The following quick reference divides common residual pre-emerge soybean herbicide mode of action families into general categories based upon their effectiveness against amaranth species (specifically waterhemp). This resource also notes general effectiveness against grasses, large seeded broadleaves, and small seeded broadleaves. The reference does not substitute for the grower reading the label to determine a product’s ability to control specific weed species. Instead, this list should be viewed as a tool. Consult it initially, but follow that consultation with a review of the specific product’s label. Remember, the label is the law.
Additionally, this resource does not incorporate resistance concerns. Multiple modes of action improve a product’s ability to stall resistance development. To review a more complete presentation of resistance concerns as they relate to pre-emerge amaranth control, tune into our three part Burrus Agronomy U series. Here is sesson one:
* Significant concern over the long-term viability of single modes of action
** Products arranged in relative descending amaranth efficacy
*** Also includes HRAC 2
**** Not suited to minimum/no-till systems
Note: always consult the label before making final pest management decisions
Note: always consult the label to review cropping intervals before making final pest management decisions