(Reuters)—Researchers in the key corn-growing state of
Illinois are finding significant damage from rootworms in farm
fields planted in a rotation with a genetically modified corn that
is supposed to protect the crop from the pests, according to a new
report.
Evidence gathered from fields in two Illinois counties suggests that
pest problems are mounting as the rootworms grow ever more resistant
to efforts to fight them, including crop rotation combined with use
of the biotech corn, according to the report issued by Michael Gray,
a professor of crop sciences at the University of Illinois.
On August 26, Joe Spencer an entomologist with the Illinois Natural
History Survey, and I traveled to Livingston and Kankakee counties
and confirmed significant western corn rootworm larval injury in
first-year cornfields that had been planted to Bt rootworm hybrids
(VT Triple PRO RIB — expresses the Cry3Bb1 protein). The
fields in question were brought to our attention by Bryan Johnston,
Cabery Fertilizer, Cabery, Illinois. Bryan indicated that many
first-year Bt cornfields in the area had severe root pruning and
lodging. The fact that rotated corn is now showing susceptibility to
rootworm damage, even when planted to certain Bt hybrids, is
evidence that crop rotation in central and east central Illinois
does not adequately confer a consistent level of root protection.
Joe Spencer collected numerous adult western corn rootworms in the
damaged corn and adjacent soybean fields. The number of beetles in
the soybean fields was reminiscent of densities in the late 1990′s
and early 2000′s — very impressive. The density of western
corn rootworm adults in both crops, along with the severe pruning
and lodging, was additional evidence that the Bt hybrids (VT Triple
PRO RIB) had failed to offer the necessary root protection.
Bioassays on the offspring from the adults collected by Joe Spencer
will be required to determine if these rotation resistant western
corn rootworms are also resistant to the Cry3Bb1 protein. If the
bioassays confirm resistance to the Cry3Bb1 protein, producers
across a wide swath of Illinois will have a formidable insect foe
capable of overcoming both crop rotation and at least one Bt protein
(Cry3Bb1)….
Back to the Reuters story:
“People are taking efforts to address it,” he said. “Rotating modes
of action, that will be one of the best things we can do.”
A Monsanto official had no immediate response to a request for
comment, but the company has said in the past that it is working
with growers to address resistance concerns.
Too busy gloating over their money, I suppose.
Meanwhile, our experience with the mutant pigweed here in Lowndes County
has been that on our land where we don’t spray we don’t get much of it,
perhaps because when its natural competition isn’t killed off,
it’s not such a big threat.
Apparently only when Roundup and other chemicals kill off all the competition
can mutant pigweed become a real pest.
Perhaps it’s the same with corn rootworm.
Might be
time to find out….
(Reuters)—Researchers in the key corn-growing state of Illinois are finding significant damage from rootworms in farm fields planted in a rotation with a genetically modified corn that is supposed to protect the crop from the pests, according to a new report.
On August 26, Joe Spencer an entomologist with the Illinois Natural History Survey, and I traveled to Livingston and Kankakee counties and confirmed significant western corn rootworm larval injury in first-year cornfields that had been planted to Bt rootworm hybrids (VT Triple PRO RIB — expresses the Cry3Bb1 protein). The fields in question were brought to our attention by Bryan Johnston, Cabery Fertilizer, Cabery, Illinois. Bryan indicated that many first-year Bt cornfields in the area had severe root pruning and lodging. The fact that rotated corn is now showing susceptibility to rootworm damage, even when planted to certain Bt hybrids, is evidence that crop rotation in central and east central Illinois does not adequately confer a consistent level of root protection. Joe Spencer collected numerous adult western corn rootworms in the damaged corn and adjacent soybean fields. The number of beetles in the soybean fields was reminiscent of densities in the late 1990′s and early 2000′s — very impressive. The density of western corn rootworm adults in both crops, along with the severe pruning and lodging, was additional evidence that the Bt hybrids (VT Triple PRO RIB) had failed to offer the necessary root protection. Bioassays on the offspring from the adults collected by Joe Spencer will be required to determine if these rotation resistant western corn rootworms are also resistant to the Cry3Bb1 protein. If the bioassays confirm resistance to the Cry3Bb1 protein, producers across a wide swath of Illinois will have a formidable insect foe capable of overcoming both crop rotation and at least one Bt protein (Cry3Bb1)….
Meanwhile, our experience with the mutant pigweed here in Lowndes County
has been that on our land where we don’t spray we don’t get much of it,
perhaps because when its natural competition isn’t killed off,
it’s not such a big threat.
Apparently only when Roundup and other chemicals kill off all the competition
can mutant pigweed become a real pest.
Perhaps it’s the same with corn rootworm.
Might be
time to find out….