Herbicide label
Grassmaster Herbicide Label
Grassmaster (EPA 81927-42) is a Group 4 2,4-d and dicamba herbicide labeled for 16 crops. The label lists 79 controlled weeds, plus partial-control, suppression, and partner-control categories.
Grassmaster label facts
Crops on the Grassmaster label
Grassmaster is labeled for these 16 crops and uses, per the EPA label.
Weeds on the Grassmaster label
The Grassmaster label names 89 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 control79- amaranth, palmer
- beebalm, spotted
- bindweed, field
- bittercress
- broomweed, annual
- buckwheat, wild
- buffalobur
- burdock
- buttercup
- carrot, wild
- chickweed, common
- chicory
- clover, bur
- cockle, cow
- cocklebur, common
- coreopsis, plains
- croton, woolly
- dandelion, common
- devil's claw
- dock, curly
- dogfennel
- evening primrose
- falseflax, smallseed
- fleabane, annual
- flixweed
- goldenrod, common
- goldenrod, missouri
- groundsel, texas
- henbit
- honeysuckle, hairy
- poison ivy
- knapweed, black
- knapweed, russian
- knapweed, spotted
- knotweed spp.
- kochia
- lambsquarters, common
- prickly lettuce
- mallow, common
- marestail (horseweed)
- marshelder
- mayweed
- milkweed
- morningglory, ivyleaf
- morningglory, tall
- mustards, annual
- nightshade, black
- nightshade, silverleaf
- pennycress, field
- pepperweed, virginia
- pigweed, prostrate
- pigweed, redroot
- pigweed, rough
- pigweed, smooth
- pigweed, tumble
- poorjoe
- purslane, common
- ragweed, common
- ragweed, lanceleaf
- ragweed, western
- ragwort, tansy
- sage, lanceleaf
- salsify, western
- shepherd's-purse
- smartweed, pennsylvania
- sneezeweed, bitter
- sorrel, red
- sowthistle, annual
- sunflower
- thistle, bull
- thistle, musk
- thistle, plumeless
- thistle, russian
- velvetleaf
- vetch, hairy
- waterhemp, common
- yankeeweed
- starthistle, yellow
- sedge
Suppression
suppression10- buckeye species
- bullnettle
- dewberry, southern
- horsenettle
- mesquite
- rabbitbrush
- redvine
- sowthistle, perennial
- spurge, leafy
- thistle, canada
Grassmaster 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.
Grassmaster FAQ
What weeds does Grassmaster control?
The Grassmaster label names 89 weeds, including palmer amaranth, spotted beebalm, field bindweed, bittercress, annual broomweed, and wild buckwheat. Control varies by crop, rate, and timing.
What crops is Grassmaster labeled for?
Grassmaster is labeled for 16 crops and uses, including field corn, soybeans, wheat, cotton, and barley.
What is the active ingredient in Grassmaster? Is it a generic?
Grassmaster's active ingredient is 2,4-d and dicamba (MOA Group 4). 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.