Pitchers B. auteur aut IRD Do Frédéric auteur aut IRD Pradal C. auteur aut IRD Dufour L. auteur aut IRD Lauri P. E. auteur aut IRD text journalArticle eng text/pdf born digital access PREMISE The expression of shade adaptation traits is expected to be stronger in low light and can be detrimental to flowering and yield. Our study focused on the expression of shade adaptation traits of apple trees (Malus domestica Borkh. 'Dalinette') in an agroforestry system. METHODS The architecture of 45 apple trees in their third and fourth year was extensively described and analyzed at the tree scale and compared depending on the light quantity received during the growing season. Flower cluster phenology and the relation between leaf area and floral initiation were also investigated. RESULTS The number of growing shoots and the leaf area were reduced by shade even if specific leaf area increased with increasing shade. Shade did not modify primary growth but did decrease secondary growth, so that apple tree shoots in shade were slender, with a lower taper and reduced number and proportion of flower clusters. The correlation between floral initiation and leaf area was high both in full and moderate light but not for apple trees in low light. Shade did not impact the date of bud burst and the early phenological stages of flower clusters, but it reduced the number of days at full bloom. CONCLUSIONS Our results suggest that while the architecture of apple trees is modified by a reduction in light intensity, it is not until a reduction of 65% that the capability to produce fruit is impeded. These results could help optimize the design of apple-tree-based agroforestry systems. specialized floral initiation floral phenology plant architecture plurispecific agrosystems shade shoot allometry vegetative shoots FRANCE 076 082 108 5 732-743 2021 0002-9122 https://www.documentation.ird.fr/hor/fdi:010081411 10.1002/ajb2.1652 0002-9122 [F B010081411] https://www.documentation.ird.fr/hor/fdi:010081411 https://www.documentation.ird.fr/intranet/publi/2021-06/010081411.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2021-06-15 2025-02-24 fdi:010081411 fre