Vol. 51—1997 - NorthEastern Weed Science Society

70
EVAL ATION OF BRUSH CONTROLPROVIDEDBY ACCORDWl1H BASAL BARK
APPLICATIONS
Chad W. Spackman, Jon M. Johnson, and Larry J. Kuhns-/
ABSTRACT
As part of a cooperative project between the Pennsylvania State University and the
Pennsylv .a Department of Transportation,a trial was establishedevaluating the effect of
herbicides n the control of tree-of-heavenor ailanthus (AilanthusaltissimaMill.), green ash
iFraxinus ennsylvanica Marsh.), and red maple (Acer rubrum L.) treated with basal bark
application . Treatments included an untreated check, Accord 21 in combination with Stalker'",
QwikWet -399 EX, or water; Accord in combination with Thinvert R4/;Garlon 4 5 / plus
Penevator asal Oil; and a combination of Krenite S6/,Stalker, QwikWet M-399 EX, and water.
Treatmen were applied to three separatecolonies, or replications,of ailanthus divided into equal
portions 0 April 12 and 15, 1996,near Lewistown, PA. Treatments were applied to ten stems
each of n ash near Port Matilda, PA, on April 10; and red maple on April 5 near Ebensburg,
PA. The e rimentallayout for ailanthus was a randomized complete block design with three
replication ; and the layout for ash and maple was completelyrandomized,with each stem being an
experimen unit Treatments of Accord in combinationwith only QwikWet M-399 EX plus water
or with Th vert R were applied at a coverage up to a height of 24 in, and all other treatmentswere
applied to height of approximately 12in. Applicationequipment included a CO2-poweredhand
held spray r equipped with a Spraying Systems #5500 adjustableconejet with a Y2 nozzle,
operating t 25 psi. Stem diameters ranged from 0.25 to 5 in for ailanthus, 1 to 6.25 in for ash,
and 1 to 5. in for maple, with an overall average of 2.5 in. Ratings of tree injury were taken
August 9 d 13 for ash and maple, respectively; while tree injury and percent groundcoverof
resprouts as rated for ailanthus on September 16, 1996. Injury was rated on a scale of 1 to 10; in
which '1' i dicates no injury, '5' indicates moderate defoliation including the terminal, and '10'
indicatesc mplete control of the treated stem. The data were subjectedto analysisof variance.
Analysis 0 covariance was used to adjust tree injury values according to stem caliper in ash.
Results reported in Table 1.
Garlon 4 and Krenite S plus Stalker were the only treatmentsthat provided excellentcontrolof
all three s ies, They also allowed little resprouting of ailanthus. Accord plus Stalkerprovided
good con I of all three species and ailanthus resprouting.
Acco
ailanthus.
ailanthus.
plus Thinvert R provided no control of maple and poor to moderate control of ash and
ccord plus QwikWet M-399 EX provided moderateto excellentcontrolof maple and
Garlon 4 is still the standard by which other basal bark treatments must bejudged. Krenite S
plus Stalk and Accord plus Stalkerprovided moderate to excellent control, but at higher cost and
risk to adj ent desirable vegetation. QwikWet M-399 EX is a much better surfactantto use with
basal bark plications of Accord thanThinvert R.
1/Research echnologist, Project Assistant, and Professor of Ornamental Horticulture, respectively, The
Pennsyl ia State University, University Park, PA.
2/ Accord, lb glyphosate/gal, Monsanto Co., S1.Louis, MO.
3/ Stalker, 2lb imazapyr/gal, American Cyanamid Co., Wayne, NJ.
4/ Thinvert , Waldrum Specialties, Doylestown, PA.
5/ Garlon 4, lb triclopyr ester/gal, DowEianco, Indianapolis, IN.
6/ Krenite S 4 lb fosamine ammonium/gal, EJ. du Pont de Nemours and Co., Wilmington, DE.