Abstract: The daily relative thermal effectiveness(RTE) was taken as an indicator to assess the impact of temperature on the development rate of tomato.The model based on the exponential function was established to describe the relationship of the RTE to temperature,through studying the characters of Beta function.RTE determined the daily physiological development effectiveness(PDE),which accumulated to be daily physiological development time(PDT).Based on the PDT,the simulation model for tomato growth and development in the green house was established and validated by the experiments in the greenhouse from 2003 to 2005.The results showed that the model could predict the time and duration of the different growing period,such as germination,seedling,flowering and fruit setting,fruit ripening and harvest.The standard error by regression analysis(RMSE) between simulated and observed values was 1.32,1.73,0.35,1.58 and 2.52 days for the germination,seedling,flowering and fruit setting,fruit ripening and harvest period respectively.The prediction accuracy by this model was higher than by simulation model based on efficiency accumulate temperature(EAT),by which the RMSE was 2.55,9.74,2.06,9.72 and 11.99 days for the germination,seedling,flowering and fruit setting,fruit ripening and harvest period respectively.

Key words: Solar greenhouse, Solar greenhouse, Tomato, Physiological development time(PDT), Growth and development stages, Simulation model