Development of a simulation model for studying kiwi fruit orchard management

The paper presents a model designed for studying the effect of orchard mana gement on fruit number and size in kiwi fruit plots. It summarises the subm odels (previously published) that take place at different levels of organis ation (flower/fruit, cane, plant) and compose the global model (flowering o f female and male vines, pollination and fruit growth), explains their rela tionships and focuses on the way technical operations are incorporated. The characteristics of both planting scheme and choice of pollenisers are inpu ts of the flowering and pollination submodels. Winter pruning options (plan t level) modify the inputs of the female flowering model. Thinning (plant l evel) influences the overlap of female and male flowering (outputs/inputs o f the flowering/pollination models) and vine crop load that acts on fruit g rowth (individual fruit growth model). Irrigation scheduling participates w ith the rainfall regime to the calculation of a series of water stress effe ct at the plot level, which is used to affect individual fruit growth rates . After testing the model against real field data, simulations of the model are presented for sake of illustration. They include the effect of climate and of each technique (comparison of contrasted choices) with the other on es controlled on the performance of a reference plot, and an example with s everal techniques changed together. The results indicate that the model is sensitive both to climate and to changes in technical operations. (C) 1999 Elsevier Science Ltd. All rights reserved.