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Abstract
The acoustic frequency technology is to treat the plant with a specific frequency sound wave. Acoustic studies have found that plants can produce low frequency sound spontaneously. With the addition of the technology, the specific frequency sounds to make a match-absorption and resonance on the target plants. Thus, the technology strengthens photosynthesis and speeds of cell split and makes plant grow and develop faster. Treated plants are blooming and bearing fruits ahead of time. Acoustic frequency technology was applied to sweet pepper, cucumber and tomato in greenhouse. Various controlled experiments were made and all results indicted that the technology could increase the output of vegetables notably, improve crops quality, strengthen the capability of disease-resistance. The yields of treated sweet pepper, cucumber and tomato were 63.05%, 67.1% and 13.2%, respectively higher than that of control group. Moreover, the incidence of treated tomato disease decreased by 6, 8, 9, 11 and 8 percentage points, respectively, including red spider, aphids, grey mold, late blight and virus disease.
... 9 Hou et al. showed that sound waves with different frequencies, sound pressure level (SPL), stages of exposure and distance from the source, could affect plant growth. 10 The experiments were performed in open media as well as under glasshouse growth conditions with different levels of audio frequency range, and a SPL about 80 dB. The treated plants included pepper, cucumber and tomatoes. ...
... The results showed that this technology could specifically increase vegetable production, improve product quality, and strengthen disease resistance. 10 As the world's most expensive agricultural and medicinal product, saffron (Crocus sativus L.) is rich in apocarotenoids that have been known for their anti-cancer and anti-tumour effects. Saffron stigma also contains many compounds including carbohydrates, proteins, fats, vitamins, minerals (such as calcium, magnesium, iron, phosphorus, potassium, sodium, and zinc) and pigments. ...
... Picrocrocin analysis was performed with the eluents of water solvent system (solvent A) and acetonitrile (solvent B) at 30 C.The used programmed gradient was: 80% A, 0-5 min; 80 to 20% A, 5-15 min; and 20% A, 15-20 min with a flow rate of 0.8 mL/min.26,27 In case of safranal, 10 mg of standard of safranal was dissolved in 1 mL methanol and desired dilutions(10,20,30,40 and 50 mg/L) were made. HPLC analysis of safranal was performed the same as picrocrocin.28 ...
Introduction:
Plant acoustic frequency technology (PAFT) is the effect or treatment of a plant with a specific frequency sound wave.
Objective:
The sound waves with different frequencies and a sound pressure level 77 dB were emitted on the saffron corms in a controlled environment using aeroponic cultivation and the contents of crocin, picrocrocin and safranal in their produced stigmas were analysed by high-performance liquid chromatography. For this purpose, the corms were divided into two groups. In group 1, sound waves with the frequencies of 0.5, 1 and 2 kHz were emitted on saffron corms in different stages of sprouting, flowering and the whole stage of sprouting and flowering. In group 2, sonication was performed on the corms during the flowering stage at 4, 8, 12 and 16 kHz frequencies.
Results:
The changes in the contents of crocin, picrocrocin and safranal were not significantly compared to the control at 0.5, 1 and 2 kHz frequencies in the stages of sprouting and flowering of corms. While the higher frequencies (4, 8, 12 and 16 kHz) in flowering stage were affected significantly, the crocin and picrocrocin content increased 8.5% and 30%, applying the frequency of 12 and 8 kHz, respectively. Also, the effect of sound exposure time per day with the frequency of 16 kHz at 15, 30 and 60 min were investigated.
Conclusion:
The findings showed that the corms could be affected by sounding in the different stages of growth of the corm and also in the content of secondary metabolites.
... Shoot 500 80 1 h Ghosh et al., 2016 Cotton Increased yield Shoot 100-1000 70 3 h (every other day) Hassanien et al., 2014 Cucumber Increased yield Shoot 100-1000 70 3 h (every other day) Hassanien et al., 2014 Chrysanthemum Changes in hormone levels Mature callus 1400 95 1 h Bochu et al., 2004 Increased levels of soluble proteins ripening, senescence, and defense responses ( Hou et al., 2009;Qi et al., 2009;Hassanien et al., 2014;Kim et al., 2015). Recent studies showed that, in Arabidopsis, treatment with 500 Hz sound induces the production of the growth-related hormones indole3-acetic acid (IAA) and gibberellin (GA) 3 and the defenserelated hormones salicylic acid (SA) and jasmonic acid (JA) ( Ghosh et al., 2016). ...
... 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., 2016). 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., 2009;Chowdhury et al., 2014;Mishra et al., 2016;Choi et al., 2017) ( Figure 2). The Ca 2+ ions influx the cytosol from outside the plants membrane by 1000 Hz sound exposure. ...
... Sound treatments have been broadly applied to alter plant growth. For example, sound-treated tomato showed 13.2% increased yields compared with the control ( Hou et al., 2009). In contrast, high-frequency, high-decibel sound damages cells ( Bochu et al., 1998). ...
Sound is ubiquitous in nature. Recent evidence supports the notion that naturally occurring and artificially generated sound waves contribute to plant robustness. New information is emerging about the responses of plants to sound and the associated downstream signaling pathways. Here, beyond chemical triggers which can improve plant health by enhancing plant growth and resistance, we provide an overview of the latest findings, limitations, and potential applications of sound wave treatment as a physical trigger to modulate physiological traits and to confer an adaptive advantage in plants. We believe that sound wave treatment is a new trigger to help protect plants against unfavorable conditions and to maintain plant fitness.
... Plants exposed to sound were found to activate innate immunity and more specifically JA and SA defense pathways . Multiple plant species such as pepper, tomato, cucumber and strawberry exposed to sound showed enhanced systemic defense response (Choi et al., 2017;Hou et al., 2009;Qi et al., 2009). ...
... Exposure to classical music was found to improve the quality of grapevine by altering its native microbiome (Wassermann et al., 2021). In case of plants, sound exposure results in increase in certain phytohormones, enzymes and metabolites that imparts tolerance to various biotic and abiotic stresses (Appel and Cocroft, 2014;Bhandawat et al., 2020;Ghosh et al., 2016;Hou et al., 2009;López-Ribera and Vicient, 2017;Mishra et al., 2016). Thus, sound therapy holds an open opportunity in the recovery of stressed plants and increasing their survival rates. ...
Sound plays a critical role in all life forms in one way or the other. Higher organism such as vertebrates have evolved sophisticated auditory organs to perceive as well as emit specific range of sound frequencies. Extensive studies have been done on implication of sound in animal kingdom. Plants at the other side lack specialized organs for the same, which makes them mysterious as well as interesting subjects. In recent years significant advancement has been made towards understanding of sound emission and perception in plants. Through this review an attempt is made to unveil the current advancements in plant acoustics, its significance in overcoming the environmental challenges, biotic threats, facilitating pollination, inter-kingdom communication for mutual benefits and learning by association. Along with this, the application of sound in boosting plant growth, yield, enhancing functional metabolite production, evading pests and postharvest management has been emphasized. In this respect, several examples are presented to strengthen our understanding of plant responses to sound at behavioural, physiological and molecular level. At last, in the light of existing knowledge, we discuss current challenges in plant acoustic research, ecological hazards associated with artificial sound wave treatments and plausible ways alleviate it.
... A wellestablished behavioral response of sound is bending of Pisum sativum roots toward flowing water playback sound [5]. Application of defined frequency of sound waves to improve various agronomic traits like germination rate [9], growth [10], and stress tolerance [6] has been documented. But the use of artificial sound/ music for conditioning (defensive) plants to environmental stress remains elusive. ...
... Surprisingly, all the heatresponsive genes showed varied degree of up-regulation after music treatment (S9) compared to (S8; Figure 2). There are reports that suggest plants perceive high intensity sounds (>80dB) and elicit specific response such as seedling growth in Arabidopsis (Johnson et al. 1998) and stress tolerance in many plants [6,10]. However, this study suggests even lower intensity sound (50 dB), is capable to impart an advantage to the plant as evident from up-regulation of heat-responsive genes. ...
Plants are analogous to animals by responding physiologically and phenotypically to environmental changes. Until recently, the meaning of sound in the plant’s life remains undiscovered. In this study, we investigated the role of music in response to heat stress and its application in memory and associative learning for stress tolerance in Arabidopsis. Significant upregulation of heat-responsive genes (HSFA3, SMXL7, and ATHSP101) in response to music suggests music has an advantage during heat stress. Moreover, the defensive conditioning experiment showed that plant learns to associate music with stress (heat) and elicit better response compared to music alone. Two heat-responsive genes, HSFA3 and ATCTL1, which are well known for their interaction and regulation of an array of heat shock proteins were found to play a key role in associative learning for heat stress in Arabidopsis. Our experiment highlights the application of sound in plant conditioning and as a stress reliever. Nonetheless, the persistence of memory awaits further experiments. We foresee the potential of artificial sound as an environment-friendly stimulus in conditioning the crops for upcoming stresses and reduce the yield loss, as an alternative to breeding and genetic modifications.
... Moderate sound stimulation can increase the activity of ATP synthase and is conducive to the level of energy metabolism of plants (Yang Xiaocheng et at., 2003;Yang Xiaocheng et at., 2007). By using QGWA-03 plant audio apparatus (frequency range: 100-2000Hz), tomato's yield increased by 13.2%, and its disease of grey mold decreased by 9.0% (Hou Tianzhen et at., 2009). At present, the sound wave stimulation studies on the impact of plants are increasing, but the sound effect and mechanism are still controversial. ...
... We did the pre-test by using the He-Ne laser Doppler vibrometer to measure the sound frequency of Alocasia, and found that in normal growth conditions, plants' spontaneous sound frequency was in low-frequency range of 40-2000Hz (Luan Jiyuan, et at., 1995;Hou Tianzhen, et at., 1994). At the same time, we used low-frequency sound waves to stimulate more than 50 kinds of crops, and achieved remarkable effects (Hou Tianzhen, et at., 2009). To sum up, we believe that the mechanism of sound effect to plants can be explained in two ways. ...
In this paper, we adopt the QGWA-03 plant audio apparatus to investigate the sound effects on strawberry in the leaf area,
the photosynthetic characteristics and other physiological indexes. It was found that when there were no significant differences
between the circumstances of the two sunlight greenhouses, the strawberry after the sound wave stimulation grew stronger than
in the control and its leaf were deeper green, and shifted to an earlier time about one week to blossom and bear fruit. It
was also found that the resistance of strawberry against disease and insect pest were enhanced. The experiment results show
that sound wave stimulation can certainly promote the growth of plants.
Keywordsenvironmental factors-sound wave stimulation-sunlight greenhouse-strawberry
... It has been hypothesized that sound increases growth in plants, and some companies even use a growth system that incorporates sound to try to increase growth. Studies have been done on the use of music to improve crop yield and quality in plants such as tomato plants (Hou and Mooneyham, 1999), barley (Xiao, 1991), and vegetables (Hou et al., 2009); Hou et al. (2009) used audible sound waves to stimulate more than 50 different crops, and achieved remarkable effects. This field of science is known as acoustic biology. ...
... It has been hypothesized that sound increases growth in plants, and some companies even use a growth system that incorporates sound to try to increase growth. Studies have been done on the use of music to improve crop yield and quality in plants such as tomato plants (Hou and Mooneyham, 1999), barley (Xiao, 1991), and vegetables (Hou et al., 2009); Hou et al. (2009) used audible sound waves to stimulate more than 50 different crops, and achieved remarkable effects. This field of science is known as acoustic biology. ...
There are studies indicate that audible sound wave could have effects on propagation growth through catalyzing hearing sense organs, which would bring a series of physiological and biological chemistry reaction. The sound-pressure level and frequency are important factors in propagation growth. In this study, an experimental system of audio generator was developed for investigating sound wave effect on propagation growth promotion, and an embedded development platform based on ARM+DSP+FPGA was built for the system. The DDFS(Direct Digital Frequency Synthesis) method was used to make various waveforms in the system. A feedback analysis networks was added in the system for reliable output of sound waves. Results show that the audio generator system can produce sound waves with frequency of 20 Hz~20,000Hz accurately and make octave analysis of the sound in experimental environments. The new-type audio generator system will facilitate scientific researches on the field of acoustic biology.
... QGWA-03 plant sound device (frequency range: 100-2000 Hz), tomato yield increased by 13.2% and gray mold disease decreased by 9.0% (Tianzhen et al., 2009). In a study, five different types of music (Indian classical music, Vedic chants, Western classical music and rock music) were played to the rose (Rosa chinensis) for 1 hour each in the morning and after sunset for 62 days. ...
The effect of music on people has been known for years and is still being researched from different aspects. The effects of music and sound waves on ornamental plants, whose effects on some vegetables, fruits and grains are examined, are also inquired. Especially the positive change in the development and showiness of the flowers of ornamental plant species with commercial importance will increase the market value of the plant. Again, with the effect of this sound wave, in order for the plants and their flowers to show the expected development, they should benefit from the planting environment and growing conditions at the maximum level. In the measurements taken from hyacinths (Hyacinthus orientalis L.) at the end of the duration that the plants were exposed to different types of sounds in different intensities, it was observed that these factors positively affected these parameters successively; 1 hour of bird sound in 50 dB, the number of leaves; 1 hour of bird sound in 90 dB, leaf width and floret length; 3 hours of bird sound in 70 dB, floret number; 3 hours of bird sound in 90 dB, the plant and flower height; 1 hour of bee sound in 50 dB, the stem thickness; 3 hours of vehicle sound in 50 dB, flower and floret width; 3 hours of vehicle sound in 70 dB, leaf length. At the end of the study, whereas it was determined that the bee sound had the least effect on the growth and flowering of the hyacinth, it was observed that the bird and vehicle sounds, that the plants were expose to in different intensities and durations, had a positive effect.
... Recently plant acoustic frequency technology (PAFT) is being used to treat plants with an intermittent pulse of sound frequency with specific intensity. By applying PAFT treatment a significant increase in biological responses have been found in various fruits and vegetables (Meng et al., 2012a;Hou et al., 2009). The application of PAFT in greenhouses also had enhanced yields of vegetables with increased disease resistance capacity (Jiang and Huang, 2012). ...
Plants are highly sensitive organisms and can indeed benefit from specific sound signals in multi-layered processes. Scientific evidences have shown the potential applications of sound wave treatment in plant biology. However, there are some limitations to sound wave treatment that must be overcome. We still do not understand how do plants initially perceive and recognize sound signals, which is very critical to maximize the effectiveness of the use of sound treatment from practical viewpoint. Proper setup of sound treatment equipment and detailed understanding and evaluation of the effects of selected frequencies and intensities along with sound exposure times are also very crucial during sound treatment. More experimental studies with different models need to be done in a multidisciplinary approach toward establishing suitable mechanism for sound treatment application in agriculture production. The aim of this paper is to provide an overview of findings associated with potential effects of audible sound waves including music on different biological, physiological and biochemical processes in plants.
... The 'organ' responding to sound has not been identified in plants but may be a systemic response to vibrational waves through liquids in the plant as discussed above. A table in Jung et al. (2018) lists the results of studies on thirteen different plants and fruits, where effects range from yield changes and delayed ripening in tomatoes (Hou et al. 2009;Hassanien et al. 2014;Kim et al. 2018) to effects on photosynthesis (Kwon et al. 2012;Hassanien et al. 2014). Kim et al. (2018) later linked the tomato delayed ripening effects to regulation of both coding and non-coding RNAs and transcription factor genes. ...
https://www.tandfonline.com/doi/full/10.1080/09553002.2020.1834162
... The assimilation rate for plants stimulated with 350 Hz (60 dB) is the greatest compared to other treatments, including the control (Figure 4a). The current finding contradicts those of Hou et al. (2009), who reported that when using four speakers as sound wave treatment at a different planting distance in cotton, the minimum yield was obtained in plants grown at a relatively far distance (30 m) with a sound wave intensity range of 75-110 db. Evidence from another study showed that net photosynthesis measured weekly in strawberry plants treated with sound waves of 100 dB and a frequency of 40-2,000 Hz was not significant compared to the control (no sound wave), except during the fourth sound stimulation. ...
Various attempts have been made to increase rice production, including breeding for high-yielding and stress-tolerant varieties, a good crop management system, and increased agricultural input in rice production. Soundwave stimulation has been demonstrated to affect plant growth; thus, this method can be employed in the current rice production methods to improve yield. The study aims to determine the effects of different sound wave qualities on the general growth, physiological, and morphological of rice seedlings. Rice seeds of the MR219 variety were grown under a glasshouse condition in a nested design with five replications and were stimulated with various sound wave frequencies. Various sound wave frequencies, 380, 359, 357, 353, and 350 Hz, were obtained by placing the pot at varying distances (80, 160, 240, 320, and 400 cm, respectively) from the sound source, except control treatment. There were significant effects in some of the parameters: plant height, leaf physiology, and stomatal pore and length when treated with varying sound wave qualities. Plants can be stimulated with 380, 357, and 350 Hz soundwaves frequencies for the best 440 Pertanika photosynthetic experience. In addition, 359 Hz of sound wave stimulation resulted in high water use efficiency, which is beneficial in improving crop performance in drought conditions. Thus, it was demonstrated that the sound wave stimulation method has the potential to enhance rice performance in addition to the regular agronomic practices of rice production in farmers' fields.
... The assimilation rate for plants stimulated with 350 Hz (60 dB) is the greatest compared to other treatments, including the control (Figure 4a). The current finding contradicts those of Hou et al. (2009), who reported that when using four speakers as sound wave treatment at a different planting distance in cotton, the minimum yield was obtained in plants grown at a relatively far distance (30 m) with a sound wave intensity range of 75-110 db. Evidence from another study showed that net photosynthesis measured weekly in strawberry plants treated with sound waves of 100 dB and a frequency of 40-2,000 Hz was not significant compared to the control (no sound wave), except during the fourth sound stimulation. ...
Various attempts have been made to increase rice production, including breeding for high-yielding and stress-tolerant varieties, a good crop management system, and increased agricultural input in rice production. Soundwave stimulation has been demonstrated to affect plant growth; thus, this method can be employed in the current rice production methods to improve yield. The study aims to determine the effects of different sound wave qualities on the general growth, physiological, and morphological of rice seedlings. Rice seeds of the MR219 variety were grown under a glasshouse condition in a nested design with five replications and were stimulated with various sound wave frequencies. Various sound wave frequencies, 380, 359, 357, 353, and 350 Hz, were obtained by placing the pot at varying distances (80, 160, 240, 320, and 400 cm, respectively) from the sound source, except control treatment. There were significant effects in some of the parameters: plant height, leaf physiology, and stomatal pore and length when treated with varying sound wave qualities. Plants can be stimulated with 380, 357, and 350 Hz soundwaves frequencies for the best photosynthetic experience. In addition, 359 Hz of sound wave stimulation resulted in high water use efficiency, which is beneficial in improving crop performance in drought conditions. Thus, it was demonstrated that the sound wave stimulation method has the potential to enhance rice performance in addition to the regular agronomic practices of rice production in farmers’ fields.
... The 'organ' responding to sound has not been identified in plants but may be a systemic response to vibrational waves through liquids in the plant as discussed above. A table in Jung et al. (2018) lists the results of studies on thirteen different plants and fruits, where effects range from yield changes and delayed ripening in tomatoes (Hou et al. 2009;Hassanien et al. 2014;Kim et al. 2018) to effects on photosynthesis (Kwon et al. 2012;Hassanien et al. 2014). Kim et al. (2018) later linked the tomato delayed ripening effects to regulation of both coding and non-coding RNAs and transcription factor genes. ...
Objectives: This commentary reviews and evaluates the role of sound signals as part of the infosome of cells and organisms. Emission and receipt of sound has recently been identified as a potentially important universal signalling mechanism invoked when organisms are stressed. Recent evidence from plants, animals and microbes suggests that it could be a stimulus for specific or general molecular cellular stress responses in different contexts, and for triggering population level responses. This paper reviews the current status of the field with particular reference to the potential role of sound signalling as an immediate/early bystander effector (RIBE) during radiation-induced stress.
Conclusions: While the chemical effectors involved in intercellular and inter-organismal signalling have been the subject of intense study in the field of Chemical Ecology, less appears to be known about physical signals in general and sound signals in particular. From this review we conclude that these signals are ubiquitous in each kingdom and behave very like physical bystander signals leading to regulation of metabolic pathways and gene expression patterns involved in adaptation, synchronisation of population responses, and repair or defence against damage. We propose the hypothesis that acoustic energy released on interaction of biota with electromagnetic radiation may represent a signal released by irradiated cells leading to, or complementing, or interacting with, other responses, such as endosome release, responsible for signal relay within the unirradiated individuals in the targeted population.
... In addition, exposure of Arabidopsis plants to 500 Hz of SV has been shown to increase the production of plant defense-related hormones such as salicylic acid and jasmonic acid (Ghosh et al., 2016). In tomato (Solanum lycopersicum), 0.08-2 kHz SV treatment decreases the population of multiple pests and pathogens, including spider mites, aphids, viruses, and gray mold, in the greenhouse (Tianzhen et al., 2009;Hassanien et al., 2014). ...
Sound vibration (SV) is one of the several environmental stimuli that induce physiological changes in plants including changes in plant immunity. Immune activation is a complicated process involving epigenetic modifications, however, SV-induced epigenetic modifications remain unexplored. Here, we performed an integrative analysis comprising chromatin immunoprecipitation (ChIP) and microRNA sequencing (miRNA-seq) to understand the role of SV-mediated epigenetic modifications in immune activation in Arabidopsis thaliana against the root pathogen Ralstonia solanacearum. Plants exposed to SV (10 kHz) showed abundant H3K27me3 modification in the promoter regions of aliphatic glucosinolate biosynthesis and cytokinin signaling genes, leading to transcriptional changes that promote immunity. Additionally, 10 kHz SV down-regulated miR397b expression, thus activating three target LACCASE transcripts that mediate cell wall reinforcement via lignin accumulation. Taken together, SV triggers epigenetic modification of genes involved in secondary metabolite biosynthesis, defense hormone signaling, and pre-formed defense in A. thaliana, leading to the activation of plant immunity against R. solanacearum.
... The treated strawberries with the PAFT were grown stronger than the control group and had significantly higher resistance against disease and insects (Qi et al., 2010) [101] . [51,24,91,23] . SVs have been found to exhibit increased immune responses against plant diseases and insect pests, for instance, the spread of sheath blight in rice has been found to be reduced by 50% as a result of SV treatment (Hassanien et al., 2014) [47] . ...
Like other environmental factors, Sound vibrations also reported to greatly influence the plants at physical, biochemical and gene level. Based on relevant literature, this manuscript discusses the influence of Sound vibration in stimulating various growth and developmental parameters in plants like seed germination, root elongation, photosynthesis, nutrient uptake, yield, post harvest shelf-life, and also highlights various researches carried out to support influence of acoustic frequencies in defense, metabolism, cell cycle, and production of secondary metabolites, hormones and enzymes. Application of wide range of sound frequencies, infrasonic to ultrasonic, could provide myriad possibilities in advancement of future agriculture; however, a more comprehensive knowledge on signalling and regulation mechanisms is required to exploit the full potential.
... It is remarkable that AE has an impact over phytohormones and these compounds are responsible for biomass production as regulators of downstream signaling cascades throughout a plant's life cycle in growth, flowering, ripening, senescence, and defense responses (Hou et al. 2009). Also, it has been reported important bioactivities of these plant hormones in human health (Chanclud and Lacombe 2017). ...
Plants are the main source of secondary metabolites, which can be used in different sectors such as pharmaceutics, food, cosmetics, agriculture, etc. turning them into an attractive source of income. Primary metabolites (carbohydrates, lipids, and proteins) have been linked to vital processes such as growth, development, and fruiting, while the secondary metabolites (phenols, flavonoids, and carotenoids, to name a few) are the result of adaptation and evolution of the plants with respect to changes in the environment. Therefore, it can be said that the secondary metabolites are secreted when the plant is under biotic and abiotic stresses. These secondary metabolites possess several bio-active functions and, hence, are well recognized for industrial applications. Due to difficulties for extracting these natural plant bio-active compounds, they are usually produced alternatively through plant cell/tissue culture methods. Further, several approaches, such as the use of plant and tissue cell cultures, the application of metabolism-inducing factors or elicitation, control of biological factors, such as intensity of light, induction by sound waves, and application of nanoparticles are used to alter/enhance in vitro production of these bio-active metabolites. Overall, these approaches interact with the biochemical routes of the plant either in positive or negative ways to produce secondary metabolites in high quantities. Although there is information on this aspect, the effect of these strategies cannot be generalized, since it has been observed that the metabolism of the plant response depends on the study model, the concentration and time of use of the stimulus, as well as its nature. Considering the above facts, this chapter discusses on the most current strategies for the production of secondary metabolites in plants in a continuous and reliable manner.
... Some of the studies experimented in the range from 1000 Hz to 2500 Hz which showed the different ways plants reacted to different frequencies [1]. Studies have also showed that the use of music improves crop yield and quality in plants such as tomato, vegetables, and barley [2][3][4] used audible sound waves to stimulate more than 50 different crops and studies its effects. ...
This research studied the interactions and effects of low-frequency audible sound waves with the germination and growth of pea seeds. Experiments were conducted in 3 aspects, seed germination time, weight gain of seeds and stem elongation. It was identified that the frequency range from 660Hz to 680Hz has detrimental effects on germination, weight gain and stem elongation. It was also found that the radiation has direct effects on the production of enzymes in the plant system namely alpha-amylase
... Some of the studies experimented in the range from 1000 Hz to 2500 Hz which showed the different ways plants reacted to different frequencies [1]. Studies have also showed that the use of music improves crop yield and quality in plants such as tomato, vegetables, and barley [2][3][4] used audible sound waves to stimulate more than 50 different crops and studies its effects. ...
This research studied the interactions and effects of low frequency audible sound waves with the germination and growth of pea seeds. Experiments were conducted in 3 aspects, seed germination time, weight gain of seeds and stem elongation. It was identified that the frequency range from 660 Hz to 680 Hz has detrimental effects on germination, weight gain and stem elongation. It was also found that the radiation has direct effects on the production of enzymes in the plant system namely alpha amylase.
Keywords: Sound waves; Growth reduction; Frequency resonance; Seed storage; Enzyme inhibition
... Along these same lines, Takikawa et al. (2016) described an electrostatic nursery shelter that successfully caught M. persicae. Another study applied low-frequency acoustic signals to tomato and found that this increased yield, improved crop quality, and had a reduced incidence of infestation by aphids (Hou et al., 2009). Further research with sound wave technology has been shown to stimulate plant growth of a variety of vegetable crops, including tomato (Hassanien et al., 2014). ...
... In previous research, effect of physico-stimulation such as addition of audible sound in plant growth has been performed by several researchers (Cai et al., 2014;Creath and Schwartz, 2004;Gu et al., 2013;Hassanien et al., 2014;Hou and Mooneyham, 1999;Hou et al., 2009). For microalgae experiment, Jiang et al. (2012) conducted the audible sound effect experiment on chlorella and Cai et al. (2016) conducted on Picochlorum oklahomensis. ...
Physico-stimulant like audible sound is one of the new promising methods for enhancing microalgae growth rate. Here, microalgae Haematococcus pluvialis was cultivated with the addition of audible sound with titles “Blues for Elle” and “Far and Wide.” The objective of this research was to evaluate the effect of audible sound to the growth and productivity of microalgae. The experiment has been conducted by exposing the audible sound for 8 h in 22 days to microalgae cultivation. The result showed that microalgae H. pluvialis treated by the music “Blues for Elle” shows the highest growth rate (0.03 per day), and 58% higher than the one without audible sound. The average number of cells in stationary phase is 0.76 × 10⁴ cells/mL culture and the productivity is 3.467 × 10² cells/mL/day. The pH of microalgae medium slightly decreases because of proton production during photosynthesis process. The kinetic rate constant (kapp) is 0.078 per day, reaction half-life (t1/2) is 8.89 days, and catalytic surface (Ksurf) is 1.66 × 10⁻⁵/day/cm². In conclusion, this audible sound is very useful to stimulate microalgae growth rate, especially H. pluvialis.
... (Niklas 1998). Conversely, stimulation by pure-tone airborne sound reportedly increased yield and various physiological parameters in several species of crop plants (Tianzhen et al. 2009;Lirong et al. 2010), although this phenomenon is still controversial. Other beneficial organisms include natural enemies of pests, such as spiders, with IPM methods actively promoting their abundance (Sunderland and Samu 2000;Landis et al. 2005). ...
Widespread use of substrate-borne vibrational signals by insects presents a unique opportunity to develop alternative methods of pest control, enabled by better understanding insect behaviour and advances in technology. One such method is currently under development for use against the invasive leafhopper Scaphoideus titanus, a vector of Flavescence dorée in European vineyards. Basic understanding of the vector’s sexual behaviour and observations of naturally occurring antagonistic interactions between males enabled development of vibrational broadcasts that obscured signal characteristics important for mate recognition and localization in small-scale field tests. The naturally occurring antagonistic interactions constitute acoustic noise that can be characterized, adjusted and broadcasted using modified acoustic technology. Steps in development of this technology to maximize reliability and energy efficiency are outlined, as well as plans for large-scale field testing and future perspectives. While several specific factors work in favour of using vibrational disruption in the system S. titanus (pest) and grapevine (host) and possibilities of direct transfer to other systems are limited, success of this approach is nevertheless hoped to stimulate the development of vibrational playback in general for control of other insect pests.
... last accessed 2015) in Florence appeared to confirm this. That is not to say that sound does not affect plants; in fact several experiments strongly suggest that they do [22] [23] but a thorough investigation into this phenomena would involve testing thousands of species and is beyond the scope of the current work. ...
This paper discusses a series of sound installations that combine plant electrophysiology with 3D sonic art. A brief introduction to plant electrophysiology is given. The sonification of electrophysiological signals in the mycorhizzal network is discussed explaining how art and science are combined in this project in a way that differs from simply the sonification of data. Novel 3D audio spatialization techniques, the 3D audio mapping of natural environments and immersiveness are also discussed, along with some technical details of how to read the electrical signals in plants known as action potentials. Other topics which are addressed include, acoustic signaling in the forest, spectral composition and interaction with forest flora and fauna.
... Their finding concluded that acoustic waves affected the growth of strawberry plants in direct proportion to the treatment time. This finding was similar to finding found in rice, cucumber and lettuce, as reported by Hou [3]. ...
... Acoustic encouragement technology has been applied to many agriculture food applications. Literature review indicates that by listening to music the plants can increase production output and improve the production quality (Hou et al., 2009(Hou et al., , 2010Spillan, 1991). There are some researches addressing on the production promotion of bacteria and other microorganisms (Robrish et al., 1976;Xiao, 1991) and their findings suggest that the different frequencies of sound waves have different influence on microbial breeding time (Li et al., 2008). ...
This study aims to investigate the synchronization mechanism for music and dance in the production encouragement system of edible fungus. The synchronization between the music and dance may significantly influence the stimulating effect on the growth of edible fungus. However, very limited work has been done to address this issue. To deal with the synchronization problem of music and dance, the Hevner music emotion model based on adjective circle is proposed in this study to achieve matching mechanism of audio streams and video. By doing so, the proposed algorithm can improve the synchronization between the music and dance. In emotion driven model with the theoretical basis of Hevner emotion ring, the music matches to the dance successfully, which can not only provide matching method for chimes-driven dance editing system, but will also provide a simple and feasible matching pattern for any other applications.
... Recently, studies have been done on the use of music to improve crop yield and quality in plants such as tomato, vegetables, and barley [15,16]. Hou et al. [17] used audible sound waves to stimulate more than 50 different crops and achieved remarkable effects. ...
Audible sound (20-20000 Hz) widely exists in natural world. However, the interaction between audible sound and the growth of plants is usually neglected in biophysics research. Not much effort has been put forth in studying the relation of plant and audible sound. In this work, the effect of audible sound on germination and growth of mung bean (Vigna radiate) was studied under laboratory condition. Audible sound ranging 1000-1500 Hz, 1500-2000 Hz, and 2000-2500 Hz and intensities [80 dB (A), 90 dB (A), 100 dB (A)] were used to stimulate mung bean for 72 hours. The growth of mung bean was evaluated in terms of mean germination time, total length, and total fresh weight. Experimental results indicated that the sound wave can reduce the germination period of mung bean and the mung bean under treatments of sound with intensity around 90 dB and frequency around 2000 Hz and significant increase in growth. Audible sound treatment can promote the growth of mung bean differently for distinct frequency and intensity. The study provides us with a way to understand the effects and rules of sound field on plant growth and a new way to improve the production of mung bean.
... In addition, it improved crop quality and enhanced disease resistance. The spider mites, aphids , gray mold , late blight and virus disease of tomatoes in greenhouses decreased by 6.0, 8.0, 9.0, 11.0, and 8.0%, respectively (Hou et al. 2009;Cai 2012;Jiang and Huang 2012). ...
Sound waves technology has been applied to different plants. It has been found that sound waves were at different frequencies, sound pressure levels (SPLs), exposure periods, and distances from the source of sound influence plant growth. Experiments have been conducted in the open field and under greenhouse growing conditions with different levels of audible sound frequencies and sound pressure levels. Sound waves at 1 kHz and 100 dB for 1 h within a distance of 0.20 m could significantly promote the division and cell wall fluidity of callus cells and also significantly enhance the activity of protective enzymes and endogenous hormones. Sound waves stimulation could increase the plant plasma-membrane H+-ATPase activity, the contents of soluble sugar, soluble protein, and amylase activity of callus. Moreover, sound waves could increase the content of RNA and the level of transcription. Stress-induced genes could switch on under sound stimulation. Sound waves at 0.1–1 kHz and SPL of (70±5) dB for 3 h from plant acoustic frequency technology (PAFT) generator within a distance ranged from 30 to 60 m every other day significantly increased the yield of sweet pepper, cucumber and tomato by 30.05, 37.1 and 13.2%, respectively. Furthermore, the yield of lettuce, spinach, cotton, rice, and wheat were increased by 19.6, 22.7, 11.4, 5.7, and 17.0%, respectively. Sound waves may also strengthen plant immune systems. It has been proved that spider mite, aphids, gray mold, late blight and virus disease of tomatoes in the greenhouses decreased by 6.0, 8.0, 9.0, 11.0, and 8.0%, respectively, and the sheath blight of rice was reduced by 50%. This paper provides an overview of literature for the effects of sound waves on various growth parameters of plant at different growth stages.
... From 1999 to 2009, experiments on pepper, cucumber, and tomato had demonstrated that PAFT could increase their production by 13-40% or so and decrease the incidence of diseases such as pseudomonas syringae pv. lachrymans of cucumber (Hou T. Z., 2009). It also decreased the use of chemical fertilizer and biocide . ...
Plant Acoustic Frequency Technology (PAFT) aims to impose the plant with sound wave in special frequency which accords with plant meridian system so that it can increase plant production and decrease the use of fertilizer. The objective of this study was to identify indicators which relate to the effects of PAFT through analysis of photosynthetic processes and chlorophyll fluorescence traits in strawberry (Fragaria ananassa) leaf. The results showed that all these indicators were affected by sound wave frequency treatment. The number of flowers and fruits as well as the content of chlorophyll augmented. The net photosynthetic rate (PN) also remarkably increased. The maximal fluorescence (Fm), maximum photochemical efficiency of photosystem II (Fv/Fm), and non-photochemical quenching (NPQ) increased markedly under PAFT of 35 days while the change of the initial fluorescence (F0) and photochemical quenching (qP) showed actual but unobvious increases. These results further revealed that the acoustic frequency treatment could improve the activity of photosystem reaction center, and enhance the electron transport and the photochemical efficiency of photosystem II
Responses of plants to environmental signals have been studied for a long time. These responses are exhibited in the form of morphological and physiological adaptations, and relaying the signal to environment (including other plants) through volatile organic compounds and extrinsic chemicals as well as proteins. However these signals do not correspond to the consciousness in the plants. Recent research in this field has produced evidence of non-physical signals e.g. sound and (electro) magnetic field. Plants produce such signals as well as perceive and respond to these signals. There are many novel techniques that have been used in last three-four decades to understand such signals, mostly acoustic signals. This review summarizes the old knowledge as well as recent developments in the area of generation, perception, integration and processing of acoustic signals by the plants as a response to the environment as well as to communicate among themselves. If understood fully, technological interventions and manipulations of these signals can add an extra tool for crop improvement.
Muscular dystrophies are inherited myogenic diseases and considered by progressive muscle wasting and weakness with variable distribution and severity. The essential characteristics of muscular dystrophies are selective involvement, significant wasting and weakness of muscles. The most common and frequent types of muscular dystrophies are Duchenne Muscular Dystrophy (DMD), Becker Muscular Dystrophy (BMD), Facioscapulohumeral Dystrophy (FSHD) and Limb Girdle Muscular Dystrophy (LGMD). Metabolic disturbance is observed in muscular dystrophy patients (DMD, BMD, FSHD and LGMD-2B). Alteration in the level of metabolites (BCAA, Glu/ Gln, Ace, alanine, glucose, histidine, propionate, tyrosine and fumarate) in dystrophic muscle reflects the alteration in the activity of enzymes. Collectively, these observations propose that there is alteration in the rate of glycolysis, TCA cycle, fatty acid oxidation, gluconeogenesis pathway and protein metabolism (catabolism & anabolism) in the muscular dystrophy patients. Metabolic disturbance, further provide the explanation about the pathophysiology of muscular dystrophy.
Please note this thesis accompanies accompanies online content which can be found here :
http://www.augustineleudar.com/Offline%20Website/indexphd.html
Abstract: This thesis accompanies a portfolio of site specific sound installations that were delivered in the UK, Europe and South America between 2012 and 2016. The principle focus of the research is to combine plant electrophysiology and 3D sonic art with a particular emphasis on spatial audio. By using networks of electrodes, audio spatialisation and various artistic techniques, electrical activity in the biosphere was made tangible through sound in real-time. Installations based on this research were presented at public events, immersing listeners in the complexity of these processes. Bespoke software was created to meet creative and technical objectives. The main research question asks 'How can plant electrophysiology and art be integrated?' The case is made that the artistic and scientific side of this interdisciplinary research should meet on an equal footing, in which art does not occupy a subordinate role to science. The research therefore aimed to create a combination of both fields that enables a genuine dialogue between them. Novel sound installations were created that were designed to stand as works of art in their own right regardless of whether or not the audience knew there was a scientific component to the piece; at the same time new approaches to monitoring electrical activity in plants were developed. A description of how these two elements are combined and how scientific needs influence artistic work and vice versa is given. The case is also made that, for site specific work, the context and location in which the sounds are presented are just as important as the sounds themselves. The principle object of this research is not to gather qualitative or quantitative data, but to convert signals into sound in real-time and create art installations that engender a space where independent elements of both disciplines can merge as well as develop independently from each other. Technical and artistic gaps in the field are identified through the literature review and addressed in the installations. The software created forms a bridge between the creative and the technical side of the research and is described by means of videos. During the course of the research some discoveries were made, that although do not directly address the original research questions, nonetheless form interesting subjects in their own right and potential avenues for future investigation, as such they are included. This commentary is accompanied by a USB stick that has relevant software and audio documentation. It also includes an offline website which contains important information such as videos, and is referred to throughout the text and forms an essential component of the thesis. P a g e | 3 ii) Acknowledgements I would like firstly to thanks my supervisor, Professor Michael Alcorn for his guidance and for supporting me to conduct the research and create the art installations I had dreamed about for years, both in the Amazon rainforest and at home.
Some kind of audible sound can help plants or animals to grow healthily and faster. However, the acoustic waves was hard to be produced accurately as they would be absorbed or reflected back and forth in controlled environments such as greenhouse, plant factory, or aquaculture factory. A solution for improving audible sound output based on a closed-loop feed-forward control method was proposed. The output sound can be corrected by updating the transfer function of sound generation system. Proof tests were conducted in an artificial climate cabinet with 1.2 m×0.53 m×0.9 m. The results showed that pure tones, combination sound of pure tones, and normal music can be produced with over 98% output accuracy.
In order to investigate audio frequency influence on the growth, yield and nutrient component of edible mushroom, the audio stimulating technology was applied to the mycelium of six kinds of edible mushroom (Agrocybe Cylindracea, high-temperature Pleurotu corucopiae, Pleurotus ap., Pleurotus eryngii, Pleurotu cornucopiae and Pleurocybella poprrigens) and the fruiting body of three edible mushrooms (Pleurotu corucopiae, Pleurotus ap. and Pleurotu corucopiae 18). The audio was generated by mixing classical music and cricket voice with a self-developed audio player equipment. The results showed that the sound increased the mycelium growth of all the six mushrooms by 10.2%~21%, accelerated their fruiting, advanced the body fruiting harvest time by 1-5 days and extended the picking period by about 3-8 days. The audio treatment also increased the yields of edible mushrooms by 15.76%, 13.38%, 13.05% and 7.95% in four tests respectively. By comparison of fruiting body nutrient component, the mass fraction of fat, protein and polysaccharide of Pleurotu corucopiae 18 increased by 5.88%, 8.74% and 2.78%, respectively; the mass fraction of protein and polysaccharide of Pleurotus ap. fruiting body increased by 2.37% and 43.27%, respectively. The results can provide a scientific basis for audio stimulating technology applied to edible mushroom production.
Acoustic frequency technology can promote the growth of plants in horticulture, but the promotion mechanism is not clear. Therefore, the method of spontaneous acoustic frequency (SAF) measurement was explored, and the spontaneous spectrum of cucumber seedlings was examined. Using a laser PDV-100 vibrometer, the SAF of cucumber seedlings in different locations (main vein, mesophyll and stem) and different environments (light intensity changes and drought stress) was measured in a semi-anechoic room by non-contact measurement. The power spectrum and autocorrelation of SAF were analyzed and the spontaneous spectral characteristics of cucumber seedlings were obtained. The results showed that the basic frequency of cucumber seedlings' SAF was in 4.98~5.86 Hz and the spontaneous acoustic signal variations under different environments in the three parts of the cucumber were consistent.
To know the effects of acoustic frequency technology on rice growth, yield formation, and quality, the field experiment was carried out in the China National Rice Research Institute. The Tianfengyou 5 which belongs to the indica type hybrid rice and Yongyou 13 which belongs to the japonica type hybrid rice were taken as test cultivars. Split plot design was used with cultivars in the main plots and acoustic frequency treatment (AFT) and control (CK) in the sub-plots. The plots, each 100 m2 were repeated 4 times. The acoustic frequency generator developed by Zhejiang University of Science and Technology was used in AFT to regulate the acoustic wave. This acoustic frequency generator was a kind of autoplay and autocontrol system, it could play the classical music and mixed sound of birdsong and cricket song. The main frequency of AFT was about 50 Hz, and ranged from 300 to 6000 Hz, and the audio loudness was about 80 dB. The playing time was designed by the programmable timer. From rice transplanting stage to 5 days before harvest stage, the acoustic frequency generator broadcasted everyday and lasted 3 hours (08:30-11:30). The results showed that the rice yield of AFT for Tianfengyou 5 and Yongyou 13 was 5.11% and 5.38% higher than that of CK, respectively. And the yield differences between AFT and CK for these two cultivars were significant. Compared with CK, the AFT increased the rice tillers of the early growth period. After 7 days (Sep. 8) and 14 days (Oct. 6), the average tillers per hill of Tianfengyou 5 for AFT were 0.3 and 0.5 higher than that of CK, respectively, and the average tillers per hill of Yongyou 13 for AFT were 1.1 and 1.0 higher than that of CK, respectively. Compared with CK, the effective panicle number of AFT for Tianfengyou 5 and Yongyou 13 were increased 8.40 panicles/m2(3.88%) and 5.80 panicles/m2(3.33%), respectively. Compared with CK, the average filled grains per panicle of AFT for Tianfengyou 5 and Yongyou 13 were increased 2.46 grains (1.45%) and 4.46 grains (1.71%), respectively. The increasing effective panicles number and filled grains became dominant factors of high yield. Compared with CK, the SPAD of AFT for Tianfengyou 5 in booting stage (Sep. 8) and grain filling stage (Oct. 6) were 11.36% and 10.41% higher than that of CK, respectively; and the SPAD of AFT for Yongyou 13 in booting stage (Sep. 22) and grain filling stage (Oct. 20) were 5.20% and 4.91% higher than that of CK, respectively. The AFT significantly improved the rice qualities. Compared with CK, the rice transparency of AFT for both Tianfengyou 5 and Yongyou 13 were improved 1 grade, the chalkiness of AFT for Tianfengyou 5 and Yongyou 13 was decreased by 21.31% and 5.88%, respectively, the gel consistency of AFT for Tianfengyou 5 and Yongyou 13 was increased by 2.0 and 8.0 mm, respectively, the head rice rate of AFT for Tianfengyou 5 and Yongyou 13 was increased by 6.99% and 2.22%, respectively, the rice quality index for Tianfengyou 5 and Yongyou 13 was increased by 6.58% and 10.94%, respectively. These indictors all improved the rice qualities.
Understanding the effects of acoustic frequency technology (AFT) on the growth of cotton would be helpful to cotton production in Xinjiang Uygur Autonomous Region. An experiment including two different treatments was set in order to investigate the effects of AFT on the growth of cotton. One treatment was to impose the plants with sound wave in special frequencies, the other was control. The results showed that compared to the control sites, by using AFT, the treated plant height of cotton, the width of the fourth expanded leaf from terminal one, boll-bearing branches, number of bolls and single boll weight were increased by 1.71%, 5.25%, 1.14%, 9.22% and 3.34%, respectively. Acoustic waves could increase the treated cotton yield by 11.1%-13.5%, which showed significant difference and average yield increased by 12.7% in the past three years. The effect of treatment was negatively correspondent with the distance between plants and the source of sound. The study show that AFT can both promote vegetative and reproductive growth of cotton, and it can provide a scientific basis for the AFT effects on plant production.
Audible sound (20-20000Hz) widely exists in natural world. However, the interaction between audible sound and the growth of plants is usually neglected in biosystems engineering research. Not much effort has been put forth in studying the relation of plant and audible sound. In this work, the effect of audible sound on germination and growth of mung bean (Vigna radiata) was investigated under laboratory condition. Audible sound ranging 1000-1500Hz, 1500-2000Hz, 2000-2500Hz and intensities [80dB (A), 90dB (A), 100dB (A)] were used to stimulate mung bean for 72 hours. The growth of mung bean was evaluated in terms of mean germination time, total length, and total fresh weight. Experimental results indicated that the sound wave can reduce the germination period of mung bean and the mung bean under treatments of sound with intensity around 90dB and frequency around 2000Hz significant increase in growth. Audible sound treatment can promote the growth of mung bean differently for distinct frequency and intensity. It is a preliminary investigation, and more experimental studies need to be done in order to understand the effects of sound on plant growth and to develop models for application.
Previous research indicates that audible sound stimulation can promote microalgae growth. The improvement in growth rate depends on the frequency of the sound waves and the microalgae strain used. This study examined the effect of sound waves with frequency of 1100Hz, 2200Hz, and 3300Hz to stimulate the productivity of an Oklahoma native strain, Picochlorum Oklahomensis. The effect of the frequency of sound on biomass was examined. A sound-aid algae growth experimental system was developed. Various audible sound signals were generated at different frequencies and applied to algae samples. The optimal frequency of the sound wave was selected and tested using the developed sound-aid algae growth system.
This review presents an overview of potential use of substrate-borne vibrations for the purpose of achieving insect pest control in the context of integrated pest management. Although the importance of mechanical vibrations in the life of insects has been fairly well established, the effect of substrate-borne vibrations has historically been understudied, in contrast to sound sensu stricto. Consequently, the idea of using substrate-borne vibrations for pest control is still in its infancy. Our review therefore focuses on theoretical background, using it to highlight potential applications in field environment, and lists the few preliminary studies that have been or are being performed. We also note conceptual similarities with the use of sound, as well as limitations inherent in this approach.
In this paper, FT-IR is used to investigate the effects of strong sound waves at different frequency and strength on the secondary conformation of the cell wall proteins of tobacco cells. The experiment shows the changes on the Amide I and Amide II . While the frequency is at 400Hz and the power is at 11OdB and 100dB,β⊥ sheet at Amide I transform into βII sheet, vibration form transform from ν⊥(π,0) to νII(0,0). While the power is at 90dB and the frequency is at 800Hz and 8000Hz, α helix at Amide II has little change. The result is helpful to understand the effects of strong sound wave on the plant cells.
In this article, we adopt the apparatus invented by ourselves to investigate on the sound effects on paddy rice seeds in the germination index, height of stem, relative increase rate of fresh weight, rooting ability, activity of root system and the penetrability of cell membrane. The experiment results show that 400 Hz and 106 dB are the ‘best frequency and intensity’. But when the sound wave stimulation is in excess of 4 kHz or 111 dB, it is harmful for paddy rice seeds. The study not only validates sound field stimulation can certainly promote the growth of plant, but also indicates the practicability of the apparatus.
More and more attentions have been taken to the effects of environmental stresses on the growth and development of plant cells and tissues. Making efforts on this field would enhance plant adaptability to varied environments and implement extensively efficient agricultural technologies. Using callus cultured from stalks of Actinidia chinensis, this study dealt with the effects of sound stimulation on plant cell energy metabolism, i.e., content of ATP. The results indicated that there occurs bi-directional effect of ATP content on sound field stimulation. The sound intensity of about 100 dB and sound frequency of approximately 1000 Hz are optimal external stresses for energy metabolism of A. chinensis. The experimental data showed that moderate sound field would be advantageous to growth and development of woody plants. The mechanisms of ATP content effects of sound stimulation on A. chinensis callus were comprehensively discussed in the light of cytobiology and molecular biology. Whereas the essential mechanisms of biological effects of environmental stresses remain further research.
Environmental factors can greatly influence the growth of plants. In this paper, the effect of sound stimulation on the metabolism of chrysanthemum roots was studied and it was found that the growth of roots was not inhibited but accelerated under suitable sound stimulation. And the content of soluble sugar and protein and the activity of amylase all increased significantly, which indicated that sound stimulation could enhance the metabolism of roots and the growth of chrysanthemum.
Studies on the sound characteristics of phylodendron performed by measuring the power of plant leaves with a laser beam found that the leaves of phylodendron could produce sound waves at relatively low frequencies (from 50 Hz to 120 Hz). Furthermore, it was found that those leaves could accept external sound wave stimulations, with frequencies lower than 150 Hz giving the strongest responses. When the plants were under stress, such as drought, the sound emissions from the plant's leaves increased approximately 20-30 dB, while the range of response to external sound wave stimulation decreased 10-20 dB. However, these increased emissions returned to normal six minutes after watering. When the stainless steel needles were inserted into the petiole of the plant, spontaneous sound production was increased about 40 dB for the main vein and 6 dB for the mesophyll. This is our third report on experimental evidence that plants might have a meridian system as in humans and other animals.
Agri-wave technology is composed of both a special frequency sound wave and a microelement fertilizer. In both components, the effect of sound waves on plants is more than that of fertilizers, but the best function is a combination of the two. Treatment by Agri-wave technology stimulated the growth rate and increased the yield of spinach. In small plot tests, the length and width of the treated spinach leaf was 50.8 cm and 20.3 cm, respectively, whereas the untreated leaves were 29.20 cm and 8.9 cm. The fresh weight of treated spinach was 0.42 kg. This was 5.5 times higher than that of the untreated spinach. In large area testing (17 hectares), the results of two tests show that the yields of the treated spinach were increased 22.7% and 22.2% over those of the control group. Sugar content of the treated spinach was increased by 37.5%, vitamin A, C, and B were increased 35.63%, 41.67% and 40.00%, respectively, above the levels of the control group. Niacin content was decreased by 7.69%. Of 33 elements analyzed in the spinach, 29 elements were increased by Agri-wave technology. The spinach was infected with "rot disease" in the control group while there was no disease present in the treated group. In greenhouse testing, the average weight of 3 species of lettuce treated by Agri-wave technology was increased 44.10% over that of the control group (P < 0.0001). The average weight of 3 species of lettuce by only sound and only fertilizer treated separately increased 29.92% and 16.19% above that of the control group (P < 0.0001). Sampling survey results in the field test were comparable to the above mentioned greenhouse test. The fresh weight of treated lettuce by Agri-wave technology was increased 41.67% over that of the control group (P < 0.0001). The fresh weight of treated lettuce by only sound and only fertilizer was increased 30.88% and 19.61%, respectively, over the control group (both P < 0.0001).