The chatter of plants that “speak”

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It presents itself as a real revolution in the field of botany. From cactus to tomato, from tobacco to nettle, it seems that even plants “speak” and even if they don’t have vocal cords, they do it by emitting ultrasounds. In fact, for the first time, researchers at the Israeli University of Tel Aviv have resolved an ancient scientific controversy by recording the sounds emitted by plants, similar to the crackling of popcorn and inaudible to the human ear, but probably audible to different animals, such as bats , mice and insects.

The stress

The study, published in the journal Cell, indicates that plants emit these sounds above all when they are under stress conditions (because without water or with damaged leaves and stems): information which, thanks to special sensors, could be exploited by beings for example to know when the crops need to be watered. To all intents and purposes this discovery makes it possible to create a monitoring system on the state of health of the crops also bringing numerous advantages from the point of environmental and food protection. The research was coordinated by Lilach Hadany and Yossi Yovel who placed the plants in a silent and isolated place, positioning ultrasound microphones about ten centimeters from each specimen. In particular, tomato and tobacco plants were used, as well as those of wheat, corn, cacti and nettles.

The recordings revealed sounds emitted at frequencies between 40 and 80 kilohertz: for comparison, the maximum frequency detected by an adult human being reaches 16 kilohertz. The unstressed plants emitted about one sound per hour, while the dehydrated ones or wounds made dozens of sounds every hour. The collected recordings were then analyzed by artificial intelligence algorithms, developed specifically for this study, which learned to distinguish between different plants and different types of sounds, identifying the plant and determining the type and level of stress. Furthermore, the algorithms were able to identify the ‘language’ of plants even in a greenhouse characterized by a lot of background noise.