Simulation dynamique des interactions génotype x environnement x conduite de culture : application à l'évaluation variétale en tournesol

Paying more attention to Genotype x Environment x Management interactions should improve variety assessment and recommendations to cope with the increasing diversification of cropping systems and production goals. To do that, dynamic crop modelling could assist the traditional approach used to compare genotypes on multi-environment trials. The SUNFLO model was developed to simulate the grain yield and oil concentration of sunflower crop with a special attention paid to the description of cultivar diversity. A cultivar was characterized by 12 parameters of phenology, leaf area development, allocation, oil production and response to water stress. These parameters were measured either in field conditions (dense stands) or in greenhouse pot experiments. The model was evaluated on pre- and post registration networks from GEVES and CETIOM respectively; the average gap between observed and simulated grain yield ranged from 2.7 to 4.9 q.ha-1. The model could be used to rank environments (through abiotic stresses experienced by probe genotypes) in a variety assessment network and to separate varieties with sufficient phenotypic differences. The management suitable to each new variety could be proposed from virtual experiments with SUNFLO.