Hoagland’s solution, solidified with 5% agar, was poured into the rhizotron
chamber. One day old, pregerminated (at 25°C) cucurbit seeds (variety Hercules C.
moschata × C. maxima) were placed onto the upper face of the solidified Hoagland’s
medium of each rhizotron. Groups of rhizotrons were incubated at 25°C in the dark. At
approximately 12 hour intervals rhizotrons were removed from the incubator and roots
growth was traced onto the outer face of the plexiglass. Different coloured markers were
used for successive periods of root growth. After 7 days, the outer face of each rhizotron
was scanned at high resolution and the images obtained were analysed using ImageJ
software. Root systems were analysed for primary root length, number of secondary roots,
length of secondary roots, distance between secondary roots and lead distance between
the tip of the primary root and the youngest emerging secondary root.