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

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CONTROLLING 40 YEAR OLD KUDZU SITES IN PENNSYLVANIA. M. Bravo, The
Pennsylvania State Univ., University Park.
ABSTRACT
Pennsylvania appears to be the first state in the U.S. to have received kudzu
(Pueraria montana (Lour.) Merr.). In 1876 the Japanese pavilion of the Philadelphia
Centennial Exposition displayed live kudzu. A herbarium specimen (Carnegie Museum)
currently on loan to the PA Agriculture Museum in Harrisburg dates kudzu in West End
Park, Pittsburgh to 1920. It is unknown if this is the same kudzu patch that was eradicated
in West End Park by Pittsburgh Public Works employee Jim Foley in 2003. Current sites
in PA are most often roadside banks, forest areas, quarries, slag mine deposits,
homeowner property boundaries and rarely open space locations such as pipelines.
Kudzu locations in PA have routinely been monitored since the early 1980’s. Since the
advent of soybean rust, renewed interest in limiting the spread of kudzu began in PA.
During Summer 2006, the Department sought to confirm the known locations of kudzu in
the state. As of October at least 71 known sites of kudzu are documented. At least 48 of
these sites were actively producing vegetation. Seed production has been documented at
many sites in the state since the 1980’s and most of the untreated sites in 2006 were
producing seed. Historical information and the physical data collected at each site
suggests all current kudzu sites in PA are at least 30 years old and were purposely
planted for soil stabilization or other recommended uses provided during the height of its
promotion in the late 1930’s. The current distribution range of kudzu in PA seems limited
to Zone 6.
A pilot Kudzu Eradication Program began in 2000 with 5 locations treated. By the
end of 2006, 18 more locations were enrolled. Herbicides used since 2000 include
aminopyralid, clopyralid, metsulfuron and triclopyr. The goal of the program is to treat
sites for 3 consecutive years to assist property owners in eradicating persisting sites of
kudzu. Treatments at 6 sites in Lebanon County were used as a research plot to collect
baseline data on clopyralid efficacy, rate and longevity. These sites were a combination of
virgin sites, previously treated sites, roadside banks, forest areas and open space areas.
Treatment applications included: high volume (HV) foliar, low volume (LV) broadcast and
a 2% v/v cut stump application. Applications were monitored at 4, 7, 10, 11, 13 and 16
wk after treatment (WAT).
In summary, all May-cut stump, HV foliar and LV broadcast treatments were still
preventing vegetative re-growth at 16 WAT. However, “missed” vegetation was common
at every site and untreated vegetation was discovered at every site through July. A single
HV foliar application followed by LV broadcast spot treatments successfully prevented
vegetative re-growth of all open space and roadside bank infestations. Cut stump
applications were critical to 100% control in all forest areas due to mature vines
throughout the sites. Alarmingly, a cohort (> 50) of kudzu seedlings emerged in late July
in a construction road that was cut through one of the virgin forest area sites in 2005. This
indicates that seeds are viable and movement of soil may allow naturalized populations of
kudzu to become established in PA.
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