Toward an optimal control strategy for sweet pepper cultivation : a dynamic crop model

Sweet pepper production is characterized by large fluctuations in fruit yield per week. Synchronization of yield patterns between nurseries in response to weather conditions leads to variations in market supply and affects price formation. In order to improve supply chain efficiency, auctions and wholesalers require nurseries to supply production forecasts several weeks in advance. At the nursery level, yield prediction is helpful for efficient labour planning. Because the dynamics of sweet pepper production are complex, growers find it difficult to understand and effectively control the production process. A model can be useful to assist growers in making efficient decisions with regard to crop and climate management. It is hypothesized that a phase-shift in the feedback-regulation of fruit set by growing fruits could be the cause of the periodic yield pattern observed in practice. This paper describes a dynamic model of sweet pepper production based on this principle. Model output was compared with measurements of sweet pepper production obtained from a commercial nursery. The calibrated model was able to simulate the measured data fairly well, in particular the yield fluctuations. These results are consistent with the hypothesis and serve as a promising starting point for further research aiming at a better understanding of the underlying processes and, consequently, model improvement.