ROYER Pierrick

PhD student
in Plant Ecophysiology and Modeling

Équipe: MAGE

I graduated from the Biology-Agrosciences master of  the Université de Montpellier in 2024 . After one year of engineer work on Sirius Quality Maize at LEPSE, I started my PhD on the development of a generic crop model for representing Maize and Sorghum genetic variability.

Start of PhD : 14.07.2025

Sujet :   Development of a crop model capable of integrating the interspecific variability in sorghum and maize responses to abiotic stress

Résumé
In the context of climate change exacerbating tensions over water use, the sustainability of irrigated maize is increasingly being called into question. Sorghum, known for its superior tolerance to heat and drought, is emerging as a efficient alternative. However, this reputation does not take into account the full genetic diversity of both crops. Yet, both species exhibit significant genetic variation, which could offer new forms of adaptation to water and heat stress. This project explores the hypothesis that certain “non-elite” or “sorghum-like” maize varieties—early-maturing, short, and robust—could achieve performances comparable to sorghum under climatic stress conditions, thereby challenging the traditional dichotomy between the two species.
Evaluating the impact of the genetic variability of both crops across the diversity of European scenarios can only be achieved through model simulations. However, to date, no crop model exists that allows for simulations encompassing such diversity in both species. In this PhD project, a generic and interoperable crop model will be developed using the Crop2ML language, capable of simulating both maize and sorghum across a wide range of genetic and environmental scenarios. Building on twenty years of ecophysiological research conducted at LEPSE, the model will first be finalized for maize, then adapted to include sorghum-specific processes such as tillering, while ensuring compatibility of model formalisms with maize through parameter adjustments. This model will enable large-scale simulations to evaluate the impacts of various combinations of heat- and drought-related traits on water use and agricultural productivity. Ultimately, it will help propose sorghum and/or maize ideotypes adapted to different types of rainfed scenarios representative of current and future European agro-environments..

Key words : crop modeling, abiotic stress, maize, sorghum.

Encadrants
UMR LEPSE, MAGE Team: Boris PARENT (PhD co-supervison)
UMR LEPSE, MAGE Team: Pierre MARTRE (PhD supervison)