Method of indirect measurement of fruiter biomass

Abstract

Fruiter biomass is one of the crucial parameters for precision spraying. This paper is to research measurement method for ground-based fruiter biomass by integrating direct and virtual plant technology based on real guava. Firstly, a real guava fruiter with 274 leaves and 228 branch segments was selected and its leaves and branch segments were encoded. Secondly, the coordinates of the guava's leaves and branches were gained by 3D digitalizer named Fastrak produced by Phohelmes and then a virtual guava model with a virtual direct beam environment was built by VC++ with OpenGL. Meanwhile, the guava's leaf parameters such as length, area, wet weight, and dry weight and branch segment parameters such as length, diameter, wet weight, and dry weight were measured by direct methods. Hereinto, a kind of useful leaf area process method was outlined for dealing area detection with different sides and holes .Using a kind of shadowing method, virtual guava could be shadowed in different horizontal height or in different vertical width and its shaded area, total biomass and so forth in different layers were calculated by integrating real guava's parameters. After regression analysis using SPSS, for the real guava the R2 between total leaf area and leaf dry weight is beyond 0.988 with the near regression formula between direct method and virtual plant method, the R2 between total leaf dry weight and branch dry weight is 0.89, the R2 between branch diameter and leaf dry weight is 0.80, the R2 between branch D2H(diameter's square multiply height) and leaf dry weight is 0.97. And in the virtual fruiter, the R2 between leaf area and leaf dry weight is beyond 0.95, which proved the relation in the real tree. Additionally, more detail relations like height and leaf area, leaf shadowed area and leaf area were analyzed in the virtual fruiter data which provided important information to build a LAI and biomass calculation model.