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 ?
Effect of light regime on the growth and physiology of Pentaclethra macroloba (Wild.) Kuntze, in Costa Rica.
Algal cells traveling at the same velocity experience a faster oscillating light regime in a shallowly mixed layer than in a deeply mixed layer.
The direction of polarization was predominately horizontal (0 [degrees]; [ILLUSTRATION FOR FIGURE 1F OMITTED]); however, in several cases, the direction of this polarized reflection changed by up to 30 [degrees] within 1 s, without the animal exhibiting any movement or change in coloration, nor any detectable changes in the light regime in the tank.
Contract notice: offer for light regime on danish education for adult foreigners etc.
the services will fall under the light regime of the directive.
Light regime was experimentally altered by cutting trees and branches at four sites along a 700-m stretch of upper White Oak Creek, a second-order stream on the Oak Ridge Reservation in eastern Tennessee.
Contract notice: Offer for light regime on employment efforts to svendborg municipality
Purchase of hotel accommodation constitutes a service covered by the light regime of the public procurement act, Which is governed by title iii of the public procurement act.
Sdu provides for the light regime agreement for the purchase of patent agent services.
1564 of 15 december 2015), section iii, sections 186-189, which deals with procurement after the so-called light regime of social and other specific services above the threshold.
The production technology corresponds to the world standards: modern equipment monitors the light regime, regulates the temperature and controls ventilation.
description of the procurement: The tender is covered by section iii (light regime) of the public procurement act and is therefore implemented in accordance with sections 186-189, As well as the present advance notice.