V-Mango, a functional-structural plant model of mango tree growth, development and fruit production: from model design to applications

Mango (Mangifera indica L.) is the fifth most produced fruit in the world, mainly in tropical and subtropical regions. Its cultivation raises a number of issues such as low yield, irregular fruit production across years, phenological asynchronisms resulting in long periods of susceptibility to pests and diseases, and heterogeneity of fruit quality at harvest. To address these issues, a functional-structural plant model, V-Mango, has been developed and implemented in the 'vmango-lab' virtual modelling environment. V-Mango has two objectives: to improve our understanding of tree functioning, and to assist in the design of sustainable mango production systems. V-Mango, developed for the cultivar 'Cogshall' in Réunion Island, is structured with modules representing interrelated processes of architectural development and fruit growth. Appearance of growth units and inflorescences was decomposed into elementary stochastic events conditioned by structural and temporal architectural factors. Daily growth and phenology of growth units and inflorescences were modelled using empirical distributions and thermal time. Fruit growth was determined by carbon- and water-related processes modeled at the fruiting branch scale and affected by climatic variables and source–sink relationships. Currently, V-Mango allows the simulation and interactive 3D visualization of vegetative and reproductive development of unpruned mango trees, over one or successive growing cycles, on simulated or empirical architectures. Integration into the model of other important processes (e.g., pest damages, leaf senescence, mortality of growth units, light interception, light-related photomorphogenesis) is underway, as well as the effects of pruning on vegetative and reproductive development. In this way, V-Mango will better account for and simulate the effects of cultivation practices and pests on fruit production. These advances will enable the design of simulation-based management solutions to improve mango production.