Hydrogen Peroxide as a Water Conditioner Adjuvant
Question: Some growers are looking at using industrial grade hydrogen peroxide as a water conditioner to replace ammonium sulfate under the assumption that it will “fix” hard water and offer uptake into the plant. They will be mixing it (at a 1 quart use rate) with the herbicides, insecticides, and fungicides in all their crops except for wheat.
One grower in particular has been using industrial grade hydrogen peroxide for a few years and says he’s seen better herbicide efficacy. He also uses it as a “fungicide” in his wheat at heading and for cercospora control in sugarbeets. Is there any validity to these statements?
Answer: I do not know the effect of hydrogen peroxide on insecticides and fungicides. Ammonium sulfate (AMS) is viewed as the standard for all water conditioning adjuvants. The sulfate in AMS ‘fixes’ water by binding with the antagonistic mineral (Ca, Na, Mg, Fe, etc). The ammonia has an equally important role as sulfate - by increasing absorption and translocation of weak acid herbicides. Weed scientists have found most water conditioners that do not contain any AMS are less effective than those that contain AMS – this includes hydrogen peroxide. Hydrogen peroxide (H2O2) does not have any sulfate or phosphate to bind antagonistic minerals nor does it have any nitrogen or ammonia to enhance absorption and translocation of herbicides. Hydrogen peroxide may have some other effect of helping herbicide through leaf barriers like the cuticle but it does not have components that condition water (sulfate) or enhance absorption and translocation through binding with nitrogen contained in fertilizer products.
You may want to reread the section in the weed control guide that addresses spray water quality:
Above you comment that the grower says: “he’s seen better herbicide efficacy” using industrial grade hydrogen peroxide. Better efficacy than what - no hydrogen peroxide? To make that statement valid the grower spray should spray part of the field with just the herbicide, then another part of the field with the herbicide and hydrogen peroxide. To determine if hydrogen peroxide “fixes” water the grower should also spray another part of the field with the herbicide plus current standard of AMS at 8.5 lb/100 gallons of water.