Herbicide label
Princep 4L Herbicide Label
Princep 4L (EPA 100-526) is a Group 5 simazine herbicide labeled for 3 crops. The label lists 46 controlled weeds, plus partial-control, suppression, and partner-control categories.
Princep 4L label facts
- Product Princep 4L
- EPA Reg. No. 100-526
- Registrant Syngenta Crop Protection, LLC
- Active ingredient simazine
- MOA group 5
Crops on the Princep 4L label
Princep 4L is labeled for these 3 crops and uses, per the EPA label.
Weeds on the Princep 4L label
The Princep 4L label names 47 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 control46- alyssum
- barnyardgrass, common
- bassia, fivehook
- bluegrass, annual
- brome, downy
- burclover
- carelessweed
- carpetweed
- chickweed, common
- crabgrass
- rattail fescue
- fiddleneck
- filaree, broadleaf
- fireweed
- foxtail
- goosegrass
- groundsel, common
- hairgrass, silver
- henbit
- junglerice
- knawel
- lambsquarters, common
- prickly lettuce
- morning glory, annual
- mustard, tansy
- mustard, wild
- nightshade, annual
- wild oats
- paintbrush, flora's
- panicum, fall
- pepperweed
- pepperweed, yellowflower
- pigweed
- pineapple-weed
- purslane, common
- pusley, florida
- ragweed, giant
- redmaids
- ryegrass, annual
- shepherd's-purse
- signalgrass
- smartweed, annual
- needles, spanish
- speedwell
- thistle, russian
- witchgrass
Controls with a tank-mix partner
needs partner1- velvetleaf
Princep 4L 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.
Princep 4L FAQ
What weeds does Princep 4L control?
The Princep 4L label names 47 weeds, including alyssum, common barnyardgrass, fivehook bassia, annual bluegrass, downy brome, and burclover. Control varies by crop, rate, and timing.
What crops is Princep 4L labeled for?
Princep 4L is labeled for 3 crops and uses, including field corn, popcorn, and sweet corn.
What is the active ingredient in Princep 4L? Is it a generic?
Princep 4L's active ingredient is simazine (MOA Group 5). 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.