A single layer model to simulate plant canopy temperature in basis on energy budget approach,is improved in this research.The temperature of the upper canopy is estimated from microclimatic data by the numerical method.The temperatures simulated by this model fit the observed values well.The duration of dew formation and the amount of dew are estimated by predicting the time when the temperature of upper leaves falls below the dew point.The results show that dew occurs at about 17∶00,and ends at about 6∶00...