photoperiodic

/ˌfoʊtoʊˌpɪriˈɑdɪk/
adjective
  1. Relating to or affected by the length of daylight in a day.
    • Gardeners use photoperiodic lighting to keep poinsettias blooming for the holidays.
    • The photoperiodic response of soybeans determines when they start producing pods.
    • Many animals have a photoperiodic clock that tells them when to prepare for winter.
What does "photoperiodic" mean? | whatsthatwordmean | whatsthatwordmean