East Lansing, Michigan
November 12, 2007
When Asian soybean aphids first
appeared in Michigan in 2000, the state’s second largest
commodity was at risk. Out of all the states, Michigan had the
heaviest aphid population, and no information was available to
help growers solve the problem.
Now, farmers have control methods to prevent staggering crop
losses, thanks to the success of
Michigan State University (MSU) Project GREEEN-funded
research and the efforts of David Pratt, MSU Extension (MSUE)
specialist; Christine Difonzo, MSU entomologist; and researchers
across the soybean growing region.
“We did not know much about the soybean aphid, so our first goal
was to determine if the pest was causing damage to the fields,”
Pratt said. “Our next goal was to find ways to control the pest,
and we were able to do both.”
The research helped develop the current control method of pest
scouting to detect when the aphid population reaches the per
plant threshold that indicates when treatment would be most
effective. Farmers were able to find out about soybean aphid
control methods through educational programs, publications,
information on Web sites and direct contact, Pratt said.
Soybeans are the second largest crop grown in Michigan, with
almost 2 million acres harvested.
Difonzo worked with representatives of 20 other Midwestern
states and Canada to coordinate the development of uniform
recommendations for growers. The threshold recommendations have
been in use since 2002.
“Working to solve the aphid problem has been a real regional
effort,” Difonzo said. “It is an example of an exotic species --
the aphid originated in China -- taking over an area that never
had a pest problem before and scientists working together to
solve the problem. It takes a major effort from all soybean
growing regions to inspect and control this issue.”
Aphid damage can cause yield losses of 25 percent to 30 percent.
Currently, insecticides are the only method of control, but
researchers are looking at host plant resistance, classical and
biological controls.
Difonzo is involved with research on small, parasitic wasps
introduced into MSU soybean fields. These wasps lay their eggs
in the aphids; when the eggs hatch, the aphids are killed.
Host plant resistance may also be an option. MSU holds a patent
on a soybean line that is more aphid-resistant than others.
Researchers are also looking at the relationship between low
levels of plant potassium and high numbers of aphids per plant,
Difonzo said.
“We want to move beyond insecticide use by reducing it or
completely eliminating it,” Difonzo said. “It will help reduce
production costs, environmental impacts and human exposure.”
Founded in 1997, Project GREEEN (Generating Research and
Extension to meet Economic and Environmental Needs) is a
cooperative effort between plant-based commodities and
businesses together with the Michigan Agricultural Experiment
Station, MSU Extension and the Michigan Department of
Agriculture to advance Michigan’s economy through its
plant-based agriculture. Its mission is to develop research and
educational programs in response to industry needs, ensure and
improve food safety, and protect and preserve the quality of the
environment.
To learn more about the state’s plant agriculture initiative at
MSU, visit
www.greeen.msu.edu. |
|
