Study Of Growth Visualization Model On Red Globe Grape In Gansu

With the rapid development of information technology,virtual plant has become an important research content of modern agriculture.Until now,the domestic and foreign scholars have deeply focused on virtual models of wheat,barely and maize for a long time,but grape is still in its infancy.Grape is a popular fruit with huge economic benefits.The visualization model of grape would make a progress in promoting the cultivation of grape and reveal the mechanism of grape growth and developmental regulation.The Red-globe grape planted at the experimental vineyard of Gansu Agricultural University was the experimental material.The grape geometrical parameters of the trunk,main stem,indeterminate shoots and bearing shoots were measured in selected time during whole growing season,and the testing field temperature and air speed were collected at the same time,the growth models were fitted with two years of repeated rounds experiments.Geometrical model of the bearing shoot organs were reconstructed,and combination between the growth model and the virtual morphological change was realized,adopting the cpfg to form the topological structure by L-studio platform.The experimental results showed that the built visualization models of grapevine could simulate the growth of bearing shoot.The main contents in this dissertation are the followings:1.The experiments of the growth simulation model of the leaf main vein and berry were constructed.Based on the field experiment data,SLogisitc3 equation was used to simulate the relationship between the morphological changes of the bearing branch organs and Growth degree days,and the dynamic simulation model of the growth about the main veins and berries was constructed.RMSE and rRMSE were used to test the main vein model,among which RMSE range was 0.50~1.81 cm,rRMSE maximum was 0.277,less than 0.3,and the fitting effect was medium.The curve by berries growth measured data presented “double S” pattern as slow-fast-slow-fast – slow.Cubic polynomial and SLogistic3 was used to simulate berries transverse and longitudinal diameter growth,the fitting results show that the cubic polynomial is better than the SLogistic3.The RMSEwas 1.84 mm and 1.92 mm and rRMSE value is less than 0.2.The accuracy of the model is high,and the simulation value is in good agreement with the measured value.2.The testing experiments of relative growth rate of berry,soluble solid content and average single particle weight were carried out.The growth rate of the Red-globe berry was the highest in mid-June,then the value has been decreasing until mid-july.The berry was in another fast growing period from late July to late August.In September,the growth of Red-globe berries was basically stopped.The growth of berries can be divided into two expansions.The first expansion period was over 60% of the final size.The average content of soluble solids in mature berries was 15.2% and the average weight of that was about 8g.3.Using a predefined surface method building the geometry of a bearing branch with L-studio as platform.Bi-cubic Bezier surface patches were used to form a cylinder and an ellipsoid,so that the geometry of organs such as internodes,stalk and berries were built respectively.The geometry of leaves was constructed by bi-cubic Bezier.The organ of bearing branch was connected by L-system to generate the visual static model of grape bearing branch.4.Based on the fractal function of the parameter L system,the morphological development model of each organ of grape fruit was built.On basis of growth degree days,geometry model with the organ growth model were combined,and the changing of bearing shoot topology and the growth of the organ were simulated.Based on simulation of the bearing shoot,the growth simulation of grapevine was preliminarily completed.5.Through rendering the geometric model of the bearing shoot with color and texture,the visualization effect of the model was enhanced and optimized.After the visual model of the branch was simulated,the results showed that the growth of grape branch could be simulated.The visual simulation of bearing shoot is the basis of the grapevine growth visualization.Grapevine visualization model is great important to forecast and develop growing mechanism in Red-globe cultivation.