Evaluation of General Weed Management (GWM) Model: A Computerized Bioeconomic Weed Decision Aid for Row Crops

Document Type

Book Chapter

Publication Date



With the large number of herbicide options available, deciding which herbicide is best for a given situation may be overwhelming resulting in poor or incorrect decisions. GWM, General Weed Management, a bioeconomic model, has been proposed as an approach to simplify herbicide selection. Estimated net return is based on predicted yield and commodity price minus the loss from weed competition and control cost. Weed species and density in the evaluation areas are used as input parameters and a list of herbicide options based on predicted net return and efficacy is generated. The experiment evaluated different weed management strategies at different landscape positions. Five different strategies were tested in a RCBD at three locations in two fields in 1996 and 1997. Locations within fields were selected based on landscape position and previously mapped weed populations. Treatments included a weedy control, the weed management strategy selected by the producer, and three GWM generated treatments (preemerge, postemerge and preemerge plus post emerge). Preliminary results suggest that GWM may perform as good or better than the producer blanket herbicide treatment. Model generated decisions with regards to economics may play a role in the future of weed management as cropping practices move to more intensive management practices with precision farming techniques, and therefore need to be further evaluated. Specific results will be presented later.

Publication Title

Precision Agriculture

First Page


DOI of Published Version



American Society of Agronomy


P.C. Robert, R.H. Rust and W.E. Larson (ed.)

ISBN: 978-0-89118-258-0