「植物にクラシックを聴かせると育つ」説、論文を探したら“曲”より“振動”の話だった

Some people say that plants grow better if they listen to classical music. But there is little good evidence for this. Many old tests used only a few plants, and the conditions were not the same.

However, plants can react to some sounds. One study found that flowers made their nectar sweeter within three minutes after hearing the sound of a flying bee.

You may have heard that plants grow better when they listen to Mozart. However, scientists have found little solid evidence that a particular type of music helps plants. Many past experiments used only a few pots and did not control things like heat from speakers or differences in light.

On the other hand, plants do seem to sense certain vibrations. In 2014, researchers recorded the vibrations of caterpillars chewing and played them back through the leaves of a small plant, which later produced more defensive chemicals. In 2019, flowers increased the sugar in their nectar within three minutes when they heard the sound of a flying bee. Plants seem to listen to sounds that matter for survival.

Stories of tomatoes sweetened by Mozart or plants killed by rock music have circulated for decades, yet a careful search of the scientific literature reveals almost no rigorous evidence that particular genres affect growth. Many popular experiments from the 1970s used few pots and failed to control confounding factors: speakers give off heat, pots placed in different spots receive different light, and hopeful experimenters may unconsciously care for one group better. What research does support is more specific.

In 2014, Appel and Cocroft played recordings of caterpillar chewing vibrations directly into the leaves of Arabidopsis; when later attacked by real caterpillars, these plants produced more defensive chemicals, whereas vibrations from wind or insect songs had no such effect. In 2019, Veits and colleagues found that evening primrose flowers raised nectar sugar concentration within three minutes of hearing a flying bee or synthetic sounds at similar frequencies, possibly because the petals vibrate and work like an ear, while high-frequency sounds had no effect. Note, however, that vibrations through leaves and sound through air are physically different, and most studies remain small. Any claim about music would require random assignment, blinding and preregistration.