(redirected from photoperiodical)
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The daily duration of light and dark to which an organism is exposed, considered especially with regard to its effect on growth and development.

pho′to·pe′ri·od′ic (-ŏd′ĭk) adj.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.


(Botany) the period of daylight in every 24 hours, esp in relation to its effects on plants and animals
ˌphotoˌperiˈodic adj
ˌphotoˌperiˈodically adv
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˌfoʊ təˈpɪər i əd)

the interval in a 24-hour period during which an organism is exposed to light.
pho`to•pe`ri•od′ic (-ˈɒd ɪk) adj.
pho`to•pe`ri•od′i•cal•ly, adv.
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