A Comparison and Modeling of the Growth of Tomatoes in Greenhouse using the Color Change

In Korea, tomatoes are primarily grown in greenhouses, which are widely distributed through the country.Greenhouse cultivation provides greater stability and control of the environment, including light, temperature, and carbon dioxide levels, resulting in higher quality and yield compared to open fields.Therefore, greenhouse environment management is a important because quality and yield, which are directly related to profits, could vary depending on greenhouse environment.In addition, developing growth model for crops grown hydroponic system in the greenhouse is useful for describing and comparing the response of crops in terms of environmental conditions.In this study, we use the logistic growth equation to describe the growth of tomatoes.The logistic growth equation is used to model the color change of tomatoes, and we compared the differences in the growth process of tomatoes at two different growing seasons by using the parameters in the model.According to the logistic model, tomatoes grew slightly faster in winter than in summer and the discoloration period of tomatoes, in terms of changing from green to red, was about two days shorter in winter than in summer.In the process of growing, there was no significant difference in the daily average temperature and accumulated temperature in summer and winter.However, the solar radiation inside the greenhouse was 590.7 J/cm 2 in winter and 347.4 J/cm 2 in summer, which was higher in winter than in summer.This is because that the screen was used to maintain temperature and reduce the light intensity on very sunny day in summer.This study shows unexpected results that the growing period of tomatoes is shorter in winter than in summer due to the way of greenhouse environmental management.Therefore, based on these results, it is necessary that we need to consider the appropriate ways of controlling environments in greenhouse, depending on growing season.