Des Moines, Iowa
May 27, 2008
Recent university reports show
significant captures of black cutworms throughout the Corn Belt,
and there are indications the pest is moving further north into
Midwestern cornfields. Experts from
Pioneer Hi-Bred, a DuPont
business, recommend growers begin monitoring fields closely now
for signs of black cutworms - ranging from small pinholes the
pest may have left behind to the actual cutting of the corn
stalk.
"Recent wet conditions and southerly winds this spring have been
conducive for black cutworms to move further into the Midwest,"
says Paula Davis, Pioneer senior manager for insect and disease
traits. "Several Midwestern universities have reported
significant black cutworm captures in Missouri, Illinois,
Indiana and Iowa."
Corn plants are the most susceptible from emergence to V5 stage.
Once the plant emerges, begin scouting for black cutworm
problems. Black cutworms will cut the plant, resulting in stand
loss or irregular stands.
"Growers can look to their Pioneer agronomist or local Extension
office for the first cutting date," says Davis. "Following the
first cutting, growers should continue to monitor their crop.
The threat for black cutworms can last up to three weeks after
the first cutting date."
Once black cutworms reach the fourth instar, approximately
one-half inch long, they can cut the plant. Black cutworms also
can create small shot holes in the leaves of corn plants.
No-till fields or fields with annual or perennial weeds are at
higher risk for black cutworms. Egg-laying females are attracted
to these areas. Additionally, soybean stubble is more attractive
than corn stalks.
Pioneer® brand hybrids with Herculex® I protection offer growers
very good protection against black cutworms. The Herculex I
trait is the only Bt that helps control western bean cutworm and
black cutworm.
The suggested threshold for considering an insecticide treatment
has been lowered recently due to higher corn commodity prices.
Consider using an insecticide treatment if 1 percent to 2
percent of plants are cut and larvae are present. For additional
information on timing an insecticide treatment, growers can
contact their local Extension office or Pioneer agronomist.
"At this point, grower concerns have been minimal in northern
Iowa. This doesn't mean a grower should quit monitoring. It is
important to regularly monitor your corn crop," says Chris Doud,
Pioneer Iowa agronomist. "Growers need to walk their fields,
inspect their crop emergence and take stand counts. If a grower
suspects a problem, they should start by digging in the soil to
look for cutworms. Black cutworms oftentimes can be found in the
surrounding soil profile near corn plants during the day and are
more prevalent feeders at night or on overcast days when
temperatures are cooler."
Pioneer Hi-Bred, a DuPont business, is the world's leading
source of customized solutions for farmers, livestock producers
and grain and oilseed processors. With headquarters in Des
Moines, Iowa, Pioneer provides access to advanced plant genetics
in nearly 70 countries.
DuPont is a science-based products and services company. Founded
in 1802, DuPont puts science to work by creating sustainable
solutions essential to a better, safer, healthier life for
people everywhere. Operating in more than 70 countries, DuPont
offers a wide range of innovative products and services for
markets including agriculture and food; building and
construction; communications; and transportation.
® Registered trademarks of Pioneer Hi-Bred.
Herculex I insect protection technology by Dow AgroSciences and
Pioneer Hi-Bred.
® Herculex and the HX logo are registered trademarks of Dow
AgroSciences LLC. |
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