Can old friends become new enemies?

Soybeans in particular, it seems, had a hard time with chemical carry over in 2023. But it was also noticed at the margins back in 2022.

Should we be considering this issue for 2024, given the current drought status?

Much beyond the generic charts and label info on "months to next crop", more specific info about required rainfall/soil types/soil characteristics/degradation processes for each a.i./etc is difficult to come by.

Not for the lack of data, as the company responsible for a specific product would have said data. More likely, said data's shadowy existence, is likely due to the legal departments opinion on it's liability exposure. To be fair, that's probably smart given all the uncontrollable variables they're exposed to.

WITH THAT SAID, HERE'S SOME POPULAR PRODUCTS and pertinent WARNINGS:

• STINGER: (clopyralid)

  • 10.5 months to soybeans.

  • Also in WideMatch or Resicore.

  • 15" rain from application & can be released from degrading crop residue.

• ATRAZINE:

  • 10 months to soybeans.

  • "If applied after June 10th, do not rotate to crops other than corn or sorghum"

  • "Injury may occur to soybeans planted the year following application on soils having a calcareous surface layer"

• NORTRON: (ethofumesate)

  • 12 months to soybeans, following total rates of 12 oz or more.

  • 6 months to soybeans, following postemergence split applications, totaling 12 oz or less.

• CAPRENO:

  • 10 months to soybeans.

  • "15" rainfall accumulated from application to planting"

• ACURON:

  • "If applied after June 1, rotating to crops other than corn may result in injury"

  • The label also has a calcareous soil surface warning if atrazine is added.

• CALLISTO: (mesotrione)

  • 10 months to soybeans.

• ARMEZON PRO:

  • 9 months to soybeans.

Generally speaking, some other look outs that exacerbate herbicide carryover are drought, low organic matter soils, high pH soils, sandy soil structure.

Also of note. Late season rain doesn't have the same effect on chemical degradation that in season rain does. As the primary function for breaking down chemistry is microbial activity. Which gradually slows down as the fall progresses towards winter. So this "cruel joke" nature is playing on us the past few weeks, won't quite have the catch up effect one would hope.

RAIN FALL TOTALS FROM mid JUNE - late OCTOBER for 2020 - present.