The idea of a plant making noise can evoke a vision of the mandrakes from Harry Potter.
But a new study suggests that plants do make distress calls when they’re not getting enough water.
They also appear to make alarm sounds after being cut, with these sounds coming from tomato and tobacco plants, as well as corn and the vines used to make Cabernet Sauvignon.
Ultrasonic vibrations have previously been recorded from plants, with sensors touching them directly.
Now, the new study provides the first evidence that plants emit airborne sounds that researchers estimate could be heard up to five meters away by keenly hearing animals like mice and moths.
Now, a study has found that plants do make noises when they’re stressed — albeit more like popping than screaming
The idea of a plant making noise can evoke a vision of the mandrakes from Harry Potter
For people who don’t hear in the high-frequency “ultrasonic” range, researchers helpfully lowered the frequency so we could hear the plant sounds — which are delivered fairly loudly at the same volume as normal human conversation.
Typically, less than once an hour, plants make a popcorn-like sound — thought to be caused by air bubbles bursting in their stalk.
But tomato plants that hadn’t been watered for up to five days produced that popping sound much more frantically — more than once every two minutes on average.
When cut, the tomato plants made an alarm sound about every two and a half minutes.
Professor Lilach Hadany, an evolutionary biologist at Tel Aviv University and senior author of the study, which examined hundreds of plants, said: “Our results suggest that the world around us is full of plant sounds and that these sounds carry information – about water scarcity, for example.” or injuries.
“We assume that in nature, the sounds emitted by plants are perceived by nearby creatures such as bats, rodents, various insects and possibly other plants, which can hear the high frequencies and derive relevant information.
Typically, less than once an hour, plants make a popcorn-like sound — thought to be caused by air bubbles bursting in their stalk
Do plants feel “pain”?
When a beetle bites a plant leaf, the wound triggers the release of calcium, University of Wisconsin researchers said last year.
This sets off a chain reaction in the cells along the plant leaves and stem.
It takes about a minute or two for the response to reach every part of the system.
The calcium creates a hormonal response from the plant to protect its leaves.
Some plants release harmful chemicals that make them taste bad to other invading insects.
Others, like grass, release hormones that attract nearby parasitic wasps, which eat the attacking insects.
“We believe that people can also use this information if they have the right tools, such as B. Sensors that tell growers when plants need to be watered.
“Apparently, an idyllic flower meadow can be a pretty noisy place. It’s just that we can’t hear the sounds!’
The ultrasound footage, captured by two microphones positioned next to each plant in the study, supports the theory that they could use sound to warn each other of dangers from drought or hungry animals.
If plants knew in advance that water would be scarce, they could close pores in their leaves to conserve water.
If a plant heard a sound from another plant whose stalk had been severed by an animal eating it, that plant could give off volatile compounds to scare off the hungry animal.
The researchers used artificial intelligence algorithms to compare the sounds of tomato and tobacco plants to those that were cut or drained in a soundproof acoustic chamber for up to two weeks.
The team found that plants that hadn’t been watered began making emergency calls before they became visibly dehydrated, with the sounds peaking after five days without water before fading before the plants dried up completely.
In the future, the noise could help people use a sensor to tell when their houseplants are unhappy and need a spray of water, or help farmers conserve water by only watering plants when they’re dehydrated.
The researchers also found that plants like grapevines, wheat, corn and cacti made noises when they were cut or dehydrated.
Sounds lasted longer when a plant was dehydrated than when it was cut, and different plants seemed to make different sounds based on factors like sound frequency.
Experts suggest these sounds could be helpful to creatures like moths, which lay larvae on plants and therefore find dehydrated ones unsuitable.
In the future, the noise could help people use a sensor to tell when their houseplants are unhappy and need a spray of water, or help farmers conserve water by only watering plants when they’re dehydrated