Herbicide label
T-Square Herbicide Label
T-Square (EPA 279-9636) is a Group 2 thifensulfuron and tribenuron-methyl herbicide labeled for 13 crops. The label lists 64 controlled weeds, plus partial-control, suppression, and partner-control categories.
“T-SQUARE herbicide is absorbed primarily through the foliage of plants, rapidly inhibiting the growth of susceptible weeds.”
T-Square label facts
- Product T-Square
- EPA Reg. No. 279-9636
- Registrant FMC Corporation
- Active ingredient thifensulfuron and tribenuron-methyl
- MOA group 2
Crops on the T-Square label
T-Square is labeled for these 13 crops and uses, per the EPA label.
Weeds on the T-Square label
The T-Square label names 77 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 control64- knawel, annual
- sowthistle, annual
- mustard, black
- mustard, blue
- dock, broadleaf
- buttercup, bur
- wallflower, bushy
- pepperweed, clasping
- fiddleneck
- buckwheat, common
- chickweed, common
- groundsel, common
- lambsquarters, common
- radish, common
- sunflower, annual
- chamomile, corn
- gromwell, corn
- spurry, corn
- cowcockle
- cress, mouse-ear
- dock, curly
- chamomile, false
- chickweed, field
- pennycress, field
- filaree, redstem
- filaree, texas
- flixweed
- smartweed, green
- henbit
- kochia
- ladysthumb
- rocket, london
- marshelder
- mayweed, chamomile
- miner's lettuce
- lambsquarters, narrowleaf
- catchfly, nightflowering
- smartweed, pennsylvania
- pineapple-weed
- prickly lettuce
- knotweed, prostrate
- pigweed, prostrate
- redmaids
- pigweed, redroot
- thistle, russian
- chamomile, scentless
- shepherd's-purse
- lambsquarters, slimleaf
- buttercup, smallflower
- falseflax, smallseed
- chickweed, stinking
- mayweed, stinking
- swinecress
- tansymustard
- fiddleneck, tarweed
- mustard, tumble
- lentil, volunteer
- pea, volunteer
- sunflower
- buckwheat, wild
- chamomile, wild
- garlic, wild
- mustard, wild
- radish, wild
Partial control
partial10- thistle, canada
- carolina geranium
- bedstraw, catchweed
- eveningprimrose, cutleaf
- mallow, common
- mallow, little
- nightshade, cutleaf
- nightshade, hairy
- vetch
- vetch, hairy
Controls with a tank-mix partner
needs partner3- cocklebur, common
- ragweed, common
- sage, lanceleaf
T-Square 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.
T-Square FAQ
What weeds does T-Square control?
The T-Square label names 77 weeds, including annual knawel, annual sowthistle, black mustard, blue mustard, broadleaf dock, and bur buttercup. Control varies by crop, rate, and timing.
What crops is T-Square labeled for?
T-Square is labeled for 13 crops and uses, including field corn, soybeans, wheat, cotton, and sugar beet.
What is the active ingredient in T-Square? Is it a generic?
T-Square's active ingredient is thifensulfuron and tribenuron-methyl (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 2026-09-30.