How to Prune radish 'Sparkler'?
No pruning required

radish 'Sparkler' · Raphanus sativus 'Sparkler'
Grow in full light or light shade, ideally in light, rich, near-neutral, and moist but well-drained soil; sow seed at frequent intervals from early spring to late summer, so that there is a succession of crops; sow in rows 15cm apart, at a depth of 1-2cm, and sow at or thin to a spacing of about 3 cm apart, and harvest them when young so that they do not become woody; for more advice, see radish cultivation
No pruning required