New research suggests plants can hear. Is this the start of acoustic farming?

Jurriaan Kamp | December 2007 issue
Prince Charles was widely ridiculed 20 years ago when he declared on television that he talked to his plants. “I just come and talk to the plants, really. It’s very important to talk. They respond, don’t they?” In the 1990s, Dutch princess Irene van Lippe-Biesterfeld caused a similar furor when she wrote in her book Dialogue with Nature that she talked to trees. But what was once dismissed as eccentricity has recently gained some scientific credibility. Researchers at the National Institute of Agricultural Science and Technology in Suwon, South Korea, have discovered two genes in rice that react to sound.
The Korean study, which succeeds a series of similar but often controversial studies conducted in recent decades, is significant because if plants really do respond to sound, a whole new, ecologically friendly field could be inaugurated: acoustic farming.
The Koreans began their research by playing 14 different pieces of classical music, including Beethoven’s Mondschein Sonatas, to rice plants in their laboratory. At first, they detected no reaction to the music from the rice genes. That changed, however, when they ex-posed the rice to specific sound frequencies. The genes rbcS and Ald became more active at frequencies of 125 and 250 hertz and less active when exposed to lower 50 hertz frequencies. To rule out the possibility that light could affect the results, the study was repeated in the dark. The outcome was the same.
According to the Korean team, the results indicate it might be possible to turn certain crop genes on and off through acoustic
signals—for example, genes that determine when a plant flowers. This could decrease costs and would be more environmentally friendly than the current method of activating genes using chemicals. “These results suggest that sound could be an alternative to light as a gene regulator,” the researchers wrote in Molecular Breeding (published online on July 20, 2007). The possibility of regulating crop growth with sound offers—eco-friendly—prospects for agriculture. Sound could replace chemical fertilizers as a way to stimulate growth, and sound could also be used—instead of pesticides—to keep weeds at bay.
The Korean researchers were also able to isolate the genes and use them in different combinations. The effect of sound on the genes remained the same. This finding suggests it might be possible to transplant the sound-sensitive genes into another organism to realize the same effects.
Scientists have reacted with skepticism to the intriguing results of the Korean study. Among other things, they point out that on an actual farm, windy conditions could cancel out the effects of the sound. Such criticisms miss the bigger question: Can plants hear? Plants have a variety of other senses. They respond to light. They have “taste”—they grow better when they receive more nutritious food. Plants also react to wind by becoming more rigid. So the idea that sound could influence plants isn’t as strange as it might appear. Ultimately, sound—like light—is just another part of the electromagnetic spectrum.
Back in 1994, the French physicist and musician Joel Sternheimer created a stir when he filed a patent application for this approach. Sternheimer claimed he could influence certain plant amino acids and proteins with particular “compositions.” His trial produced tomatoes that were two-and-a-half times larger—and sweeter—than normal. Since then, not much has been heard about Sternheimer’s work, which is now mostly referenced in holistic circles as proof that everything is connected.
The Secret Life of Plants by Peter Tompkins and Christopher Bird, published in 1973, has a similar message. The
book’s cover blurb— “a fascinating account of the physical, emotional and spiritual relations between plants and man”—speaks for itself. Tompkins and Bird describe various experiments. The American lie-detector expert Cleve Backster plays a prominent role in the book. In the 1960s, Backster conducted experiments on plants using his lie detector. He was curious to see whether plants—like the humans he interrogated every day—would also respond to physical threats. As part of his experiment, he decided to set one of his plants’ leaves on fire. He was appalled to see the pen on the graph paper surge upward, even before he got out the matches! Did the plant read his thoughts?
When Backster returned with the matches, he saw another sharp peak on the graph paper. In a subsequent experiment, Backster had five students walk through a room past the same two plants. One of the students was instructed to destroy one of the two plants. Backster didn’t know himself which of the five students had done the deed, but when the students separately re-entered the room, he could clearly tell who had demolished the plant by the intense reaction on the lie detector hooked up to the other plant.
Backster, the director of the Backster School of Lie Detection in San Diego, California, published the results of his study in the International Journal of Parapsychology. More recently, he has presented his findings during conferences at the Institute of Noetic Sciences and the Institute for Transpersonal Psychology in California. His work remains controversial. That is not surprising. The concept that plants can hear, and even observe, doesn’t fit very well into the conventional mechanistic image of the world.