Light Regime

Light Regime

 

the amount of illumination to which a plant is exposed; the illumination may be sunlight or light from one of various artificial sources. The light regime is determined by the influx of radiant energy and its distribution in a biocenosis or crop planting. Of particular importance are the intensity and spectral composition of the radiation and changes therein in time and space. The ratio of day length to night length is also significant.

An evaluation of light regime takes into account visible (physiologically active) radiation, during the absorption of which by pigments photosynthesis and other photobiological processes are carried out. Also important are invisible ultraviolet and infrared rays, which play a major role in the water and heat regimes of plants. Favorable light conditions are achieved by regulating the density of crop plantings and selecting the direction of rows in relation to the source of light. In hothouses plants are exposed to photosynthesis-effecting radiation from incandescent, xenon, or fluorescent lamps. To prevent a plant from growing toward the light all sides should be evenly illuminated.

I. A. SHUL’GIN

References in periodicals archive ?
Light regime helps to increase the embryonic plasma T3 levels which have a positive correlation with metabolic rate and development of chicken embryos (Decuypere et al.
The fixed orientation is characterized by following features--it depends on the ambient magnetic field, it represents a polar response, and thus does not involve the inclination compass, it is not displayed in the context of migratory orientation, it probably involves magnetite-based magnetoreception, yet the fixed orientation is dependent, in a still unclear way, on the specific light regime.
Phytochromes that are biliprotein photoreceptors enable some microorganisms to adapt to the light regime in the soil (Rottwinkel et al.
hispanica seeds, there is no information about light regime, temperature and suitable substrate to provide a secure germination test.
From an ecological perspective, it is possible that these results obtained at the 45% shade treatment seems to coincide with light regime perceived inside natural large gaps (>400 [m.
My Christmas cactus Schlumbergera Truncata is in full flower right now and frustratingly its never in bloom at Christmas despite altering its watering and light regime.
Canopy structure and light interception in Quercus petraea seedlings in relation to light regime and plant density.
This light regime approximated the local natural photoperiod.
Kim continued to exercise while she was expecting; following a light regime devised by celebrity fitness trainer Tracy Anderson.
He stressed that he would stand by his wife, even though she looks certain to receive a lengthy prison sentence for violently orchestrating a red light regime that preyed on vulnerable women.
The light regime was 3 h of light followed by 7 h of darkness and ending with 2 h of light controlled by an outlet timer.