By Scout Nelson
As May begins, warm weather across southern and central Minnesota is speeding up planting and insect emergence, including the seed corn maggot (SCM). Farmers are being urged to use current forecasts to avoid planting corn and soybeans during peak SCM adult flights.
SCM larvae feed on seeds and emerging seedlings, often damaging crops before they can establish. The pest thrives in cool, wet springs, especially in fields with high organic matter, such as recently tilled cover crops or manure applications.
“Seed corn maggot eggs hatch quickly, and the maggots feed on germinating plants,” experts warn. “Damage is highest when planting overlaps with peak adult emergence.”
The peak emergence of the overwintering generation is now occurring in southern Minnesota, especially along the Iowa border. With warmer temperatures forecasted—highs in the 70s and lows above 50°F—this flight will likely reach central counties around May 5.
As of April 28, USDA reports 26% of corn and 13% of soybeans planted statewide. Farmers with fields prone to SCM damage may benefit from delaying planting by a week, especially in southern counties.
However, predicting SCM population levels remains uncertain. Fields with a history of damage, high organic matter, or recent tillage should be managed carefully. No-till fields are generally less attractive to SCM.
In high-risk situations, delaying planting until after peak SCM activity is advised. Insecticide seed treatments or in-furrow applications are only helpful when used before planting in known problem areas. Once damage appears, treatments are no longer effective.
Forecast maps are updated twice weekly and can help farmers adjust their planting plans throughout the season. Taking preventive steps now can protect crop yields later in the year.
Photo Credit:gettyimages-tlillico
Categories: Minnesota, Crops, Corn