Abstract:
Vegetable production in greenhouses has greatly benefited from the crop growth models. Crop growth models are effective tools for crop production management and environmental optimization in greenhouses. It is necessary to validate the current model at many spatial scales in a variety of environmental situations. The applicability of the models is still unclear, because the majority of tomato growth models can only be used in multi-span greenhouses with favorable environmental conditions or the same greenhouse. Particularly, plastic greenhouses and Chinese solar greenhouses are very popular during this time. Some production challenges remain under human experience management. This study aims to build a greenhouse tomato growth model suitable for solar and plastic greenhouses. Three independent experiments were conducted in the solar greenhouses (span 11.0 m) and thermal insulation plastic greenhouses (span 18.0 m) in Yangling County, Shaanxi Province, China from 2021 to 2022. Specifically, the tomato production of spring stubble was set in the heat-insulating plastic greenhouse (Experiment 1) using environmental data, such as light and temperature. An external morphology model was constructed with the thermal effectiveness and PAR (TEP) as an independent variable, according to the relationship between the growth dynamic of external morphology and key meteorological factors (temperature and radiation) of tomatoes in a greenhouse. The TEP was also used to establish the dry matter accumulation and distribution model. The mathematical model of plant daily absorption was established to consider the simulation modules of photosynthesis and respiration. A module of dry matter accumulation in the tomato was then constructed under the amount of training. A new model of fresh matter accumulation was established to combine the relative water content of each organ at each embryonic stage. The whole growth model of the tomato was realized in a greenhouse from each sub-module. The accuracy of the sub-modules was verified using the experimental data of autumn stubble in the thermal insulation plastic greenhouse (Experiment 2) and winter stubble in the Chinese solar greenhouse (Experiment 3). The results showed that: 1) In the external morphology model, the coefficients of determination R2 and Root Mean Square Error (RMSE) for simulated values of tomato plant height were 0.907 4 and 13.66 cm, respectively. 2) In the dry matter accumulation model, the predicted dry matter weight of tomato organs in different greenhouses were estimated to fit well with the measured values. The coefficients of determination R2 for simulated values of dry matter weight of the whole tomato plant, above-ground parts, stem, leaf and fruit ranged from 0.854 1 to 0.975 1, and RMSE ranged from 2.87 to 6.98 g/plant. 3) In the fresh matter weight, the coefficients of determination R2 for simulated values of fresh weight accumulation of the whole tomato plant, above-ground parts and fruits ranged from 0.887 2 to 0.905 0 and RMSE from 109.83 to 171.16 g/plant. The improved model can be expected to accurately predict the plant height and weight accumulation of dried and fresh tomatoes. The strong practicability of the model can provide a theoretical basis and decision-making assistance for tomato production in facilities.