At all NAA strengths all explants initiated callus formation except
internode which did not respond at NAA 0.9mg/L. Minimum time taken for callus
initiation was 20 days by leaf blade while maximum time was 27 days taken by
nodes. In all callus, colour was green or shades of green as in IAA. Mostly it was
green (14 readings) followed by light green (7 readings) and yellow green (3
readings). Texture of the callus was again based on explant used. Petiole and
leaf produced granular callus whereas internodes and nodes produced mostly
compact callus.