Effect of agroecological management and pesticide reduction on noxious organisms and natural enemy abundance in oilseed rape

Abstract: Agroecological pest management aims to reduce pesticide reliance by redesigning
cropping systems to enhance ecological processes for pest control, yet its performance under
real farming conditions remains uncertain. Throughout three years (2020-2022), we compared agroecological and Swiss standard integrated management systems in paired oilseed rape fields across a Swiss network of 22 commercial farms. We quantified the extent of implementation of 17 different agroecological pest management practices and pesticide use reduction, and assessed their effects on weeds, insect pest pressure, natural enemy abundance, and yield. We also evaluated how environmental factors – landscape structure, weather conditions, and soil properties – contributed to variability in these response parameters. This study provides insights into the challenges of agroecological transitions in oilseed rape and highlights the importance of environmental context in shaping their agronomic performance.