Early assessment of pest dynamics on new crop varieties : A modelling approach applied to banana-nematode systems

Breeders develop an increasing number of new crop varieties with potentially interesting characteristics in regards to their resistance or tolerance to pests. Nevertheless, the long-term assessment often requires heavy multi-local in-field measurements. Furthermore, the interactions between two or more pest many limit the relevance of field results on the long-term. Here, we present a methodology that use cropping system model to evaluate both the long-term evolution of the pest dynamics and the overall sustainability of the cropping systems based on include new varieties. We illustrate our method with the case of the new synthetic banana hybrid FB920 (Musa spp., AM group) - plant-parasitic nematodes complex. FB920 was designed to be resistant to the Sigatoka Disease and Black Leaf Streak Disease, caused respectively by Mycosphaerella musicola and Mycosphaerella fijiensis. Herein, we used the SIMBA model (a model to simulate phenology, growth, and plant-parasitic nematode/banana interactions) to examine the population dynamics of plant-parasitic nematodes in cropping systems with this new synthetic hybrid FB920 in various initial conditions. We used short term experiments to calibrate the SIMBA model to account for the growth and the development of the FB920 variety and to simulate the dynamics of the burrowing nematode (Radopholus similis) and the spiral nematode (Helicotylenchus multicinctus). Results from simulations show that in the long term the spiral nematode populations can overtake the burrowing nematode populations and that nematodes populations are smaller than in Cavendish banana fields. (Texte intégral