Table I. Overview of crown traits derived for the root stock

N/A, Not available.

NameDefinitionClosest Trait Analog in Shovelomics
Average root densityRatio between foreground and background pixels of the extracted rootScoring of density
STA XAngle between an RTP at x% length and the x axis calculated as arctan(m), where m is the slope of the fit lineShovelomics angle at certain depth for dicots
Dominant STA 1 and 2Average of the first and second significant peak in the in the histogram of calculated solid tissue angles binned in 10° stepsShovelomics angle for dicots
Min/median/max STAMinimal, median, and maximal of all calculated STAsN/A
Dominant RTA 1 and 2Average of the first and second significant peak in the histogram of calculated RTAs binned in 10° stepsN/A
Min/median/max RTAMinimal, median, and maximal of all calculated RTAsN/A
Median/max widthMedian/maximum of the calculated width in the width height diagramOnly max width or selected representative width
D10 to D90Accumulated width over the depth at x%. The change in width accumulation denotes a change of the root-top angleN/A, but closely related to the root-top angle for maize
DS10 to DS90Slope of the graph of D valuesN/A
Spatial root distribution (as separate X and Y components)Displacement of the center of mass between the bounding box of the RTP skeleton and the RTP skeleton excluding the central pathN/A
Stem diameterDiameter at the beginning of the root top. We use the first branching point of the filtered medial axis as a characteristic diameterCaliper measurement
Central path diameter XThe diameter at x% length of the central pathDiameter at a defined depth below the soil line
Max diameter at 90% depthMaximal tip diameter in the last 10% of the imageMeasured for dicots
Tip diameter distributionExponent of the exponential function fitted through the tip diameter histogramN/A
Median/mean tip diameterMedian and mean tip diameters of all tipsN/A