Research Association of
Electric Field Screen SupportersTEL.+81-0742-43-5223
|Project 1||Is an electrostatic attractive force useful to collect fungal spores?|
|Project 2||Is an electrostatic technique applicable to control pathogens and insects pests in a greenhouse?|
|Project 3||What is an electrostatic mechanisms for insect attraction?|
|Project 4||Is an electrostatic technique is useful to solve public health problems?|
|Project 5||Is our review article useful for the readers to understand electrostatic approaches?|
|Project 6||Is an arc-discharge (spark) exposure technique useful to control insect pests and weeds?|
|Project 7||Is our association able to meet the demands of farmers?|
1 Is an electrostatic attractive force useful to collect fungal spores?
This inquiry was the first theme that we encountered in the electrostatic research. Powdery mildew pathogen of tomato was first selected as a model pathogen to solve this problem, since the pathogen produced typical white colonies (pustules) on the leaves, where numerous conidiophores were produced in the pustule, and spores (conidia) were developed successively at the tip of the conidiophore. The point of this theme was to examine whether we can collect all conidia that were produced on the conidiophores throughout their life, using an electrostatic attractive force. In the related articles given below, you are informed of 1) the method of generating an attractive force, 2) the electrostatic principle of spore attraction, and 3) the lifelong production of conidia by some powdery mildew pathogens and hyperparasitic fungi. Eventually, these investigations brough birth to different types of an electrostatic spore collection apparatus.
1) Consecutive monitoring of lifelong production of conidia by individual conidiophores of Blumeria graminis f. sp. hordei on barley leaves by digital microscopic techniques with electrostatic micro-manipulation (PDF-01).
2) An apparatus for collecting total conidia of Blumeria graminis f. sp. hordei from leaf colonies using electrostatic attraction (PDF-02).
3) Collection of highly germinative pseudochain conidia of Oidium neolycopersici from conidiophores by electrostatic attraction (PDF-07).
4) Digital microscopic analysis of conidiogenesis of powdery mildew pathogens isolated from melon leaves (PDF-22).
5) Quantitative analysis of the lifelong production of conidia released from single colonies of Podosphaera xanthii on melon leaves using electrostatic techniques (PDF-33).
6) Hyperparasitic fungi against melon powdery mildew pathogens: quantitative analysis of conidia released from single colonies of Podosphaera xanthii parasitised by Ampelomyces (PDF-55).
2 Is an electrostatic technique applicable to control pathogens and insect pests in a greenhouse ?:
This inquiry introduced the breakthrough invention of electrostatic devices to control fungal pathogens and insect pests of greenhouse. The first opening was the device of a single-charged monopolar electric field screen (SM-screen) for realizing a spore-free seedling shelter settled inside a non-guarded greenhouse. To cope with small flying insect pests that passed through a conventional insect-proof net, we devised a single-charged dipolar electric field screen (SD-screen), which exhibited insect-repelling and capturing functions. The repelling function of this screen was applied to a window-installed apparatus for excluding pests from a greenhouse, while the insect-capturing function was used to make an electrostatic insect sweeper to trap pests on plant leaves. A double-charged dipolar electric field screen (DD-screen) was an additional device to capture insect pests inside a greenhouse. The DD-screen technique was used to construct an electrostatic nursery shelter or cabinet, an electrostatic flying insect catcher, a bamboo blind-type screen, a colored screen to attract phototactic insect pests, and a motor-driven apparatus for an unattended insect trap. These approaches made it possible to realize pesticide-independent physical methods for managing pathogens and insect pests in a greenhouse cropping system.
Related articles (SM-screen):
1) A new spore precipitator with polarized dielectric insulators for physical control of tomato powdery mildew (PDF-03).
2) Dual protection of hydroponic tomatoes from rhizosphere pathogens Ralstonia solanacearum and Fusarium oxysporum f. sp. radicis-lycopersici and airborne conidia of Oidium neolycopersici with an ozone-generative electrostatic spore precipitator (PDF-04).
Related articles (SD-screen):
1) Practical application of an electric field screen to an exclusion of flying insect pests and airborne conidia from greenhouses with a good air penetration (PDF-09).
2) An electric field strongly deters whiteflies from entering window-open greenhouses in an electrostatic insect exclusion strategy (PDF-12).
3) Electrostatic insect sweeper for eliminating whiteflies colonizing host plants; a complementary pest control device in an electric field screen-guarded greenhouse (PDF-20).
Related articles (DD-screen):
1) Prevention of whitefly entry from a greenhouse entrance by furnishing an airflow-oriented pre-entrance room guarded with electric field screens (PDF-17).
2) An electrostatic nursery shelter for raising pest and pathogen free tomato seedlings in an open-window greenhouse environment (PDF-23).
3) Elimination of whiteflies colonizing greenhouse tomato plants using an electrostatic flying insect catcher (PDF-26).
4) Successful single-truss cropping cultivation of healthy tomato seedlings raised in an electrostatically guarded nursery cabinet with non-chemical control of whiteflies (PDF-27).
5) Exclusion of whiteflies from a plastic hoop greenhouse by a bamboo blind-type electric field screen (PDF-34).
6) Developing a phototactic electrostatic insect trap targeting whiteflies, leafminers, and thrips in greenhouses (PDF-46).
7) Unattended trapping of whiteflies driven out of tomato plants onto a yellow-colored double-charged dipolar electric field screen (PDF-49).
3 What is an electrostatic mechanisms for insect attraction ?
This question was the natural consequence after we found that insects were captured effectively by the SD- and DD-screens. We held an intensive series of investigations to clarify the mechanism of insect capturing. Insects that entered an electric field (static electric field) were subjected to a force to push negative charge (free electrons) out of their bodies and then polarized positively. Positively charged insects were attracted to the oppositely charged pole of the SD- or DD-screen. This mechanism was called a discharge-mediated positive electrification of an insect. Movement of free electrons was conducted by insect body water, and the free electron movement was measured as a transient electric current from the insect. Moreover, the insects were killed by the current-flow-mediated-heating (Joule heating). By these electric phenomenon, the screens were shown to exert an excellent trap-and-kill function.
1) A newly devised electric field screen for avoidance and capture of cigarette beetles and vinegar flies (PDF-08).
2) An electric field screen prevents captured insects from escaping by depriving bioelectricity generated through insect movements (PDF-10).
3) A newly devised electric field screen for avoidance and capture of cigarette beetles and vinegar flies (PDF-11).
4) An oppositely charged insect exclusion screen with gap-free multiple electric fields (PDF-13).
5) Electrostatic measurement of dischargeable electricity and bioelectric potentials produced by muscular movements in flies (PDF-15).
6) Body water-mediated conductivity actualizes the insect-control functions of electric fields in houseflies (PDF-38).
7) Physical methods for electrical trap-and-kill fly traps using electrified insulated conductors (PDF-47).
(Project 4) Is an electrostatic technique
is useful to solve public health problems?
The first step to answer this question was to fix an objective to which we should apply an electrostatic technique. The targeted objectives were various biotic and abiotic environmental nuisances, which involved pollen grains causing a pollinosis, infectious agents such as airborne spores and viruses in droplet, and tobacco fine particles causing a passing smoking. The aim of the works provided a simple apparatus to eliminate them from the air. The three-layered DD-screen was highly effective to capture airborne spores and pollens, and the newly developed corona-discharge generator was powerful to catch tobacco fine particles and virus-containing water droplets. These works demonstrated that these electrostatic apparatuses were applicable to practical air-purification of the air in the public spaces.
Related articles: 1) Electrostatic guarding of bookshelves from mould-free preservation of valuable library books (PDF-16). 2) An electrostatic-barrier-forming window that captures airborne pollen grains to prevent pollinosis (PDF-24). 3) Electrostatic elimination of fine smoke particles by a newly devised air purification screen (PDF-25). 4) A simple electrostatic device for eliminating tobacco sidestream to prevent passive smoking (PDF-30). 5) A simple electrostatic precipitator for trapping virus particles spread via droplet transmission (PDF-43).
5 Is our review article useful for the readers to understand electrostatic
This question reflected the situation that many related articles have been published, such that it may be difficult for the readers to read all of them. To ease this situation, we have published several review articles to provide clear overall picture of what the electrostatic principles and techniques actually mean. The readers that have an interest in these approaches can download the PDFs of the six review articles published.
1) Novel electrostatic devices for managing biotic and abiotic nuisances in environments (PDF-31).
2) A promising physical pest-control system demonstrated in a greenhouse equipped with simple electrostatic devices that excluded all insect pests (PDF-32).
3) High voltage electric fields have potential to create new physical pest control systems (PDF-36).
4) An electrostatic pest exclusion strategy for greenhouse tomato cultivation (PDF-48).
5) Electrostatic spore-trapping techniques for managing airborne conidia dispersed by the powdery mildew pathogen (PDF-50).
6) Electrostatic insect repulsion, capture, and arc‐discharge techniques for physical pest management in greenhouses (PDF-51).
6 Is an arc-discharge (spark) exposure technique useful to control insect
pests and weeds?
An arc-discharge exposure technique was a new technique devised for large insects that could not be controlled by the previous electrostatic screen method. The distinct characteristics of this technique was to use a non-insulated charged conductor, which generated an arc-discharge-mediated spark toward a target insect when it entered the discharge space of the charged conductor. The spark exposure damaged the insect in two ways; a strong impact and instantaneous electric current. This method was also effective to eradicate weed seedlings, such that we proposed a new type of weed control methods.
1) Electrocution of mosquitoes by a novel electrostatic window screen to minimize mosquito transmission of Japanese encephalitis viruses (PDF-28).
2) Selective electrostatic eradication of Sitopholus oryzae nesting in stored rice (PDF-29).
3) Use of pulsed arc discharge exposure to impede expansion of the invasive vine Pueraria montana (PDF-39).
4) Use of electric discharge for simultaneous control of weeds and houseflies emerging from soil (PDF-40).
5) Selective arcing electrostatically eradicates rice weevils in rice grains (PDF-44).
6) A simple and safe electrostatic method for managing houseflies emerging from underground pupae (PDF-53).
7) Use of a pair of pulse-charged grounded metal nets as an electrostatic soil cover for eradicating weed seedlings (PDF-54).
7 Is our
association able to meet the demands of farmers?
In our district (Osaka, Nara and Wakayama Prefecture, Japan), there are many farmers who engages in different types of farming on a small scale. From an interview-based investigation, we have taken into account the farmers’ voices and attempted to develop new electrostatic methods for controlling all classes of pests (pathogens, insect pests and weeds) according to their requirements. As a result, we have achieved a measure of success in providing some apparatuses that could be fabricated easily and inexpensively by themselves using affordable common materials. These devices involves 1) a bamboo blind-type electric field, applicable to a plastic hoop greenhouse, 2) a drone-carried electric field screen to monitor flying insect pests in field cropping system, 3) an electric field screen, which was electrified by a colored-water, to attract and trap phototactic insect pests in a greenhouse, and 4) an unattended motor-driven dolly, which was equipped with a spark exposer, to eradicate floor weeds in an orchard greenhouse.
1) Exclusion of whiteflies from a plastic hoop greenhouse by a bamboo blind-type electric field screen (PDF-24).
2) Remote-controlled monitoring of flying pests with an electrostatic insect capturing apparatus carried by an unmanned aerial vehicle (PDF-42).
3) Developing a phototactic electrostatic insect trap targeting whiteflies, leaf miners, and thrips in greenhouses (PDF-46).
4) An unattended control of floor weeds in an orchard greenhouse with a motor-driven dolly armed with an electric spark exposer (under submission).