Researchers from the AGH University of Science and Technology in Kraków and the University of Life Sciences in Wrocław are investigating whether plants produce noises in stressful situations, such as water shortages, excessive dryness, or pest attacks.
Plants emit sounds at frequencies inaudible to the human ear, which is why researchers from AGH University are using specialized ultrasound-sensitive microphones to record these sounds.
The data collected by the acousticians could soon provide valuable support for farmers and improve the quality of the crops they grow.
In a greenhouse in Wrocław, scientists attempted to capture the sounds of tomato seedlings, which grow rapidly under the right conditions. The tomato plants tested reached up to 30 cm per week. ‘Measurements in the greenhouse showed that indeed the plants emitted pulses in ultrasound and their frequency varied depending on the time of day. More pulses were generated by the plants during the day,’ noted Dr Bartlomiej Chojnacki from the AGH Technical Acoustics Laboratory.
The next stage of research was conducted in an anechoic chamber of the AGH Technical Acoustics Laboratory. The specialised equipment used there made it possible to record sounds with frequencies above 200 kHz. Such high sensitivity is needed because different plants emit sounds at different frequencies. While the range of sounds emitted by tomatoes is 20-50 kHz, it is known from the literature that cereals or grape vines produce sounds of 80-150 kHz.
The tests in the anechoic chamber lasted several weeks. The plant placed in it was surrounded by 8 specialised microphones, so that the direction of sound emission could also be checked. Several planted tomatoes were tested in this way. First they were properly fertilised and watered, then they were dried until they were completely dry. It turned out that as the family dried, it emitted increasingly intense sound pulses. Now the scientists are busy analysing the changes in the sounds made by the drying plant.
The AGH scientists pointed out that acoustic testing could find applications in controlled plant cultures, which are gaining in popularity. In addition to data related to humidity or ambient temperature, growers could use the signal directly from the plant to decide whether to intensify fertilisation, water more intensively or protect against pests, without being physically present on site.
Laboratory of Technical Acoustics at the AGH University of Science and Technology in Kraków_ photo: K. and B. Chojnacki
Source:
https://kr24.pl/krakow/czy-rosliny-ze-stresu-wydaja-dzwieki-krakowscy-naukowcy-to-sprawdzili/
https://kopalniawiedzy.pl/dzwiek-roslina-pomidor-stres,37348
