Simulating coconut growth, development and yield with the InfoCrop-coconut model.

Simulation modeling of perennial crops has immense potential for generating information for plantation managers. We report the development of the InfoCrop-coconut model and its application to coconut (Cocos nucifera L.) growing in diverse tropical and subtropical environments. The model is based on the generic crop model InfoCrop that simulates various annual crops in tropical and subtropical regions. The InfoCrop-coconut model was calibrated and validated with data compiled from published studies comprising many physiological, agronomical and nutritional experiments conducted between 1978 and 2005 in diverse geographic locations throughout India. The treatments included various water and nutrient regimes and varieties of coconut. Time to first flowering varied between 4 and 6 years, leaf production varied from 8 to 15 leaves year(-1) and nut yield ranged from 3000 to 27,000 nuts ha(-1) year(-1). The genetic coefficients used for calibration and validation were generated from field experiments conducted during 1995-2005. Model efficiency and validation performance were analyzed statistically. Simulated trends in phenological development, total dry mass and its partitioning, and nut yield agreed closely with observed values, although a 15% error was observed in a few cases. Considering that field measurements have an experimental error of 10-15% and wide variation existed within treatments, the model adequately simulated the effects of management practices and agro-climatic conditions over short periods. For a range of agro-climatic zones, simulated potential yields varied from 26 to 30 Mg ha(-1) year(-1) and potential annual dry mass production varied from 52 to 62 Mg ha(-1), depending on environment. We conclude that InfoCrop-coconut can be used to increase the efficiency of agronomic experiments designed to aid coconut crop management.