NC State Extension Publications

Introduction

Trade Name: Marengo, Specticle Common Name: indaziflam Formulations: 0.622 SC* / 0.0224 GR

Uses

Selective preemergence residual control of many annual grasses and broadleaf weeds in field and container grown nursery crops, Christmas trees, non-production areas in container nurseries, and in greenhouses and similar covered structures. The SC formulation should be used as a directed spray avoiding contact with crop foliage. Sold as Specicle for landscape and turfgrass uses. Recommended rates of application differ between use sites. Check the label for details.

Amount of Active Ingredient Amount of Formulation Herbicide
0.622 SC 0.0224 GR
Per Acre

0.0224 – 0.075 lb*

*note: rate differences between formulations

7.5 to 15.5 fl oz 100 – 200 lb
Per 1,000 sq. ft. 0.17 to 0.36 fl oz 2.3 – 4.6 lb

Major Weeds Controlled

Annual grasses such as crabgrass, goosegrass, foxtails, barnyardgrass, and annual bluegrass; annual broadleaf weeds including bittercress, doveweed, eclipta, oxalis, pigweed, spurge; and annual sedges from seed.

Major Weeds Not Controlled

Emerged weeds are not controlled. Poor control of Japanese stiltgrass and marsh parsley have been observed. Weeds sprouting from vegetative organs like rhizomes, tubers and bulbs are not controlled. Does not control nutsedge. Efficacy on large-seeded broadleaf weeds such as morningglory and ragweed is unknown.

For Best Results

Use the SC formulation as a directed spray only. Apply before weeds emerge. In newly planted ornamentals, water plants to settle the soil before applying. Marengo must be incorporated with about 12-inch of rainfall or irrigation as soon as possible after application.

Cautions and Precautions

Spray applications over the top of crop plants can be injure plants. Young, tender foliage is more sensitive to injury than mature foliage. Do not use the SC formulation in container crops. Not for use in propagation beds, herbaceous perennials, or liner production. Injury to hydrangea and euonymus has been reported. Excess doses have cause stem girdling and root inhibition in young, newly planted liners in some species, including red maple.

Residual Activity

About 4 months of residual weed control is expected. Under some environmental conditions, longer residual may be observed. In field sites, residual may last more than 6 months. Spring applications may interfere with establishment of fall-seeded cover crops; annual ryegrass is especially sensitive to indaziflam residues.

Volatility and Leaching Potential

Adsorbed by soil; not readily leached. Low volatility.

Symptoms and Mode of Action

Absorbed through roots and shoot tissues. Inhibits root and shoot growth, through interference with cell wall formation and cell division; specifically by inhibiting cellulose biosynthesis. Foliar symptoms include stunted, yellowed new growth. Stem girdling and swelling at the soil line may occur in some sensitive species. HRAC Group L; WSSA Group 29.

Additional Information

Worker Protection Standards REI: 12 hours
PPE: coveralls, waterproof gloves, shoes plus socks
Manufacturer: OHP EPA Reg. # 432-1518-53207

* Caution: When the product is available in more than one formulation, the formulation designated with the asterisk (*) was used as the primary source of information for this publication.

Author:

Professor of Weed Science and Extension Specialist
Horticultural Science

Publication date: May 30, 2014

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