photoperiod


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photoperiod

 [fo´to-pēr″e-od]
the period of time per day that an organism is exposed to daylight (or to artificial light). adj., adj photoperiod´ic.

photoperiod

(fō′tō-pîr′ē-əd)
n.
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.

photoperiod

the length of daylight as compared with the length of darkness in each 24 hour cycle. see PHOTOPERIODISM.
References in periodicals archive ?
Keywords: Dry mass allocation; Floret differentiation; Morphological; Physiological; SD photoperiod; Yield
Many studies have been conducted to see the influence of photoperiod on the reproductive functions of male birds in view of their economic interest.
The effect of photoperiod on gonadal development and reproduction on fish is mediated by endogenous rhythms and sex hormones synthesis and secretion (Elisio et al., 2014, 2015).
The effects of long-day photoperiod on growth, body composition and skin color in immature gilthead sea bream (Sparus aurata L.).
The pelage development of many fur-bearing animals is related to the changes in photoperiod and is controlled by a variety of hormones including melatonin (MEL) [9-12].
Fish were reared at a commercial fish farm (Himalaya Fish Hatchery, Sheikhupura) under ambient water temperature and photoperiod throughout the study period (November, 2007 - October, 2008; Age: 18 months - 29 months).
For example, in a human study, the levels of 5-MTX were investigated between January and March, which is called the short photoperiod, and it was found to have higher concentrations during the day and lower concentrations during the night.
deflexus was observed during 14 days in the photoperiod of 12 light hours, obtaining 3 and 1.5% in the interval from the seventh to the twelfth day after sowing (DAS), in treatments -0.3 and -0.6 MPa, respectively.
We used a full factorial design, with hypomethylation (demethylated or control), photoperiod (24hr or 8hr), and population (California, Fast plant, or biennial) as factors.
Notably, how a circadian rhythm synchronizes to a light-dark cycle to produce stable entrainment is dependent on the length of the photoperiod, with different photoperiods producing characteristic phase angles of entrainment [28].
Yield can also be significantly increased by optimizing irradiance levels and photoperiod length.