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International audience; Apple cultivation has evolved tremendously in the past decades to increase tree productivity and fruit quality. However, this was achieved at the cost of an increasing dependence on external inputs such as water, fertilizers and pesticides. This dependence is now questioned because of the generated environmental pollution and health issues. Different solutions have been considered to reduce this dependence including more efficient practices that improve resilience of agricultural systems to external pressures (climatic disturbances, new diseases, economic crises). To reduce pest and disease pressure, to improve resources use and to buffer extreme climatic events, agroforestry systems (AFS), i.e., the association, in one field, of tailored perennial and annual crops and possibly animals, are proposed as a way to use positive interactions between various plants. In temperate climate, AFS associate a tree stratum and a (or several) crop stratum, e.g., fruit trees and vegetables. An original AFS located in southeastern France, characterized by a Mediterranean climate and composed of mature walnut grown for timber, apple trees in an intermediate vertical stratum, and alfalfa at the lowest stratum, is being used to study the impact of an AFS on apple trees. Comparing apple trees in the AFS and in full sun, we first showed a significant effect of walnuts on the below-canopy microclimate reducing incoming global radiation and acting as a buffer on temperatures surrounding the apple trees. Secondly, AFS significantly altered the apple tree stem geometry (lesser tapering), growth dynamics (more growth cessation) and morphology (higher individual leaf area and specific leaf area). Results will be discussed with regard to the putative long-term effects of agroforestry conditions on the apple tree architecture and fruiting.

The mango tree is a large tropical tree giving in general low and irregular yields across consecutive years. Researches on canopy management have been a cornerstone to lessen, but not resolve, these problems. Mango production now faces new commercial and societal demar_ids besides higher yields: better fruit quality, in particular sanitary and nutritional quality, and reduced impacts on the environment. These issues bring challenges for the design of canopy management strategies since these objectives are interacting and sometimes conflicting. A better knowledge of the mango tree canopy functioning, in relation toits environment, appears necessary to design appropriate canopy management practices and to deal with the necessary compromises between these objectives. The study of tree architectural development, cou pied with ecophysiological researches, appears as a relevant approach to tackle these points. ln this paper we draw the current trends in terms of canopy management and vigour contrai for the manga tree, we present the recent advances made in architectural analysis and ecophysiology, and we outline the research needs for the future. The importance of the cultivar factor is highlighted, leading to the conclusion that a unique canopy management strategy is probably utopian, and cultivar-specific strategies must be considered. Another key point is the necessary interdisciplinarity of these approaches, in order to gather and process ecophysiological, architectural and genetic data to design canopy management strategies. Finally, the complexity of the canopy functioning requires a conceptual and quantitative modelling approach to synthesise the knowledge and to support the design of management strategies. (Texte intégral)