A Simulation Model as the Core for Integrated Weed Management Decision Support Systems: The Case of Avena fatua-Winter Wheat in the Semiarid Pampean Region of Argentina

Abstract

This chapter describes a mathematical simulation model for the multiannual assessment of Integrated Weed Management (IWM) strategies. The model allows to simulate the competitive interaction between an annual weed species and a grain crop. From the weed’s side, the following processes are represented: (1) demographic dynamics on a daily basis considering the numeric composition of the different phenological states, (2) intra- and interspecific competition, (3) seed production and (4) the effect of different control methods. Regarding the crop, the following variables are computed: (1) leaf area index (LAI), (2) competition on the weed and (3) expected yield as a function of weed competition. The model was developed on Microsoft Excel® with Visual Basic complements. Results are provided for the wild oat (Avena fatua)-winter wheat (Triticum aestivum) system, a typical system of the south-west area of the semiarid Pampean region of Argentina. The model was calibrated and validated with experimental data collected along 4 years. Several multi-year scenarios were generated to evaluate the effect of different IWM strategies against common herbicide-based practices. Finally, possible improvements to the model and some guidelines towards the development of a long-term DSS for weed management are provided.