Effects of Electrical and Electromagnetic Fields on Plants and Related Topics

Abstract

Anyone reading this book cannot fail to realize the importance of self-generated electric fields and currents in the energetics and control of metabolism in plants. We should therefore not be too surprised to find that externally applied fields also have effects. In this chapter, I will describe a few of the more significant findings from over a century of research and try to explain and sometimes reinterpret them in the light of more modern knowledge. The work is divided into three sections. Section 1 is on the non-polar effects of DC fields, where the effects are not related to the direction of the field. It ranges from responses to massive electric fields, such as those found in thunderstorms, to the effects of much weaker ones on the growth and differentiation of tissue cultures. Section 2 is on the polar effects of DC fields, where the direction of the response is related to the direction of the field and includes effects on polar growth and tropisms. Section 3 is on the effects of time-varying and alternating electromagnetic fields, where I will present evidence that a simple change in membrane stability can account for virtually all of the hitherto mysterious biological effects of weak electromagnetic radiation. Non-polar effects of DC electric fields High voltage natural fields and the rise and fall of electroculture PhenomenologyWork on the effects of electrical fields on plants goes back several centuries, but the first person to carry out large scale experiments was Karl Lemström, who was a Professor of Physics at Helsinki. He had paid several visits to the Arctic, and was surprised how green and healthy the vegetation looked, despite the low light and temperature. He wondered whether this might be due to the weak electric currents carried through the atmosphere by air ions from the aurora borealis. His suspicions were confirmed when he looked at

Magnetic fields: how is plant growth and development impacted?

“…In contrast, the extra energy gained by each K + may be small. As there are about 10,000 K + ions competing with just one Ca 2+ for each place on the membrane implies that a slight increase in their energies due to resonance is enough to overwhelm those calcium ions, as their sympathetic and synergistic support for each other can easily produce more than twice the work function (that is the energy required to dislodge Ca 2+ from the surface of the cell membrane) to replace and substitute K + for Ca 2+ , which is a binding or cementing agent for cell membranes and thereby undermine the overall quality and integrity of such plants or crops (Goldsworthy 2006(Goldsworthy , 2007Naidu and Kamaraju 2007;Asemota 2010). This push-and-pull mechanism of valuable Ca 2+ as a binder and symbol of membrane integrity is essentially MF dependent.…”

“…Living organisms, including plants, themselves generate and use different electrical fields (currents, signals) during their functioning, such as (trans)membrane, electric, action, or streaming potential; therefore, it is expected that MF and EMF can affect and influence the development and metabolism of plants when interacting (Goldsworthy 2006;Trontelj et al 2006). The mechanisms of the interaction of MFs with biological systems are still not well understood.…”

“…At 10 mM CaCl 2 , the length of radicals increased significantly indicating a change in the calcium efflux due to the MF. Goldsworthy (2006) described the (non-specific) effects of non-polar and polar DC fields, and alternating EMF. According to his explanations, the growth-affecting effects of non-polar effects of DC fields can be due to changes in the membrane potential and membrane permeability of the cells to Ca 2+ ions.…”

“…Moreover, theory is massively divided from practice, making a clear understanding of the practical effects of MFs on plant growth and development difficult to understand from the physical and mathematical theorems currently available and thus beyond the reach or comprehension of most plant scientists. Due to the complexities of the theoretical nature of MFs, the mathematical understanding of MFs on plant growth will be covered in a separate review, although some broad understanding can be obtained from Goldsworthy (2006) and Asemota (2010).…”

Extremely low frequency electromagnetic field generator suitable for plant in vitro studies

“…Compared to the research of the ELF-EMF effect on animals and humans, to date, only limited studies on the effects of ELF-EMF on in vitro plants have been documented (Goldsworthy 2006), where the stability and uniformity of the ELF-EMF applied to the in vitro plant subjects were not clearly described. The ELF-EMF generators commercially available at present are generally based on the Helmholtz coil concept.…”