Project
LWV23071 Crop residues management 2.0: Breaking the Pathogen Cycle (BreakPaths)
After harvesting arable crops, residues are left in the field as dead plant material. Results observed in current PPS projects showed that the pathogens Alternaria solani (potato early blight) and Cercospora beticola (Cercospora leaf spot in sugar beet) can survive in crop residues of the host and in some other crops grown in rotation (including cover crops). These results were found in four years of sampling in a crop rotation system in sand, however it is necessary to have a more complete overview, not only in sand but also in clay, and to further gain knowledge of other key fungal pathogens in other arable crops.
For this reason, the presented PPS project aims to keep tracking the potential role of crop residues on fungal pathogen survival throughout rotation systems, being those residues from susceptible and resistant crops, cover crops and weeds, by assessing the population dynamics of A. solani and C. beticola, as well as of Botrytis allii/aclada (onion) and Alternaria radicina/dauci (carrot).
This PPS project will also focus on gathering information about the type of management practices needed to reduce fungal plant pathogen populations in these residues. Several treatments will be assessed and improved: (1) mechanical processing, to accelerate decomposition of crop residues, (2) treatments with microbial decomposers and competitors (MDC), which are adapted to the ecological niche of crop residues and have potential to degrade and decompose these substrates as well as to outcompete the pathogenic populations, and (3) application of side streams rich in chitin from the mushroom and insect production industries, as well as side streams from sugar beet production such as digestate, to steer the resident microbial population towards resilient beneficial microorganisms and bioactive compounds in detriment of the fungal plant pathogens. The most efficient treatments will be selected by their ability to accelerate crop residues decomposition, hinder/outcompete the pathogenic populations and promote the beneficial microbial communities. Treatments will also be chosen so that they can be easily integrated, standing alone or in combination, into growers practices, i.e., during or shortly after harvest, ensuring low impact with regards to CO2 emissions and, in case of side streams, to guarantee their safe application into the field and to keep the food production system safe, following a circular agriculture model. The expected reduction in the survival and proliferation of fungal pathogens in crop residues will help to reduce the disease pressure during the crop season.