We know that fruit production, especially in the Mediterranean, will need to adapt to climate change to ensure the sustainability of fruit tree-based agroecosystems. However, there is a lack of evidence on the long-term effects of this change on sustainability indicators. To fill this gap, we used a fruit tree model, QualiTree, to analyze the impacts ofclimate change on the ecosystem services provided by apple orchards in south-eastern France. To do this, a blooming model was parameterized to simulate blooming date on the basis of climate data, and QualiTree was supplemented with a model of nitrogen processes in the tree and a soil module describing resource input (irrigation, mineral and organic fertilization), transfer in the soil (water and nitrogen) and metabolic transformation-immobilization (mineralization, (de)nitrification). This type of extension makes it possible to simulate a wide array of ecosystem services, including C sequestration, nitrate leaching and nitrous oxide emissions. The model was compared with data from an apple orchard in southeastern France. The predicted daily mean and variability over time of fruit growth, composition and soil water content were consistent with observed data. QualiTree was then used to assess the potential impacts of climate change on the ecosystem services supplied by apple orchards. For this purpose, weather variables from 2020 to 2100 were generated for three contrasted greenhouse gas emission scenarios, and simulations were performed under two irrigation schemes (no restriction and restricted use of water). Model outputs indicated that, on average, marketable apple yields would increase until 2050 and then subsequently decrease. The fruit refractometric index, an indicator of fruit quality, was projected to sharply decrease with the intensity of climate change. Ecosystem services such as C sequestration by the orchard will decrease with climate change severity, mainly due to a higher mineralization of soil humus, whereas N2O emissions will increase with larger denitrification rates. Soil water availability, fertility, drainage and leaching were predicted to depend more on the irrigation strategy than on climate change severity. The new functions performed in QualiTree broadened its predictive capabilities and allowed for a better understanding of ecosystem service delivery in fruit orchards under varying climate conditions.

A significant reduction in chemical pesticide use is strongly recommended in fruit production systems to reduce environmental and consumer health risks. Our objectives were to assess the consequences of pesticide reduction use on peach orchards' agronomic and economic performance. Three management strategies were tested at six sites in France during the 2013-2019 period within a network using the system experiment methodology: conventional reference systems (REF) representatives of current commercial orchards, low-input (LI) systems with reduced chemical use and according to Integrated Production guidelines and organic systems (ORG). The last two systems combine many action levers ranging from structural planting strategy and combined with many alternative methods carried out throughout the years to progress towards agroecological orchards. The perfor-mance indicators were statically compared to those observed in the conventional REF system growing under the same experimental conditions over seven years. Chemical pesticides were reduced by 55% in LI compared to REF systems (20.4 treatment frequency index). Marketable yield was significantly lower in LI (-13%) than in REF systems (33.0 t ha1). The reduction in production costs per hectare in LI systems (-11.4%) did not compensate for the decrease in gross revenues (-14.2%), resulting in a significant reduction in margins (gross revenues minus production costs,-15.8%). In the ORG systems, chemical pesticides were reduced by 80% compared to REF systems. The marketable yield was strongly reduced (-68%), but economic margins were close to REF systems thanks to the premium prices. The agroecological systems achieved in a quarter (LI) and half (ORG) of the situations (system x year) a 50% reduction in chemical pesticides and similar margins to the REF system. However, the reduction of pesticides in LI and ORG systems was accompanied by increased production costs expressed per kg of fruit and the lowest yield stability. These results highlight the importance of commercial labels to promote more eco-friendly orchards considering the impact on production costs.

EcoPeche 2 project (2019-2023) is financed by the French Biodiversity Agency (OFB) within the framework of the French national ECOPHYTO Plan and DEPHY farm network. EcoPeche 2 Project follows a previous INRAE-CTIFL co-led project, called EcoPeche 1 (2013-2018), whose aim was to reduce the treatment frequency index (TFI), measuring pesticide use, by 50% compared to current practice. The first project demonstrated that the TFI reduction of 50% could be achieved but the agronomic and technical-economic results decreased to varying degrees depending on the cultivar, the climate conditions and the pest and disease pressure. This present project aims to conceive and evaluate innovative peach orchard management systems designed to reduce TFI by 80% compared to a conventional management system. At the CTIFL research center of Balandran (Bellegarde, Gard, France), the experiment is being carried out on a yellow flesh peach cultivar (PAJALADE cov). Tested practices focus on tree training, density, irrigation system and rain cover to protect the trees until harvest. 'Non-biocontrol' plant protection products are used as a last resort only. Woven foil is laid on the ground for weed management. Fruits undergo thermotherapy after harvest to reduce losses generated by brown rot. First mid-term results show that the environmental objectives can be achieved; TFI reduction in the innovative compared to Reference system was: 60% in 2019; 69% in 2020 and 93% in 2021; but involve a loss of 40 to 50% in yield or irregularity in production and high investment for specific practices. This project highlights how complex it is to develop new orchard management system, taking into account environmental issues.

EcoPeche 2 (2019-2023) project is financed by the OFB (French Biodiversity Agency) within the framework of the ECOPHYTO Plan and the DEPHY farm network. The EcoPeche 2 Project follows a previous INRAE-CTIFL co-led project, called "EcoPeche 1" (2013-2018), whose aim was to reduce the chemical Treatment Frequency Index (TFI) by 50%. The first project demonstrated that the TFI reduction of 50% could be achieved but the agronomic and techno-economic results decreased to varying degrees depending on the cultivar, climate conditions and pest and disease pressure. EcoPeche 2 project aims to develop and evaluate innovative peach orchard management systems designed to reduce TFI by 80% compared to a conventional management system. The project involves 6 partners (CTIFL, INRAE PSH Avignon, INRAE Gotheron, SEFRA, SUDEXPE and CENTREX) evaluating different combinations of levers. Innovative orchard management systems are compared using a global approach, including environmental, agronomic and techno-economic performance. Each partner compares different combination of variable to an Integrated Fruit Production (IFP) management. Many types of variables are mobilized: cultivar choice, orchard management, weed management, biodiversity, phytosanitary protection, and physical variables. First mid-term network results show that the environmental objectives can be achieved (TFI reduction compared to Integrated fruit Production (IFP): -75% in 2019; -84% in 2020 and -89% in 2021) but involve a loss of production (-20% of commercial yield) and, consequently, important economic losses (partial margin -13 to -16% depending on the year).

Fruit tree orchards are an important land-use type in the Mediterranean regions despite limited information on their potential role as carbon sinks to mitigate climate change and their capacity to store soil organic carbon (SOC). The objective of this study was to evaluate the ability of peach orchards (Prunus persica (L.) Batsch) to fix and accumulate carbon (C) in three contrasting management systems. The first system was representative of the current management recommended to French producers with high yield objectives (REF). The second system was managed with a Low-Input strategy (LI-1) for chemical pesticide application (-70%), nitrogen fertilization and water irrigation (similar to-25%). Lastly, the third system (LI-2) had the same low-input strategy but included a higher planting density (similar to 2-fold) and a new tree shape training system. The experiment was conducted in the South of France for 7 years from planting (2013-2019). The aboveground biomass and C repartitions in various components of systems (tree organs and grass growing in alleys) were carried out by destructive measurements each year to determine Net Primary Production (NPP), Net Ecosystem Production (NEP) and Net Ecosystem Carbon Balance (NECB). The REF system had very high productivity during the mature tree period with 45.9 Mg ha(-1) yr(-1) of fresh fruit yield and 16.8 Mg ha yr 1 of aboveground biomass, corresponding to 7379 kg C ha(-1) yr(-1) (738 g C m(-2) yr(-1)). Orchard NPP (tree and grass) reached 11,003 +/- 353 kg C ha(-1) yr(-1) (1100 +/- 35 g C m(-2) yr(-1)) and soil respiration was 3366 +/- 776 kg C ha(-1) yr(-1) (337 +/- 78 g C m(-2) yr(-1)) leading to an NEP of 7637 +/- 853 kg C ha yr 1 (764 +/- 85 g C m(2) yr(-1)) and an NECB of 4919 + 858 kg C ha(-1) yr(-1) (492 + 86 g C m(2) yr(-1)). Carbon accumulation was distributed 53% in perennial biomass, and the soil had an annual SOC stock change of 3.8 parts per thousand. In the LI-system, the reduction of inputs and chemical pesticides did not impact the average NEP and NECB, even though pest infestations reduced biomass in 2015 and 2019. The same input reductions in the LI-2 system but with increased planting density provided significant increases in NPP (+10.5%) and NEP (+20.0%), leading to an NECB of 5876 + 890 kg C ha(-1) yr(-1) (588 +/- 89 g C m(-2) yr(-1)), or 19.4% greater than the REF system during the mature tree period. This positive C accumulation was distributed 46% in the perennial biomass, which could reach 35.5 Mg C ha (3550 g C m(-2)) after 15 years of orchard life. The SOC stock change was 10.0 parts per thousand in the LI-2 system, greater than the 4 parts per thousand initiative of the Paris COP21. Innovative peach orchards with agroecological management can mitigate environmental impacts by combining high-quality fruit production with enhanced CO2 sink capacity objectives.

The sustainable management of phosphorus (P) fertility in agroecosystems depends on either soil- or plant-based diagnosis methods. Our overall objective was to determine the relationship between the P nutrition index based on a critical P dilution of maize (Zea mays. L.) and indicators of the soil P supply assessed using either a process-based approach or the common chemical extraction of the Olsen' method. Long-term field experiments on mineral P fertilization, conducted at four sites with contrasting soil types representative of the main types of cropped soils in France, were selected to have deficient to excessive plant-available soil P. Three annual rates of superphosphate including no-P (P0) and about one (P1) and two (P2) times the annual P exported in harvests were studied, while the N and K supply was non-limiting. The shoot biomass (W, Mg DM ha(-1)) and its P concentration (P-maize, g P kg(-1) DM) were determined at 5-8 dates during the plant cycle after more or less two decades of P applications. Plant-available soil P in the ploughed layer was assessed by a functional and process-based approach that consists in determining together orthophosphate ions (oPions) concentration (C-P, mg P L-1), and the oPions amount (Qw) in solution, and the amounts of diffusive oPions bound to soils (Pr, mg P kg(-1) soil) that equilibrates the solution over time (t in minutes). We also assessed plant-available soil P by the Olsen' extraction (Olsen-P). Shoot biomass significantly decreased for the P0 treatment while there was no significant differences between the P1 and P2 treatments. The P-maize decreased as W increased. The criticalP(maize) curve, the minimum P-maize required to achieve maximum growth, was estimated using all data of the P1 treatment from the four sites: 3.66 x W-0.238 (r(2) = 0.61 for 78 observations). At maturity, the P nutritional index (PNI), calculated as the measured P-maize divided by the criticalP(maize), ranged from 53 % to 92 % for the P0 treatment and from 94 % to 128 % for the P1 and P2 treatments. The C-P values ranged from 0.04 to 2.25 mg P L-1. The Pr values were described accurately by: Pr = v x C-P(w) x t(p) for t <400 min with (v, w, p) highly different across soils types. Calibrations of PNI to C-P or to Olsen-P were both soil-specific. The new result brought by this study was that a unique calibration curve for all sites was obtained for PNI vs (Qw + Pr) considering a period of resupplying soil solution oPions of about one day. All points fell on the same regression line suggesting that this soil- and plant-based methods of diagnossis would both equally effective. This result provides new evidence of much better relevance and reliability of the process-based assessment rather than chemical extraction to adequately estimate the fraction of soil P that contributes to plant nutrition. The plant available soil P stock was better evaluated by the process-based approach because oPions buffering capacity of soils was accounted for. Consequently, the relationship between plant and soil indicators was highly improved.

A new mathematical modeling framework able to simulate the combined effect of fruit growth and post-harvest storage conditions (temperature and relative humidity) on nectarine quality is here proposed. The seasonal course of fruit surface conductance to water vapor, fruit mass loss during storage, and sugar concentration dynamics in fruit pulp were modeled. The three sub-models were integrated into a model capable of calculating a fruit sweetness index and relative water loss during storage, which were selected as nectarine quality criteria. Sub-models parameters were calibrated through results from experiments carried on during 2018 and 2019, where horticultural practices (irrigation and fruit load) and storage conditions were jointly varied. Irrigation level influenced fruit surface conductance to water vapor at harvest, but experimental results point out that this variable may have little influence on fruit mass loss during storage, which was mainly driven by relative humidity in the storage chamber. Irrigation intensity was also influential on sugar dynamics, along with storage temperature, with fruit stored at the higher temperature (25 degrees C) being sweeter than those stored at lower ones (2 and 15 degrees C). These experimental results were well replicated by the sub-model outputs. Model simulations during storage revealed a trade-off between the two selected quality criteria, which increased with increasing storage temperature and decreasing relative humidity. The best scenario in terms of acceptable fruit mass loss and sweetness index was for fruit from water-stressed and low crop-loaded trees, 15 degrees C and 70% relative humidity. Moreover, storage duration was shown to increase fruit mass loss and, to a lesser extent, the sweetness index, while fruit from late harvest dates had higher sweetness at the end of storage. The model can potentially be used to manage and optimize pre-harvest and storage practices that will maximize sweetness and minimize mass loss to meet fruit quality standards along supply chains.

Fungal infections caused by Monilinia species are responsible for severe losses in the postharvest stage of stone fruit. Storage and market environmental conditions (namely temperature and humidity) could play a key role in brown rot spread. It is recognized that fruit sensitivity to the disease could be influenced by both cultural practices and environmental conditions before harvest. In this context, we try to include these phenomena in a compartmental model, where we consider the classes of susceptible, exposed and infected fruit in order to predict the spread of brown rot during the postharvest stage. We calibrated the model against experimental data of Prunus persica var. nucipersica (nectarine) grown in Avignon (southern France). Different fruit loads, irrigation conditions and fungicide treatments were applied in the orchard, to induce different fruit sensitivity to brown rot at the beginning of the storage. Then, fruit were subjected to the same standard storage conditions (4 degrees C for 2 days and then 20 degrees C) and were visually assessed to quantify disease spread. Fruit from the well-irrigated treatments were generally more prone to disease spread. The model fits well experimental data, stressing the need to pay more attention to fruit growth conditions, to allow the prediction of brown rot diffusion patterns in postharvest stage. Moreover, the model could be used to evaluate possible management strategies to reduce the impact of the disease.

In this study, we analyzed the patterns of relationships between multiple ecosystem services in apple orchards by considering the cascade that links agricultural practices to ecosystem functions and then to ecosystem services. Five major ecosystem services were considered: fruit production, soil nitrogen availability, climate regulation, water cycle maintenance and regulation, including water quality, and pest and disease control. We derived indicators of ecosystem functions and of ecosystem services from model simulations of orchards driven by virtual cropping systems combining various modalities of nitrogen fertilization, irrigation, and pest control. We deciphered the links between practices and ecosystem functions and between those functions and ecosystem services and clustered cropping systems according to their ecosystem service supply. Noticeable synergies were found between yield, fruit mass and sequestrated carbon. The contribution of carbon allocation to fruit in sequestrated carbon was considerable. Nitrogen absorption, impacted by fertilization and irrigation, was a major driver of these relationships. The typology built from these virtual cropping systems clearly followed a gradient of provisioning and regulating ecosystem services. Five cropping systems optimized the compromise between provisioning and regulating services and were essentially characterized by organo-mineral fertilization, comfort irrigation, apple scab-resistant cultivars and exclusion nets against codling moth. Our approach could contribute to the design of cropping systems that would provide an acceptable compromise between multiple ecosystem services in orchards.

Phenological development can be seen as the biological clock of crops and crop model developers used this timeline for describing various processes associated with leaf area dynamics. The critical shoot nitrogen concentration (cNcrit; a reference to quantify crop nitrogen status), leaf-stem partitioning and specific leaf area (SLA) are often simulated as a function of developmental stages or thermal time driven functions. However, the impact of environmental variability might be better incorporated by considering process formulations related to biomass. Using published and novel data, this paper compares the simulation of processes associated with leaf area dynamics of winter wheat and maize using (a) BBCH (decimal code similar to the scale of Zadoks), xsatge or thermal time scale and (b) alternative formulations based on shoot dry mass (DM) or leaf area index (LAI). For both cNcrit and leaf-stem partitioning, the model based on DM was superior to the developmental approaches, as reflected in lower RMSE. Owing to the allometric link between LAI and DM, leaf-stem partitioning and SLA are not independent. Consequently, LAI explained canopy SLA better than developmental traits. Developmental stages are necessary to determine certain events like the switch from vegetative to reproductive development, but our results indicate that phenology cannot capture the allometric relationship between LAI and DM.

Fruit tree production faces the major challenge of ensuring maximal productivity with due consideration for the environment and human health. The increasingly recognized concept of ecosystem service could help to address this duality. In this paper, we propose an analytical framework based on a soil crop model to investigate how agricultural management and pedoclimatic conditions affect the joint production of marketed and non-marketed ecosystem services through underlying ecosystem functions in apple orchards. The ecosystem services considered on an annual scale were soil nitrogen availability, climate regulation, water regulation and fruit production. Ecosystem functions and services were described by specific indicators that were quantified using the STICS soil crop model. This model was parameterized using data collected on two experimental apple orchard sites under conventional and low-input or organic management in southeastern France. The interdependencies between environmental components, cultural operations and ecosystem functions were dynamically integrated by the model and highlighted significant interactions between the indicators of ecosystem services. Thus, the service indicators soil organic nitrogen variation and the prevention of nitrogen denitrification and of leaching were positively correlated and in conflict with soil mean nitrate concentration and mean soil humidity. They were also linked negatively to nitrogen mineralization enhanced by irrigation and positively to soil carbon sequestration impacted by fertilization; these two functions were impacted by soil conditions. Yield and carbon sequestration presented a strong synergy and were positively correlated to nitrogen absorption increased by mineral fertilization. Globally, nitrogen fertilization management and planting density were particularly important for the delivery of multiple ecosystem services, but soil and climate effects were far from negligible, especially for nitrogen and water-related services. The ecosystem service profiles of the studied cropping systems were diversified, with contrasted profiles showing high yield and carbon sequestration but low prevention of nitrogen denitrification and of nitrogen leaching, and more balanced profiles. The STICS crop model made it possible to quantify and analyze profiles of ecosystem services and should be helpful in instrumenting the dialogue between fruit growers and other stakeholders by simulating scenarios to optimize multiple services. However, it has to be improved to address the impact of grass cover on soil functions and the long-term functioning of apple orchards.

La reduction de l’utilisation des pesticides est un enjeu majeur en arboriculture. Le dispositif BioREco a permis d’explorer dans la duree le potentiel de reduction de l’utilisation des pesticides en verger de pommiers. Par rapport a la reference regionale, pour la periode de pleine production (2009-2015), il a en moyenne ete possible de reduire l’utilisation des pesticides de 38 a 45 % en combinant des varietes peu sensibles ou resistantes aux maladies, un ensemble de pratiques alternatives aux pesticides et une evaluation fine du risque de degâts. Cette reduction a ete atteinte pour des niveaux de rendement equivalents (systemes bas-intrants) ou moindres (systemes en Agriculture Biologique). L’evaluation multicritere realisee (agronomique, environnementale, technico-economique et faisabilite) a permis d’identifier les points forts et les points d’amelioration des systemes experimentes. Ce dispositif a egalement permis de creer une dynamique au sein de la filiere, autour de l’approche experimentale, des vergers, de leur evaluation multicritere, des resultats et des connaissances necessaires pour repenser les vergers de demain.

Arboriculture must maintain acceptable fruit production levels while preserving natural resources. This duality can be analyzed with the concept of ecosystem service. We reviewed the literature on orchards to explain how ecological functions modified by agricultural practices provide six ecosystem services - fruit production, climate regulation, soil nitrogen availability, water regulation, pest and disease control, and pollination - and which indicators could describe them. The major points are, first, that orchards have a high potential of multiple services. They can sequester from 2.4 to 12.5 t C/ha/year. Their perennial character and multi-strata habitat, as well as the opportunity of creating diversified hedgerows and cover crops in alleys, may contribute to a high level of biodiversity and related services. Second, every service depends on many functions. Fruit yield, which could reach up to 140 t/ha in apple orchards, is increased by light interception, carbon allocation, and nitrogen and water uptake. Third, agricultural practices in orchards have a strong impact on ecosystem functions and, consequently, on ecosystem services. Overfertilization enhances nitrogen leaching, which reduces soil nitrogen availability for the plant and deteriorates the quality of drained water. Groundcover increases humification and reduces denitrification and runoff, thus enhancing soil nitrogen availability and water regulation. It also enhances biotic interactions responsible for pest control and pollination. Pruning may increase fruit quality trough a better carbon allocation but decreases pest control by fostering the dynamics of aphids.To study multiple ecosystem services in orchards, we suggest using models capable of simulating service profiles and their variation according to management scenarios. We then refer to the available literature to show that conflicts between provisioning and regulating services can be mitigated by agricultural practices. Improved knowledge of soil processes and carbon balance as well as new models that address multiple services are necessary to foster research on ecosystem service relationships in orchards.

Dynamique d'accumulation de matiere seche et d'azote dans les vergers de pommiers. N-Perennes : un outil de raisonnement de la fertilisation azotee en cultures perennes, application a la vigne et a certains arbres fruitierscolloque de restitution du projet CASDAR