NC State Extension Publications


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Trade Name: Devrinol Common Name: napropamide Formulation: 50 DF

Preemergence control of many annual grasses and some broadleaf weeds in container- and field-grown ornamentals, groundcovers, and flowers. May be used in liner stock, newly transplanted, or established nursery crops, and Christmas trees.

Amount of Active Ingredient Amount by Formulation
50 DF
Per Acre 4 to 6 lb 8 to 12 lb
Per 1,000 sq. ft. 3 to 4.4 oz.

Major Weeds Controlled

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Annual grasses and some annual broadleaves including chickweed, groundsel, knotweed, pineappleweed, knawel, and filaree. Suppression of yellow nutsedge.

Major Weeds Not Controlled

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The following are generally not controlled from seed: bindweed, morningglory, mustard, nightshade, horsenettle, jimsonweed, yellow woodsorrel, horseweed, spurge, evening primrose, and fleabane daisy. Purple nutsedge, large-seeded broadleaf weeds, perennials, and established weeds are not controlled.

For Best Results

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Apply to freshly weeded (or cultivated) soil before weeds germinate. Incorporate immediately by tillage, irrigation, or rainfall. Control may decrease if water is not provided within two to three days of application.

Cautions and Precautions

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Apply to newly planted container stock after soil has settled from first watering. The 50 DF formulation can injure young, tender foliage on some plants. It is best applied before bud break or after the new growth has matured. Devrinol is registered for use in warm-season turf but will injure cool-season species.

Residual Activity

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Full-season grass control can be expected from a single spring application. At the higher rates, carry-over can affect the establishment of grass cover crops seeded in late summer or early fall.

Volatility and Leaching Potential

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Moderately volatile. Photo-labile. Incorporation via irrigation or cultivation will reduce losses due to volatility and photodegradation. Leaching is negligible.

Symptoms and Mode of Action

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Inhibits root growth. Susceptible weeds do not emerge. Root growth of crops may be inhibited resulting in wilting during periods of stress. Young, tender crop foliage may exhibit contact-burn-type injury. In rare cases, plant height and vigor of herbaceous ornamentals is reduced. HRAC Group K3; WSSA Group 15.

Additional Information

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Worker Protection Standards REI: 12 hours
PPE: coveralls, chemical resistant gloves, shoes plus socks
Distributor: United Phosphorus EPA Reg. # 70506-38


Professor of Weed Science and Extension Specialist
Horticultural Science

Publication date: Nov. 18, 2014

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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