S06 - Session P1 - A process-based crop model for greenhouse smart-farming cultivation of cucumber.

Authors: Hyungmin Rho *, Hsi-Chun Hung, Won Jun Jo, Sung Kyeom Kim

Process-based crop models are representations of crop systems describing the relationship between environmental factors and physiological mechanisms. The specific aim of this study is to capture the phenological and morphological changes of cucumber for possible further smart agricultural usage. Therefore, a new process-based cucumber model tailored for specific cultivation practice was constructed. The cucumber model in our study is based on the hard-neck garlic model, which can capture the non-linear temperature-dependent leaf development. Parameters and system configurations were changed to match the growing pattern of cucumber. Additional systems were also added to fit the leaf defoliation, which was used to maintain 15-18 leaves per plant and fruiting behavior. The model was constructed using two rounds of data obtained from the cucumber cultivated in a smart-farming greenhouse. The phenological and morphological data were collected one or two times every two weeks during cultivation periods. The environmental factors of the greenhouse were maintained for optimal growth of cucumber in two cultivation rounds. Calibration was done with the first round of the data, and then validated with the second round of the data. The model is able to capture the time-series changes both in vegetative and reproductive stages throughout the cultivation period. In the vegetative stage, the simulation results of leaf area index, leaf numbers, biomass and net photosynthesis rate are well-matched with the observed data. In the reproductive stage, the model also simulates the timing of flowering and fruit weight with high accuracy. The model provides a measure to track the phenological, morphological, and physiological changes of the cucumber. The process-based characteristic of the model also shows the flexibility of being able to adjust for certain kinds of cultivation practice. Further study is required to examine the capability of using in agricultural production.