Also found in: Thesaurus, Medical, Encyclopedia, Wikipedia.

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
-Ologies & -Isms. Copyright 2008 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
Therefore, the germination response recorded in the laboratory simulates germination in the dry forest with these ranges of temperature variation and with similar conditions of photoperiodicity (i.e., direct white light for 12 hours).
Unknown Helianthus exilis Unknown Helianthus paradoxus Habitat segregation due to salt tolerance; differences in photoperiodicity; hybrid sterility (Lai et al., 2005; Henry et al., 2014; Palacio ct al., 2014) Flowering time differences and selection against hybrids Howea forsteriana and (Savolainen et al., 2006; Hipperson H.
The plastic containers were kept in the laboratory under temperature conditions of 25 [+ or -] 2[degrees]C, relative humidity of 70 [+ or -] 5%, and photoperiodicity of 12L/12D [5].
Photoperiodicity and increasing salinity as environmental cues for reproduction in desert adapted rodents.
In present study some aspects of reproductive behavior of adult male helmeted guinea fowl were studied under the effect of seasonal photoperiodicity. Long days stimulated testicular growth and increased plasma testosterone by stimulating gonadotropin production as described by Boon et al., 2000.