Current pruning recommendations for clonal cacao (Theobroma cacao) lack scientific support regarding tree architectural development. This study investigates the relationship between tree architecture and production potential using data from a long-term trial in Bolivia. We measured architectural and production traits on 331 seventeen-year-old grafted trees across five cropping systems, ranging from conventional monocultures to input-free dynamic agroforestry, and four genotypes. We differentiated the productive “leafless zone” from the “leafy crown,” measuring branch orders, diameters, lengths in the former, and crown geometry traits in the latter. Results demonstrate that, while cropping systems and genotypes significantly influence vegetative biomass, the structural drivers of pod production remain consistent. Production was strongly related to the vigor (diameter) and number of low-order scaffold branches (orders 1 and 2) after accounting for cropping system type and genotype. Modelling confirmed that trees with complex scaffold structures and thicker 1st-order branches produced significantly more pods and beans than those with simple structures, with crown projected surface and foliage height further enhancing production potential. These findings challenge standard pruning recommendations focusing mainly on leafy crown management. We conclude that production potential is determined by the development of scaffold branches in combination with effective crown management. Consequently, pruning strategies should evolve from simple canopy control toward preserving vigorous scaffold branches and optimizing the tree’s physiological capacity for fruit production. To support this shift, we propose an architectural typology based on the branching structure of the leafless zone in grafted cacao trees to assess production potential and guide pruning decisions.

The transition of incumbent agrifood value chains toward agroecology remains poorly understood. We examined 11 French sustainability-oriented niche markets being linked to some of the FAO "10 elements of agroecology." Our analysis identified key innovation activities (knowledge development, market signal and communication, network governance and expansion) and the blockages these initiatives encounter to go further for transformative change. The results reveal slow and path-dependent changes toward agroecology, and highlight the intertwined technical, organizational, and institutional changes that limit the depth and scalability of agroecological transitions in conventional value chains, questioning how to support niche innovations in value chains.

Diversification of farming systems at plot scale is increasingly seen as an essential option to meet agriculture sustainability challenges and support agroecological transition. Significant progress has been made in recent years on methods for designing diversified cropping systems based on annual crops. However, few methods have been tested for designing diversified cropping systems based on perennial crops, and in particular perennial crop-based agroforestry systems, despite their important dietary and economic roles in the world. In this study, we argue that the characteristics of perennial crops induce specific structural and functional changes that impact the design process. We identified four key concepts for the design of diversified perennial crop-based agroforestry systems: (i) the targeted productivity must be considered over the long term and at the plot level, and encompass not only the productive and non-productive stages of perennial crops but also of associated plants; (ii) these systems will eventually face shocks and crisis in their lifetime, so they should be designed with resilience and adaptability in mind; (iii) initial designs will necessarily evolve throughout the long lifespan of perennial crops, and so a combination of de novo design from scratch and step-by-step design approaches for regeneration or transformation will be required; and (iv) due to the high complexity of these systems and the difficulty of setting up trials, the design process should draw from a range of knowledges from academics and practitioners and hybrid them. These four key features show that perennial crops offer distinct opportunities for the design of sustainable diversified cropping systems, but also face specific challenges that require more transdisciplinary research.

ABSTRACT The expansion of apple cultivation into subtropical climates has necessitated effective strategies to ensure high and consistent productivity. Adapting apple trees to mild winter regions involves challenges in lateral sprouting, which is partly related to the accumulation of chill. This study aimed to investigate the budding patterns of different apple tree cultivars in two sites with contrasting environmental cultivation. The study was conducted in two orchards in a mild winter region of Brazil: Horizonte orchard (ideal cultivation environment) and Lovo orchard (marginal cultivation environment). The selected apple cultivars included ‘Eva’, ‘Fuji Suprema’, and ‘Galaxy’. The experimental design involved marking five one-year-old shoots on five plants at each site and cultivar during the winter for two consecutive years. At the onset of the subsequent autumn, the marked branches were collected to assess the development of lateral shoots. In addition, the total number of spurs and shoots was counted in each orchard. The ‘Gala’ cultivar exhibited consistent spurs per plant across both sites. However, the ‘Fuji’ cultivar demonstrated a substantial increase in total spurs per plant in the low chill environment, with no discernible change in the development of lateral spurs, suggesting a high bourse-over-bourse formation. In orchards with higher chill accumulation, both cultivars necessitated high pruning due to excessive long shoots, underscoring the importance of adapted training systems and cultural practices to each growing region. Further research must enhance our understanding of plant architecture in mild winter regions.

Agroforestry is a major adaptation and mitigation strategy facing climate warming, but its agronomic viability depends on actual plant responses to shade conditions. Growing fruit trees under dominant trees may reduce the risks related to extreme climatic events, such as frost or heat waves. Nonetheless, except for some sciaphilous plants, such as coffee or cacao, their physiological and architectural responses to agroforestry conditions are little known, especially in temperate climate. We present a dataset describing the architecture and morphology of 45 young apple trees, acquired in two consecutive years, along a radiative gradient, as in three growing conditions of an agroforestry plot: (i) the open field, (ii) between, and (iii) along rows of dominant walnut trees. The data are stored as standard multi-scale tree graphs that allow to store the topology, geometry, and attributes of the plant at different scales. It includes plant traits at three topological scales: whole tree, growth unit, and the internode. The traits include organ fate (latent, vegetative, floral bud, and bud extinction sites); length and an estimate of the leaf area of growth units; diameter, zenith, and azimuth angles of second-order branches. The number of leaves, flowers, fruits, and fruit drops is also counted on a sample of 10, possibly apical, flower buds per tree. The dataset includes ancillary measurements on sampled shoots, used to derive allometric relationships between shoot length and leaf area; and an estimate of the radiation reaching each apple tree during the vegetative season. The multi-scale description and the different light growing conditions characterizing the digitized trees allow to investigate relationships between the shade-related agroforestry environment and the apple tree morphological and architectural plasticity, during the early tree development, from the internode to the whole tree.

BACKGROUND AND AIMS:Theobroma cacao L., a tropical sciaphilous tree, exhibits cauliflory, with persistent flowering sites known as flower cushions. Cushions develop from floral buds located at the axils of leaves or cataphylls. They can sustain recurrent flowering and contribute to the fruit production of the tree throughout its lifespan. However, factors influencing their formation and flowering activity remain poorly understood. METHODS:Architectural and geometrical measurements, combined with weekly monitoring of flowering activity at the node scale, were conducted on plagiotropic branches of two cacao genotypes under medium and heavy shade. We investigated how architecture and geometry influence cushion formation, frequency and duration of flowering episodes, and synchrony of flowering among cushions at different scales. KEY RESULTS:Flower cushions developed once a flush (growth unit) had reached a specific ontogenetic age, defined by its position along the shoot (axis). The probability of flower cushion formation was then determined primarily by the position of the node (phytomer) within the flush and its basal diameter. Heavy shade (90 % light reduction) greatly limited cushion formation, regardless of the architectural traits or growth characteristics of the node, flush or shoot. In contrast, the temporal activity of the flower cushions was not related to architectural or geometrical factors, and flowering occurred with moderate synchrony at the growth unit, axis and branch scales. CONCLUSIONS:These findings indicate the dual importance of shoot ontogeny and node-specific traits in flower cushion formation in this cauliflorous species. They also demonstrate the overall negative influence of heavy shade on flower cushion development, and the absence of architectural constraints on the flowering activity of cushions during the first reproductive phase of the tree. Further analyses are needed to gain a better understanding of the hormonal and carbohydrate regulation of flowering and fruiting in productive trees of this cauliflorous species.

Agroforestry is promoted as a way to improve the sustainability of horticultural systems through plant diversification and also to mitigate climate change through carbon sequestration. It could also alleviate excessive light and temperature in high-radiation regions of the world. However, little is known about the long-term shade adaptation of the temperate fruit tree in agroforestry systems. A study was developed to investigate apple growing under walnut trees in two shade conditions compared to a full light condition. Our aim was to quantify the plasticity of traits and the covariations between traits in these three light conditions using a multiscale approach considering different scales from whole tree to annual shoot and inflorescence. Shade did not affect the height of the apple trees, while it reduced the diameter of the trunk and branches. On the other hand, the total number of growing shoots was reduced in shade, and flowering and fruiting were fewer and more irregular than in full light. Strikingly, at the whole tree scale, covariations between vegetative traits (trunk cross-sectional area versus mean branch cross-sectional area) and between vegetative and reproductive traits (trunk cross-sectional area versus total number of inflorescences) were not altered by shade. However, at the shoot scale, return-bloom was significantly reduced by shade, whereas at the inflorescence scale shade did not affect leaf number or leaf area. We propose a shade adaptation syndrome that includes not only shade intensity but also shade dynamics during the growing season and over consecutive years.

Agroforestry, the integration of trees, crops, and animals, is expected to increase environmental sustainability of fruit production compared to traditional orchards. Virtual experiments with models would allow the performance and sustainability of these systems to be evaluated in a range of pedoclimatic and management scenarios, taking into account the interactions of fruit trees with crops. The models should represent tree and crop growth in 3D, run simulations over the whole life cycle of the orchard, and account for management practices that influence tree-crop interactions. We reviewed existing fruit tree and agroforestry models and have proposed a decision tree to guide future modellers in choosing a model that meets their simulation objectives. None of the reviewed models met all requirements, but we identified improvements that could be made to two existing models to accurately simulate temperate fruit tree based agroforestry systems.

Theobroma cacao, a tropical cauliflorous fruit tree, typically produces flowers and fruits twice a year and exhibits alternate harvesting patterns over consecutive six-monthly seasons in regions with bi-modal rainfall distribution, such as Côte d'Ivoire. This study investigated seasonal variations in flowering and fruiting among trees in populations of mixed cacao genotypes. The intensities of crown and trunk flowering and pod production were monitored for eight consecutive six-monthly seasons on 114 adult cacao trees grown from seedlings. We investigated distributions of seasonal flowering and fruiting values, relationships between flowering and pod production, and the effects of seasonal cumulative rainfall. The patterns of seasonal flowering and fruiting series were analyzed using two descriptors: the first distinguishing between regular and variable patterns, and the second analyzing the structure of such variability, classifying it as either irregular or alternating. Despite being subjected to similar climate and agronomic management, individual trees exhibited highly variable flowering and fruiting behaviors within each season, as well as variable patterns of flowering and fruiting across seasons. Seasonal alternate fruiting on a population scale masked highly variable patterns among trees, and only 19 % of the trees exhibited marked alternate fruiting patterns. Variations in pod production on a tree scale were mainly related to variations in trunk flowering. Endogenous factors seemed to control seasonal variations in flowering and fruiting, even though exogenous factors, both climatic and agronomic, could structure flowering and fruiting patterns at the orchard scale.

This study aimed to characterize the occurrence, duration, and intensity of the flushes of vegetative growth in two peach cultivars of Prunus persica L. Batsch, grown as a pioneer endeavor at a high-altitude tropical climate site in the State of Minas Gerais, Brazil. The observational experiment was carried out in 2017/18 and 2018/19 on the 'Tropic Beauty' and 'BRS Kampai' cultivars by an evaluation of the number and duration of flushes of vegetative growth during the year over two cycles. The number of fruit-bearing shoots, total number of leaves and shoot length were also assessed. At harvest, fruit load and diameter were determined and grouped into diameter ranges. The number of hours recorded at different temperature ranges, < 10.0 degrees C; 10.1-15.0 degrees C; 15.1-20.0 degrees C; 20.1-25.0 degrees C; > 25.1 degrees C, were summed separately and divided into daily and nightly periods. The peach tree has an unusual vegetative growth pattern when cultivated in a tropical area, which occurs in two flushes, with the first flush occurring from budbreak to fruit harvest between June and Sept, forming short shoots (less than 10 cm), with early shoot growth cessation, with a limited leaf number that can potentially diminish the supply of carbohydrates to the fruit, leading to smaller growth. The second flush occurs after harvest, between Oct and Dec, when there is an increase in daily temperature and precipitation, and no competition with fruits. Notabily, these second flush shoots grow with greater vigor and regularization of the growth cycle, forming fruit-bearing shoots with abundant leaf and flower buds for the next production cycle.

Duru et al. (Agron Sustain Dev 35:1259-1281, 2015) highlighted a missing tool for studying and improving the performance of cropping systems in the transition to highly diversified agriculture. In response, this paper proposes a concept for designing, modeling, monitoring, and auditing desired ecosystem services, in intercropping and agroforestry systems. We have labelled this concept ESSU (Ecosystem Services functional Spatial Unit). It delimits the smallest spatial unit encompassing all the interacting species and other functional components (e.g., crops, trees, livestock, spontaneous vegetation, semi-natural habitats such as hedges, ditches, forest patches, and animals) that together provide a specified set of ecosystem services. The novel ESSU concept allows representation of an entire diversified agroecosystem by the repetition of the spatial unit that provides the same sets of targeted ecosystem services as the agroecosystem it represents. It can then be used for various activities, such as the (i) design of more efficient agroecological systems according to the targeted ecosystem services; (ii) rapid audit of farming practices for biodiversity/resilience across large tracts of farmland as part of achieving Sustainable Development Goal 2 targets of sustainable food systems; and (iii) modeling such diversified agroecosystems using a motif adapted to represent the targeted ecosystem services and the species spacing design. We demonstrate that the ESSU concept is highly flexible and applicable to a wide range of diversified agroecosystems, like arable intercropping, crop-tree intercropping, tree-tree agroforestry, and agro-pastoralism. We also show its relevance and suitability for representing temporal changes over 1 year, across several years, and over decades, indicating its generalizability and flexibility. We argue that ESSU could open new theoretical and practical research avenues for the study of diversified agroecosystems. Considered with all the knowledge available on practices, biodiversity, and ecosystem services, ESSU might provide a learning-support tool to fill the knowledge gap about relationships among practices, biodiversity, and associated ecosystem services.

The conventional cultivation of olive trees can lead to environmental degradations such as soil erosion and loss of biodiversity. Agroforestry systems could bring solutions to these environmental degradations. A simulation model able to represent the growth and interactions between olive trees and annual crops would be useful to rapidly test and evaluate innovative olive-based agroforestry systems without the need for space and time-consuming field experiments. The Hi-sAFe model simulates agroforestry systems in three dimensions according to interactions between forest trees and annual crops for water, nitrogen and light. However, this model was developed and parameterised only for forest trees and not for fruit trees whose balance between the vegetative and the fruit organs is crucial. Two main adaptations were made to the model to simulate olive-based agroforestry systems: the addition of a fruit-setting module and the carbon allocation module adaptation. Here, we present the experimental estimation of two important parameters of these modules, both at tree scale: the maximum number of fruits m-2 leaf area and the maximum daily carbon allocation to fruits. The maximum fruit load per olive trees was estimated at 1356 fruits per m(2) leaf area using three genotypes of an ' Arbequina' x 'Oliviere' progeny. To determine the maximum daily carbon allocation to fruits, we hypothesized a cultivar effect. For these reason, nine olive trees, of three cultivars ('Leccino', 'Cypressino' and 'Manzanille'), with a low fruit load were selected from the three cultivars, and samples of fruits were dry-weighted every week for 12 weeks during fruit growth. The maximum daily carbon allocation to fruits (g carbon olive(-1) day(-1)) varied significantly between 'Leccino' and 'Cypressino' (3.9x10(-3) and 4.3x10(-3), respectively) and 'Manzanille' (7.3x10(-3)). The value of these two parameters not identifiable in the literature can be set to 1356 fruits m(-2) of leaf area (maximum number of fruits m-2 leaf area) and at 7.3x10(-3) g carbon olive(-1) day(-1) (maximum daily carbon allocation to fruits).

This study was conducted at the Station Expérimentale Fruits et Légumes in the South-East Mediterranean region of France and aimed to explore the effects of water-deficit stress on fruit production, water status, and growth responses. It was carried out on a 9-year-old top worked apple cv. “JoyaTM” on Pajam‑1 rootstock.Water stress (at 50%) applied after vegetative growth was completed, from the beginning of July to the end of the irrigation season decreased size but increased soluble solids content in fruit. Water-stressed trees showed relatively high water use efficiency without causing a significant effect on yield. Indeed, the water amount used for one fruit was 11.4 l (median) in water-stressed trees and 15.9 l (median) in well-watered trees, although tree volume and leaf area were similar between the two water regimes. A within-tree network of dendrometers was installed in four locations (bottom of a branch and end of the same branch, fruit, and trunk). The branch and trunk’s maximum and minimum diameter growth were observed in the morning and noon, respectively, over the diurnal period, whatever the water regime. The maximal diameter growth of fruit in both water regimes was during the afternoon on a diurnal basis, unlike vegetative tree portions.

Crop losses from pests threaten global food security and safety. In the last six decades, pest control using chemical pesticides has resulted in important yield gains per unit area, worldwide. However, the long-term sustainability of chemical pest control has been increasingly thrown into doubt due to the negative impact on human health, biodiversity, and the environment. Consequently, there is an urgent need to improve the science of crop protection in order to tackle the five key challenges of 21st century agriculture holistically: (i) maintaining or improving agricultural productivity, (ii) producing healthy food, (iii) reducing the negative impacts of agriculture on ecosystem and human health, (iv) ensuring the economic viability of farms, and (v) adapting agriculture to climate change. Agroecological Crop Protection (ACP) can be a powerful approach to address these challenges, as we demonstrate in this paper. ACP is the application of the principles of agroecology to crop protection in order to promote virtuous and sustainable changes in agriculture and food systems. ACP combines multiple approaches and disciplines including ecology, agroecology, and Integrated Pest Management. It promotes a crop protection system compatible with healthy agricultural and food systems, agroecological principles and the “one health” approach. We predict that ACP will meet the challenge of pesticide-free agriculture in the future. In this paper, we will first present the scientific, agricultural and social components of ACP. We will then analyze the research approaches, questions, methods and tools needed to adopt ACP. Finally, we suggest key mechanisms to facilitate the transition to ACP, which will ultimately provide sustainable food, feed, and fuel in a context of major global change.

Many factors are affecting the fruit growth dynamics of fruit trees. The vapour pressure deficit (VPD), the measure of the drying power of the air, integrates temperature and air humidity data, is one of the crucial factors affecting this process. In the current study carried out in an apple orchard in southeastern France, fruit diameter and VPD values were recorded by a wireless sensor network. A regression model was created utilizing feed-forward learning and predicting algorithms. With the obtained model, the relationships between VPD and fruit growth can be computed. As an example, when we keep the humidity conditions constant and increase the temperature by 2 °C in the model, the fruit diameter decreases by 0.18%.

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Conventional fruit-tree farming systems are highly productive and strongly dependent on external inputs, including pesticides, fertilisers, and water. To reduce this dependence, various initiatives have been developed in past decades, such as Integrated Fruit Production, Organic Farming, and more recently, Agroecology which is strongly inspired by research in ecology. These initiatives include plant diversity as the main driver to improve the sustainability of the orchard. Plant diversity can either be planned (choice of productive and not productive species) or associated (unintentional) and at different scales (within the cultivated plot and/or the surrounding landscape). To increase plant biodiversity, companion, i.e., mostly non-productive, plants can be either herbaceous, bushes, or trees. The interest of plant diversity to improve the sustainability of agrosystems is documented from three points of view: composition, structure, and function. First, companion plants have to fulfil precise functions within the system, such as sustaining nitrogen provisioning (e.g., herbaceous legumes between fruit-tree rows), hosting natural enemies of main pests, or attracting herbivore insects outside the orchard. Recent works on agroecology analyze fruit-tree based agrosystems documenting fruit production and the various "services" (e.g., mitigation of CO2 emission, soil nitrogen availability) companion plants can provide. Second, to optimise plant functioning, it is necessary to define rules of plant assemblage at spatial (e.g., distance between plants) and temporal (e.g., plantation at the same time period or not) levels. Based on a literature survey and current experiments, we will show that agrosystems that combine trees grown for fruit and possibly for timber or firewood and agricultural crops, i.e., fruit-tree based agroforestry systems (FT-AFS), provide promising results in the temperate climate context, including the Mediterranean zones. Further, the introduction of plants providing pest regulation services opens to challenging perspectives toward friendly fruit-tree-based agrosystems.