A methodology for the assessment of the potential of precision weed management based on geostatistical and crop growth model simulations

The reduction of the use of herbicides is a valuable objective both from economic and environmental perspectives and can be attained by the adoption of precision weed management, i.e. spraying only the areas of the field in which weeds are detected (patch-spraying). The definition of thresholds for spraying, based on agronomic and economic considerations, is needed in order to assess the convenience of patch-spraying. In the present work, a novel methodology, based on the geostatistical simulation of weed spatial patterns coupled with crop growth simulations using the APSIM model (Keating et al., 2003), is illustrated as a tool to identify convenient weed density thresholds. The method is illustrated in an application concerning two weeds species (Avena sterilis L. and Apera spica-venti L.) in wheat. The proposed methodology can be applied in order to choose the best herbicide spraying strategy among uniform, binary patch-spraying or patch-spraying according to a weed density threshold based on economic criteria.