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An organism's response or ability to respond to changes in photoperiod.
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 response of plants and animals by behaviour, growth, etc, to photoperiods
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014


(ˌfoʊ təˈpɪər i əˌdɪz əm)

also pho•to•pe•ri•o•dic•i•ty (-ˌpɪər i əˈdɪs ɪ ti)

the effect of photoperiods on an organism's growth, fitness, and behavior.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.

photoperiodism, photoperiodicity

the effect on the growth and reproduction of plants or animals of varying exposures to light and darkness. Cf. thermoperiodism. — photoperiod, n.photoperiodic, adj.
See also: Biology
the study of the relative amounts of light and darkness in a 24-hour period required to best effect the growth, reproduction, and flowering of plant species or the growth and reproduction of animals. Also photoperiodicity. Cf. thermoperiodism. — photoperiodic, photoperiodical, adj.
See also: Plants
-Ologies & -Isms. Copyright 2008 The Gale Group, Inc. All rights reserved.


The response of plants to changes in day length, e.g. flowering.
Dictionary of Unfamiliar Words by Diagram Group Copyright © 2008 by Diagram Visual Information Limited