Des Moines, Iowa
May 22, 2008
A wet spring and late planting
could lead to additional pest challenges early in the growing
season. Growers should begin scouting for insects early and take
measures to protect their crops, say insect control experts from
Pioneer Hi-Bred, a DuPont
business.
Begin monitoring fields as soon as the crop emerges, says Paula
Davis, Pioneer senior manager for insect and disease traits.
With late planting and cooler, wetter conditions, some insects
may thrive and could become a problem quickly. Scouting for
armyworms, black cutworms, white grubs and wireworms is vital
since they typically can surface in early growing stages of the
corn crop.
"This is a critical period during the growing season," says
Davis. "Growers need to monitor their corn crop, looking at
specific indicators, then follow a management plan to resolve
any issues."
This year, high flights of armyworm moths have been reported in
Tennessee, Kentucky, and southern parts of Ohio, Illinois and
Indiana. Moths prefer to lay eggs in grassy areas. No-till
fields, small grains and pastures are considered high pressure
locations for monitoring. Small armyworms may stay and feed on
grassy foliage, but as the pests grow, larger armyworms have the
ability to migrate.
"Larger armyworms may pose a threat to nearby or adjacent
cornfields, especially no-till fields," says Davis. "Growers in
this region need to monitor fields frequently."
Armyworms are defoliators. If growers notice chewing of leaves
and multiple larvae per plant, use an insecticide treatment.
Recommendations may vary for each state, but generally, if 50
percent to 75 percent of the plants have signs of armyworm
feeding, further action should be considered.
Wireworms are another pest of significant concern this year.
Wireworms tend to thrive in extended periods of cool, wet
conditions. They may feed directly on the seed or tunnel into
the below-ground portion of the plant. The main indicator of
wireworm is stand reduction. The good news is that many growers
already have protection in place through insecticide seed
treatment. However, if there is heavy infestation, consider an
insecticide or high rate insecticide seed treatment next year.
"With today's technology, the risk of heavy infestation is
greatly reduced," says Davis. "Insecticide seed treatments offer
growers added crop protection. All Pioneer® brand seed is
treated."
Black cutworms are yet another pest to monitor. Small black
cutworms will show small shot holes in corn leaves. Once black
cutworms reach the fourth instar, approximately one-half inch
long, they can cut the plant, resulting in stand loss or
irregular stands. Corn hybrids with Herculex® I technology have
very good protection against black cutworms.
The suggested threshold for considering an insecticide treatment
has lowered recently due to the high 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.
Additionally, growers should scout for white grubs. White grubs
feed on roots of seedlings. In problem areas, growers will see
irregular stands since pruning takes place on the roots. While
there isn't much to remedy a heavily infested field, growers can
develop a plan for the following growing season - looking at
soil insecticide or investing in a higher rate of seed
treatments.
"The best advice we can offer growers is to get into the field,
do some digging and regularly monitor their stands. The key is
to monitor fields early and often," says Chris Doud, Pioneer
agronomist. "If there any indicators of a pest issue, growers
can look to their local Pioneer agronomist for guidance."
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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