
Read the
full story in Agricultural Research magazine. The Fort Knox of Microbial Weed WhackersBy Jan Suszkiw May 12, 2000 As yellow starthistle and other exotic weeds begin their spring
assault on crop fields, rangeland, parks and even backyard gardens, researchers
are testing the microbial mettle of fungi, bacteria and other organisms to
check the pesky plants' advance. The approach, called classical biological control, is only one
front in America's multi-billion dollar war on exotic weeds like yellow
starthistle. In California alone, this invasive species has expanded its range
from 1.2 million acres in 1958 to the present 7.9 million acres. Like other
such weeds, the thistle thrived after escaping from its homelands natural
enemies. More stories about weed biocontrol
research: But scientists at the
Foreign Disease-Weed Science
Research Unit in Frederick, Md., are planning a long-overdue reunion. The
facility, which includes three microbial containment greenhouse facilities, is
operated by the Agricultural Research
Service, the U.S. Department of
Agricultures chief scientific arm. Since the 1970s, Frederick researchers have sought to slow the
advance of exotic weeds with biological, rather than chemical means. Cost,
environmental concerns, and the extent of infestations themselves are three
reasons for this approach. Biocontrol agents that pass muster and safety protocols, like the
rust fungus Puccinia carduorum Jacky, also apply constant pressure on
invasive weeds that tillage, chemicals and other controls often cant,
notes Bill
Bruckart, an ARS plant pathologist. Unleashed onto a Virginia exotic musk thistle infestation in 1987,
the rust fungus has since pursued the weed with dogged persistence, often
reducing its hosts populations up to 90 percent, as far west as Wyoming
and California. Charged with determining a foreign weed pathogens identity,
host range, and biocontrol potential, the ARS lab is first stop in a national
campaign that also involves USDAs Animal and Plant Health Inspection
Service, the U.S. Environmental Protection
Agency, the Weed Science
Society, and state ag departments. You can read more about it in the May
issue of Agricultural
Research magazine. Click
here to
read the story on the web. Scientific contact: William Bruckart, ARS
Foreign Disease-Weed Science
Research Unit, Frederick, Md., phone (301) 619 7340, fax (301) 619-2880,
[email protected]. U.S. Department of Agriculture | |