EAST ATLON, IL – New research findings from local
Terrestrial Ecologist Lyle Guyon are changing the game for Japanese hops
control and management in large floodplains.
Guyon, who holds a doctorate in Natural
Resources and Environmental Sciences from the University of Illinois at
Urbana-Champaign, is a senior scientist at Lewis and Clark Community College’s
National Great Rivers Research and Education Center (NGRREC) and
has over 15 years of experience in floodplain research.
His recent paper, “Japanese Hops (Humulus
japonicus) Control and Management Strategies in Large River Floodplains”
was published in the Journal of Forestry earlier this spring.
“Japanese hops is a fairly new invasive
species that many individuals may not be familiar with,” Guyon said.
“Unfortunately, it is spreading rapidly and can create a real problem where it
His research findings show that the most
effective long-term strategy to manage Japanese hops invasion is to pair
post-emergent herbicide treatments with tree plantings to restore the
floodplain forests to closed-canopy.
“Findings from this study will help guide
efforts by natural resource managers and landowners, not just in the local
Riverbend community, but throughout the Upper Mississippi River watershed,”
The study, conducted in partnership with
the U.S. Army Corps of Engineers and Great Rivers Cooperative Ecosystem Studies
Unit, was conducted from 2012-2015 on five different island sites along the
confluence of the Illinois, Missouri and Mississippi Rivers.
The study compared different herbicide
treatments and tree planting methods to determine which method may work the
best when used on Japanese hops.
The three strategies included:
or treating the site before Japanese hops have emerged from the soil
or after the plants have emerged
pre- and post-emergent
At all management sites, eastern
cottonwood and American sycamore bare root and containerized trees were also
planted as part of the study, since Japanese hops is a shade-intolerant
Data suggests that herbicide treatments
in floodplain forests are only a short-term solution because with each new
flood, new Japanese hops seeds are added back into the soil and are able to
sprout once the water recedes. Field observations indicate that reforesting an
area is likely a more effective long-term control method.
“I hadn’t even
encountered Japanese hops before I started working in the Mississippi River
floodplains about 15 years ago, but immediately thought ‘wow – this is going to
be a problem,’ when I finally did,” Guyon said. “It seemed like not a lot of
folks were giving it the attention I thought it deserved, so I took a more
active interest in researching control and management options.”
Guyon said any landowner who comes across
Japanese hops should get rid of it immediately. “Hand pulling, mowing and/or
spot herbicide treatment can all be effective for smaller outbreaks,” he said.
Guyon’s published paper is available
through the Journal of Forestry at https://doi.org/10.1093/jofore/fvab055
For more information contact him at email@example.com.
National Great Rivers Research and
Education Center (NGRREC )
Founded in 2002 as a collaborative
partnership between the University of Illinois at Urbana-Champaign and Lewis
and Clark Community College, NGRREC is dedicated to the study of great river
systems and the communities that use them. The center aspires to be a leader in
scholarly research, education, and outreach related to the interconnectedness
of large rivers, their floodplains, watersheds, and their associated