Diel root extension patterns of three Serianthes species are modulated by plant size

Diel root extension was observed for Serianthes grandiflora, Serianthes kanehirae, and Serianthes nelsonii plants ranging in size from seedlings to 2-m tall saplings. The percentage of daily root extension that occurred at night declined from 65% for seedlings to 51% for 200-cm tall plants for S. grandiflora, from 58% for seedlings to 54% for 200-cm tall plants for S. kanehirae, and from 72% for seedlings to 55% for 200-cm tall plants for S. nelsonii. These results indicate the timing of root extension rates throughout a diel cycle may be included in the list of phenology and physiology traits that change as plants increase in size.