Researchers at Tel Aviv University have succeeded in demonstrating that plants can emit sounds in stressful situations and have recorded their acoustic responses. In their study, published in the journal Cell, the scientists recorded the ultrasonic sounds emitted by tomato and tobacco plants under stress in an acoustic chamber in a greenhouse. The plants were dehydrated and subjected to cuttings to test their reaction. The results showed that the plants emitted sounds at frequencies between 40 and 80 kilohertz and that stressed plants emitted dozens of sounds every hour, while unstressed plants emitted less than one sound per hour on average.
Although plant sounds are imperceptible to the human ear, ultrasonic frequencies can be detected from a distance of three to five meters by many mammals and insects that have increased hearing sensitivity, such as mice and moths. The researchers analyzed the recordings using artificial intelligence machine learning algorithms developed specifically for this task.
The Israeli researchers’ discovery could facilitate agricultural tasks. For example, special sensors could tell when plants need more water. It could also help farmers detect stressful situations in plants before irreparable damage occurs. This new knowledge about plant sounds can contribute to the development of new technologies to improve plant performance and health, as well as better understand the communication between plants and their environment.