NC State Extension Publications

Introduction

Trade Name: HGH 75 Common Name: oxyflurofen + trifluralin Formulation: 5G (2+ 3)

Uses

Preemergence control of certain annual grasses and broadleaf weeds in container, nursery stock, and woody landscape ornamentals. Preemergence control of certain annual grasses and broadleaf weeds in container, nursery stock, and woody landscape ornamentals.

Amount of Active Ingredient Amount by Formulation
5G
Per Acre 5 (2 +3) lbs 100 lbs
Per 1,000 sq. ft. 2.3 lbs

Major Weeds Controlled

Many annual broadleaf and grass weeds including spurge, bittercress, crabgrass, oxalis, groundsel, and many others.

Major Weeds Not Controlled

Perennial weeds and emerged weeds. Weak on doveweed, phyllanthus, eclipta, morningglory, and a few other “tough to control” species.

For Best Results

Apply to weed free substrate or soil. Irrigate after application.

Cautions and Precautions

Apply to dry foliage only. Water in immediately to wash the particles off the plant foliage and to activate the herbicide. Do not apply while plants are producing a new flush of spring growth. Do not apply to plants such as daylily, liriope, yucca, or Hosta with leaves that channel granules to the leaf base. Do not use in greenhouses. Not recommended for bedding plants, liner production beds, groundcovers, flowers, turf, or plants bearing edible fruit.

Residual Activity

In container nurseries, six to eight weeks of residual weed control can be expected, depending on the growing substrate, temperature, and irrigation practices.

Volatility and Leaching Potential

Low to moderate volatility and low leaching potential. Do not apply in enclosed structures as volatilization is possible.

Symptoms and Mode of Action

Oxyfluorfen acts as a contact herbicide, disrupting cell membranes via a mechanism that requires light for activation. Triflurlalin inhibits root development by affecting cell division. Injury symptoms on ornamentals include contact-type burn where granules are trapped on the foliage and girdling at the soil line on some azalea cultivars. Oxyfluorfen mode of action: HRAC Group E; WSSA Group 14. Pendimethalin mode of action: HRAC Group K1; WSSA Group 3.

Worker Protection Standards

Worker Protection Standards REI: 12 hours
PPE: coveralls, chemical resistant gloves and footwear, chemical resistant eyewear
Manufacturer: Harrell's EPA Reg. # 52287-15

Author:

Professor of Weed Science and Extension Specialist
Horticultural Science

Publication date: Feb. 27, 2015

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