Finding the optimum wavelength of light for the best plant growth

P Aphalo pedro at castle.ed.ac.uk
Mon Apr 18 00:46:10 EST 1994


John Cheeseman (j-cheeseman at uiuc.edu) wrote:
(some text deleted)
: Varying the levels of UV could do things ranging from nothing (depending on
: the species and the amount of UV and its wavelength, to killing the platns
: if you hit them hard enough for long enough.  If you are interested in the
: possibility that UV will help the plants or augment the growth that results
: from visible light, I think you can forget it.

I would like to add these comments:

UV-A and UV-B can have effects on plants that are not caused by damage,
but which are morphological or physiologuical responses through specific
photoreceptors.

One might want to give some UV if the plants are going to be moved to
sunlight arfterwards. Many species accumulate UV absorbing compounds
in the epidermis in response to UV. These compounds then partially
shield the inner tissues of the leaf from UV.

Depending on the species the red:far-red ratio and the blue/UV-A and
UV-B bands can have a very marked effect on morphology (internode
length, size and shape of leaves, etc.), so usually although plants
will grow "well" under different kinds of lamps, they may look
differently. Is not uncommon to mix mercury, metal halide, sodium or
fluorescent lamps with tungsten lamps so as to achieve a red:far-red
ratio similar to that in sunlight.

A good reference for UV-B responses is a recent book edited by Manfred
Tevini:

Tevini, N (ed) (1993) UV-B raduation and ozone depletion: effects on
humans, animals, plants, microorganisms and materials. Lewis Publishers,
Boca Raton.

: In article <bmm.765614307 at ardu.dsto.gov.au>, bmm at ardu.dsto.gov.au (B.M.
: Murrell (Bruce)) wrote:

: > Could anyone provide information on the which wavlengths of light provide
: > the best growth rate for plants.  I need information for a project I am
: > devising and would appreciate any help I could get.  I also need to know
: > what the effect of varying levels of UV have on plant growth.
: > 
: > Thankyou, Bruce Murrell
: > bmm at ardu.dsto.gov.au
: >  
: > --
: > SGT B.M. (Bruce) Murrell
: > Aircraft Research & Development Unit (ARDU)
: > Royal Australian Air Force (RAAF)
: > 61-8-256-3116

: **************************************************************************
: John Cheeseman                                 "We haven't the money,
: Department of Plant Biology                     so we've got to think."
: University of Illinois                          -- Lord Rutherford (1962)
: Urbana IL 61801 USA

--

=============================================================================
 Pedro J. Aphalo

Formerly at:
 Intitute of Ecology and Resource Management
 University of Edinburgh
Now at:
 Finnish Forest Research Institute
 Suonenjoki Research Station
 SF-77600 Suonenjoki, Finland

 Janet: Pedro.Aphalo at fi.metla
 World: Pedro.Aphalo at metla.fi
=============================================================================



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