Bioeconomic Modeling to Simulate Weed Control Strategies for Continuous Corn (<i>Zea mays</i>)

Abstract

Grass and broadleaf weed densities and seed numbers, weed control practices, and grain yields were included in a bioeconomic model that evaluates alternative weed management strategies for continuous corn ( Zea mays L.). Weed seed numbers in soil and herbicide carry-over provided intertemporal links. Four weed management strategies – two fixed, one mixed, and one flexible – were evaluated with annualized net returns as the performance indicator. The flexible strategy (weed control based on observed conditions) had the largest annualized net return for high and low initial weed seed numbers. The fixed weed management strategy (weed control predetermined) of an annual application of only a preemergence herbicide ranked second in terms of annualized net returns for high weed seed numbers. The mixed weed management strategy of alternative year applications of preemergence herbicide and “as needed” applications of postemergence herbicide ranked second for low initial weed seed numbers. The fixed weed management strategy of alternate year application of preemergence herbicide only generated the lowest annualized net return, regardless of initial weed seed numbers.