Have you ever wondered if plants feel pain or stress when they are cut, bitten or deprived of water? Well, it turns out they do, and they have a way of expressing it: by making high-pitched noises that are too ultrasonic for human ears to detect.
A recent study by researchers from Tel Aviv University in Israel found that tomato and tobacco plants emit popping or clicking sounds in frequencies between 20 and 100 kilohertz when they are stressed by drought or physical damage. These sounds could be heard by microphones placed about 10 centimeters away from the plants, both in a soundproof box and in a greenhouse setting.
The researchers also used a machine-learning algorithm to analyze the sounds and distinguish between different types of stress. They found that the algorithm could correctly identify the plant species and the stressor with about 70% accuracy.
Why do plants make these sounds, and what do they mean? The researchers suggest that the sounds are caused by a process called cavitation, where air bubbles form and collapse within the plant’s vascular tissue, disrupting the flow of water and nutrients. This process creates vibrations that can be transmitted through the air as sound waves.
The sounds may serve as a way for plants to communicate with other organisms, such as animals, insects and even other plants. For example, some animals may be able to hear and interpret these sounds as signals of distress or danger, and avoid eating or damaging the plants. Some insects may be attracted by these sounds and help pollinate or protect the plants. Some plants may sense these sounds from their neighbors and adjust their own behavior or physiology accordingly.
The study also has implications for human agriculture, as it could provide a new way of monitoring crop health and productivity. By using recording devices and artificial intelligence, farmers could detect signs of dehydration or disease in their plants and intervene before it’s too late. This could help improve crop yield and quality, as well as reduce water and pesticide use.
The study is not yet peer-reviewed, but it adds to the growing evidence that plants are not silent or passive organisms, but rather complex and dynamic beings that can sense and respond to their environment in various ways. The next time you water your plants or prune your roses, remember that they may be listening and screaming back at you.
