Pierre Valsesia | Institut National de la Recherche Agronomique (original) (raw)
Papers by Pierre Valsesia
Organic Farming (OF) has been expanding recently around the world in response to growing consumer... more Organic Farming (OF) has been expanding recently around the world in response to growing consumer demand and as a response to environmental concerns. Its share of agricultural landscapes is expected to increase in the future. The effect of OF expansion on pest abundance and Conservation Biological Control (CBC) in organic and conventional fields is difficult to predict. Given the inherent complexity of CBC and the lack of CBC data across situations of OF expansion, and the probable interactions with landscape context, modeling is a useful tool to understand and forecast how pests and their control may vary during OF expansion. Here, we used a neutral spatially explicit landscape model simulating pests and predators interacting on an agricultural landscape to investigate the impact of different organic deployment strategies on the CBC. We modeled three spatial strategies of conversion of conventional fields to organic fields (Random, Isolated fields first, and Grouped fields first) i...
Scientific Reports, 2019
Agronomic practices can alter plant susceptibility to diseases and represent a promising alternat... more Agronomic practices can alter plant susceptibility to diseases and represent a promising alternative to the use of pesticides. Yet, they also alter crop quality and quantity so that the evaluation of their efficacy is not straightforward. Here we couple a compartmental epidemiological model for brown rot diffusion in fruit orchards with a fruit-tree growth model explicitly considering the role of agronomic practices over fruit quality. the new modelling framework permits us to evaluate, in terms of quantity and quality of the fruit production, management scenarios characterized by different levels of regulated deficit irrigation and crop load. Our results suggest that a moderate water stress in the final weeks of fruit development and a moderate fruit load provide effective control on the brown rot spreading, and eventually guarantee monetary returns similar to those that would be obtained in the absence of the disease.
The development of a new organ is the result of coordinated events of cell division and expansion... more The development of a new organ is the result of coordinated events of cell division and expansion, in strong interaction with each other. This paper presents a dynamic model of tomato fruit development that includes cell division, endoreduplication and expansion processes. The model is used to investigate the potential interaction among these developmental processes, in the perspective of the neo-cellular theory. In particular, different control schemes (either cell-autonomous or organ-controlled) are tested and compared to experimental data related to two contrasted genotypes. The model shows that a pure cell-autonomous control fails to reproduce the observed cell size distribution, and an organ-wide control is required in order to get realistic cell size variations. The model also supports the role of endoreduplication as an important determinant of final cell size and suggests that a direct effect of endoreduplication on cell expansion is needed in order to obtain a significant c...
Frontiers in Plant Science, 2016
Process-based models are effective tools to predict the phenotype of an individual in different g... more Process-based models are effective tools to predict the phenotype of an individual in different growing conditions. Combined with a quantitative trait locus (QTL) mapping approach, it is then possible to predict the behavior of individuals with any combinations of alleles. However the number of simulations to explore the realm of possibilities may become infinite. Therefore, the use of an efficient optimization algorithm to intelligently explore the search space becomes imperative. The optimization algorithm has to solve a multi-objective problem, since the phenotypes of interest are usually a complex of traits, to identify the individuals with best tradeoffs between those traits. In this study we proposed to unroll such a combined approach in the case of peach fruit quality described through three targeted traits, using a process-based model with seven parameters controlled by QTL. We compared a current approach based on the optimization of the values of the parameters with a more evolved way to proceed which consists in the direct optimization of the alleles controlling the parameters. The optimization algorithm has been adapted to deal with both continuous and combinatorial problems. We compared the spaces of parameters obtained with different tactics and the phenotype of the individuals resulting from random simulations and optimization in these spaces. The use of a genetic model enabled the restriction of the dimension of the parameter space toward more feasible combinations of parameter values, reproducing relationships between parameters as observed in a real progeny. The results of this study demonstrated the potential of such an approach to refine the solutions toward more realistic ideotypes. Perspectives of improvement are discussed.
Frontiers in plant science, 2016
Drought stress is a major abiotic stress threatening plant and crop productivity. In case of fles... more Drought stress is a major abiotic stress threatening plant and crop productivity. In case of fleshy fruits, understanding mechanisms governing water and carbon accumulations and identifying genes, QTLs and phenotypes, that will enable trade-offs between fruit growth and quality under Water Deficit (WD) condition is a crucial challenge for breeders and growers. In the present work, 117 recombinant inbred lines of a population of Solanum lycopersicum were phenotyped under control and WD conditions. Plant water status, fruit growth and composition were measured and data were used to calibrate a process-based model describing water and carbon fluxes in a growing fruit as a function of plant and environment. Eight genotype-dependent model parameters were estimated using a multiobjective evolutionary algorithm in order to minimize the prediction errors of fruit dry and fresh mass throughout fruit development. WD increased the fruit dry matter content (up to 85%) and decreased its fresh we...
Annals of botany, Aug 8, 2016
Plant growth depends on carbon availability and allocation among organs. QualiTree has been desig... more Plant growth depends on carbon availability and allocation among organs. QualiTree has been designed to simulate carbon allocation and partitioning in the peach tree (Prunus persica), whereas MappleT is dedicated to the simulation of apple tree (Malus × domestica) architecture. The objective of this study was to couple both models and adapt QualiTree to apple trees to simulate organ growth traits and their within-tree variability. MappleT was used to generate architectures corresponding to the 'Fuji' cultivar, accounting for the variability within and among individuals. These architectures were input into QualiTree to simulate shoot and fruit growth during a growth cycle. We modified QualiTree to account for the observed shoot polymorphism in apple trees, i.e. different classes (long, medium and short) that were characterized by different growth function parameters. Model outputs were compared with observed 3D tree geometries, considering shoot and final fruit size and growt...
Frontiers in plant science, 2018
Climate change projections predict warmer and drier conditions. In general, moderate to severe wa... more Climate change projections predict warmer and drier conditions. In general, moderate to severe water stress reduce plant vegetative growth and leaf photosynthesis. However, vegetative and reproductive growths show different sensitivities to water deficit. In fruit trees, water restrictions may have serious implications not only on tree growth and yield, but also on fruit quality, which might be improved. Therefore, it is of paramount importance to understand the complex interrelations among the physiological processes involved in within-tree carbon acquisition and allocation, water uptake and transpiration, organ growth, and fruit composition when affected by water stress. This can be studied using process-based models of plant functioning, which allow assessing the sensitivity of various physiological processes to water deficit and their relative impact on vegetative growth and fruit quality. In the current study, an existing fruit-tree model (QualiTree) was adapted for describing ...
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Annals of Botany
Background and Aims Sugar composition is a key determinant of fruit quality. Soluble sugars and s... more Background and Aims Sugar composition is a key determinant of fruit quality. Soluble sugars and starch concentrations in fruits vary greatly from one species to another. The aim of this paper was to investigate similarities and differences in sugar accumulation strategies across ten contrasting fruit species using a modeling approach. Methods We developed a coarse-grained model of primary metabolism based on the description of the main metabolic and hydraulic processes (synthesis of other compounds than sugar and starch, synthesis and hydrolysis of starch, water dilution) involved in the accumulation of soluble sugars during fruit development. Key Results Statistical analyses based on metabolic rates separated the species into six groups according to the rate of synthesis of compounds other than sugar and starch. Herbaceous species (cucumber, tomato, eggplant, pepper and strawberry) were characterized by a higher synthesis rate than woody species (apple, nectarine, clementine, grape...
Acta Horticulturae
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Acta Horticulturae
QualiTree is a generic fruit tree object -based model in which the effects of management practice... more QualiTree is a generic fruit tree object -based model in which the effects of management practices on the development of fruit quality are explicitly modelled. It considers a large range of fruit quality traits important for growers, retailers and consumers, including: fruit size, the proporti on of total mass consisting of fruit flesh, flesh dry matter content, flesh concentrations of various sugars, and sweetness, a linear combination of sugar concentrations. Though parsimonious in terms of 3D representation of the plant architecture, it is able to express a high degree of within- tree variability of fruit quality criteria. QualiTree has been successfully tested using several datasets. A range of peach cultivars – from very-early to late – has been parameterised into QualiTree. Simulation studies show the potential of QualiTree to predict how fruit quality profiles may change under various levels of biotic and abiotic stress, which will become common wi thin the context of global change. We simulated patterns of foliar attacks by parasites and showed that reductions in fruit quality were lower when attacks were late in the season. Other simulation studies indicated that severe water stress during stage III of fruit development decreased fruit size whereas it dramatically enhanced sugar accumulation in the fruit flesh, especially in the case of glucose and fructose. Hence, QualiTree might be useful in the design of innovative horticultural practices combining regulated deficit irrigation strategies and plant-mediated control of pests.
Journal Of Experimental Botany
The development of a new organ is the result of coordinated events of cell division and expansion... more The development of a new organ is the result of coordinated events of cell division and expansion, in strong interaction with each other. This paper presents a dynamic model of tomato fruit development that includes cell division, endoreduplication and expansion processes. The model is used to investigate the potential interaction among these developmental processes, in the perspective of the neo-cellular theory. In particular, different control schemes (either cell-autonomous or organ-controlled) are tested and compared to experimental data from to two contrasted genotypes. The model shows that a pure cell-autonomous control fails to reproduce the observed cell size distribution, and an organ-wide control is required in order to get realistic cell size variations. The model also supports the role of endoreduplication as an important determinant of the final cell size and suggests that a direct effect of endoreduplication on cell expansion is needed in order to obtain a significant ...
Irrigation Science, 2013
Your article is protected by copyright and all rights are held exclusively by Springer-Verlag. Th... more Your article is protected by copyright and all rights are held exclusively by Springer-Verlag. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
![Research paper thumbnail of Corrigendum to “Assessment of the water stress effects on peach fruit quality and size using a fruit tree model, QualiTree” [Agric. Water Manage. 128C (2013) 1–12]](https://attachments.academia-assets.com/44461796/thumbnails/1.jpg)
](Agricultural Water Management, 2013
Agricultural Water Management j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l... more Agricultural Water Management j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / a g w a t Corrigendum Corrigendum to "Assessment of the water stress effects on peach fruit quality and size using a fruit tree model, QualiTree" [Agric. Water Manage. 128C (2013) 1-12] The authors regret to inform you that Fig 2 present in the article is incorrect. The correct version of Fig. 2 is below:
Agricultural Water Management, 2013
Low water availability has increased the use of regulated deficit irrigation strategies in fruit ... more Low water availability has increased the use of regulated deficit irrigation strategies in fruit orchards. However, these water restrictions may have implications on fruit growth and quality. The current paper assesses the suitability of an existing fruit tree model (QualiTree) for describing the effects of water stress on peach fruit growth and quality. The model was parameterised and calibrated for a mid-late maturing peach cultivar ('Catherine'). Mean and variability over time of fruit and vegetative growth were consistent with observed data on trees submitted to full irrigation or to regulated deficit irrigation. The relative root mean square errors of the model for growth ranged between 0.09 and 0.31.
Trees, 2011
In this paper, QualiTree, a fruit tree model designed to study the management of fruit quality, a... more In this paper, QualiTree, a fruit tree model designed to study the management of fruit quality, and developed and described in a companion paper (Lescourret et al. in Trees Struct Funct, 2010), was combined with a simple light-interception sub-model, and then parameterised and tested on peach in different situations. Simulation outputs displayed fairly good agreement with the observed data concerning mean fruit and vegetative growth. The variability over time of fruit and vegetative growth was well predicted. QualiTree was able to reproduce the observed response of trees to heterogeneous thinning treatments in terms of fruit growth. A sensitivity analysis showed that the average seasonal growth rates of the different organs were sensitive to changes to the values of their respective initial relative growth rates and that stem wood was the tree organ the most affected by a change in the initial relative growth rates of other organs. QualiTree was able to react to simulated scenarios that combined thinning and pest attacks. As expected, thinning intensity and the percentage damage caused by pests significantly affected fruit yield and quality traits at harvest. These simulations showed that QualiTree could be a useful tool to design innovative horticultural practices.
Organic Farming (OF) has been expanding recently around the world in response to growing consumer... more Organic Farming (OF) has been expanding recently around the world in response to growing consumer demand and as a response to environmental concerns. Its share of agricultural landscapes is expected to increase in the future. The effect of OF expansion on pest abundance and Conservation Biological Control (CBC) in organic and conventional fields is difficult to predict. Given the inherent complexity of CBC and the lack of CBC data across situations of OF expansion, and the probable interactions with landscape context, modeling is a useful tool to understand and forecast how pests and their control may vary during OF expansion. Here, we used a neutral spatially explicit landscape model simulating pests and predators interacting on an agricultural landscape to investigate the impact of different organic deployment strategies on the CBC. We modeled three spatial strategies of conversion of conventional fields to organic fields (Random, Isolated fields first, and Grouped fields first) i...
Scientific Reports, 2019
Agronomic practices can alter plant susceptibility to diseases and represent a promising alternat... more Agronomic practices can alter plant susceptibility to diseases and represent a promising alternative to the use of pesticides. Yet, they also alter crop quality and quantity so that the evaluation of their efficacy is not straightforward. Here we couple a compartmental epidemiological model for brown rot diffusion in fruit orchards with a fruit-tree growth model explicitly considering the role of agronomic practices over fruit quality. the new modelling framework permits us to evaluate, in terms of quantity and quality of the fruit production, management scenarios characterized by different levels of regulated deficit irrigation and crop load. Our results suggest that a moderate water stress in the final weeks of fruit development and a moderate fruit load provide effective control on the brown rot spreading, and eventually guarantee monetary returns similar to those that would be obtained in the absence of the disease.
The development of a new organ is the result of coordinated events of cell division and expansion... more The development of a new organ is the result of coordinated events of cell division and expansion, in strong interaction with each other. This paper presents a dynamic model of tomato fruit development that includes cell division, endoreduplication and expansion processes. The model is used to investigate the potential interaction among these developmental processes, in the perspective of the neo-cellular theory. In particular, different control schemes (either cell-autonomous or organ-controlled) are tested and compared to experimental data related to two contrasted genotypes. The model shows that a pure cell-autonomous control fails to reproduce the observed cell size distribution, and an organ-wide control is required in order to get realistic cell size variations. The model also supports the role of endoreduplication as an important determinant of final cell size and suggests that a direct effect of endoreduplication on cell expansion is needed in order to obtain a significant c...
Frontiers in Plant Science, 2016
Process-based models are effective tools to predict the phenotype of an individual in different g... more Process-based models are effective tools to predict the phenotype of an individual in different growing conditions. Combined with a quantitative trait locus (QTL) mapping approach, it is then possible to predict the behavior of individuals with any combinations of alleles. However the number of simulations to explore the realm of possibilities may become infinite. Therefore, the use of an efficient optimization algorithm to intelligently explore the search space becomes imperative. The optimization algorithm has to solve a multi-objective problem, since the phenotypes of interest are usually a complex of traits, to identify the individuals with best tradeoffs between those traits. In this study we proposed to unroll such a combined approach in the case of peach fruit quality described through three targeted traits, using a process-based model with seven parameters controlled by QTL. We compared a current approach based on the optimization of the values of the parameters with a more evolved way to proceed which consists in the direct optimization of the alleles controlling the parameters. The optimization algorithm has been adapted to deal with both continuous and combinatorial problems. We compared the spaces of parameters obtained with different tactics and the phenotype of the individuals resulting from random simulations and optimization in these spaces. The use of a genetic model enabled the restriction of the dimension of the parameter space toward more feasible combinations of parameter values, reproducing relationships between parameters as observed in a real progeny. The results of this study demonstrated the potential of such an approach to refine the solutions toward more realistic ideotypes. Perspectives of improvement are discussed.
Frontiers in plant science, 2016
Drought stress is a major abiotic stress threatening plant and crop productivity. In case of fles... more Drought stress is a major abiotic stress threatening plant and crop productivity. In case of fleshy fruits, understanding mechanisms governing water and carbon accumulations and identifying genes, QTLs and phenotypes, that will enable trade-offs between fruit growth and quality under Water Deficit (WD) condition is a crucial challenge for breeders and growers. In the present work, 117 recombinant inbred lines of a population of Solanum lycopersicum were phenotyped under control and WD conditions. Plant water status, fruit growth and composition were measured and data were used to calibrate a process-based model describing water and carbon fluxes in a growing fruit as a function of plant and environment. Eight genotype-dependent model parameters were estimated using a multiobjective evolutionary algorithm in order to minimize the prediction errors of fruit dry and fresh mass throughout fruit development. WD increased the fruit dry matter content (up to 85%) and decreased its fresh we...
Annals of botany, Aug 8, 2016
Plant growth depends on carbon availability and allocation among organs. QualiTree has been desig... more Plant growth depends on carbon availability and allocation among organs. QualiTree has been designed to simulate carbon allocation and partitioning in the peach tree (Prunus persica), whereas MappleT is dedicated to the simulation of apple tree (Malus × domestica) architecture. The objective of this study was to couple both models and adapt QualiTree to apple trees to simulate organ growth traits and their within-tree variability. MappleT was used to generate architectures corresponding to the 'Fuji' cultivar, accounting for the variability within and among individuals. These architectures were input into QualiTree to simulate shoot and fruit growth during a growth cycle. We modified QualiTree to account for the observed shoot polymorphism in apple trees, i.e. different classes (long, medium and short) that were characterized by different growth function parameters. Model outputs were compared with observed 3D tree geometries, considering shoot and final fruit size and growt...
Frontiers in plant science, 2018
Climate change projections predict warmer and drier conditions. In general, moderate to severe wa... more Climate change projections predict warmer and drier conditions. In general, moderate to severe water stress reduce plant vegetative growth and leaf photosynthesis. However, vegetative and reproductive growths show different sensitivities to water deficit. In fruit trees, water restrictions may have serious implications not only on tree growth and yield, but also on fruit quality, which might be improved. Therefore, it is of paramount importance to understand the complex interrelations among the physiological processes involved in within-tree carbon acquisition and allocation, water uptake and transpiration, organ growth, and fruit composition when affected by water stress. This can be studied using process-based models of plant functioning, which allow assessing the sensitivity of various physiological processes to water deficit and their relative impact on vegetative growth and fruit quality. In the current study, an existing fruit-tree model (QualiTree) was adapted for describing ...
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Annals of Botany
Background and Aims Sugar composition is a key determinant of fruit quality. Soluble sugars and s... more Background and Aims Sugar composition is a key determinant of fruit quality. Soluble sugars and starch concentrations in fruits vary greatly from one species to another. The aim of this paper was to investigate similarities and differences in sugar accumulation strategies across ten contrasting fruit species using a modeling approach. Methods We developed a coarse-grained model of primary metabolism based on the description of the main metabolic and hydraulic processes (synthesis of other compounds than sugar and starch, synthesis and hydrolysis of starch, water dilution) involved in the accumulation of soluble sugars during fruit development. Key Results Statistical analyses based on metabolic rates separated the species into six groups according to the rate of synthesis of compounds other than sugar and starch. Herbaceous species (cucumber, tomato, eggplant, pepper and strawberry) were characterized by a higher synthesis rate than woody species (apple, nectarine, clementine, grape...
Acta Horticulturae
HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.
Acta Horticulturae
QualiTree is a generic fruit tree object -based model in which the effects of management practice... more QualiTree is a generic fruit tree object -based model in which the effects of management practices on the development of fruit quality are explicitly modelled. It considers a large range of fruit quality traits important for growers, retailers and consumers, including: fruit size, the proporti on of total mass consisting of fruit flesh, flesh dry matter content, flesh concentrations of various sugars, and sweetness, a linear combination of sugar concentrations. Though parsimonious in terms of 3D representation of the plant architecture, it is able to express a high degree of within- tree variability of fruit quality criteria. QualiTree has been successfully tested using several datasets. A range of peach cultivars – from very-early to late – has been parameterised into QualiTree. Simulation studies show the potential of QualiTree to predict how fruit quality profiles may change under various levels of biotic and abiotic stress, which will become common wi thin the context of global change. We simulated patterns of foliar attacks by parasites and showed that reductions in fruit quality were lower when attacks were late in the season. Other simulation studies indicated that severe water stress during stage III of fruit development decreased fruit size whereas it dramatically enhanced sugar accumulation in the fruit flesh, especially in the case of glucose and fructose. Hence, QualiTree might be useful in the design of innovative horticultural practices combining regulated deficit irrigation strategies and plant-mediated control of pests.
Journal Of Experimental Botany
The development of a new organ is the result of coordinated events of cell division and expansion... more The development of a new organ is the result of coordinated events of cell division and expansion, in strong interaction with each other. This paper presents a dynamic model of tomato fruit development that includes cell division, endoreduplication and expansion processes. The model is used to investigate the potential interaction among these developmental processes, in the perspective of the neo-cellular theory. In particular, different control schemes (either cell-autonomous or organ-controlled) are tested and compared to experimental data from to two contrasted genotypes. The model shows that a pure cell-autonomous control fails to reproduce the observed cell size distribution, and an organ-wide control is required in order to get realistic cell size variations. The model also supports the role of endoreduplication as an important determinant of the final cell size and suggests that a direct effect of endoreduplication on cell expansion is needed in order to obtain a significant ...
Irrigation Science, 2013
Your article is protected by copyright and all rights are held exclusively by Springer-Verlag. Th... more Your article is protected by copyright and all rights are held exclusively by Springer-Verlag. This e-offprint is for personal use only and shall not be self-archived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Agricultural Water Management, 2013
Agricultural Water Management j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l... more Agricultural Water Management j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / a g w a t Corrigendum Corrigendum to "Assessment of the water stress effects on peach fruit quality and size using a fruit tree model, QualiTree" [Agric. Water Manage. 128C (2013) 1-12] The authors regret to inform you that Fig 2 present in the article is incorrect. The correct version of Fig. 2 is below:
Agricultural Water Management, 2013
Low water availability has increased the use of regulated deficit irrigation strategies in fruit ... more Low water availability has increased the use of regulated deficit irrigation strategies in fruit orchards. However, these water restrictions may have implications on fruit growth and quality. The current paper assesses the suitability of an existing fruit tree model (QualiTree) for describing the effects of water stress on peach fruit growth and quality. The model was parameterised and calibrated for a mid-late maturing peach cultivar ('Catherine'). Mean and variability over time of fruit and vegetative growth were consistent with observed data on trees submitted to full irrigation or to regulated deficit irrigation. The relative root mean square errors of the model for growth ranged between 0.09 and 0.31.
Trees, 2011
In this paper, QualiTree, a fruit tree model designed to study the management of fruit quality, a... more In this paper, QualiTree, a fruit tree model designed to study the management of fruit quality, and developed and described in a companion paper (Lescourret et al. in Trees Struct Funct, 2010), was combined with a simple light-interception sub-model, and then parameterised and tested on peach in different situations. Simulation outputs displayed fairly good agreement with the observed data concerning mean fruit and vegetative growth. The variability over time of fruit and vegetative growth was well predicted. QualiTree was able to reproduce the observed response of trees to heterogeneous thinning treatments in terms of fruit growth. A sensitivity analysis showed that the average seasonal growth rates of the different organs were sensitive to changes to the values of their respective initial relative growth rates and that stem wood was the tree organ the most affected by a change in the initial relative growth rates of other organs. QualiTree was able to react to simulated scenarios that combined thinning and pest attacks. As expected, thinning intensity and the percentage damage caused by pests significantly affected fruit yield and quality traits at harvest. These simulations showed that QualiTree could be a useful tool to design innovative horticultural practices.