Validation and Modification of the Shoot Growth Model in Cut Roses

In the climate of Korea, it is difficult to maintain consistent year-round production of cut roses in greenhouses because of high temperature in summer and low radiation in winter. Therefore, it is important to determine the optimal growing conditions by analyzing the effect of seasonal environmental changes in greenhouses on the growth of cut roses. In this study, a model for rose shoot growth developed by a previous study was validated and modified. The results of the experiment showed that the model had a high coefficient of determination for growth of shoots and performed well for predicting the growth in four cultivars of cut roses: Rosa ‘Antique Curl’, R. ‘Beast’, R. ‘Ahoi’, and R. ‘Fuego’ (R² = 0.84, 0.87, 0.79, and 0.90, respectively). However, at the harvest stage, the model over-and under-performed, respectively, for the cultivars ‘Antique Curl’ and ‘Fuego’. The maximum leaf area coefficient of the leaf area equation was modified to take into account the leaf area of cultivars ’Antique Curl’ and ’Fuego’. Re-experimentation showed that the modification improved the performance of the model for both cultivars while maintaining the high coefficient of determination. The growth model developed by the previous study is applicable for greenhouse production of cut roses in Korea. Therefore, this shoot growth model may be used to aid growers in maintaining the optimal growing environment within greenhouses and to provide base data for greenhouse environmental control and monitoring systems.