Apart from the PAR a plant needs some UV and IR, how much? (regardless of species). How can i measure if the light emmited from a source is right for plant growth(light flux intensity, uniformity, light distribution efficiency)
Dear Orfeas Voutsinos.
Do you want to built an artificial lighting for a green house or plant factory? Then better for you to learn about basic of artificial lighting for plant for example you can read the document in the link below. You need light sources with spectrum distribution required for plant growth and then you can determine the wattage of the lamp according to the area.
http://www.arguscontrols.com/resources/Light-and-Lighting-Control-in-Greenhouses.pdf
Dear Orfeas, The link given by Dimas Firmanda is quiet sufficient. If need further- ideal light quanta for plant growth is 1500- 2500 mE/m2/sec .
Dear Orfeas
I'm not sure that UV and NIR are essential wavebands for plant growth. Nevertheless photons from those wavebands are detected by plantes. This ability allows plants to appreciate their environnement. These spectral signals are called MAR for Morphologically Active Radiation.
For exemple, red to far-red ratio (R:FR) is a signal which enables shade avoidance.
Review articles describe this mecanisme :
- Ballaré 1999, Keeping up with the neighbours: phytochrome sensing and other signalling mechanisms. Trends in plant science, march 1999. p97-102).
- Smith 2000, Phytochromes and light signal perception by plants — an emerging synthesis. Nature, october 2000. p585-59.
And blue light receptor has an action band between 350 and 500 nm (Morgan 1981, Non photosynthetic response to light, Physiological Plant Ecology).
You can caracterize spectra with a spectroradiometer (ADC, PP-system, Ocean-Optics).
If you already know the spectrum of your light source, you can use a Quantum meter (Li-cor, Solems ...).
I hope it will help you.
Hello Orfeas
Previous comments are very relevant to the problem you raise. But the question is perhaps too generally expressed. What plant species? That is very important. What growth processes? When deciding what is required, it helps to narrow the question. For a given species it might be useful to aim to reproduce the light flux density, spectrum /temperature etc in the environment from which it originates. That is very difficult and is mostly only achieved approximately, even with sophisticated modern CE cabinets. For species. used in agriculture - most cereals for example - current CE aim to provide a general environment which is acceptable to a range of species. So a large photon flux in the range 400-700 micrometers is important, ideally above 1000 micromole m-2 s-1 ( please note that micro Einstein is not an accepted SI unit ) for several hours a day. Also the red/far-red ratio must be correct as others have emphasised. Then grain yields will approximate the field. There is flexibility in the plant's (actually a species') ability to grow in a range of conditions, but the biochemistry and morphology may not be identical that found in the field. There is a wide literature, and suppliers of CE cabinets are a good source of information.
Regards
David Lawlor
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