A Simple Phenological Model of Muskmelon Development

Utilizing information gathered in previous growth chamber and field experiments, we developed a simple temperature-driven crop phenology model of muskmelon (Cucumis melo L.) to help commercial growers time crop phenological events and predict harvest dates. The model quantifies vegetative development in terms of main vine node numbers which allows the model to simulate either a direct-seeded or a transplanted crop. The model operates on an hourly time-step but requires only daily weather data and a few cultivar-specific parameters including plastochron interval and thermal time requirements to reach six predefined developmental stages. The model was tested against an independent data set consisting of three muskmelon cultivars grown at five transplanting dates. Tests of the model indicate an average ability to predict main vine node numbers to within one to two nodes of observed values. Estimated harvest date predictions were more variable than those for main vine node number but an average model accuracy of 1 to 3d was obtained in model tests with a data set used to construct the model. Procedures for calibrating the model for different cultivars, cultural practices or environments are outlined.