Skip to main content Accessibility help

Substitutes for Ammonium Sulfate as Additives with Glyphosate and Glufosinate

  • David Pratt (a1), James J. Kells (a1) and Donald Penner (a1)


Glyphosate and glufosinate are now options for postemergence weed control in herbicide-resistant corn and soybean. Velvetleaf is one of the more difficult to control annual weeds with these herbicides at commonly used rates. Ammonium sulfate (AMS) is generally used with these herbicides to overcome hard water antagonism and to increase herbicide activity. Greenhouse and field trials were conducted with commercial adjuvants that might substitute for AMS. The adjuvants were evaluated in deionized water, tap water, and deionized water containing 500 mg/L CaCO3. In the absence of AMS, hard water reduced velvetleaf control with both herbicides. Regardless of water source, AMS increased velvetleaf control with both glyphosate and glufosinate. Several adjuvants increased velvetleaf control with either herbicide; however, none were superior to 2% w/v AMS. Other adjuvants decreased velvetleaf control with either herbicide.


Corresponding author

Corresponding author's E-mail:


Hide All
Blair, A. M. 1975. The addition of ammonium salts or a phosphate ester to herbicides to control Agropyron repens (L.) Beauv. Weeds Res. 15: 101105.
Hall, G. J., Hart, C. A., and Jones, C. A. 2000. Plants as sources of cations antagonistic to glyphosate activity. Pest Manag. Sci. 56: 351358.
Nalewaja, J. D. and Matysiak, R. 1993. Influence of diammonium sulfate and other salts on glyphosate phytotoxicity. Pestic. Sci. 38: 7784.
Nelson, D. W. 1983. Determination of ammonium in KC1 extracts of soils by the salicylate method. Commun. Soil Sci. Plant Anal. 14: 10511062.
O'Sullivan, P. A., O'Donovan, J. T., and Hamman, W. M. 1981. Influence of non-ionic surfactants, ammonium sulfate, water quality and spray volume on the phytotoxicity of glyphosate. Can. J. Plant Sci. 61: 391400.
Pline, W. A., Hagood, E. S., and Hatzios, K. K. 1999. Absorption, translocation, and metabolism of glufosinate in five weed species as influenced by ammonium sulfate and pelargonic acid. Weed Sci. 47: 636643.
Suwunnamek, U. and Parker, C. 1975. Control of Cyperus rotundus with glyphosate: the influence of ammonium sulfate and other additives. Weed Res. 15: 1319.
Thelen, K. D., Jackson, E. P., and Penner, D. 1995. The basis for the hard water antagonism of glyphosate activity. Weed Sci. 43: 541548.
Turner, D. J. and Loader, M. P. C. 1975. Further studies with additives: effects of phosphate esters and ammonium salts on the activity of leaf applied herbicides. Pestic. Sci. 6: 110.


Substitutes for Ammonium Sulfate as Additives with Glyphosate and Glufosinate

  • David Pratt (a1), James J. Kells (a1) and Donald Penner (a1)


Altmetric attention score

Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed.