Ontario producers who want to apply sulphur in dry beans have considered using ammonium thiosulphate (ATS) as a herbicide carrier. Jar tests are a good way to evaluate mixes before putting them in the spray tank. A jar was test conducted with ATS and Dual II Magnum.
In the photo below, the jar on the right contains the standard mixture of Dual II Magnum and water at a ratio consistent with 700 mL/ac Dual and 20 gal/ac of water, resulting in the expected “skim milk” consistency. The jar on the left contains Dual II Magnum and ATS at the same ration, and the two products did not mix well.
This result is consistent with jar tests of ATS as a carrier for other liquid herbicides, particularly emulsified concentrates. Application of a mixture like the jar on the left, where products remain separated, could results in poor weed control or elevated crop injury. Using ATS rather than water is not recommended in most cases. Including ATS at lower doses may result in better mixing, but mixing sequence is important. Herbicides should be mixed as usual first, before adding ATS.