Controlling Brush With Non-crop Herbicides (Stone Valley Forest)

This study was established to investigate the effectiveness of several herbicides, rates, and combinations for controlling brush using a foliar application.
Researcher applying roadside herbicide (photo courtesy of Jon Johnson)

Researcher applying roadside herbicide (photo courtesy of Jon Johnson)

Escort XP (metsulfuron methyl) is a new dispersable granule formulation that was introduced by DuPont in 2003. This product and the others are common to the right-of-way market.

The trial was established along a shale road within the boundaries of the Penn State Stone Valley Forest located near McAlevy's Fort, PA. A mixed stand of brush was divided into 63 plots. Plots were situated along the edge of the roadway and were 10 ft. deep by 75 ft. long. Trees varied from 3 to 15 ft. in height with most ranging from 6 to 10 ft. high.

The study was arranged in a randomized complete block design with twenty-one treatments and three replications. Treatments were applied as a foliar application on August 24, 2005 using a CO2-powered backpack sprayer equipped with a Spraying Systems 30 GunJet handgun and single TeeJet OC-40SS nozzle. This apparatus was able to apply a broadcast pattern approximately 12 ft. high and reaching to the back border of the 10 ft. deep plots. The application volume was 25 gal/ac. Herbicides used in the study included: Arsenal (imazapyr), Escort (metsulfuron), Garlon 3A (triclopyr), Glyphosate (glyphosate), Krenite S (fosamine), Overdrive (dicamba + diflufenzopyr), and Tordon 22K (picloram). 0.25% v/v Activator 90, surfactant, was added to all treatments, except those containing glyphosate alone which came premixed with surfactant.

On September 15, 2005, 22 days after treatment, necrosis/defoliation was rated on a scale from 0 to 10 for each species, where "0" represents no symptoms, "5" indicates moderate discoloration and/or loss of foliage, and "10" is completely brown and/or defoliated. Percent control by species is planned for evaluation during the 2006 season. The most common species included: black oak (Quercus velutina), white oak (Quercus alba), hickory (Carya spp.), red maple (Acer rubrum), witchhazel (Hamamelis spp.), yellow birch (Betula alleghaniensis), white pine (Pinus strobus), American beech (Fagus grandifolia), flowering dogwood (Cornus florida), hawthorn (Crataegus spp.), green ash (Fraxinus pennsylvanica), northern red oak (Quercus rubra), black cherry (Prunus serotina), and Carpinus spp.

Preparing for Application

Researchers prepare the application equipment (photo courtesy of Jon Johnson)

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