Surfactant and/or additive burn reported in Midsouth cotton

We heard a couple of reports late in the week about burning in cotton. The effect appears to be linked to surfactants and/or additives.

• Tennessee Extension Cotton Specialist Scott Stewart said he looked at some cotton that “extreme” surfactant burn. “Products used were Roundup Original Max + Bidrin + surfactant + AMS. Roundup Original Max has a heavy surfactant load as is, and adding more surfactant to it - along with Bidrin or really any OP insecticide which can act like a surfactant - will often cause serious leaf burn. Adding surfactants to the glyphosate products that already contain surfactant and then mixing with insecticides like Bidrin, Orthene or dimethoate is not recommended.”
• In his firm’s Sunday Ag Report, Roger Carter of AMS, Inc., in Clayton, La., noted: “We have noticed some extreme burn this year from combinations of glyphosate, Staple, and/or insecticide and various additives. When adding Staple or insecticide to OMax or WeatherMax, do not add any adjuvant including ammonium sulfate. Otherwise, expect more physical burn. Cotton will recover quickly and be a green field once again in about 10 days, but will look ugly for at least seven days.”