LWV23071 Crop residues management 2.0: Breaking the Pathogen Cycle (BreakPaths) (TS-02-208-027)

After harvesting arable crops, residues remain in the field as dead plant material. Current PPS projects have shown that pathogens like Alternaria solani (potato early blight) and Cercospora beticola (Cercospora leaf spot in sugar beet) can survive in crop residues of the host and other crops grown in rotation, including cover crops. These findings were based on four years of sampling in a crop rotation system in sand. However, a more comprehensive overview is needed, including clay soils, and further knowledge of other key fungal pathogens in different arable crops.

This PPP project aims to track the role of crop residues in fungal pathogen survival throughout rotation systems. This includes residues from susceptible and resistant crops, cover crops and weeds. The project assesses population dynamics of A. solani and C. beticola, as well as Botrytis allii/aclada (onion) and Alternaria radicina/dauci (carrot).

Additionally, the project gathers information on management practices to reduce fungal plant pathogen populations in these residues.

Several treatments are assessed and improved:

Mechanical processing to accelerate decomposition of crop residues.

Treatments with microbial decomposers and competitors (MDC), adapted to the ecological niche of crop residues, to degrade and decompose substrates and outcompete pathogenic populations.

Application of side streams rich in chitin from mushroom and insect production industries, and side streams from sugar beet production, to steer the resident microbial population towards resilient beneficial microorganisms and bioactive compounds, reducing fungal plant pathogens.

The most efficient treatments are selected based on their ability to accelerate crop residue decomposition, hinder pathogenic populations and promote beneficial microbial communities. Treatments are chosen for easy integration into growers' practices, ensuring low CO2 emissions and safe application into the field, following a circular agriculture model. The expected reduction in fungal pathogen survival and proliferation in crop residues helps reduce disease pressure during the crop season.