Pierre Casadebaig

• PhD
• Researcher at French National Institute for Agriculture, Food, and Environment (INRAE)

Yield improvement certainly depends on breeding new genotypes, but also on identifying the best genotype for a given location and crop management system. Hence we need to quickly evaluate the performance of each new variety in different cropping systems and environmental conditions. Our objective was to develop a model (SUNFLO) which can help to im...

The sunflower (Helianthus annuus L.) crop in southern Europe suffers from intense and frequent periods of water deficit. Minimisation of water loss in response to water deficit is a major aspect of drought tolerance and can be achieved through the lowering of either leaf area expansion rate or transpiration per unit leaf area (stomatal conductance)...

A crop can be viewed as a complex system with outputs (e.g. yield) that are affected by inputs of genetic, physiology, pedo-climatic and management information. Application of numerical methods for model exploration assist in evaluating the major most influential inputs, providing the simulation model is a credible description of the biological sys...

Numerical plant models can predict the outcome of plant traits modifications resulting from genetic variations, on plant performance, by simulating physiological processes and their interaction with the environment. Optimization methods complement those models to design ideotypes, i.e. ideal values of a set of plant traits resulting in optimal adap...

Growing mixtures of annual arable crop species or genotypes is a promising way to improve crop production without increasing agricultural inputs. To design optimal crop mixtures, choices of species, genotypes, sowing proportion, plant arrangement, and sowing date need to be made but field experiments alone are not sufficient to explore such a large...

Increasing crop diversification is crucial for developing more sustainable agricultural systems, and cereal-legume intercropping is a promising strategy. This study investigates the factors influencing the yield of cereal-legume intercrops using data from six field experiments in southwestern France, where durum wheat was intercropped with either f...

Drought, as a major environmental factor that limits plant growth and photosynthesis, is a challenge for agriculture in the context of climate change. High temperatures and drought stress impact crops as a function of their stage of development and genotypic tolerance. Choosing adapted sunflower (Helianthus annuus L.) varieties and management pract...

The automatic measurement of developmental and physiological responses of sunflowers to water stress represents an applied challenge for a better knowledge of the varieties available to growers, but also a fundamental one for identifying the biological, genetic and molecular bases of plant response to their environment.On INRAE Toulouse's Heliaphen...

Key message Using in silico experiment in crop model, we identified different physiological regulations of yield and yield stability, as well as quantify the genotype and environment numbers required for analysing yield stability convincingly. Abstract Identifying target traits for breeding stable and high-yielded cultivars simultaneously is diffi...

Dans le chapitre: Tournesol : des outils pour bien choisir les variétés

Maintaining yield when reducing inputs is one prime objective of sustainable agriculture. In this context, cereal-legume intercropping is a practice that can achieve increased yield under low-input conditions through the complementary use of abiotic resources and facilitation mechanisms. Many management options exist to design cereal-legume intercr...

Key message Crop simulation helps to analyze environmental impacts on crops and provides year-independent context information. This information is of major importance when deciding which cultivar to choose at sowing time. Abstract Plant breeding programs design new crop cultivars which, while developed for distinct populations of environments, are...

Cereal-legume intercropping is known to improve the sustainability of crop production. However, it remains uncommon on commercial farms in Europe due to a number of socio-technical lock-ins and the many practical issues raised when integrating intercrops in cropping systems (e.g. which species, cultivars, sowing densities). Crop modelling is an opt...

Calls for the application of ecological principles in agriculture have gained momentum. Intercropping systems are designed by growing two, or more, annual crop species in the same field, aiming for a better resource use efficiency. However, assembly rules for their design are lacking. Notably, it is unknown whether species performances are maximize...

Calls for ecological principles in agriculture have gained momentum. Intercropping systems have long been designed by growing two, or more, annual crop species in the same field, aiming for a better resource use efficiency. However, assembly rules for their design are lacking. Notably, it is still unknown whether species performances are maximized...

As a rainfed spring-sown crop, sunflower ( Helianthus annuus L.) is increasingly exposed to negative impacts of climate change, especially to high temperatures and drought stress. Incremental, systemic and transformative adaptations have been suggested for reducing the crop vulnerability to these stressful conditions. In addition, innovative croppi...

Forecasting sunflower grain yield a few weeks before crop harvesting is of strategic interest for cooperatives that collect and store grains. With such information, they can optimize their logistics and thus reduce the financial and environmental costs of grain storage. To provide these predictions, data assimilation approaches involving the crop m...

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 decreas...

In order to make more efficient plant breeding and gain in competitiveness, the sector of oil-protein crops decided to intensify agronomic research on sunflower crop. The “Sunflower” Joint Technological Unit (Unité Mixte Technologique (UMT) “Tournesol”, in French) was launched in the Toulouse area in 2006, associating closely INRA and Terres Inovia...

Crop models contain a number of genotype‐dependent parameters, which need to be estimated for each genotype. This is a major difficulty in crop modeling. We propose a hybrid method for adapting a crop model to new genotypes. The genotype‐dependent parameters of the model could be obtained by phenotyping (or gene‐based modeling). Then, field data (e...

Growing mixtures of annual arable crop species or genotypes is a promising way to improve crop production without increasing agricultural inputs. To design optimal crop mixtures, choices of species, genotypes, sowing proportion, plant arrangement, and sowing date need to be made but field experiments alone are not sufficient to explore such a large...

Crop models contain a number of genotype-dependent parameters, which need to be estimated for each genotype. This is a major difficulty in crop modeling. We propose a hybrid method for adapting a crop model to new genotypes. The genotype-dependent parameters of the model could be obtained by phenotyping (or gene-based modeling). Then field data for...

Heliaphen is an outdoor platform designed for high-throughput phenotyping. It allows the automated management of drought scenarios and monitoring of plants throughout their lifecycles. A robot moving between plants growing in 15-L pots monitors the plant water status and phenotypes the leaf or whole-plant morphology. From these measurements, we can...

L’objectif du projet est de proposer des méthodes permettant à terme de construire un outil de prévision du rendement et de la qualité (teneur en huile et teneur en acide oléique) du tournesol quelques semaines avant sa récolte, à l’échelle d’un bassin de collecte, à l’aide de modèles plus ou moins complexes associés à des observations d’états de c...

One of the challenges in low-input annual arable mixed crops (i.e. species and variety mixtures) is to determine which species / varieties go well together to improve overall system performance. Theories coming from community ecology suggest that two ecological processes are particularly involved in mixed crops performance by improving resource use...

This article presents a 3D approach in plant growth monitoring and deals with the tracking of leaves of sunflower plants. Our aim is to compute time-series of individual leaf area, under water stress and control conditions. These data will then be used by biologists to study the drought resistance of various sunflower species. Our method to track t...

This article presents experimental data describing the physiology and morphology of sunflower plants subjected to water deficit. Twenty-four sunflower genotypes were selected to represent genetic diversity within cultivated sunflower and included both inbred lines and their hybrids. Drought stress was applied to plants in pots at the vegetative sta...

Heliaphen is an outdoor pot platform designed for high-throughput phenotyping. It allows automated management of drought scenarios and plant monitoring during the whole plant cycle. A robot moving between plants growing in 15L pots monitors plant water status and phenotypes plant or leaf morphology, from which we can compute more complex traits suc...

Stomatal control of transpiration was implied as the major strategies by which plants cope with water stress. Here we did investigate the genetic control of this process using the following trait: Fraction of Transpirable Soil Water threshold (FTSWt) representing the threshold of soil water content at which the stomatal control of transpiration sta...

Accounting for the interannual climatic variations is a well-known issue for simulation-based studies of environmental systems. It often requires intensive sampling (e.g., averaging the simulation outputs over many climatic series), which hinders many sequential processes, in particular optimization algorithms. We propose here an approach based on...

Understanding the genetic basis of phenotypic plasticity is crucial for predicting and managing climate change effects on wild plants and crops. Here, we combined crop modeling and quantitative genetics to study the genetic control of oil yield plasticity for multiple abiotic stresses in sunflower. First we developed stress indicators to characteri...

Understanding the genetic basis of phenotypic plasticity is crucial for predicting and managing climate change effects on wild plants and crops. Here, we combined crop modelling and quantitative genetics to study the genetic control of oil yield plasticity for multiple abiotic stresses in sunflower. First, we developed stress indicators to characte...

Assessing the performance and the characteristics (e.g. yield, quality, disease resistance, abiotic stress tolerance) of new varieties is a key component of crop performance improvement. However, the variety testing process is presently exclusively based on experimental field approaches which inherently reduces the number and the diversity of exper...

Climate change is characterized by higher temperatures, elevated atmospheric CO2 concentrations, extreme climatic hazards, and less water available for agriculture. Sunflower, a spring-sown crop often cultivated in southern and eastern regions of Europe, could be more vulnerable to the direct effect of heat stress at anthesis and drought during its...

Assessing the performance and the characteristics (e.g. yield, quality, disease resistance, abiotic stress tolerance) of new varieties is a key component of crop performance improvement. However, the variety testing process is presently exclusively based on experimental field approaches which inherently reduces the number and the diversity of exper...

Water deficit influences leaf transpiration rate and photosynthetic activity. The genotype-dependent response of the latter has not been assessed in sunflower (Helianthus annuus L.), particularly during the reproductive period when grain filling and lipogenesis depend greatly on photosynthate availability. To evaluate genotypic responses to water d...

Simulation models can be used to predict the outcome of plant traits modifications resulting from the genetic variation (and its interaction with the environment) on plant performance, hence gaining momentum in plant breeding process. Optimization methods complement those models in finding ideal values of a set of plant traits, maximizing a defined...

Range of variation used for function parameters. Each graph represents one function parameter (x and y vectors), except for grouped parameters (i.e. leaf, stem and pod nitrogen demand). The graph titles match the Process column in S1 Table. Nominal values are indicted in green, while minimum and maximum values are displayed blue and red, respective...

Description of the APSIM-wheat parameters included in the sensitivity analysis. Module refers to the sub-model where the parameter is used in APSIM-wheat, Process refers to the physiological process targeted by the considered parameter and Factor is the parameter name used in the present study and in the APSIM documentation [29], where a complete d...

Prédiction du gène au phénotype par une approche couplant génétique quantitative et écophysiologie. (rapport de stage)Nous proposons une nouvelle approche permettant d’identifier les combinaisons alléliques pouvant apporter un gain génétique dans des conditions de cultures données. En alliant un modèle génétique d’association avec un modèle de cult...

A crop can be represented as a biotechnical system in which components are either chosen (cultivar, management) or given (soil, climate) and whose combination generates highly variable stress patterns and yield responses.

Accounting for the annual climatic variability is a well-known issue for simulation-based studies of environmental models. It often requires intensive sampling (e.g., averaging the simulation outputs over many climatic series), which hinders many sequential processes, in particular optimization algorithms. We propose here an approach based on a sub...

A crop can be represented as a biotechnical system in which components are either chosen (cultivar, management) or given (soil, climate) and whose combination generates highly variable stress patterns and yield responses. Here, we used modeling and simulation to predict the crop phenotypic plasticity resulting from the interaction of plant traits,...

A crop can be represented as a biotechnical system in which components are either chosen (cultivar, management) or given (soil, climate) and whose combination generates highly variable stress patterns and yield responses. Here, we used modeling and simulation to predict the crop phenotypic plasticity resulting from the interaction of plant traits (...

Sunflower (Helianthus annuus L.) raises as a competitive oilseed crop in the current environmentally friendly context. To help targeting adequate management strategies, we explored statistical models as tools to understand and predict sunflower oil concentration. A trials database was built upon experiments carried out on a total of 61 varieties ov...

The diversity of growing conditions and the development of new outlets for agricultural products favour a diversity of crop management systems requiring various cultivars, with specific characteristics. Genotype performance is usually assessed through multi-environment trials comparing a variable number of genotypes grown in a wide range of soils,...

Plant or soil water status are required in many scientific fields to understand plant responses to drought. Because the transcriptomic response to abiotic conditions, such as water deficit, reflects plant water status, genomic tools could be used to develop a new type of molecular biomarker. Using the sunflower (Helianthus annuus L.) as a model spe...

To understand crop responses to drought or drought-interacting stresses, plant molecular physiologists, eco-physiologists, agronomists and breeders need to estimate the water available to plants in the soil during their growth. Commonly, they use soil- and plant-based measurements such as pre-dawn leaf water potential. Because transcriptomic respon...

In the ANR project “Archidemio” (2009 - 2012, SYSTERRA), we explored whether characteristics of the plant and the canopy (architecture, development, resistance levels) could be major determinants of epidemic development of air-borne diseases and could be used as control strategies in integrated plant protection. The project was structured in three...

In a context of pesticide use reduction, alternatives to chemical-based crop protection strategies are needed to control diseases. Crop and plant architectures can be viewed as levers to control disease outbreaks by affecting microclimate within the canopy or pathogen transmission between plants. Modeling and simulation is a key approach to help an...

In a context of global climatic change, improving yield in drought conditions is a major challenge for crop production sustainability. Most of the previous genetic studies on sunflower response to drought have been performed on a limited number of genotypes in controlled conditions, or were based on phenotypic per se responses of recombinant inbred...

Present work focussed on improving the description of organogenesis, morphogenesis and metabolism in a biophysical plant model (SUNFLO) applied to sunflower (Helianthus annuus L.). This first version of the model is designed for potential growth conditions without any abiotic or biotic stresses. A greenhouse experiment was conducted to identify and...

The sunflower (Helianthus annuus L.) crop in southern Europe suffers from intense and frequent periods of water deficit. Minimisation of water loss in response to water deficit is a major aspect of drought tolerance and can be achieved through the lowering of either leaf area expansion rate or transpiration per unit leaf area (stomatal conductance)...

Owner: pcasadeb, Added to JabRef: 2011.02.17

Owner: casadebaig, Added to JabRef: 2011.10.13

Variety assessment could be supported by the use of dynamic crop modelling. The SUNFLO model was developed to simulate the achene yield and oil concentration of sunflower crop with a special attention paid to the description of varietal diversity. For that purpose, a variety was characterized in the model by 12 parameters of phenology, leaf area de...

Variety assessment could be supported by the use of dynamic crop modelling. The SUNFLO model was developed to simulate the achene yield and oil concentration of sunflower crop with a special attention paid to the description of varietal diversity. For that purpose, a variety was characterized in the model by 12 parameters of phenology, leaf area de...

Owner: casadebaig, Added to JabRef: 2011.10.13

In France, there is a need for improved sunflower crop management, in order to meet the greater requirement for oil by increasing both seed yields and the area of this crop. The objective of this article is to review the main characteristics of sunflower crop management in France and in other countries, in order to emphasize the need for improvemen...

In France, there is a need for improved sunflower crop management, in order to meet the greater requirement for oil by increasing both seed yields and the area of this crop. The objective of this article is to review the main characteristics of sunflower crop management in France and in other countries, in order to emphasize the need for improvemen...

La stagnation actuelle des rendements de la culture de tournesol résulte d'une surprenante compensation entre les progrès génétiques (+ 1.3 % de productivité par an) et la dégradation des conditions de cultures du tournesol : l'arrêt de l'irrigation, son déplacement vers des terres présentant un moindre potentiel et une augmentation des contraintes...

Added to JabRef: 2008.06.23

Les systèmes de grande culture français sont soumis à des conditions hydriques de plus en plus limitantes et incertaines (augmentation de l’occurrence d’épisodes de déficit hydrique, tensions croissantes entre usagers). Il est donc impératif de s’interroger sur la façon d’adapter ces systèmes à une disponibilité en eau réduite et variable (sol, pré...

L’agronomie systémique a pour objet d’étude le fonctionnement de la parcelle ou de l’espace cultivé englobant pour des échelles de temps infra-annuelles à pluri-annuelles (succession de cultures). Ceci passe par un aller-retour organisé entre l’expérimentation au champ et la modélisation dynamique. Trois types de processus en interaction sont modél...