JP2007099696A - Germicidal material for aerial application - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a germicidal material for aerial application capable of efficiently contacting harmful microorganisms with a germicidal agent. <P>SOLUTION: The germicidal material for aerial application charges the surface of a germicidal material with electric charge reverse to the charge of the surface of a harmful microorganism to attract the harmful microorganism floating in air and charged with electric charge reverse to the charge of the charged material scattered in air together with a germicidal agent and contact the microorganism with the germicide. The germicidal effect of the germicide is fully exhibited by the method to increase the controlling effect on the harmful microorganisms. The surface charge of harmful microorganism is positive at pH 4 or below and is negative at pH of higher than 4. Since the quantity of electric charge is ≥10 μV or ≤-10 μV or thereabout, the surface charge of the germicidal material for aerial application is preferably ≥10 μV or ≤-10 μV. The germicidal agent is an antagonistic microorganism, a chemical germicide or an antibacterial substance. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an aerial sterilizing material (hereinafter referred to as a sterilizing material).

  Conventionally, in agricultural cultivation of agricultural crops, agricultural chemicals such as chemical bactericides have been sprayed to control diseases that occur on the ground. Generally, agricultural chemicals for spraying are an aqueous solution and a powder type, and are sprayed regularly using a spray type spraying device or a duster.

  In recent years, powder-type pesticides that are harmless to human livestock have been developed, and materials for spraying have been studied. Agricultural crops are cultivated throughout the year, and warm air heaters are operated to raise the temperature during the cold winter season. Japanese Unexamined Patent Publication No. 2001-302407 discloses a method of spraying a powder type agricultural chemical into a facility using this hot air heating apparatus.

However, there are cases in which the expected bactericidal effect cannot be obtained by spraying powder-type pesticides by the above method. Specifically, there is an example in which even if effective against gray mold, no effect is observed against tomato leaf mold (Fulvia) or cucumber brown spot (Corynespora). As described above, there is a phenomenon in which a high disease control effect is exhibited for a specific disease, but no disease control effect is exhibited against other diseases despite having antibacterial activity. This is probably because the harmful microorganisms to be sterilized and the bactericide are not in efficient contact.
JP 2001-302407 A

  The present invention has been made to solve the above-mentioned problems, paying attention to the fact that the surface of harmful microorganisms is charged, and by charging the surface of the sterilizing material with the opposite charge, the harmful microorganisms can be efficiently treated. It aims at providing the sterilization material which can be made to contact a disinfectant.

  In order to achieve the above object, the sterilizing material according to claim 1 is a mixture of a sterilizing agent and a charging material capable of charging the surface opposite to the charge charged on the surface of microorganisms when sprayed in the air. It is characterized by.

  The sterilizing material according to claim 2 is characterized in that, in the configuration according to claim 1, the surface charge charged on the surface of the charging material is 10 μV or more or −10 μV or less.

  The sterilizing material according to claim 3 is the structure according to claim 1 or 2, wherein the sterilizing agent is an antagonistic microorganism.

  The sterilizing material according to claim 4 is the structure according to claim 1 or 2, wherein the sterilizing agent is a chemical sterilizing agent.

  The sterilizing material according to claim 5 is the structure according to claim 1 or 2, wherein the sterilizing agent is an antibacterial substance.

  Further, the sterilizing material according to claim 6 is the configuration according to any one of claims 1 to 5, wherein the specific gravity of the mixed charging material and the sterilizing agent is 2.0 or less, and the particle diameter is It is 100 μm or less.

  According to the sterilizing material according to claim 1, the sterilizing agent attracts harmful microorganisms floating in the atmosphere by charging a charge opposite to the charged charge of the charged substance dispersed in the atmosphere together with the sterilizing agent, It becomes possible to make it contact, and the bactericidal effect of the added bactericidal agent can fully be expressed.

  According to the sterilizing material of the second aspect, since the charge charged on the surface of the charged substance is 10 μV or more or −10 μV or less, harmful microorganisms can be attracted electrically and efficiently. The surface charge of harmful microorganisms varies depending on PH, and when PH4 or less, it has a positive charge, and when PH4 or more, it has a negative charge. And since the charge amount is about 10 μV or more or −10 μV, it is desirable that the charge on the sterilization surface for air spraying is 10 μV or more or −10 μV or less.

  According to the sterilizing material of claims 3 to 5, the sterilizing agents to be used are antagonistic microorganisms, chemical sterilizing agents, and antibacterial substances, respectively, which do not release charged charges on the charged substances, Will not cancel the charge. Therefore, the sterilizing material can surely attract and contact harmful microorganisms and sufficiently exhibit the sterilizing effect of the sterilizing agent.

  According to the sterilizing material according to claim 6, since the specific gravity of the mixed charging material and the sterilizing agent is 2.0 or less and the particle diameter is 100 μm or less, it can float in the atmosphere for a long time after being sprayed. The bactericidal effect of the bactericidal agent can be fully expressed.

  As the charged substance constituting the sterilizing material of the present invention, mineral powders such as zeolite, clays, diatomaceous earth, talc, clay and white clay are used. One or more suitable types are selected from these and used. In addition, polyacrylic acid, polyvinyl alcohol, or the like can be added in order to enhance the adhesion of the bactericide.

  Bactericides include antagonistic microorganisms such as Bacillus bacteria, Pseudomonas bacteria, Erbinia bacteria, Streptomyces bacteria, chemical fungicides such as benomyl, captan, azoxystrobin, or silver, copper or nickel Use inorganic antibacterial substances. These do not cause the charged substance to discharge a charged charge, and do not cancel the charged charge.

  The sterilizing material constituted by mixing the charged substance and the sterilizing agent is suspended in the atmosphere for a long time after being sprayed, so that the specific gravity is 2.0 or less and the particle diameter is 100 μm or less. Quality. In addition, the surface charge of harmful microorganisms floating in the atmosphere changes with PH, and when PH4 or less, it has a positive charge, and when it is PH4 or more, it has a negative charge. It is necessary that the surface charge of the charged substance is charged to 10 μV or more or −10 μV or less when sprayed.

  In view of the above conditions, an attractive adhesion experiment between a charged substance and harmful microorganisms was conducted. As a charging substance, 0.1 g of talc having a particle diameter of 20 μm was used and charged by applying an electrostatic charge of 15 μV. About 30,000 gray mold spores were used as harmful microorganisms. These were placed in a glass container having a volume of 5 liters and stirred with a small electric fan. Then, a slide glass was placed in the glass container, and talc particles falling on it were collected. The slide glass was mounted with a cover glass, and the state of adhesion between talc and gray mold spores was observed with a microscope.

  As a result, it was observed that 1 to 20 gray mold spores were attached per grain of talc, and it was found that all gray mold spores adhered to talc. This experimental result suggests that if harmful microorganisms adhering to agricultural products blow up and float in the atmosphere, they are attracted to and attached to talc as a charged substance. It can be conceived that the same result can be easily obtained by using powders of mineral substances such as zeolite, clays, diatomaceous earth, clay and clay as well as the talc as the charged substance.

Next, an experiment was conducted on the difference in sterilization effect between charging and simple spraying (charging effect by friction). In this case, as a charging method, a charging policy is attached to a discharge hole of a sterilizing material provided in a polypipe, and charging is performed by rubbing between the policy and the charged substance at the time of discharge. And the bactericidal effect was confirmed by controlling tomato leaf mold and cucumber brown spot. For this reason, the processing area which performs the following processes in the forcing cultivation facility of tomato and cucumber, respectively was provided.
(1) Bacillus subtilis spores were admixed with fine talc and adsorbed to 10 ¹⁰ cfu / g, and released upward using a polypipe (charged by applying 15 μV of static charge to 5 g of talc at the time of release). ) Treatment area A,
(2) Treatment area B in which 15 g of Bacillus subtilis wettable powder (trade name: Botokiller wettable powder) is sprayed daily for 1 month using a heater duct,
(3) Treatment Zone C in which Bacillus subtilis wettable powder (trade name: Botokiller wettable powder) was sprayed twice a month at a concentration of 10 ⁹ cfu / ml, 300 liters / 10 are.
(4) Untreated section D was installed.

  Tomato was forcibly cultivated (fixed planting in late September), and from 1 month after the planting, the above-mentioned treated sections A to C and untreated section D were examined every 30 days for the pathogenic strain rate and the diseased leaf rate. The results are shown in Tables 1 and 2. During the survey period, the disinfectant was not sprayed.

  As shown in Tables 1 and 2, in the treatment group A from which the charge was released, the onset of tomato leaf mold was observed after 90 days, but the occurrence was extremely small even after 120 days. On the other hand, in treatment area B sprayed with ducts, onset of leaf mold was observed after 30 days, and the disease strain rate was 30% after 120 days. In addition, in the treatment area C in which the aqueous solution was sprayed twice, although the amount of Bacillus subtilis was more than double that of the treatment areas A and B, the diseased strain rate was 85% and the diseased leaves were 120 days later. The rate was significantly high at 21.5%. On the other hand, in the untreated section D, the disease incidence rate was 100% after 120 days and the disease incidence rate was 30.6%. As a result, it can be seen that the method of mixing the bactericide and the charged substance and charging the charged substance at the time of release has a high control effect against tomato leaf mold.

  Next, the cucumber was forcing cultivation (fixed planting in early October), and the treatment was started 45 days after the fixed planting, and the leafing rate of brown spot was determined every month. The results are shown in Tables 3 and 4. During the survey period, the disinfectant was not sprayed.

  As shown in Table 3 and Table 4, in the treatment area A where the charge was released, the occurrence of cucumber brown spot disease was not observed. On the other hand, in treatment area B sprayed with ducts, disease was observed after 90 days, and the disease strain rate was 80% after 120 days. Further, in the treatment area C in which the aqueous solution was sprayed twice, although the Bacillus bacteria more than double of the treatment areas A and B were sprayed, the disease rate was 100% and the diseased leaf rate was 56% after 120 days. The incidence was high. On the other hand, in the untreated section D, the leaf disease rate was remarkably high at 90% after 90 days, with the disease leaf rate being 100% and the disease leaf rate being 55%. As a result, it can be seen that the method of mixing the bactericide and the charged substance and charging the charged substance at the time of release shows a high control effect against cucumber brown spot disease.

  As a result, the so-called charged release method described above is not limited to tomato leaf mold and cucumber brown spot, but also to various powdery mildew (Powder mildew), gray mold (Botrytis) and downy mildew (Downy mildew). In addition, it is easily conceivable that the controlling effect is exerted on the above-ground diseases of a large number of agricultural products such as ring rot (Alternaria).

  Next, the effect on harmful microorganisms when the type of fungicide was changed was investigated. Instead of the type of fungicides against tomato gray mold and cucumber downy mildew (Pseudoperonospora), they were added and combined with talc to release the charge. Antibacterial agents used were Bacillus subtilis (bacteria) and Pseudomonas fluorescens (bacteria) as antagonistic microorganisms, benomyl agents, captan agents and azoxystrobin agents as chemical fungicides, and silver, copper and nickel as antibacterial agents. And the release area which discharge | releases each fungicide was provided in the forcing cultivation facility of a tomato and a cucumber.

For tomato gray mold, release group E releasing B. subtilis (bacteria) (10 ⁹ cfu / g), release group F releasing benomyl agent (500 mg / g), azoxystrobin agent 500 mg / g) releasing zone G, silver (3 mg / g) releasing zone H, and nickel (30 mg / g) releasing zone I.

For cucumber downy mildew, Pseudomonas fluorescens (bacteria) (10 ⁹ cfu / g) release zone J, captan agent (700 mg / g) release zone K, azoxystrobin agent ( 500 mg / g) release zone L, silver (3 mg / g) release zone M, copper (420 mg / g) release zone N, nickel (30 mg / g) release zone O Each was provided.

  In the release method, a sterilizing material obtained by mixing these bactericides with talc as a fine powder of 1 μm or less was charged and discharged. In the charging method, discharge holes having a diameter of 1 to 5 cm are provided at intervals of 2 to 3 m in a polypipe having a diameter of 30 cm for discharge, and the policyl for charging is attached to the discharge hole, and this policyl and talc rub against each other at the time of discharge. It will be charged. The release procedure was as follows. A polypipe was connected to the blower, and 5 g was released every day during the cultivation period for 15 minutes per hour at an upward wind speed of about 10 m / s.

  The method for investigating the occurrence of the disease was performed by the same methods as those for tomato leaf mold and cucumber brown spot. Then, as a control group, a release zone P in which only talc was released and a non-release zone were provided. In addition, a potato dextrose plate (PDA medium) was placed on the ground in the facility, and the fallen filamentous fungi were collected to count colonies. The results are shown in Table 5 for the control effect against tomato gray mold and Table 6 for the control effect against cucumber downy mildew.

  As seen in the release zones E to I shown in Table 5, when talc is added and combined with a bactericidal agent and continuously released into the air in the facility every day, it exhibits a high control effect against gray mold disease of tomatoes. It was proved. Moreover, the occurrence of filamentous fungi collected on the PDA medium placed on the ground was remarkably small. In the release zone P that releases only talc and the non-release zone, no control effect against tomato gray mold disease is observed.

  As shown in Table 6, almost the same effect as in the case of the above-mentioned tomato gray mold disease was also observed against cucumber downy mildew. In addition, the number of colonies was remarkably small as compared with the release zone P that released only talc and the non-release zone.

  Next, the amount of scattering by height when the specific gravity of the sterilizing material was changed and released into the atmosphere was investigated. Silver ceramic fine powder as an antibacterial substance was added and bonded to talc, and the specific gravity was tempered to 0.1, 0.5, 0.8, 1.0, 1.5, 2.0 and 3.0, respectively. These powdery sterilizing materials were discharged upward from the ground by 5 g per 10 ares by making a discharge hole 2 cm in a 20 cm diameter polypipe. The discharge was carried out by using a polypipe attached to a power duster. The slide glass coated with petroleum jelly was placed at a height of 0, 30, 60, 90, 120, and 150 cm from the ground, and after 2 hours, the number of particles collected by height was measured under the microscope. And examined using a micrometer. The results are shown in Table 7.

  As shown in Table 7, it was found that the powdered sterilizing material floats up to a specific gravity of 2, but does not float sufficiently beyond that. For this reason, it is considered appropriate that the specific gravity of talc or other charged substance in the case of charge discharge is 2 or less.

  Next, the scattering situation for each particle diameter of the charged substance after the sterilizing material was released was investigated. What dried the sterilization material which added the spore of Bacillus subtilis which is an antagonistic microorganism to the talc whose particle size is 5, 10, 20, 40, 60, 80, 120 and 150 μm, respectively, and well stirred, In a tomato cultivation facility, a discharge pipe having a diameter of 0.5 to 2 cm was formed in a 20 cm diameter polypipe to release 5 g per 10 ares. For the release, a polypipe was attached to a power duster, and the air was continuously blown for 60 minutes. And NA plate culture medium was installed on the strain | stump | stock, and discharge | release precision was investigated. In addition, let the slide glass coated with petrolatum stand at heights 0, 30, 60, 90, 120 and 150 cm from the ground, and collect the number of particles collected by height after 2 hours under the microscope. And examined using a micrometer. The results are shown in Table 8.

  As shown in Table 8, when the particle diameter of talc was 5 to 60 μm, it was scattered relatively well and uniformly dispersed. However, when the particle diameter exceeded 80 μm, scattering was extremely poor, and when the particle diameter was 120 and 150 μm, almost no scattering occurred. In addition, the scattering situation was not uniform and biased. Accordingly, it has been found that the talc particle size that can be used for the charge release into the atmosphere is suitably 5 to 100 μm.

Next, the spore of Bacillus subtilis which is an antagonistic microorganism was mixed with talc having a particle size of 5, 10, 20, 40, 60, 100 and 150 μm to a concentration of 10 ⁹ cfu / g. The powder was stirred and dried, and released into the tomato cultivation facility by the same method as described above. The discharge was set at 5 g per day, and air was blown for 15 minutes at a convenient time of 15 times during 14 hours from 5:00 pm every day to 7:00 am the next day. This was carried out for 6 months from the beginning of tomato cultivation, and the incidence of leaf mold per 100 leaves was examined every month. The results are shown in Table 9.

  As shown in Table 9, when the talc particles are the finest particle size of 5 μm, the leafy mildew incidence rate is slightly inferior to those of the particle size of 10 or 20 μm, but up to 40 μm has almost the same level of high control effect. Indicated. When the particle size exceeded 60 μm, the controlling effect was lowered, and when the particle size was 150 μm, there was almost no controlling effect. This is presumably because the finer the particles, the longer the floating time, and the better the adsorption of harmful microorganisms with an appropriate particle size.

  Next, except that the amount released was 10 g per day, it was released into the cucumber cultivation facility in the same manner as described above, and the number of leaves per 100 leaves of powdery mildew and brown spot disease was examined every month. Table 10 shows the incidence of powdery mildew, and Table 11 shows the incidence of brown spot.

  As shown in Table 10, the effect of controlling the onset of cucumber powdery mildew was most effective when the particle size of talc was 40 or 60 μm, and was ineffective when the particle size was 10 μm or less and 150 μm or more. It can be seen that a moderately sized particle size is required to control powdery mildew.

  As shown in Table 11, the control effect on cucumber brown spot disease was high when the particle size of talc was 20 to 60 μm, and the control effect was poor when the particle size was 10 μm or less and 100 μm. Further, when the particle diameter was 150 μm, there was almost no controlling effect. Therefore, it is considered that the particle diameter of talc for collecting cucumber brown spot fungus is appropriately 20 to 60 μm.

Next, we investigated the incidence of cucumber brown spot in an actual cucumber cultivation field. Equal amounts of talc with a particle size of 5, 10, 20, 30, 40 and 60 μm are added, and then Bacillus subtilis spores are added to a concentration of 10 ⁹ cfu / g, and the mixture is stirred and dried. It was discharged by triboelectric charging in the same manner as the release method. Release was 5 g per day and was released every hour for 15 minutes from 7 pm to 7 pm every day. This was carried out for 6 months from the beginning of cucumber cultivation, and the incidence of brown spot disease was examined. In order to promote the disease, 10 leaves with brown spot disease were suspended in the facility. The results are shown in Table 12.

  As shown in Table 12, in the case of charge release, the occurrence of cucumber brown spot did not occur. This indicates that in a facility where a large number of pathogen spores are floating, a method of combining talc of different sizes with a bactericidal agent and releasing it is suitable.

  As described in the above embodiments, the sterilizing material of the present invention is a charged substance that is dispersed in the atmosphere together with a sterilizing agent by charging the surface of the sterilizing material with a charge opposite to the charge charged on the surface of harmful microorganisms. It is possible to attract harmful microorganisms floating in the atmosphere by charging the charge opposite to the charged charge of the substance, making it contact with the sterilizing agent, fully expressing the sterilizing effect of the added sterilizing agent, The control effect can be enhanced.

Claims (6)

  A sterilizing material for air spraying, comprising a mixture of a sterilizing agent and a charging material capable of charging a surface opposite to the charge charged on the surface of microorganisms when sprayed in the air.   The sterilizing material for air spraying according to claim 1, wherein the surface charge of the charging material on the surface is 10 µV or more or -10 µV or less.   The sterilizing material for aerial application according to claim 1 or 2, wherein the sterilizing agent is an antagonistic microorganism.   The said disinfectant is a chemical disinfectant, The sterilizing material for aerial spraying according to claim 1 or 2.   The sterilizing material for air spraying according to claim 1 or 2, wherein the sterilizing agent is an antibacterial substance. The sterilizing material for air spraying according to any one of claims 1 to 5, wherein a specific gravity of the charged material and the sterilizing agent mixed is 2.0 or less and a particle diameter is 100 µm or less.