NC State Extension Publications


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Trade Name: Sureguard Common Name: flumioxazin Formulation: 51 DG, 4L

Preemergence and early postemergence control of many annual broadleaf weeds and preemergence control of many annual grasses in established container and field grown woody ornamentals. Typically used as a directed application to avoid injury to desirable foliage but can be broadcast applied to some conifers. Often tank mixed with a non-selective herbicide, such as glyphosate, for POST and PRE weed control. Flumioxazin added to such mixtures can improve control of glyphosate-resistant weeds when applications are made to young seedlings.

Amount of Active Ingredient

Amount by Formulation

51 DG

4 L

Per Acre

0.25 - 0.375

0.5 to 0.75 lb (8 to 12 oz.)

8 to 12 fl oz

Per 1,000 sq. ft.

5.2 to 7.8 grams

5.4 ml to 8 ml

Major Weeds Controlled

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Most annual broadleaf weeds common in container and field grown nursery crops including: bittercress, spurge, woodsorrel, phyllanthus, groundsel, chickweed, morningglory, pigweed, doveweed, horseweed, liverwort and others. Eclipta control has been good at some locations and fair at others. Acceptable control of crabgrass is achieved but control declines with reduced dose and over time. Primarily used preemergence but will control many small seedling broadleaf weeds.

Major Weeds Not Controlled

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Nutsedges are not controlled. Sometimes weak on pearlwort, chickweed, evening primrose, marsh parsley and annual grasses.

For Best Results

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Apply before weeds emerge. Irrigate immediately following treatment. Postemergence applications should be applied to seedling weeds. Older weeds will be injured but not killed. Tank mixes with non-selective postemergence herbicides (such as glyphosate or glufosinate) will improve postemergence weed control.

Cautions and Precautions

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Do not apply over the top of broadleaf ornamentals. Over the top applications to some conifers is possible, but tender new growth can be severely injured. For over the top applications: treatments before budbreak or after bud-set in the fall are advised. Overwise, directed applications avoiding foliage are recommended. Do not apply in greenhouses if plants are present. Do not move plants into treated greenhouses until 24 hours after the treated area has been irrigated.

Residual Activity

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Two to three months of annual broadleaf weed control. Somewhat less for annual grasses and eclipta.

Volatility and Leaching Potential

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Moderately volatile but readily absorbed by soil organic matter. Leaching is not expected to be significant.

Symptoms and Mode of Action

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The most common injury symptom is localized necrotic spots (contact burn) on leaves and green stems contacted by the spray. Symptoms develop rapidly, within days. Herbicide is generally not systemic, but in some susceptible species young plants (e.g. wax myrtle and spiraea) development of red pigments in the main veins of leaves, suggests translocation. Mode of action: protoporphyrinogen Oxidase (PPO) Inhibitor. Mode of action Group 14.

Additional Information

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Worker Protection Standards REI: 12 hours
PPE: coveralls, chemical resistant gloves, shoes plus socks
Manufacturer: Valent EPA Reg. # 59639-120


Professor of Weed Science, Extension Specialist & Department Extension Leader
Horticultural Science

Find more information at the following NC State Extension websites:

Publication date: June 6, 2016
Revised: June 21, 2023

Recommendations for the use of agricultural chemicals are included in this publication as a convenience to the reader. The use of brand names and any mention or listing of commercial products or services in this publication does not imply endorsement by NC State University or N.C. A&T State University nor discrimination against similar products or services not mentioned. Individuals who use agricultural chemicals are responsible for ensuring that the intended use complies with current regulations and conforms to the product label. Be sure to obtain current information about usage regulations and examine a current product label before applying any chemical. For assistance, contact your local N.C. Cooperative Extension county center.

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