Dynamic Simulation Of Relationship Between Development Of Tomato And Environment

Agricultural production system is a complex, multi-factor and dynamic system which is affected by atmosphere, soil, crop, technology etc factor. That shows space-time variability is great and empirical feature and regionalism is strong. Crop growth simulation model using system analysis method and on computer simulation technology, quantitative describe and simulate crop's growth and development process and its environment the dynamic relationship. Through the crop growth simulation model can in-depth understanding of crop growth process and climate, soil environment and management measures relationship. Some of the process of sexual model describing remain empirical regional adaptability is not strong. In order to adapt to the need of tomato greenhouse production, achieve"precise management", it is necessary to set up small machine rational model. By means of modern statistics and electronic computer technology, did system analysis and quantitative description to the dynamic relationship of between tomato growth and environment and set up a corresponding mathematic model, and simulated tomato growth of tomato, used to direct production to optimize the cultivation, and keep tomato supply balanced.Tomatoes morphological development is to show its plant height, stem and leaf, flower and fruit etc development rate and quantity change etc, has its inherent laws. It is closely related to external environment condition. This study uses tomato growth and environmental temperature, light and other environmental data on experiment in three tomatoes peasant greenhouses and of CO₂ concentration gradient. Based on the systematic analysis and mathematical model, we analyzed mathematical relationship between tomatoes fruits, main stem and leaf growth and environmental factors and build some tomato growth models. During the process, concluded that the following main conclusions:(1) According to the principle of tomato physiological development time constant, established growth and development model of each sequence tomato fruits. That's PDT=SUM (RTE) and RTE is a sine index three segments function with temperature t as variable. This model can accurately forecast the fruit developing period of tomato and the result of simulation show that first to fifth sequence fruit took 28, 31, 33, 35, 33 days, respectively to complete physiological development time. The simulation results and ending accorded well with the observed ones, the root mean squared error (RMSE) being 2, 3, 1, 2 and 1 days respectively. This development model and the development based on GDD are compared, the results showed that the model can accurately predict tomato fruit growth stage, the forecast precision is significantly higher than development model based on GDD.(2) Compared maximum sink strength on the different treatment of CO₂ concentration and keeping fruit and moving leaves and got dynamic changes of sink vigor with regression analysis. Growth rate models of fruit are established and they are Logistic function type with step of natural time day's t, and with fruit diameter as variable. And draw mathematical relationship between sink strength and CO₂ concentration. They are: FDM=14.094ln(C)-25.291 and FDMM=13.74624C3-0.0002C2+0.1647C-8.8555.(3) Selected the growth and development of the main stem and leaves on flowering fruiting period of tomato, as simulation object, introduced several main environment parameter as driving factors, and removed the factors being less influence and screened larger factor influence to the tomato main stem and leaf number within sympodium, we build growth and development models of tomato main stem and leaves in sympodium base on PDT. They are: SV = 7599.5e0.0345PDT and L=3.9003PDT-3.0988. Through observation and simulation value 1:1 mapping verification, simulation degree are better, can truthfully reflect the tomato main stems and leaves growth state.