| July 23
July 23 Farmers in important crop-growing states
should consider the environmentally unfriendly practice of
deeply tilling fields to fight a growing problem with invasive
"superweeds" that resist herbicides and choke crop yields,
agricultural experts said this week.
Resistance to glyphosate, the main ingredient in widely used
Roundup herbicide, has reached the point that row crop farmers
in the Midwest are struggling to contain an array of weeds,
Extreme controls are needed to fight herbicide-resistant
weeds in some areas, University of Missouri weed scientist Kevin
Bradley said in a report to farmers. One particularly aggressive
weed that can grow 1-2 inches a day is Palmer amaranth.
"Palmer amaranth is our No. 1 weed to watch in Missouri and
the Midwest right now," Bradley said.
He said farmers facing extreme out-of-control weeds should
try deep tillage, a practice that removes weeds but can also
lead to soil erosion and other environmental concerns.
Farmers moved away from heavy tillage of the land decades
ago, and the more sustainable 'no-till' farming has become the
norm. But it relies on heavy use of herbicides like glyphosate,
and the U.S. Department of Agriculture says 70 million acres of
U.S. farmland had glyphosate resistant weeds in 2013.
Palmer amaranth is also "exploding" across Kansas this year,
according to Dallas Peterson, a weed specialist with Kansas
State University. "We have had numerous calls about poor control
of Palmer amaranth with glyphosate this year," he said.
Weed resistance has grown as farmers have increased their
use of glyphosate in conjunction with the Monsanto Co's
introduction of an array of crops genetically altered to
tolerate the herbicide.
(Reporting by Carey Gillam; Editing by Dan Grebler)