Herbicide label
GR1 Herbicide Label
GR1 (EPA 279-9623) is a Group 2 pyroxsulam herbicide labeled for 2 crops. The label lists 42 controlled weeds, plus partial-control, suppression, and partner-control categories.
GR1 label facts
- Product GR1
- EPA Reg. No. 279-9623
- Registrant FMC Corporation
- Active ingredient pyroxsulam
- MOA group 2
Crops on the GR1 label
GR1 is labeled for these 2 crops and uses, per the EPA label.
Weeds on the GR1 label
The GR1 label names 54 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 control42- barnyardgrass, common
- blackgrass
- bluegrass, bulbous
- brome, downy
- brome, japanese
- brome, ripgut
- cheat
- chess, hairy
- corn, volunteer
- foxtail, yellow
- wild oats
- ryegrass, italian
- windgrass, common
- bedstraw, catchweed (cleavers)
- bittercress, hairy
- burclover, spotted
- buttercup, smallflower
- canola, volunteer (wild turnip)
- chickweed, common
- chickweed, mouseear
- clover, white
- falseflax, smallseed
- fiddleneck
- flixweed
- carolina geranium
- gromwell, corn
- hempnettle, common
- lambsquarters, common
- mustard, black
- mustard, blue
- mustard, tumble
- mustard, wild
- mustard, wormseed
- pennycress, field
- pepperweed, virginia
- pigweed, redroot
- shepherd's-purse
- smartweed, annual
- tansymustard, pinnate
- thistle, russian
- vetch, hairy
- wallflower, bushy
Suppression
suppression10- foxtail barley
- canarygrass, hood
- canarygrass, littleseed
- foxtail, green
- quackgrass
- rescuegrass
- coreopsis, plains
- evening-primrose, cutleaf
- henbit
- buckwheat, wild
Controls with a tank-mix partner
needs partner2- lambsquarters, common over 2 inches tall
- thistle, Russian over 2 inches tall
GR1 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.
GR1 FAQ
What weeds does GR1 control?
The GR1 label names 54 weeds, including common barnyardgrass, blackgrass, bulbous bluegrass, downy brome, japanese brome, and ripgut brome. Control varies by crop, rate, and timing.
What crops is GR1 labeled for?
GR1 is labeled for 2 crops and uses, including winter wheat and triticale.
What is the active ingredient in GR1? Is it a generic?
GR1's active ingredient is pyroxsulam (MOA Group 2). Other products list the same active ingredient; rates, formulations, and labeled crops differ — verify each on its own label.
Sources
Last updated 2026-09-17.