Herbicide label
IMPACT SWT Herbicide Label
IMPACT SWT (EPA 5481-689) is a Group 27 topramezone herbicide labeled for 3 crops. The label lists 40 controlled weeds, plus partial-control, suppression, and partner-control categories.
IMPACT SWT label facts
- Product IMPACT SWT
- EPA Reg. No. 5481-689
- Registrant Amvac Chemical Corporation
- Active ingredient topramezone
- MOA group 27
Crops on the IMPACT SWT label
IMPACT SWT is labeled for these 3 crops and uses, per the EPA label.
Weeds on the IMPACT SWT label
The IMPACT SWT label names 60 weeds and rates each by how the product handles it: full control, partial control, suppression, or control with a tank-mix partner. A weed can fall at more than one level, because control varies by crop, rate, and timing.
Controls
full control40- amaranth, palmer
- amaranth, powell
- barnyardgrass, common
- bermudagrass, common
- volunteer canola
- carpetweed
- chickweed, common
- cocklebur, common
- crabgrass, large
- crabgrass, smooth
- cupgrass, woolly
- foxtail, giant
- foxtail, green
- foxtail, yellow
- galinsoga, hairy
- goosegrass
- henbit
- jimsonweed
- johnsongrass, seedling
- lambsquarters, common
- prickly lettuce
- horseweed
- millet, wild-proso
- mustard, wild
- nightshade, black
- nightshade, eastern black
- nightshade, hairy
- panicum, fall
- pigweed, prostrate
- pigweed, redroot
- pigweed, smooth
- pigweed, tumble
- pusley, florida
- ragweed, common
- ragweed, giant
- shepherd's-purse
- sunflower, wild
- thistle, russian
- velvetleaf
- waterhemp, common
Partial control
partial20- bindweed, field
- buckwheat, wild
- burcucumber
- dandelion
- devil's-claw
- rhizome johnsongrass
- kochia
- ladysthumb
- mallow, common
- mallow, venice
- morningglory, entireleaf
- morningglory, ivyleaf
- panicum, texas
- purslane, common
- sandbur, field
- shattercane
- sida, prickly
- signalgrass, broadleaf
- smartweed, pennsylvania
- thistle, canada
IMPACT SWT rates and plant-back
The label answers both with a table, not a single number. Here is what drives each answer.
Application rate
Your rate depends on your crop.
Get the rate for your field: build a program and FieldMarshal gives you the exact per-acre rate for your crop from the label line.
Plant-back and rotation
Your interval depends on your application rate and the rotational crop.
Get the interval for your rotation: build a program and FieldMarshal gives you the exact plant-back for your rotational crop from the label line.
IMPACT SWT FAQ
What weeds does IMPACT SWT control?
The IMPACT SWT label names 60 weeds, including palmer amaranth, powell amaranth, common barnyardgrass, common bermudagrass, volunteer canola, and carpetweed. Control varies by crop, rate, and timing.
What crops is IMPACT SWT labeled for?
IMPACT SWT is labeled for 3 crops and uses, including sweet corn, sugarcane, and fallow.
What is the active ingredient in IMPACT SWT? Is it a generic?
IMPACT SWT's active ingredient is topramezone (MOA Group 27). Other products list the same active ingredient; rates, formulations, and labeled crops differ — verify each on its own label.
Sources
Last updated 2026-09-30.