photoperiod
Concise Oxford English Dictionary © 2008 Oxford University Press:
photoperiod/ˈfəʊtəʊpɪərɪəd/
▶noun Botany & Zoology the period of daily illumination received by an organism.
– derivatives
photoperiodic adjective.
photoperiodic adjective.
'photoperiod' also found in these Oxford entries:

