Plants "talk" to each other

Scientists at Tel Aviv University in Israel have discovered that plants make specific, identifiable sounds when they are under stress, and that these sounds can be heard by animals such as bats, mice and insects. The research, led by Professor Lilach Hadany and published in the scientific journal Cell, resolved a long-standing scientific controversy over whether plant vibrations turn into audible sound waves.

To carry out the study, the researchers placed plants in an isolated acoustic box with no background noise. Ultrasonic microphones were positioned approximately 10 cm from each plant and captured sounds between 20 and 250 kHz (the maximum frequency detected by an adult human is approximately 16 kHz). Scientists mainly looked at tomato and tobacco plants, but also included wheat, corn, cacti and other species.

Before being placed in the acoustic box, the plants were subjected to different conditions: some were not watered for five days, others had their stems cut and some did not undergo any interventions. The results showed that plants under normal conditions emitted less than one sound per hour, while stressed plants – dehydrated or injured – emitted dozens of sounds every hour.

To analyze the recordings, the researchers developed artificial intelligence (AI) algorithms capable of distinguishing between different plants and types of sound. The algorithms identified and classified the sounds of plants even when they were in a noisy environment, such as a greenhouse.

Scientists believe that the information contained in plant sounds could be useful to humans, providing information about the need for irrigation, for example. The study also raises other intriguing questions, such as the nature of the mechanism behind plant sounds and whether other plants can also hear these sounds. Researchers will continue to explore these questions in future studies.

The full article, in English, can be read here.

About plant communication, Cultivar Magazine published a report in January 2000 (issue 12 - "Plants also ask for help"). The images can be seen below...