Estimating the Impact of Pesticide Use Reduction Policies on Irish Cereal Yields Using an Iterative Expert Panel Methodology

The European Union’s (EU) Farm to Fork strategy seeks to reduce agricultural pesticide use by 50%, both of total pesticide use and of the most hazardous chemicals. While Ireland has achieved the goal of overall pesticide use reduction, more progress is needed regarding more hazardous substances. Ireland’s cool damp climate is unique within the EU, and with little empirical data on the possible impacts of achieving this goal on Irish farming, we sought to estimate these in cereal crops using a ‘Delphi’ style iterative expert panel methodology, conducted over two rounds, rather than until consensus was reached, to allow for knowledge gaps that may exist to become apparent. A total of 17 crop production experts with at least five years of relevant experience were surveyed anonymously, and then their answers were compiled and fed back to them, allowing participants to revise their responses based on the opinion of the group. Participants estimated that reduced use of more hazardous fungicides and insecticides could both reduce yields by 10–15%, while reduced use of herbicides would reduce yields of winter cereals by up to 30%. These impacts are substantially higher than those predicted in other Europe-wide studies. Application of additional Integrated Pest Management measures was estimated to reduce yield loss but not entirely mitigate it. These findings highlight the economic and food security trade-offs that may be required to achieve the Farm to Fork strategy’s goals.