Proceedings of the Sixty-first Annual Meeting of the Northeastern ...

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EVALUATION OF HERBICIDES FOR CONTROL OF MORROW’S HONEYSUCKLE
USING FOLIAR TREATMENTS. J.M. Johnson, A.E. Gover, and L.J. Kuhns, The
Pennsylvania State Univ., University Park.
ABSTRACT
As part of an ongoing research project funded by the Pennsylvania Department
of Transportation, a study was established to investigate the effectiveness of several
herbicides and tank mixes for controlling Morrow’s honeysuckle (Lonicera morrowii
Gray, LONMO).
This trial was established in a pasture near University Park, PA. Fifty shrubs
were tagged and measured to determine average canopy width. The treatment volume
for each shrub was derived using the calculated basal area and an application volume
of 935 l/ha.
The study was arranged in a completely randomized design with ten treatments
and five replications. Each shrub represented a single replicate. Treatments were
applied as a foliar application on June 29, 2005 using a CO 2 -powered sprayer equipped
with a spray wand with a single XR8008VS tip. Herbicide treatments (kg ae/ha)
included metsulfuron at 0.042, 0.084, or 0.13; fosamine at 4.0 or 8.1; fosamine at 4.0
plus imazapyr at 0.070; glyphosate (isopropylamine) at 3.4, alone or in combination with
imazapyr at 0.07; and metsulfuron at 0.042 with the premix of dicamba at 0.28 plus
diflufenzopyr at 0.11. A non-ionic surfactant 1 was added to all treatments at 0.25
percent, v/v, except those containing the surfactant-loaded glyphosate.
Visual ratings of percent canopy reduction were taken September 1, 2005, and
July 10, 2006, 9 and 51 weeks after treatment (WAT). At 9 WAT, all treatments
containing metsulfuron resulted in almost complete canopy reduction with values
ranging from 97 to 100 percent. Glyphosate combinations were rated from 82 to 93
percent canopy reduction. Treatments that included fosamine were rated between 33
and 57 percent canopy reduction.
At 51 WAT, LONMO treated with all rates of metsulfuron, the glyphosate
combinations, and the 8.1 kg ae/ha rate of fosamine were rated between 80 and 100
percent canopy reduction. Fosamine at 4.0 kg ae/ha, alone or with imazapyr at 0.07 kg
ae/ha was rated at 48 and 52 percent reduction.
1 Activator 90, Loveland Industries Inc., Greeley, CO.
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