When weather and workload does not permit the application of preemergence herbicides prior to planting, there are options. Some preemergence herbicides are labeled for broadcast application after corn and soybean emergence without injury. Additionally, early post-crop emergence herbicide applications including these herbicides are beneficial for controlling weed species with extended emergence (e.g., waterhemp and Palmer amaranth). Overlapping residual activity from preemergence herbicides from pre-plant through canopy closure is a common approach due to herbicide resistant weeds and limited field days suitable for spraying. I do get asked on flexibility of these products. Therefore, the following herbicides are labeled for corn and soybean. There are other options for corn-only and soybean-only products. The list is not exhaustive and not an endorsement. Site of action group and active ingredients are listed after the product name and company. Please read all herbicide labels prior to purchase and application. Tank mix partners are needed or recommended with these preemergence herbicides for control of emerged weeds. As I work with numerous winter wheat and alfalfa growers in southeast Nebraska, included is the crop planting interval restriction in months.
Anthem MAXX by FMC Ag US (Group 14 – Fluthiacet-methyl, Group 15 – Pyroxasulfone). May be applied to corn through the V4 stage and soybean through the V6 stage. Some control of emerged weeds up to 2-inches. Rotational wheat interval is dependent on use rate, 3.25 oz/acres or less is 1 month, 4.87 oz/acre or more is 3 months. Alfalfa interval is 10 months. Link to website/label: https://ag.fmc.com/us/en/herbicides/anthem-maxx-herbicide
Dual II Magnum by Syngenta (Group 15 – S-metolachlor). May be applied to corn up to 40-inches tall and soybean up to 75 days before harvest. It will not control emerged weeds. The rotational wheat interval is 4.5 months and alfalfa is 4 months. Link to website/label: https://www.syngenta-us.com/herbicides/dual-ii-magnum
Outlook by BASF (Group 15 – Dimethenamid-P). May be applied to corn up to 12-inches or layby up to 36-inches tall and soybean from cracking/emergence to 5th trifoliate stage. It will not control emerged weeds. The rotational wheat and alfalfa interval is 4 months. Link to website/label: https://www.cdms.net/ldat/ld3LS013.pdf
Perpetuo by Valent (Group 14 – Flumiclorac, Group 15 – Pyroxasulfone). May be applied to corn from the 2-leaf stage through the V6 stage and soybeans through the V6 stage. Some control of emerged weeds is expected, but does vary by weed species, height, and use rate. The rotational wheat interval is dependent on use rate, 8 oz/acres or less is 1 month, 10 oz/acre or more is 4 months. Alfalfa interval is 10 months. Link to website/label: https://s3-us-west-1.amazonaws.com/agrian-cg-fs1-production/pdfs/Perpetuo_Label.pdf
Vida by Gowan (Group 14 – Pyraflufen ethyl). May be applied to corn from VE to V4 stages or directed postemergence to V8 stage and soybean emergence to V6 stage. It will control some broadleaf weeds up to 4-inches tall. The rotational wheat interval is 0 months and alfalfa is 1 month. Link to website/label: https://www.gowanco.com/products/vida
Warrant by Bayer (Group 15 – acetochlor). May be applied to corn up to 30-inches tall and soybean prior to R2 stage. It will not control emerged weeds. The rotational wheat interval is 4 months and alfalfa is 9 months. Link to website/label: https://www.cropscience.bayer.us/products/herbicides/warrant/label-msds
Zidua SC by BASF (Group 15 – Pyroxasulfone). May be applied to corn from spiking to V8 stage and soybean from emergence to 6th trifoliate. It will not control emerged weeds. Rotational wheat interval is dependent on use rate, 3.25 oz/acres or less is 1 month, 5 oz/acre is 5 months, 6.50 oz/acres is 6 months. Alfalfa interval is 10 months. Link to website/label: https://www.cdms.net/ldat/ldE0R027.pdf
For inquiries regarding this information and other agronomic resources from Nebraska Extension, contact me at or 402-821-1722. Know your crop, know your tech, know your bottom line at croptechcafe.org.
