Plants © pixabay.com
As a result of research by scientists from Tel Aviv University, a historic discovery was made: plants can produce sounds when under stress. This discovery could have significant implications for agriculture, as farmers can save water and take measures to grow healthier fruits and vegetables.
Studied plants such as tobacco, tomatoes, cacti, and others produce sounds during dehydration and cutting. Although humans cannot hear these sounds due to their high frequency, scientists have found that plants regularly emit sounds that become louder in crisis situations.
Researchers placed microphones in a greenhouse and a soundproof acoustic chamber to listen to plants in a healthy state, during dehydration, and after stem cutting. Healthy plants in control groups produced an average of less than one sound per hour, while the number of signals increased to 25 and 15 per hour for tomato and tobacco cutting, respectively.
Sounds produced by plants were longer in plants suffering from water scarcity. In the first few days without water, they made more noise, reaching maximum levels before fading away during drying. This allows researchers to determine the difference in dehydration levels of plants by sound.
One hypothesis explains that plants produce sounds due to the formation of air bubbles that burst in their vascular system as a result of cavitation. To enable humans to hear the sounds produced by plants, scientists lowered the recording frequency. During the study, various crops were examined, including corn, cacti, and wheat, which also produce sounds during stress.
According to the scientists, further research may provide more information about how plants interact with the environment. The sounds made carry certain information; moths and bats can hear them. It is not yet clear whether the crackling "ultra noise" helps to distract herbivores or vice versa to attract pollinators.
In the future, farmers will be able to determine health and needs using sensors. The application of algorithms combined with sound monitoring will save up to 50% of water used in agriculture, the scientists concluded in their research paper "Sounds emitted by plants under stress are airborne and informative".