Optimized cultivar deployment improves the efficiency and stability of sunflower crop production at national scale

Plant breeding programs design new crop cultivars which, while developed for distinct populations of environments, are nevertheless grown over large areas during their careers.Over its cultivation area, the crop is exposed to highly diverse stress patterns caused by climatic uncertainty and multiple management options, which often leads to decreased expected crop performance.In this study, we aim is to assess how finer spatial management of genetic resources could reduce the genotype-phenotype mismatch in cropping environments and ultimately improve the efficiency and stability of crop production.We used modeling and simulation to predict the crop performance resulting from the interaction between cultivar growth and development, climate and soil conditions, and management practices.We designed a computational experiment that evaluated the performance of a collection of commercial sunflower cultivars in a realistic population of cropping conditions in France, built from extensive agricultural surveys.Distinct farming locations that shared similar simulated abiotic stress patterns were clustered together to specify environment types.Optimization methods were then used to search for cultivars x environments combinations that lead to increased yield expectations.Results showed that a single cultivar choice adapted to the most frequent environment-type in the population is a robust strategy. However, the relevance of cultivar recommendations to specific locations was gradually increasing with the knowledge of pedo-climatic conditions.We argue that this approach while being operational on current genetic material could act synergistically with plant breeding as more diverse material could enable access to cultivars with distinctive traits, more adapted to specific conditions