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Posted 24 January 2007. PMN Crop News.

Controlling Corn Insects and Diseases Critical in Corn-After-Corn Fields

Pioneer Hi-Bred International, Inc.

Des Moines, Iowa (January 11, 2007)--With a significant number of growers showing a trend toward increased corn-after-corn acres, agronomists with Pioneer Hi-Bred International, Inc., say managing corn insects and diseases must be a priority for producers making those choices.


Corn residue and the insects harbored within can create a real challenge for growers – including corn rootworm (CRW), corn borer and western bean cutworm. In addition, other common corn pests must be controlled for successful stand establishment. These pests include black cutworms, wireworm, white grub, grape colaspis and seedcorn maggot.

“In the absence of rotation to soybeans, growers will need other management strategies for insects and diseases that increase in corn-after-corn production systems,” says Steve Butzen, Pioneer agronomy information manager. “Pioneer offers several plant and seed technologies for controlling these pests.”

Corn Rootworm Major Challenge

Corn rootworm is the No. 1 corn insect pest associated with corn-after-corn production. Effective control measures are critical for this pest, as CRW pressure tends to be highest in the second and third years of continuous corn.

“On the majority of corn-after-corn acres, CRW management will be necessary,” says Butzen. “For control, choose from hybrids with a transgenic trait or an insecticide seed treatment or apply a granular soil insecticide. The appropriate option depends on the level of CRW damage expected in the field and which other insects need to be managed.”

Butzen adds that in many areas agronomists recommend monitoring adult CRW populations to determine potential control options for the following year.

“A crop consultant or scout can provide weekly beetle numbers to determine the level of risk for the next season,” says Butzen. “A Pioneer sales professional can help interpret those numbers and choose the right option based on geography, field history, and the probable insect spectrum and infestation levels.”

Pioneer offers plant and seed technology options including Pioneer® brand hybrids with the Herculex® RW rootworm protection trait, Herculex XTRA insect protection or Poncho® 1250 insecticide seed treatment.

The Herculex RW trait protects against western, northern and Mexican corn rootworms, whereas Herculex XTRA offers a combination of the Herculex I trait and Herculex RW to guard against a broader range of above- and below-ground insects in corn than any other product on the market.

Controlling other plant/ear-feeding insects and diseases

In addition to CRW, several other notable insects should be monitored and managed in a corn-after-corn rotation, including corn borer, black cutworm and western bean cutworm. The Herculex I gene protects against those insects, suppresses corn earworm, and controls fall armyworm and several other pests.

Secondary soil insects such as wireworms, seedcorn maggots and white grubs can be effectively controlled by Poncho 250 and Poncho 1250 insecticide seed treatments.

“These insects tend to be active early in the season and can cause significant stand reductions, especially if emergence is slow due to cold stress,” notes Butzen. “Reducing insect feeding with these insecticides also protects against seedling diseases by depriving pathogens of points of entry.”

Butzen notes that seedling disease problems caused by Pythium, Fusarium, Rhizoctonia and other pathogens have increased throughout the United States. These diseases reduce stands and yields in corn-after-corn fields.

“Pioneer has introduced a new seed treatment fungicide – Dynasty® – for corn hybrids. Dynasty has increased activity against soil fungi that cause corn seedling diseases,” says Butzen.

For more information about managing insects and diseases in corn-after-corn fields, contact your local Pioneer sales professional. In addition to your local sales professional, Pioneer offers a national network of agronomists to answer agronomic questions associated with corn-after-corn production.