Simulation of the development of leaf number for greenhouse cut chrysanthemum flower

Based on the effects of temperature and radiation on the leaf number of chrysanthemum, experiments involving different stem numbers per plant, and planting dates were carried out under greenhouse conditions in Shanghai from 2005 to 2006. Models were developed to measure the effectiveness of mean day temperature and daily light integral for predicting the leaf unfolding of multi-stem chrysanthemum. Independent experimental data were used to validate the models. The results showed a significant increase in leaf number per plant with a decrease in stem number per ground area. The tendency to develop a sigmoid leaf unfolding pattern was also observed within days after planting. The determination coefficient (R2) and root mean squared error (RMSE) based on the 1:1 line for the leaf number per plant with treatments involving 42 stems, 84 stems, and 126 stems.m-2 were 0.99, 1.95; 0.99, 2.27; and 0.97, 2.51, respectively. The predicted precision of the logistic model based on the effectiveness of temperature and light is 67% higher than that of the model based on growth degree days (GDD). Overall, the model presented in this study can be employed to optimize the light and temperature management of multi-stem cut chrysanthemum with different stem numbers and planting densities under greenhouse conditions.