The effect of compost on aphid control and the search for key resilience indicators

Abstract: The horticultural sector faces urgent challenges, including the reduction of chemical
plant protection products and decreased reliance on peat due to their environmental impact.
This necessitates the development of more sustainable production systems with increased
resistance against pests and diseases. We show that compost enhances plant resilience against cotton aphids (Aphis gossypii) and suppression of Phytophthora nicotianae in Kalanchoe, with greenhouse experiments demonstrating significantly reduced aphid infestation and disease severity compared with conventional peat-based substrates. However, compost efficacy varied depending on its source and processing. Our current research focuses on identifying key indicators to predict compost efficacy against specific pests and diseases, supporting a shift toward circular, resilient horticulture with reduced chemical use and partial peat replacement.