Plant communication has been uncovered by researchers. But impossible to hear that directly by ear.
This is one of the great existential questions: does the environment around Man communicate? Scientists from the University of Tel Aviv, in Israel, have looked into the question by carrying out a very serious study, obtaining answers which appear to be major advances in research since their conclusions have made it possible to uncover a phenomenon so far never materialized. It is not a question of interactions between plants but of sounds emitted in a certain situation.
To conduct their study, the researchers analyzed the behavior of tomato and tobacco plants in various locations and situations. Thanks to ultra-precise microphones, they measured that plants, in a normal situation, only emit less than one noise per hour. On the other hand, in a drought or cutting situation, the number of sounds recorded is much higher: between 25 and 35 per hour for tomatoes, between 11 and 15 per hour for tobacco. These data were recorded in an acoustic box in order to be able to authenticate them precisely.
The research was also carried out in a conventional greenhouse, again using ultra-precise microphones, and in an environment with usual noise (wind, air conditioning, maintenance work). Thanks to a scientific technique, only the sounds emitted by plants could be isolated by the researchers in order to measure them. The findings established that when the plants are irrigated, they emit very little sound. On the other hand, when they begin to no longer be supplied with water, the number of sounds emitted increases, before decreasing as they dry out. When they emit significant numbers, plants typically do so between 8 a.m. and noon, as well as between 4 p.m. and 7 p.m., depending on the study.
But what exactly do we mean by “sound”? The Times of Israel claims it was “clicks, somewhat like the sound of popcorn popping.” Impossible however for the Man to hear them. Indeed, it is at frequencies well above the maximum hearing capacity of humans that they are emitted: between 49.6 and 57.8kHz according to the results of the study, when the human ear cannot hear than those between 0.02 and 20 kHz. “A pastoral flower field would actually be a pretty noisy place. Only we don’t hear those sounds,” says Lilach Hadany of the university’s School of Plant Sciences and Food Security, who co-led the study. On the other hand, they “are probably detected by nearby creatures such as bats, rodents, various insects and possibly also other plants that have the ability to hear high frequencies and pick them up. infer relevant information.” A breakthrough that could help growers manage their irrigation?
