The role of structural and temporal factors in the architectural development of the mango tree: evidences from simulation

The vegetative and reproductive development of the mango tree is affected by endogenous structural and temporal factors and their interactions. These factors likely explain the well-known phenological asynchronisms within and between trees. To test this, we developed an integrative model that synthesizes knowledge acquired on the endogenous processes and biotic and abiotic factors involved in fruit yield and quality development in mango trees. For this purpose, we first designed a mango tree architectural development model. Growth and development of growth units and inflorescences were calibrated using thermal time models. The appearance of these organs was decomposed into elementary events describing the occurrence, the intensity and the timing of vegetative and reproductive development. The corresponding probabilities were estimated using generalized linear models (GLMs). These probabilities were affected by different structural and temporal factors, such as the apical or lateral position, and the vegetative or reproductive fate of the previous growth unit. GLMs were estimated on 'Cogshall' mango tree architectures measured during two growing cycles in Réunion Island. A model of architectural development was then designed using the L-systems formalism and consisted of successive applications of development rules for parallel assemblage of new units in different topological positions and with different fates. As a result, simulations generated by the model gave an integrative view of the dynamics of the population of growth units and inflorescences of the tree. This provided the ability to assess the accuracy of the developmental process model at the whole tree scale by comparing simulated with measured tree architectures