Singh, head of the Botany Department at India's Annamalia University, experimented with the effect of musical sounds on the growth rate of plants. He initially experimented with classical music. Later, he experimented with raga music improvisations on a set of rhythms and notes played on flute, violin, harmonium, and reena, an Indian instrument. He found similar effects. Singh repeated the experiment with field crops using a particular type of raga played through a gramophone and loudspeakers.
Through his several experiments, Singh concluded that the sound of the violin has the greatest effect on plant growth. He also experimented on the effects of vibrations caused by barefoot dancing. After exposure to dancers performed Bharata-Natyam, India's most ancient dance style, with no musical accompaniment, several flowering plants, including petunias and marigold, flowered two weeks earlier than the control.
Sir Jagadish Chandra Bose , an Indian plant physiologist and physicist, spent a lifetime researching and studying the various environmental responses of plants. He concluded that they react to the attitude with which they are nurtured. He also found that plants are sensitive to factors in the external environment, such as light, cold, heat, and noise.
In order to conduct his research, Bose created recorders capable of detecting extremely small movements, like the quivering of injured plants, and he also invented the crescograph, a tool that measures the growth of plants. From his analysis of the effects specific circumstances had on plants' cell membranes, he hypothesised they could both feel pain and understand affection.
Luther Burbank , an American botanist and horticulturist, studied how plants react when removed from their natural habitat. He talked to his plants.
Based on his horticultural experiments, he attributed approximately 20 sensory perceptions to plants. The book has short description of the experiments with a brief biography of these scientists. It should be mentioned that some, including botanists Arthur Galston and Leslie Audus, consider the book to be a piece of fiction, not science. A lot of the science in The Secret Life of Plants has been discredited but nevertheless, the book has made its mark on our minds and culture.
Some studies have found a correlation between playing music for plants and plant growth. Singh also discovered that seeds that were exposed to music and later germinated produced plants that had more leaves, were of greater size, and had other improved characteristics. It practically changed the plant's genetic chromosomes! Canby's research reinforces Singh's findings. In a experiment by Dorothy Retallack, then a student of Professor Francis Brown, three groups of plants were exposed to various types of musical sounds.
The first group died within two weeks, while the second group was much healthier than the controlled group. Fascinated by Retallack's findings, two other students went on to do their own test. Plants exposed to Haydn, Beethoven, Brahms, and Schubert grew towards and entwined themselves around the speakers. Another plant group grew away from a speaker that played rock music. That group even tried to climb a glass-walled enclosure in what appeared to be an attempt to get away from the sound.
Retallack later replicated the experiment with rock music like Led Zeppelin and Jimi Hendrix on a variety of plants. She observed abnormal vertical growth and smaller leaves.
She also observed the plants to have damage similar to that associated with excessive water uptake. In the experiment, marigolds died within two weeks. No matter which way they were turned, plants leaned away from the rock music source. One study found that plants grew away from speakers playing rock music.
Plants that are exposed to country music have the same reaction as those who are subjected to no sound at all, showing no unusual growth reaction. According to some studies, jazz music appears to have a beneficial effect, producing better and more abundant growth. The science television show MythBusters did a similar experiment and concluded that plants reacted well to any type of music, whether rock, country, jazz, or classical. Their experiments, however, were not thoroughly conducted and are highly debatable.
DeMorgenzon wine estate in Stellenbosch, South Africa, uses baroque music to enhance the ripening processl.
They believe the vibrations help not just of the plants but also in the soil and produce good fungi and bacteria in the soil that are vital for healthy vines, which encourages better and stronger root development, resulting in vigorous growth and better fruit. Many commercial growers play music for their crops, regardless of the fact that there are no reliable studies to support the idea. How could music affect plant growth if plants don't have ears? To explain how it may work, let us look at how we humans receive and hear sound.
Sound is transmitted in the form of waves that travel through a medium, such as air or water. The waves cause the particles in this medium to vibrate. When you switch on your radio, the sound waves create vibrations in the air that cause your ear drum to vibrate. This pressure energy is converted into electrical energy for the brain to translate into what you understand as musical sounds.
In a similar manner, the pressure from sound waves create vibrations that could be picked up by plants. Plants would not "hear" the music; they would feel the vibrations of the sound wave. Protoplasm, the translucent living matter of which all animals and plant cells are composed, is in a state of perpetual movement.
The vibrations picked up by the plant might speed up the protoplasmic movement in the cells. This stimulation then could affect the system and improve performance, such as the manufacture of nutrients that develop a stronger and better plant.
Different forms of music have different sound wave frequencies and varying degrees of pressure and vibration. Louder music, like rock, features greater pressure, which some people think might have a detrimental effect on plants. Imagine the effect of strong wind on a plant compared to a mild breeze. In , a hectare vineyard, DeMorgenzon wine estate in Stellenbosch, South Africa, experimented with two vineyard blocks, exposing one to baroque music and the other to no music at all.
This allowed the vineyard owner to monitor and observe any differences in the production. The musical repertoire consisted of 2, pieces of classical baroque music. With this vast collection, they could play the music nonstop for 7. Despite the outcome of the experiment by Dorothy Retallack, where plants exposed for an eight-hour period died two weeks later, the DeMorgenzon wine estate played the music around the clock with no negative results, not just in the vineyard but also in the wine cellar and tasting room.
Another vineyard, Paradiso di Frassina in Tuscany, Italy, uses classical music to get better production from its vineyards. They observed that plants mature faster when exposed to the soothing sounds of Mozart, Vivaldi, Haydn, and Mahler when compared to a controlled site.
This project to wire the vineyard for musical sound started in as an attempt to keep pests away. However, when they saw better and improved plants and fruits, the project continued as a 'productivity tool'. Just like DeMorgenzon wine estate, the music is played non-stop 24 hours a day with no negative results. In both of these vineyard examples, there were no negative results noticed after extensive exposure to music, and the benefits of the music remain anecdotal.
But there are sounds that, at least theoretically, it could be advantageous for them to hear. If so, you're not alone. It is true that the positive effects of music on plant growth is still highly debated among scientists.
Because the scientific community only values results that can be repeated, and thereby verified, there are many skeptics who regard the studies mentioned above as bad science since most of them were unreplicable, meaning that when others tried to re-do the study as described, their results did not match those of the original study.
If a study's results are not scientifically significant or can't be supported by independent verification and replicable studies, they are no longer considered relevant. In some cases, upon further analysis, the original studies themselves were found to be faulty. It was reported in the The Telegraph that scientists from National Institute of Agricultural Biotechnology in Suwon, South Korea, played classical music in rice fields, and concluded that plant genes can "hear" and had improved yield.
The research was published in the August, issue of New Scientist. Levels of mechano-stimulus responsive, signaling-related, redox homeostasis, and defense-related transcripts are changed in sound-exposed plants Ghosh et al. However, the specific organs or proteins used for sound perception have not yet been identified. How can plants perceive sound and thereby respond to specific stress stimuli without a hearing organ?
The roots of Zea mays were reported to bend toward sound with a frequency of — Hz among the tested frequencies of 0— Hz in the hydroponic system Gagliano et al.
Even small environmental stimuli such as touch or wind alter the transcriptional levels of plants. A recent study described commonalities and differences between responses to sound and mechanical vibrations at the gene expression level.
Expression of some genes e. This supports the notion that sound vibrations provide a special stimulus to plants, unlike mechanical vibrations. In addition, sound vibration increased the rate of growth by changing the cell metabolism of yeast, but reduced biomass production. Theses result imply that sound affects the cell level rather than the specific structure of the organism Aggio et al.
Here, we focus on recent findings about plant responses to sound treatment based on transcriptome and proteomics technology Figure 1B. Although sound is not a visible or chemical stimulus, plants exposed to sound a physical force produce increasing amounts of mRNA Ghosh et al.
Indeed, two genes, the fructose 1,6-bisphosphate aldolase ald and Rubisco small sub-unit rbcS genes, which play critical roles in photosynthesis, were specifically induced in rice following and Hz sound treatment Jeong et al. Continuous exposure to sound is thought to enhance plant growth by promoting CO 2 fixation Uematsu et al.
These findings can be attributed to sound-mediated photosynthesis-related gene expression and increased CO 2 fixation. A similar study showed that the expression of genes in the Gene Ontology categories mechano-stimulus responsive, signaling related, redox homeostasis, biosynthesis, and defense increased in response to exposure to Hz sound waves in Arabidopsis Ghosh et al. These results imply that sound vibrations provide a stimulus to plants. More extensive research is needed on the function of the identified genes and the signaling network.
In fact, plant hormone signaling networks are already beginning to be elucidated. Plant hormones typically regulate plant cellular processes and orchestrate most aspects of plant physiology including plant growth, flowering, ripening, senescence, and defense responses Hou et al.
Recent studies showed that, in Arabidopsis , treatment with Hz sound induces the production of the growth-related hormones indoleacetic acid IAA and gibberellin GA 3 and the defense-related hormones salicylic acid SA and jasmonic acid JA Ghosh et al. Although the optimal sound treatment differs depending on the plant species, such sound-induced hormonal changes might increase plant growth and provide strong resistance against biotic or abiotic stress.
A recent study reported that plant roots can respond to environmental sound Gagliano et al. Specifically, Pisum sativum roots locate water by actively growing toward flowing water belowground Gagliano et al. This implies that plants also respond to natural sound in the environment. As mentioned above, plants appear to perceive sound, as they exhibit transcriptional and hormonal changes in response to sound wave treatment.
Next, we provide an overview of the implications of sound wave treatment in the field or growth room. Based on this information, we discuss the expansion of the use of sound in modern agriculture and plant biology. Exposing plants to sound activates plant innate immunity and more specifically elicits representative SA and JA defense signaling pathways similar to those observed in response to different chemical triggers Ghosh et al. Meta-analyses have demonstrated the occurrence of sound-mediated plant protection through the activation of the systemic immune response in crop plants such as pepper, cucumber, tomato, and strawberry Hou et al.
These ions might serve as secondary messengers upon exposure to environmental stress, thereby enhancing plant resistance against microbial pathogens. Arabidopsis calmodulin-like 38 CML38 gene, which encodes a calcium-binding messenger protein, is upregulated in response to sound treatment in Arabidopsis leaves Ghosh et al. In addition, membrane architecture changes in response to sound treatment, which may facilitate the movement of signaling components related to defense responses Mishra et al.
In addition to biotic stress responses, sound treatment increases plant tolerance to abiotic stresses such as drought. For example, rice exposed to 0. Water deficiency is first detected in the plant root, and drought stress signaling is transmitted to the shoot through the xylem.
Since membrane architecture changes in response to sound treatment, the plant is better able to absorb water in situations where water is lacking. Furthermore, among hormones, ABA is the most important regulator of the plant response to abiotic stress, especially osmotic stress Kim et al.
Consequentially, sound waves may be involved in both abiotic and biotic stress responses through the regulation of various plant hormones. Sound waves as a plant stimulant and protectant. Artificial sound treatment can elicit various effects in plants. First, enhancement of seed germination and plant growth. Sound promotes plant growth by regulating the plant growth hormones indoleacetic acid IAA and gibberellin Bochu et al.
Second, induction of plant defense responses against pathogens. Sound pretreatment enhances plant immunity against subsequent pathogen attacks by activating the plant defense hormones salicylic acid SA and jasmonic acid JA Hassanien et al. Third, induction of abiotic stress tolerance. For instance, sound treatment triggers drought tolerance by changing the elasticity and flexibility of the cell wall, which affects the ability of plants to absorb water Jeong et al.
Fourth, perturbation of ripening. Sound treatment disrupts the ripening of tomato fruit. Ethylene production is delayed by down-regulation of ethylene biosynthesis and expression of signaling-related genes Kim et al. Fifth, enhancement of the photosynthetic capacity. Sound treatment increases expression of photosynthesis-related genes, such as those encoding fructose 1,6-bisphosphate aldolase and the rubisco small sub-unit, and may induce CO 2 fixation Jeong et al.
Fruit ripening is associated with dramatic increases in ethylene production after harvest. Reducing ethylene production is an important way to delay fruit ripening. We previously showed that sound-treated tomato showed reduced ethylene production and delayed softening compared with the control Kim et al. The expression of genes encoding transcription factors RIN and HB-1, which control the expression of ethylene-related genes, was also affected in tomato treated with sound stimuli Kim et al.
Exposure to 1 kHz sound induces tomato fruit to remain firm for longer Kim et al. Although the optimal sound conditions frequency and decibels must be determined depending on crop species, the use of sound wave treatment would be a convenient way to delay fruit ripening without the use of chemical preservatives or genetic modification. In addition to delaying fruit ripening, perhaps the quality and yields of post-harvest crops can be improved by sound treatment.
Sound treatments have been broadly applied to alter plant growth. More info. Donate Join Tickets. California Academy of Sciences. Toggle Close. Search calacademy. Plants are surprising organisms—without brains and central nervous systems, they are still able to sense the environment that surrounds them.
If plants have similar receptors, they too could respond to the changes in sound waves, such as those from music. Plants also seem to listen to the vibrations of one another. Plants that are near other plants tend to grow faster and healthier than those grown in isolation. Other research indicates that vibration from sounds such as music can turn genes on and off, indicating that plants may "listen" to their surroundings to know when to express certain genes.
If scientists can gain a better understanding of this phenomenon, it is likely that sounds such as music could be used to promote growth.
Other evolutionary considerations may have caused plants to develop the ability to sense sound waves. Studies indicate that plants can feel the vibrations of insects eating leaves, and that plants may communicate danger to other plants.
The other plants then know to ready their defenses, or even stop growing until it is safe.
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