Figure 9. Diagram showing root analysis for root length, surface, volume and root–soil cone diameter calculation.

(a,b) represent the intact root system for Variety InVigor5440 and InVigorL140P, respectively. To avoid the overlap of root systems, each lateral roots is separated carefully and emerged into the water for scanning and analysis with root diameter classification (c–d). The color of the skeleton drawn over the root is related to its three–dimensional diameter (as scale shown) and can be clearly identified. (e,f,g) represent intact root system of three different planting data, i.e. April 27, May 22 and June 3. Based on the original root system analysis (h) with colour root diameter classification, root–soil cone diameter within 0.5 mm and 1 mm root diameter can be estimated indirectly, as shown in (i–j), respectively.