A Process-Based Simulation Model On Growth And Development For Greenhouse Tomato

Crop growth and development simulation model is a useful tool for the optimization of greenhouse crop and climate management. In this study, experiments with different cultivars, locations and substrates were conducted in both venlo-type greenhouse and in multi-span plastic greenhouse from 2002 to 2004 to collect data for model development and validation. Firstly, a module for greenhouse tomato development simulation was developed based on the concept of physiological development time (PDT). Secondly, a module for greenhouse tomato leaf area and dry matter production simulation was developed using the product of thermal effectiveness and PAR (TEP). Thirdly, a module for greenhouse tomato dry matter partitioning and yield prediction was developed using partitioning index and harvest index. Finally, the three modules mentioned above were integrated to develop the greenhouse tomato growth and development simulation model.In the phonological development submodel, the PDT from sowing date to germination, seedling, flowering, fruit setting and harvest were quantified as 4, 9, 45, 56 and 102 days, respectively. The submodel was validated by using independent experimental data of different cultivars, substrate and locations. The root mean squared error (RMSE) for the prediction of germination, seedling, flowering, fruit setting and harvest development stages was 0, 0, 2.16, 2.83, 3 days, respectively. The prediction accuracy of this submodel is remarkably higher than that of using the growing degree days (GDD) based model (RMSE is 0, 2, 6.27, 14.07, 14 days, respectively, for germination, seedling, flowering, fruit setting and harvest development stages).In the leaf area and dry matter production submodel, the Product of thermal effectiveness and PAR (TEP)was proposed. TEP was calculated by formula as follows:RTE is the relative thermal effectiveness. Tb, To, and Tm are the minimum, the optimum and the maximum temperature, respectively, for greenhouse tomato growth. HTEP=RTE×PAR×3600HTEP is the hourly product of thermal effectiveness and PAR. DTEP= ∑ (DTEP/1000000) DTEP is the daily total product of thermal effectiveness and PAR.