Studies On The Simulation Of Key Agronomic Characteristics For Potato

System simulation of crop growth and development has been a booming technique in the last forty years. It introduces systematic methodology and computer technology into crop science. According to crop physiology and ecology knowledge, with the systematic analysis and numerous digital calculation of field crop experiments, a dynamic model was established to reveal the relationship between the environmental factor and potato phenological development, photosynthesis, apparatus establishment, dry-matter accumulation, distribution, yield and so on. We can simulate the whole crop phenological development in the given environmental condition.Based on the review of large amount of literatures especially recent research achievements abroad and domestic, the dynamic simulation of other crop growth, we developed a set of simulation models for potato growth, and a simulation software based on Visual Basic 6.0 in Chinese format. And the software has supplied a base for application on Web.The main achievements are as follows:1 Potato phenological development modelAccording to the three-basic-point-temperature principle of crop growth, the author submitted a nonlinear model based on Gauss function for crop growth and development simulation. When the temperature changed from the lowest point for growing to the optimized temperature, the equation was an increase function; then when the temperature changed from the optimized point to the highest point, the equation was a decrease function. It was supposed that the maximum value equaled 1 in the optimized temperature. The whole change was defined as one physiological day. The modeling results showed that the potato variety "Dongnong 303", which was widely planted in Zhejiang Province, needed 11-13 physiological days from seeding to emerging, 21-23 physiological days from emerging to budding and 12-13 physiological days from budding to maturing. According to the analysis of the phenological development model, thecalculation results of soil temperature contribution for the potato planted in mulching were given. This method also improved the analysis approach from qualitative analysis to quantitative analysis.2 Simulation of plant height, leaf age and leaf area index of potatoThere was a high correlation between potato phenological development and plant height, leaf age, and leaf area index. The accumulative physiological day was used as a variable factor, and the S-curve was used to simulate plant height and growth process of leaf area index, and used exponential function to simulate leaf age and declining process of leaf area index.3 Simulation of dry-matter accumulation and distribution of potatoThe study simulated the dry-matter accumulation with the changes of leaf area index, canopy photosynthesis and temperature. The simulation results showed that the model was of high accuracy and clear mechanism. Along with the potato phenological development, the function of dry-matter distribution, the quantity change of dry-matter percentage rate in each apparatus at different stages, and the corresponding mathematics model were also given in this paper. The correlation coefficient between the modeling results and actual field yield was really acceptable.4 Software developments for potato simulationThe software for potato simulation was completed in this study, which included potato phenological development, plant height, leaf age development, leaf area index change, canopy photosynthesis of the community, dry-matter accumulation and yield formation. The software had a visual interface, direct result expression and the menus designed just like Windows. It was helpful for common researchers and extension workers with basic computer knowledge.