Re: do magnetic fields have an effect on plant growth?

Hi Belinda!

The short answer is YES, magnetic fields do appear to have an effect on the
growth of plants. However, we still don’t really understand how (the
‘mechanism’) magnetic fields affect plants. This is a very interesting
question being explored by plant scientists and physicists, since plants
are being exposed to low-level magnetic fields as a consequence of power
lines and other industrial technology, but it is very far from being
understood. Most of the research into this topic is published in Russian
scientific journals, and are therefore difficult to locate, but are
summarized in a review article by Belyavskaya (2004) in the journal
Advances in Space Research (see reference below). The bibliography of that
paper has many references that could be helpful to you.

Weak electromagnetic fields (WEF) are generally thought to suppress the
growth of plants and reduce cell division (arrest cells in G1 phase – the
‘growth phase’ leading up to cell division). A study by Sytnik et al.
(1984) reported that the growth of wheat, pea, and sugar beet roots was
significantly inhibited by WEF. In contrast, a study by Celestino and
co-workers (2000) reported that weak electromagnetic fields (WEF) increase
the germination of oak seeds (aka, acorns) and their subsequent growth
(shoot length, dry weight). Similarly, Alexander and Doijode (1995) found
that onion and rice seeds exposed to a WEF for 12 h showed significantly
increased germination, shoot and root lengths, and fresh and dry weight of
seedlings. M.V. Carbonell et al. (2000) confirmed that these low-frequency
magnetic fields increase the germination rate and percentage of rice seeds.
However, a study by Govoroon et al. (1992) observed no effect of WEF on the
growth of pea, flax, and lentil seeds. These variable and contradictory
results seem to suggest that the effects of magnetic fields on plants may
be species-specific (e.g., stimulate growth certain plant species, inhibit
growth in some species, and have no effect on others).  Even though all of
these studies use “weak electromagnetic fields”, the exact intensity of the
magnetic field is also going to be an important variable. Levels of calcium
(Ca++) inside of plant cells increases following exposure to magnetic
fields, which is one of the proposed mechanisms by which magnetic fields
may affect plants. Calcium ions (Ca++) participate in many plant growth
processes and responses to stress (heat and salt stress, wounding, etc.).
Another potential mechanism is being explored by NASA, which has done some
research showing that magnetic fields may also affect the position of
starch grains (aka amyloplasts) within plant cells, which will influence
the direction of growth of the plant (a phenomenon called geotaxis). See:
http://weboflife.nasa.gov/currentResearch/currentResearchFlight/sowingSeeds.htm
   

There is much less information available for responses of algae to magnetic
fields, since most research is focused on agriculturally important plants
(beans, peas, wheat, etc.). Please e-mail me if you have any questions or
confusions about what I have outlined here. Good luck!

~Shireef Darwish


Belyavskaya, N.A. (2001). Ultrastructure and calcium balance in meristem
cells of pea roots exposed to extremely low magnetic fields. Advanced Space
Research, 28: 645–650.

Govoroon, R.D., Danilov, V.I., Fomicheva, V.M., Belyavskaya, N.A.,
Zinchenko, S.Yu. Effects of fluctuations of a geomagnetic field and its
screening on early phases in development of higher plants. Biofizika 37,
738–743, 1992

Sytnik, K.M., Kordym, E.L., Nedukha, E.M., Sidorenko, P.G.,Fomicheva, V.M.
Plant Cell Under Alterations in Geophysical
Factors, Naukova Dumka, Kiev, 1984.

Alexander, M.P., and Doijode, S.D. (1995). Electromagnetic field, a novel
tool to increase germination and seedling vigour of conserved onion (Allium
cepa L.) and rice (Oryza sativa L.) seeds with low viability. Plant Genetic
Resources Newsletter, 104: 1– 5. 

Hirota, N., Nakagawa, J., Kitazawa, K. (1999). Effects of a magnetic field
on the germination of plants. Journal of Applied Physics, 85(8): 5717-5719.

Aksyonov, S.I., Bulychev, A.A., Yu. Grunina, T., Goryachev, S.N., and
Turovetsky, V.B. (2001). Effect of ELF-EMF treatment on wheat seedlings at
different stages of germination and possible mechanisms of their origin.
Electro- and Magnetobiology, 20(2): 231-253. 

Celestino, C., Picazo, M.L., and Toribio, M. (2000). Influence of chronic
exposure to an electromagnetic field on germination and early growth of
Quercus suber seeds: preliminary study. Electro- and Magnetobiology, 19(1):
115-120.

Belyavskaya, N.A. (2004). Biological effects due to weak magnetic field on
plants. Advances in Space Research, 34: 1566–1574.

Carbonell, M.V., Martinez, E., and Amaya, J.M. (2000). Stimulation of
germination in rice (Oryza sativa L.) by a static magnetic field. Electro-
and Magnetobiology, 19(1): 121-128.