plant Ind. Circ. 58.Google Scholar
(11)Morse, W. J. (1918). Maine Expt. Sta. Bull. 271, p. 101.Google Scholar
(12)Sanders, G. E. and Dunstan, A. G. (1919). Canada Dep. Agric., Entom. Branch Bull. 16.Google Scholar
(13)Franklin, H. J. (1919). Mass. Expt. Sta. Bull. 192.Google Scholar
(14)Pike, M. P. (1918). Fruitgrowers’ Assoc. Nova Scotia Ann. Rept. 54.Google Scholar
(15)Tartar, H. V. (1914). Oregon Expt. Sta. Res. Bull. 3.Google Scholar
(16)Shafer, G. D. (1911). Mich. Expt. Sta. Tech. Bull. 11.Google Scholar
(17)Beckerich, A. (1922). Progrès agric. et vitic. 48, p. 522.Google Scholar
(18)Lovett, A. L. and Robinson, R. H. (1916). Jour. Agr. Res. 10, p. 199.Google Scholar
(19)Goodwin, W. and Martin, H. (1925). Jour. Agric. Science, 15, p. 96.CrossRefGoogle Scholar
(20)Gooch, F. A. and Browning, P. E. (1908). United Sta. Dept. Agr. Bur. Chem. Bull. 107, p. 239.Google Scholar
(21)Bedford, , Duke of, and Pickering, S. U. (1909). 11th Rept. Woburn Expt. Fruit Farm, p. 54.Google Scholar
(22)Divers, E. and Shimidzu, T. (1884). Jour. Chem. Soc. Trans. 45, p. 270CrossRefGoogle Scholar
(23)Auld, S. J. M. (1915). Jour. Chem. Soc. Trans. 107, p. 480.CrossRefGoogle Scholar
(24)Jones, C. P. (1923). Jour. Agric. Res. 25, No. 7, p. 323.Google Scholar