Every year there are a host of pests that reduce the yield of Ohio’s corn crop. In the past however, many of these pests never received much attention simply because there was just not much that could be done about them.
Among the most damaging of these pests is the corn earworm. Damage from corn earworm (CEW) is caused by the larvae as they feed on leaves, silks and developing kernels. The pest was present in higher numbers than usual in some parts of Ohio this year and damage varied significantly throughout the state, according to Syngenta agronomists.
“CEW is a serious pest that is present in Ohio every year. The pest overwinters in some parts of Ohio and is present throughout the state on many crops including field corn, sweet corn, popcorn and many vegetable crops. Trapping data from Ohio State University indicates that while 2008 and 2009 were relatively low years for CEW, 2006 and 2007 were strong peak years in moth trapping programs,” said Jason Fettig, a Syngenta agronomist. “CEW is part of what we call the multi-pest complex, including black cutworm, fall armyworm, and Western bean cutworm that cost U.S. growers $1.1 billion per year. Growers often see some level of ear tip feeding that they may feel is not economically treatable with today’s available insecticide treatments.”
It is tough to get a handle on the economic threshold for CEW.
“Variations in crop yield, crop value, insect pressure, and control methods make an economic threshold difficult to pin down for this pest,” Fettig said. “Additionally, due to the biology of the pest and the limited efficacy of our previous control strategies, economic control has been difficult for Ohio corn producers. Integrated pest management strategies for control of CEW center around labor-intensive field-scouting and moth-trapping activities.”
With the challenges of finding and treating the pest, it is easy to let CEW slip under the radar because of what appears to be limited damage they cause, but that small amount of damage can lead to other problems.
“Presence in sweet corn, supports the presence of CEW in commercial corn, however it is often overlooked because it frequently falls below economic threshold levels. Even though damage may be below economic levels, damage is still occurring. When the damage from black cutworm and Western bean are considered together, the damage is additive,” Fettig said. “A general rule of thumb is that 3 kernels damaged or fed on per ear equals 1 bushel per acre at a population of 30,000 plants per acre. CEW also increases ear molds that lead to mycotoxins in grain.”
Beginning in 2011, growers will have the option of planting seed with the new Agrisure Viptera 3111 trait stack to protect against corn earworm and multi-pest complex damage without relying on scouting and insecticide applications. The Agrisure Viptera 3111 trait stack offers in-plant control of 14 yield- and quality-robbing insects, including CEW. Improved insect control with the Agrisure Viptera 3111 trait stack also reduces the incidence of mycotoxin contamination from both aflatoxin and fumonosins.
“Due to the fact that the insects hatch and move quickly through the silk and into the ear, where they are unreachable by the insecticide, precise insecticide application timing is both critical and maddeningly difficult,” Fettig said. “The advent of new full season in plant control options such as Syngenta’s Agrisure Viptera trait, allow for excellent control of CEW without the unpredictable results and intensive management required by traditional scout and spray programs. The best scouting strategy and timing for CEW control is to select Agrisure Viptera traited hybrids at planting time.”
In addition, the new Agrisure Viptera 3111 trait stack offers control of black cutworm, dingy cutworm, common stalk borer, fall armyworm, European corn borer, southwestern corn borer, corn rootworm and Western bean cutworm.
The Agrisure Viptera 3111 trait stack features the Agrisure 3000GT triple stack plus the Agrisure Viptera trait to provide the industry’s broadest spectrum control of above-ground and below-ground insect control. Many growers will be considering this new trait for their 2011 lineup. For more information, visit syngentaseeds.com.