Scientists to Map Battle Plan Against
March 17, 1997
Scientists from around the world will gather at a meeting March 18-19 in
Washington to develop an environmentally friendly battle plan against a weed
that infests millions of acres of lakes, streams and rivers around the world.
The researchers will meet at the World
Bank Building for a two-day session to devise a biological control strategy
for controlling the water hyacinth, a floating aquatic weed that is considered
one of the top 10 noxious weeds worldwide. It is difficult to eradicate because
of its rapid growth rate of one percent a day. At that rate, a single water
hyacinth plant in a 60-acre tropical lake would cover the entire lake in one
The weed has become a particularly serious problem in third world countries
that have not been able to control it with herbicides or mechanical cutting. At
the meeting, organized by the U.S. Department of
Agriculture and the World Bank, many of the worlds leading
researchers on the weed will form an international consortium to develop
recommendations for controlling water hyacinth. They will focus on sustainable
biological control methods such as naturally occurring insects that feed on the
weed and keep it in check.
In the 1960s and 70s, scientists with USDAs
Agricultural Research Service and the
U.S. Army Corps of Engineers
studied biological control of the water hyacinth in its native area, the
Amazon Basin of South America. There, the weed is not a problem because it is
held in check by its natural enemies.
Later, several insect species from South America were introduced in the
United States to control the weed, which was released in New Orleans in 1874
and rapidly spread in the absence of natural enemies. In Louisiana, two weevils
from South America were effective at cutting back water hyacinth infestations
from a high of 1.8 million acres to about 200,000 acres today.
But in other parts of the world, the weed is spreading faster than new
biocontrol agents can be deployed. So scientists will identify and develop new
insects and natural disease organisms for the weed. Theyll also work on
ways to increase the supply and distribution of these agents around the world,
and to transfer the technology to weed control personnel.
There is no registration fee for the meeting, which begins at 8:30 a.m. on
Tuesday, March 18. The meeting is scheduled to be held in rooms H1-200 (Tue.)
and H2-300 (Wed.) at the World Bank Building, 600 19th Street NW. At the front
door, reporters should tell the guard they are attending the
Hyacinth Meeting and they will receive a pass.
Scientific contact: Neal R. Spencer,
USDA/ARS Northern Plains Agricultural
Research Laboratory, Sidney, Mont., phone (406) 482-9407,
Raymond I. Carruthers, USDA/ARS National
Program Leader, Biological Control, Beltsville, Md., phone (301) 504-5930,