Information from Dow AgroSciences
Intense moth flights have led to heavy black cutworm (BCW) feeding in many parts of the country. All growers should be scouting their fields diligently for damage from this insect. Only hybrids containing the Herculex Insect Protection trait have a built-in defense from BCW.
Pressure from other insects, cool weather and partial delayed planting in some areas this spring is intensifying the damage caused by BCW, especially in hybrids without Herculex, noted Travis Belt, Mycogen Seeds customer agronomist.
"For growers who are just getting back into planting after some wet weather, the BCWs are getting a head start. And the bigger they are, the harder they are to kill," said Belt. "It will take more feeding on Herculex corn to have an effect on the larvae, which can lead to more damage."
According to Wayne Bailey, a professor of plant sciences at the University of Missouri, cornfields that have been damaged by BCW are sporadic, but many of those fields have reached damage levels above the economic threshold for treatment. Moth captures continue in Illinois, too, and some fields are already being treated, as reported by the University of Illinois in the May 7, 2010, issue of "The Bulletin."
Insecticide treatment may be recommended in late-planted corn or in fields where the corn is suffering from other pressures, such as cool weather or heavy pressure from other insects if BCW thresholds are reached. Following threshold recommendations for treatment is advised.
Once corn has reached the four-leaf stage of development, the threat of BCW cutting is reduced, but until that time, growers should be scouting their fields two to three times per week.
"Usually by early June the threat from BCW will be over," Belt said. "But it looks like we are going to deal with it through May; it's a threat today."
Growers who planted hybrids with Herculex Extra have season-long protection from other pests such as northern, western and Mexican corn rootworm; European corn borer and western bean cutworm, so even after the BCW threat has passed, corn remains protected from these insects all season, said Duane Canfield, marketing specialist for Dow AgroSciences traits and germplasm licensing. To learn more about hybrids with Herculex visit www.HERCULEX.net.