Creating an Ecofriendly Pest Suppression Program in Sweet Corn

Problem, novel approach and justification. Sweet corn, produced on over 5,400 Northeastern farms¹, is the second largest processing crop². In 2017, its production value in five Northeastern states (DE, MD, NJ, NY, PA) totaled $110 million². Herbicides and cultivation are used routinely in sweet corn plantings. However, herbicides registered for sweet corn are dwindling because of no-reregistration of older compounds and suspensions over environmental concerns³. Cultivation increases fuel usage, and farmers’ reliance on cultivation and manual weeding increases their production cost. Further, sweet corn is vulnerable to three yield reducing insects (corn earworm, fall armyworm, and European corn borer)^4,5,6. Although some GMO sweet corn cultivars are protected from these insects, similar to insecticides, resistance problems reduce their efficacy period⁶. Thus, there is a need for additional practices that target weeds and insects concomitantly. Reduced tillage with cover cropping can reduce insect and weed pests, and production cost through enhanced natural pest suppression and reduced tillage, pesticide and fuel use. However, farmers are reluctant to adopt this combination partially from fears of inadequate pest suppression⁷, accompanied with limited knowledge on implementation. Thus, opportunities exist to create and share innovative tactics that lessen farmers’ reliance on tillage and boosts their confidence in implementing novel solutions. Hypothesis and research plan. We hypothesize using reduced-tillage with living and dying cover crop combinations will suppress pests equally or more and at reduced cost than conventional tillage with or without herbicides. This hypothesis will be tested through field studies. Whole plot treatments will include sweet corn grown under: conventional till, no-till with cover crop residue, living mulch + cover crop residue or living mulch + winter killed residue. Subplot factors will include herbicide or no herbicide. We will collect data on insect and weed pests, natural enemy efficacy, time spent manually weeding, input cost, yield and profits. Outreach plan. Methods for disseminating findings and engaging stakeholders include: 1) field day and walking tour events at research and commercial farms, 2) direct farmer participation, 3) uploading information to MD extension and commodity websites, 4) integration of findings into local and regional extension publications and trade journals, 5) presentations at local and regional commodity meetings, and 6) training educators and crop advisors at crop schools and in-service meetings. Project objective. Objectives include generating novel information on the synergistic usage of conservation tillage and winter cover cropping to concurrently manage insect and weed pests. Further goals include using findings to help sweet corn growers reduce their disproportionate reliance on GMO technology, pesticides and/or tillage by generating knowledge on low input practices that provide similar benefits. Potential impacts include similar or enhanced yields at lower operational and environmental cost, which will boost Northeast sweet corn farmers’ confidence, profits and sustainability.