Bio-economic model on weed control in cultivation of wheat: Herbicide free wheat production in Switzerland (HerbiFree)

Abstract

Strategies to prevent and control pest pressure are required to efficiently produce high quality food products. However, the use of pesticides is associated with potential risks to humans and the environment, motivating policy actions in Switzerland and other European countries. Especially the widespread use of herbicides is increasingly criticised. The goal of this work to investigate the implications of a ban or a voluntary removal of i) specific pesticides (such as glyphosate) as well as ii) all herbicides for Swiss Extenso wheat production. Extenso wheat production implies that no fungicides, insecticides and growth regulators are allowed to be applied, but herbicides can be used on fields under current conditions. Implications of a herbicide removal comprise effects on: i) weed control strategies, ii) production costs and revenues, iii) toxicity of alternative strategies, iv) energy use of alternative strategies, and v) crop yields. We refer to Böcker et al. (2017, 2018) and develop a bio-economic model that allows to investigate optimal weed control decisions under different environmental, market and policy scenarios. This model includes a detailed representation of weed pressure as well as weed control trategies and it optimises strategy choices from a farmer’s perspective. We calculate utility maximising weed control strategies and evaluate changes of those strategies due to different policy measures with respect to effects on gross margins, yields and environmental impacts. The level of analysis consists of all regional units that are potentially suited for cultivating cereals in the Swiss land use map and that grew Extenso winter wheat.