Comparison of exemplary crop protection strategies in Swiss apple production: Multi-criteria assessment of pesticide use, ecotoxicological risks, environmental and economic impacts

Abstract

Plant protection products (PPP) are used to protect apples from pests and diseases and to maintain high yields and fruit quality. Alternatively, non-chemical plant protection measures can be applied to reduce the use and ecotoxicological risks of PPP. However, additional materials, energy or labor are needed, which can have an impact on the environmental or economic performance. To investigate possible trade-offs, this multi-criteria analysis examined different apple production systems based on exemplary crop protection strategies in Switzerland. One integrated crop protection strategy complying with the Swiss Proof of Ecological Performance (PEP2018) was used as a reference, and three exemplary strategies were compared to this reference. The integrated «PPP Reduced» strategy assumed a minimal use of synthetic PPPs in combination with a range of alternative plant protection measures to avoid yield losses. The conventional «High yield» strategy assumed maximum yields with minimal restrictions on the use of synthetic PPPs and fertilizer. Finally, the «Organic» strategy represented typical organic apple production without the use of synthetic PPPs. To compare the performance of these strategies, 13 indicators were calculated, covering four aspects. PPP use was analyzed with the treatment frequency index, local ecotoxicological risks for next-to-field habitats were modeled with SYNOPS, global environmental impacts of 1 kg apple were analyzed with life cycle assessment (LCA) and economic impact on farms was assessed with a full-cost calculation. Compared to the «PEP2018» strategy, the «PPP Reduced» strategy performed much better in terms of ecotoxicological risks and biodiversity, but was not profitable due to high investments resulting in a negative farmer's hourly wage. The ecotoxicological risks were comparable between the «PEP2018» and «High yield» strategies, with the latter performing much worse in terms of biodiversity and global warming potential. Despite the high capital and labor input, the «High yield» strategy was much better in terms of resource use and farmer's hourly wage. The «Organic» strategy had the largest impact (per kg of apples) on most global environmental indicators, but performed much better on ecotoxicological risks and also on farmer's hourly wage. The results of this study show that reducing the use of PPP and the associated risks in apple orchard without environmental or economic compromises is challenging. None of the strategies examined performed better than the other strategies in all indicators assessed. However, this approach could contribute to identify and design more sustainable crop protection systems in apple production.