
New Strategies on the Way to Help Combat WeedsBy Dawn Lyons-Johnson April 17, 199Farmers will have to wield a new combination of chemical and tillage weapons
to win the war against weeds, now a $15 billion-per-year problem in American
agriculture, Agricultural Research Servicescientists report. ARS scientists Robert Masters, Loyd Wax and Doug Buhler are developing new
weapons that are lethal to weeds but friendly to the environment. Masters is a
range scientist at Lincoln, Neb.; Wax is a research agronomist at Urbana, Ill.;
and Buhler is a research agronomist at Ames, Iowa. Each of the scientists
evaluated control strategies for common weed problems in their geographic area.
Masters combined herbicides, controlled burning and re-planting of native
warm season grasses without tillage to supplant leafy spurge, a noxious weed
that threatens Northern Plains grasslands. The result: a 60-percent reduction in
spurge populations, a boost in warm season grasses and a more stable soil
profile. Wax showed that farmers need a combination of tillage and herbicides to
thwart waterhemp, also called "pigweed" in the Midwest. Pigweed has
been increasingly resistant to a group of herbicides known as ALS-inhibiting
herbicides. But Wax reduced waterhemp populations when he applied
non-ALS-inhibiting herbicides in combination with tillage to disturb the weed's
root system. Buhler studied changes in field cultivation techniques and concluded that
some weeds such as hemp dogbane thrive in fields that get little or no
cultivation. He recommends developing cultivation strategies that best control
weeds by creating the environment least favored by the problem weed. For
example, hemp dogbane populations remained steady over a 14-year period when the
soil was tilled, but exploded when land operators switched to no-till
cultivation. A detailed story about this research is found in the April 1998 issue of
Agricultural Research magazine, the monthly publication of the
Agricultural Research Service. To view the current issue visit our website at: http://www.ars.usda.gov/is/AR/archive/apr98/weed0498.htm Scientific contacts: Robert A. Masters, Lincoln, Neb., phone (402)
472-1546; Loyd Wax, Urbana, Ill., (217) 333-9653,
[email protected]; Doug Buhler, Ames, Iowa,
phone (515) 294-5502, [email protected]. U.S. Department of Agriculture | |