Cool white FL's for lighting

Vladimir Zhurov

Lifetime Members
Lifetime Member
Aug 25, 2006
London, ON
It is funny that everyone refers to Helson et al. when dismissing special plant bulbs.

Original paper clearly states some interesting differences in plant (tomatoes to be exact) phenotype when grown under different bulbs. They compared standard daylight fluorescent, Gro-Lux, and supplemented both with incandescent bulbs.

Their original statement was whether observed small increase in growth was justifiable due to higher prices of plant bulbs and not that all the bulbs are same.



Tom Barr

Staff member
Jan 23, 2005
Well, it's a bit old, for that matter:

Helson, V.A. 1965. Comparison of GroLux and cool white fluorescent lamps with and without incandescent as light sources used in plant growth rooms for growth and development of tomato plants. Canad. J. Plant Sci. 45:461-466

and if you are inhterested in refs for fake lighting and horticulture:


Casal, J.J., V.A. Deregibus, and R.A. Sanchez. 1985. Variations in tiller dynamics and morphology in Lolium multiflorum Lam. vegetative and reproductive plants as affected by differences in red/far-red irradiation. Ann. Bot. 56:553-559.

Cathey, H.M. and L.E. Campbell. 1975. Effectiveness of five vision-lighting sources on photo-regulation of 22 species of ornamental plants. J. Am. Soc. Hort. Sci. 100:65-71.

Cathey, H.M. and L.E. Campbell. 1977. Plant productivity: New approach to efficient light sources and environmental control. Trans. Am. Soc. Agri. Eng. 20:260-266.

Cathey, H.M., L.E. Campbell, and R.W. Thimijan. 1978. Comparative development of 11 plants grown under various fluorescent lamps and different durations of irradiation with and without additional incandescent lighting. J. Am. Soc. Hort. Sci. 103:781-791.

Decoteau, D.R, H.A. Hatt, J.W. Kelly, M.J. McMahon, N. Rajapakse, R.E. Young, and R.K. Pollack. 1993.Applications of photo-morphogenesis research to horticultural systems. HortScience 28:974, 1063.

Deitzer, G., R. Hayes, and M. Jabben. 1979. Kinetics and time dependence of the far-red light on the photoperiodic induction of flowering in Wintex barley. Plant Physiol. 64:1015-1021.

Deutch, B. and O. Rasmussen. 1974. Growth chamber illumination and photomorphogenic efficacy. I. Physiological action of infra red radiation beyond 750 nm. Physiol. Plant. 30:64-71.

Doorenbos, J. 1964. The phytotron of the Laboratory of Horticulture, State Agricultural College, Wageningen. Meded. Dir. Tuinbou. 27:432-437.

Downs, R.J. 1988. Retrofitting plant growth chambers with high intensity discharge lamps. Paper 88-4016. Am. Soc. Agri. Eng. St. Josephs, MI.

Downs, R.J. 1989. Reflector design for HID lamps used in plant growth chambers. Paper 89-4581. Am. Soc. Agri. Eng. St. Josephs, MI.

Downs, R.J. and H. Hellmers. 1975. Environment and the Experimental Control of Plant Growth. Academic Press, London.

Downs, R.J. and J.F. Thomas. 1990. Morphological and reproductive development of soybeans under artificial conditions. Biotronics 19:19-32.

Duke, W.B., R.D. Hagi, J.F. Hunt, and D.L. Linscott. 1975. Metal halide lamps for supplemental lighting in greenhouses: crop responses and spectral distribution. Agron. J. 67:49-53.

Dunn, S. and F.W. Went. 1959. Influence of fluorescent light quality on growth and photosynthesis of tomato. Lloydia 22:302-324.

Eguchi, H. 1986. Biotron Institute, Kyushu University. Japan.

Krizek, D.T. and D.P. Ormrod. 1980. Growth responses of 'Grand Rapids' lettuce and 'First Lady' Marigold to increased far-red and infrared radiation under controlled conditions. J. Am. Soc. Hort. Sci. 105:936-939.
Murakami, K., K. Horiguchi, M. Morita, and I. Aiga. 1991. Growth control of sunflower (Helianthus annuus L. cv Russian Mammoth) seedlings by additional far-red radiation. Environ. Control in Biol. 29:73-79.
Tibbitts, T.W., D.C. Morgan, and I.J. Warrington. 1987. Growth of lettuce, spinach, mustard, and wheat plants under four combinations of high pressure sodium, metal halide and tungsten halogen lamps at equal PPFD. J. Am. Soc. Hort. Sci. 108:622-630.

Tischner, T.W. and D. Vida. 1981. Metal halide lamps with rare earth additives for plant growth tests. Tungsram Tech. Rev. 48:1889-1895.

Warrington, I.J. 1978. Controlled environment lighting - high pressure discharge lamps-based systems. Proc. Growth Chamber Environ. Symp. 20th Internatl. Hort. Congress, Sydney, Australia.

Warrington, I.J., K.J. Mitchell, and C. Halligan. 1976. Comparison of plant growth under four different lamp combinations and various temperature and irradiance levels. Agric. Meteorol. 16:231-245.

Warrington, I.J., E.A. Edge, and L.M. Green. 1978. Plant growth under high radiant energy fluxes. Ann. Bot. 42:1305-1313.

I'll find a few others, I recall one paper I saw that was very good, it said pretty much what many have stated for years about aquatic plant bulbs vs cool whires, PAr is PAR. I'd like to locate it, but it's lost in a pile of paper. I looked for awhile but have not located it yet.

Anyhow, folks are welcomed to dig, but a paper from 1965 etc is a bit dated, but still fairly relevant, most of the PAR discussion hits on these points, and why it's more important than "special bulbs".

Tomatos mioght not seem like Aquatic macrophtyes, I'd agree there, but in terms of adaption to light spectral outputs, I think most are very similar.

In algal studies on aquatic photosynthesis in marine pelgic systems, perhaps the oldest place on earth that adaptations for various light levels and types exists, there's little differences between the groups, they are subtle and mainly give the "first jump advantage" on a competitor, but if both are adapted, then it really is not a big difference.

Our own eyes seems to play a much more siginficant role.

I did a humber of test with a 55 gallon tank using various combinations on 1/2 the tank vs the other and I have a plastic plate in the middle with holes.

I never saw much differences, I think I saw a Triton bulb difference, but that was the only one and looking back, that might just be speculation, but at the time I thought I'd seen some differences.

I would not want to argue that I did these days though:cool:

Tom Barr