The distance between successive nodes (the points on a stem where leaves and branches emerge). Tight internode spacing indicates compact, dense bud structure; wide spacing suggests stretchy, open growth.
Mr. Q measured 10 inches of stem containing 8 nodes on the Grape Graffiti, calling it 'exaggerated' in its density. He also explained that higher silica doses can reduce internodal spacing. In the CO2 room on the previous run, CO2 from seedling caused very wide nodal spacing, which informed the decision to delay CO2 introduction this run.
Discussed in: Ep 001