Study On Model To Greenhouse Tomato Growth And Development

This research is based on large numbers of test data on greenhouse tomatoes, by sorting and analyzing the test data, the simulation models of tomatoes are founded accroding to the crop's physiological ecology theory and the tomato's greenhouse growing mechanism. These models include the greenhouse growing, up-growing of phyllotaxy, forming of organ, trending of leaf area, effecting of fertilizer, photosynthesis, accumulating of dry matter and forming of output The main research contents are as follows:1. Accroding to the basic principle of tomato physiologic, the greenhouse tomato growing model has been brought forward which set the environmental parameter as the variable.This model has described such environmental factor impacts on the growing speed of tomato as temperature, day-length and the density of CO2,etc. in the greenhouse. The model has good explanation ability and higher precision. Utilizing the test data materials to examine the model, through simulating different growing stages, the simulation result shows: the absolute error is within 3 days, the average relative error is smaller than 4%。2. The up-growing phyllotaxy model of tomatoes has described the influence of temperature and the density of CO2 to the speed of tomato leaf emergence. The model has good explanation ability and higher precision. Utilizing the test data materials to examine the model, the simulation result shows: the absolute error is within a leaf, the average relative error is smaller than 2%.3. The sunlight greenhouse tomato blade, leaf area index, fruit trend of emergence, development and decline are studied through effectively accumulated temperature (physiological development time ) as variable. The whole growth periods can be described as segmenting functions. A part of growth trend presents line sexual relations, the other part accords with Logistic curve.4. The fertilizer effect model has described the influence of nitrogen, phosphorus and potassium to the output of tomatoes. Through analyzing the model, the follows can be calculated: the amount of nutrients supplied by soil, utilization ratios of fertilizer, increasing productive effect of different nutrients and mutual effect of different nutrients cooperating used, high yield and fertilizer application of high yield, economic output and fertilizer application of economic out. These can be used as the basis of scientific applying fertilizer.5. Based on photosynthesis, the greenhouse photosynthetic productive dynamic simulation model of tomato has been brought forward, this model has composed by such sub-models as: trending of leaf area, greenhouse coronal clump distribution, simple leaf photosynthesis , coronal clump photosynthesis, breath expenditure and distribution of assimilation among organs. At the same time, the model has considered the influence of the environment (temperature, CO2 density and moisture) in the greenhouse. Result indicates that at every development and growth stage, the relative error of dry matter accumulating between observed value and simutated value is -3.0-10.0%. So simulation value and observation value have good consistency.6. The concept of distribution index has been introduced to describe the distribution of dry matters among different organs. And the integer type Beta probability function has been used to describe the expansion laws of organs at the same time, which adapt to many kinds of expansion curves in a flexible way and solve the material assignment among different ages (positions) on the same organ in a better way.The greenhouse tomato up-growing simulation model brought forward in this paper has higher accuracy, mechanism nature and practicability, which established the foundation for completing the greenhouse tomato planting simulation optimizing system. With the aid of this model, we can arrange the production of tomatoes in greenhouse reasonable, confirm the proper sowing time, predict the growth period of tomato, carry on scientific management and apply fertilizer rationally in a planned way. At the same time, utilizing th...