NC State Extension Publications

Introduction

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

Uses

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

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

Major Weeds Not Controlled

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

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

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

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

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

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

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

Author

Professor of Weed Science and Extension Specialist
Horticultural Science

Publication date: Nov. 18, 2014

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