Photoperiod

Light period of a day.
The optimum duration of light and darkness for the normal growth and maturity of a plant in nature.

photoperiod

<ecology> Recurring cycle of light and dark periods. The natural photoperiod is approximately 24 hours, and the ratio of light to dark hours slowly changes over the course of a year. In controlled experiments, the photoperiod is usually (but not necessarily) retained at 24 hours, and the light:dark ratio is typically constant. ... (09 Oct 199...
Found on http://www.encyclo.co.uk/local/20973

photoperiod

(fo´to-pēr″e-әd) the period of time per day that an organism is exposed to daylight (or to artificial light). adj., photoperiod´ic., adj.
Found on http://www.encyclo.co.uk/local/21001

photoperiod

photoperiod 1. The length of a day. 2. The amount of time that an organism is exposed to daylight.
Found on http://www.wordinfo.info/words/index/info/view_unit/2803/12

Photoperiod

The duration of the daylight period.
Found on http://www.physicalgeography.net/physgeoglos/p.html

photoperiod

natural or artificial cycle of light and darkness alternation to which living organisms may be exposed NOTE - For instance, for the natural cycle of light at the time of the equinoxes, the ratio of light duration (L = 12 h) to darkness duration (D = 12 h) is expressed as LD 12 :12.
Found on http://www.electropedia.org/iev/iev.nsf/display?openform&ievref=845-06-27

photoperiod

The length of time per day that an animal is exposed to natural or artificial light.
Found on http://www.thehorse.com/Glossary.xhtml?L=P

Photoperiod

The daily cycle of light and darkness. E.g 18/6, 18 hours of light and 6 hours of dark would be the photoperiod.
Found on http://www.rollitup.org/general-marijuana-growing/98008-glossary-terms.html

Photoperiod

The relationship between the length of light and dark in a 24 hour period.
Found on http://beebetter.info/2016/07/garden-glossary/

Photoperiod

The relationship between the length of light and dark in a 24 hour period.
Found on http://gardeningwithconfidence.com/blog/2013/03/21/garden-glossary/

Photoperiod

the amount of time per day that an organism is exposed to light (Morris 1992).
Found on http://imnh.isu.edu/digitalatlas/bio/glsry.htm

Photoperiod

A ratio of hours of light to the hours of dark.
Found on http://www.sheepusa.org/

photoperiod

Length of day (or length of period that that artificial light is provided). This also can be expressed as a ratio of daylight to darkness.
Found on http://www.extension.org/pages/27530/goat-glossary-of-terms#.Uj3dsj9rPgY

Photoperiod

the relationship between the length of light and dark in a 24-hour period.
Found on http://www.sheep101.info/201/glossary.html

photoperiod

Length of day (or length of period artificial light is provided). Also expressed as a ratio of daylight to darkness.
Found on http://www.danekeclublambs.com/Glossary.html
No exact match found