A multi-seasonal model of plant-nematode interactions and its use to identify durable plant resistance deployment strategies

Description

Root-knot nematodes of the genus Meloidogyne are soil-borne, little mobile, polyphagous pests which threaten important sheltered crops such as vegetables or small fruits. They attack plant roots to feed and reproduce and have a major impact on crop yield. Most eco-friendly plant protection strategies are based on the use of resistant crops. The emergence of virulent nematode variants, which are adapted to the resistance, challenges the durability of such methods. Because virulent root-knot nematodes exhibit a reduced fitness on susceptible crops, combining both resistant and susceptible plants can help increase the efficacy and sustainability of resistance-based nematode control. Since nematodes have poor intrinsic dispersal ability, the association between resistant and susceptible plants should rely on crop rotation over cropping seasons, rather than on spatial arrangements. We proposed a semi-discrete model describing the population dynamics of plant roots and of nematodes within and over cropping seasons. This model, inspired by epidemiological concepts, was fitted to literature data on the within cropping season dynamics of susceptible tomato plants and avirulent nematodes; it was then extended to also account for resistant plants and virulent parasites. The model was used to compute optimal crop rotation strategies with respect to the minimization of an epidemiological criterion called AUDPC to increase crop yield over different time horizons (between 2 and 40 cropping seasons)

Abstract

International audience

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