Fig. 1

a Flow chart of the process used to calculate the Integrated Puncture Score. b Image of the rind puncture test setup. The fixture supporting the plant sample has a 10 mm diameter hole, in it to allow the probe to puncture through the entire stalk without hitting the support fixture. The images were adapted from [29]. c A typical load–displacement curve resulting from a rind penetration test; key points on the plot are as follows: Point A—probe entry point, Point B—first force peak, Point C—first rind-pith transition region, Point D – midpoint of stalk cross-section, Point E—second rind-pith transition region, Point F—precalibrated zero displacement plane (i.e., the bottom of the test specimen / top of the support fixture), Point G—second force peak. d A cross-section of a test specimen with the key points labeled