Recordings Reveal That Plants Make Ultrasonic Squeals When Stressed (newscientist.com) 59
Researchers have discovered that plants make airborne sounds when stressed, which they say "could open up a new field of precision agriculture where farmers listen for water-starved crops," reports New Scientist. From the report: Itzhak Khait and his colleagues at Tel Aviv University in Israel found that tomato and tobacco plants made sounds at frequencies humans cannot hear when stressed by a lack of water or when their stem is cut. Microphones placed 10 centimeters from the plants picked up sounds in the ultrasonic range of 20 to 100 kilohertz, which the team says insects and some mammals would be capable of hearing and responding to from as far as 5 meters away. A moth may decide against laying eggs on a plant that sounds water-stressed, the researchers suggest. Plants could even hear that other plants are short of water and react accordingly, they speculate.
On average, drought-stressed tomato plants made 35 sounds an hour, while tobacco plants made 11. When plant stems were cut, tomato plants made an average of 25 sounds in the following hour, and tobacco plants 15. Unstressed plants produced fewer than one sound per hour, on average. It is even possible to distinguish between the sounds to know what the stress is. The researchers trained a machine-learning model to discriminate between the plants' sounds and the wind, rain and other noises of the greenhouse, correctly identifying in most cases whether the stress was caused by dryness or a cut, based on the sound's intensity and frequency. Water-hungry tobacco appears to make louder sounds than cut tobacco, for example. The study, which has not yet been published in a journal, can be found here.
On average, drought-stressed tomato plants made 35 sounds an hour, while tobacco plants made 11. When plant stems were cut, tomato plants made an average of 25 sounds in the following hour, and tobacco plants 15. Unstressed plants produced fewer than one sound per hour, on average. It is even possible to distinguish between the sounds to know what the stress is. The researchers trained a machine-learning model to discriminate between the plants' sounds and the wind, rain and other noises of the greenhouse, correctly identifying in most cases whether the stress was caused by dryness or a cut, based on the sound's intensity and frequency. Water-hungry tobacco appears to make louder sounds than cut tobacco, for example. The study, which has not yet been published in a journal, can be found here.
Vegans on suicide watch (Score:5, Funny)
Salad is murder! The only moral food option is to eat rocks and dirt.
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Re:Vegans on suicide watch (Score:5, Funny)
Beat me to it. Maybe we better not be so hasty to rush to assumptions about those rocks though...
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Fruitarians, not vegans.
Re: Vegans on suicide watch (Score:2)
Re: Vegans on suicide watch (Score:1)
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"Eat more animals!"
I hate to break it to you, but animals also make sounds when they are stressed, and unlike plants, they are quite in the middle of human hearing range.
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Exactly. It's our responsibility to eat organisms equitably, without discriminating based on the audio range in which they happen to scream.
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Have you considered becoming a Jain?
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Have you considered becoming a Jain?
Jains eat vegetables. Or they did until they heard about this research.
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Only some vegetables. Mostly stuff that can be harvested from a plant without killing it. They won't eat roots, for example.
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I've heard the screams of the vegetables, Watching their skins being peeled
Grated and steamed with no mercy, How do you think that feels?
Carrot Juice constitutes murder, Greenhouses prisons for slaves
It's time to stop all this gardening, Let's call a spade a spade
-The Arrogant Worms, Carrot Juice Is Murder [youtu.be]
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I knew it. Now I'm down to mushrooms. Do fungi scream?
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They're full of insects.
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Salad is murder!
Not if they're Triffids.
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Triffids are self-defense.
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Vegans are Violent!
Re: Vegans on suicide watch (Score:2)
Wait! You're into something here, cause I know that I have seen this breakfast treat worms n dirt, and the kids can't get enough of them! Sure the packaging tries to convince you that it's gummy worms and chocolate, but why buy fakes?
I heard about this (Score:1)
And I begged Angel of the Lord what are these tortured screams?
And the angel said unto me
These are the cries of the carrots, the cries of the carrots!
Re:I heard about this (Score:5, Funny)
And I begged Angel of the Lord what are these tortured screams?
And the angel said unto me
These are the cries of the carrots, the cries of the carrots!
This is why I eat mutton, I prefer the silence of the lambs.
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Translation found: (Score:5, Funny)
"Feed me, Seymour!"
Science! (Score:3, Funny)
On average, drought-stressed tomato plants made 35 sounds an hour, while tobacco plants made 11.
So, doing the math... Homer's tomacco plants make 23.
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35 + 11?
Re: Science! (Score:1)
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Well, on a first glance I can definitely say: that does not end up as 42.
I hear the screams of the vegetables... (Score:3)
Carrot juice is murder! [youtube.com]
These are the cries of the carrots. (Score:3)
To them, it is the Holocaust. [youtube.com]
Sounds as a response to attack? (Score:4, Interesting)
Most people don't spend their time listening to plants unless they are earth mother types that smoke far too much ganja while working in their organic garden. But the science is starting to show that just maybe we should start listening to our lettuce more!
Re:Sounds as a response to attack? (Score:5, Interesting)
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Plants "live in slow motion" - they have all sorts of curious behaviors when sped up, which we never notice because we live so much faster than them. But plants still could have a chemical reaction to a sound; it's certainly not beyond the realm of possibility.
If BTW anyone ever makes a device to listen for plant stress sounds - particularly if it has directionfinding and can distinguish different types of stress sounds - I am so buying it.
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Sounds like he's a scientist, to me.
You, on the other hand...
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Well that's just as fascinating as the first 89 times you told us that.
Re:Sounds as a response to attack? (Score:5, Informative)
Thank you for a comment that doesn't make lame jokes about sentient carrots or vegicide. Many of the other comments in this post misinterpret "communication" to mean deliberate, intentional, knowingly. But, communication is just the ability to transmit information from an origin to a receiving point, and that is easy enough to understand for plants.
OneoFamillion posted a response to your comment saying "I think the sound is more like wood creaking and snapping, as the microstructure of the plant changes." Exactly. Under conditions of stress such as dehydration, which the authors focused on, loss of turgor in the plant would lead to drooping or increased compliance for moving in a breeze - increased bending causing creaking. The authors themselves posit "cavitation" in the xylem as the origin. Cavitation, formation of bubbles in a fluid space, causes all kinds of noise in mechanical systems, including the popping sound when people "crack their knuckles". It is easy to appreciate that as a plant dehydrates, there is less fluid to fill the xylem. But, the xylem is rigid, thus maintaing a fixed spatial volume that a diminishing water volume must fill. Sooner or later, decreasing vapor pressure causes the fluid to cold boil, creating a vapor space that balances water volume with the spatial volume of the xylem container, each bubble formation or collapse causing micro-mechanical shock waves and vibrations.
Each plant or stem has a particular combination of materials, geometries, and mechanics. Thus, when the bubbles pop or the bends creak, multi-frequency energy is released, but there is a natural resonant frequency to the plant which filters through that primary. The plant or a part of it shakes at that frequency. If that is the natural frequency of that plant, then its neighbors, being the same species and subject to same conditions, will also have the same fundamental, so they can readily wiggle in response to the vibrations, the "sound" that their neighbor is emitting. The authors did a nice job of showing that these sounds have a certain power that allows them to be detected and transduced within such and such distance that neighboring plants or nearby insects could "hear" them. Biological systems are replete with mechanisms that transduce mechanical energy and convert that into signalling that induces a mechano-chemical response. So, one plant creates vibrational energy in response to some event. Vibrations released have the energy to induce similar motions in the surrounding space, so the plant's neighbors wiggle thereby inducing some type of internal biological response. The plants are communicating, even without any awareness or sentience of such.
People here seem to be confusing the meaning of "hearing". Our ears have a certain frequency response range, and above 20kHz or so, we cannot perceive the vibration. Other species have frequency transducers that can respond at much higher ranges. They may not perceive the vibrations as "tones" the way we think of speech and music. But, the fact that a mechanical vibrational frequency can be generated at one end, transmitted through a medium (vibration in air), then transduced at the other end is communication, aka "hearing" in biological systems. For plants, one need not invoke discussions of consciousness or intelligence. It is passive physics, which is the way a a lot of biology works.
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This sound is not voluntary, it's not from vocal chords, and it is not in response to emotions. It is the sound that is made when cells expand or contract due to availability of water. Thinking that this is emotional is about as dumb as thinking that the creaking of your old house is because it's crying.
Roald Dahl Story (Score:5, Informative)
This is the basis of a Roald Dalh story - 'The Sound Machine'. A botanist invents a machine that translates the sound of plants into speech, and it drives him insane.
https://www.youtube.com/watch?... [youtube.com]
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True enough. And this--both the claim that injured plants make sounds, and the reference in comments to this SF story--were part of a /. post several months ago. History repeats itself. Again.
Predicted in 1949, the sound machine by Roald Dahl (Score:2, Informative)
Playing music to plants (Score:2)
Is this related to certain music supposedly helping plants?
https://sciencing.com/does-mus... [sciencing.com]
Return of th Ents (Score:2)
Interesting, but not entirely new (Score:3)
One more example... (Score:1)
Oh just great (Score:2)
The real question.. (Score:2)
How does a plant produce sound? Is the sound the same per plant species? What conscious mechanism leads to the sound being produced when under stress? Or is it a byproduct of a chemical reaction? This study sounds fishy.
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Why not read the article and find out?
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Partly because the article is a typical "science journalism" summary with all the error and lack of detail attendant, but also because the researchers don't know.
One scientist suggested that the sounds are being caused by cavitation - bubbles - in the sap. In other words, plants "speak" the same way your home's plumbing "speaks" when it is short of water, or has a leak.
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Oh brother.
Try this: take a dried stick and snap it over your knee. Now take a green stick and (try to) snap it over your knee. The sound is different, right? Now let's say you wanted to start a fire - could you say which would burn better based on that sound? Easily! This is working with smaller sounds from smaller stresses, and without destroying the plant. It's structural stress, not "I'm a plant and I'm having a bad day" stress.
Of course plants make sounds when stressed (Score:3)
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This is Slashdot. No, most here have not heard the sound made by a woman's nylon stockings while they are being put on. Insensitive clod.
What we will get out of this ... (Score:2)
... is noise-cancelling to make them bitches STFU.
Latest organization (Score:1)
Roald Dahl (Score:2)
Roald Dahl was way ahead of them.
Tales of the unexpected : The Sound Machine. https://www.youtube.com/watch?... [youtube.com]
Soilent Green it is! (Score:1)
Then at least we're not harming the planet and we're solving the population explosion problem at the same time!