Mar 22, 2023
Looking Ahead: How to Control Worms in Sweet Corn

Be prepared for pest outbreaks with Radiant® SC with Jemvelva™ active

(Sponsored) Reducing fall armyworm feeding in sweet corn, and maximizing marketable yield, requires a responsive season-long control plan relying on multiple modes of action. 

South Florida sweet corn production manager Tom Perryman considers fall armyworm and silk flies his most troublesome pests. 

“Fall armyworm are a problem throughout the season,” says Perryman, Hundley Farms, Loxahatchee, Florida. “We use Radiant to control first instar worms and we try to time that application just prior to tassel push.”

Fall Armyworm

Radiant® SC with Jemvelva™ active, a Group 5 insecticide, provides fast knockdown and broad-spectrum control of damaging pests, including fall armyworm. 

Proven research 

“Larvae can feed on whorls, tassels, silks and ears leading to a yield and grade reduction. Program approaches using rotations of insecticide mode of action are necessary to reduce the chances of insecticide resistance,” says Jawwad Qureshi at the University of Florida’s Southwest Florida Research and Education Center. 

In University of Florida studies conducted in 2019 in Immokalee, Florida, rotating insecticide treatments reduced the number of larvae collected and ears damaged as compared with the untreated check. 

Untreated sweet-corn plots had 46.25% of ears damaged by fall armyworm, and averaged 1.5 larvae collected per 20 ears of corn.1 

In comparison, Radiant® SC insecticide applied May 22 with a high-clearance sprayer at a rate of 6 ounces per acre resulted in 6.25% of ears damaged and 0.25 larvae collected per 25 ears of sweet corn.1 

In the research, Radiant was included first in an insecticide rotation, including Mustang 1.5 EW and Coragen 20 SC insecticides. 

Keys to successful control 

Control of lepidopteran pests such as fall armyworm can’t wait. “With our heat and humidity, sweet-corn pest populations increase quickly,” Perryman says. 

“If you have fall armyworm populations present in the field, they can increase fast on you,” he says. “When you see 4% present, they are moving quickly. By the next day, when you can get into the field to spray, you are likely already at an 8% or higher worm population.” 

Perryman pulls the trigger on insecticide treatments as soon as fall armyworm populations reach 4% of a field’s total pest population. 

“Radiant gives us the fall armyworm control we need. It does well controlling worm species,” he says. 

Rotation matters 

Minimizing insecticide resistance by rotating chemistries is a key component in an Integrated Pest Management (IPM) program. The unique chemistry of Radiant makes it the ideal foundation for the vegetable grower’s IPM program. Positioning Radiant early in the season aids this IPM effort and offers growers an ideal rotational partner. 

“Radiant is another tool in our toolboxes for rotational purposes so we are not repeatedly spraying the same pesticides,” Perryman says. 

Radiant offers consistent season-long control of tough-to-control worms including, corn earworm, armyworm, western bean cutworm and corn borer, while the translaminar activity of Radiant controls targeted insects outside of the direct line of spray. Radiant also has a short preharvest interval and four-hour re-entry. Radiant also helps preserve populations of beneficial insects that are so important to IPM programs. 

Contact your local Corteva Agriscience representative to learn more about how Radiant® SC insecticide can help protect your crop from damaging worms. 

1Qureshi, Jawwad and BC Kostyk. “Control of Fall Armyworm with Labeled Insecticides and Experimental Surfactants in Sweet Corn, Spring 2019.” Arthropod Management Tests 45.1 (2020): tsaa022.
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