Herbicide label

Grassmaster

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.

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Official EPA label (PDF)

Grassmaster label facts

Product Grassmaster
EPA Reg. No. 81927-42
Registrant Alligare, LLC
Active ingredient 2,4-d and dicamba
MOA group 4

Crops on the Grassmaster label

Grassmaster is labeled for these 16 crops and uses, per the EPA label.

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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
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
sedge
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

Suppression

suppression10

buckeye species
bullnettle
dewberry, southern
horsenettle
mesquite
rabbitbrush
redvine
sowthistle, perennial
spurge, leafy
thistle, canada

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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 and your soil texture.

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Plant-back and rotation

Your interval depends on your application rate, the rotational crop, and your state, region, and rainfall — some intervals differ in AK, AL, AR, AZ, CO, CT, DC, DE, FL, GA, HI, IA, ID, IL, IN, KS, KY, LA, MA, MD, ME, MI, MN, MO, MS, MT, NC, ND, NE, NH, NJ, NM, NV, NY, OH, OK, OR, PA, RI, SC, SD, TN, TX, UT, VA, VT, WA, WI, WV, and WY.

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, 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.

What's the plant-back interval after Grassmaster?

It depends on your rotational crop, application rate, and region, so the label gives a table, not one number. Build a program and FieldMarshal gives you the exact interval for your rotation from the label line, so you can verify it.

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Can I tank-mix Grassmaster?

It depends on your target weeds, crop stage, and which partners the label approves. Build a program and FieldMarshal checks the label for approved partners and gives the condition on each, so you can verify it.