JP2007031294A - Controlling agent to blight occurring in rice seedling growing season - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a microbial agrochemical excellent in a controlling effect on many blights occurring in a rice seedling growing season, safe, and scarcely having an effect on the environment. <P>SOLUTION: A controlling agent to the blight occurring in the rice seedling growing season contains a fungus belonging to the Talaromyces genus having antagonism to a pathogenic bacterium causing the blight in the rice seedling growing season. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a control agent for diseases occurring at the time of rice seedling and a method for controlling diseases occurring at the time of rice seedling using the same.

  Raising healthy and homogeneous seedlings for rice cultivation is one of the most important tasks, but the seedlings are usually susceptible to various diseases from germination to seedling, and are usually thoroughly treated with chemical agents. Pest control.

  Examples of chemical synthetic agents used to control diseases during the rice seedling season that have been used in the past include trifumizole for rice seedling disease, rice blast, and sesame leaf blight, which are seed-borne diseases caused by filamentous fungi. In general, oxolinic acid and the like are widely used for rice blast blight, seedling blight and brown streak, which are seed-borne diseases caused by bacteria. In addition, rice seedling blight, which is a soil-borne disease, is controlled with chemicals containing hydroxyisoxazole, benomyl and the like.

  However, pathogenic bacteria having low sensitivity or resistance to the above-mentioned chemically synthesized drugs have emerged and become a problem. In addition, due to concerns about food safety or environmental impact, there is a need to reduce the amount of chemical synthetic drugs used and the number of uses in crop cultivation. Furthermore, with the growing demand for food safety and the like, there is a need for the development of technologies / products that can reduce the amount and frequency of use of chemically synthesized drugs even during the seedling season of crops. Specific examples of such techniques include highly safe chemicals that can be used as natural products, food additives, and the like, or agricultural chemicals using living organisms.

  As a disease control technique using living organisms, control using a microbial preparation is known. For example, Patent Document 1 describes a microbial preparation for controlling rice diseases containing Fusarium spp., And Patent Document 2 describes a microbial preparation for controlling rice seedling diseases containing Pseudomonas spp.

  In addition, the microbial fungicide Biotrust (Idemitsu Kosan Co., Ltd.), which is an active ingredient of Talaromyces flavus, a type of filamentous fungus, is used as a foliar disease control agent for strawberry anthracnose and strawberry powdery mildew. in use. However, it has not been reported so far that Tallaromyces is effective in controlling diseases in other crops.

JP-A-11-89562 JP 2002-17343 A

  This invention is made | formed from the said viewpoint, and makes it a subject to provide the microbial pesticide which is excellent in the control effect with respect to many diseases which generate | occur | produce at the seedling raising time of rice, and has little influence with respect to an environment.

As a result of intensive studies to solve the above problems, the present inventors have found that filamentous fungi belonging to the genus Talalomyces have a controlling effect against many diseases that occur at the time of rice seedling raising. Based on these findings, the present invention has been completed.

  That is, the gist of the present invention is as follows.

(1) A control agent for diseases occurring during the rice seedling raising period, comprising a filamentous fungus belonging to the genus Talaromyces that has an antagonistic action against pathogenic bacteria causing disease during the rice seedling raising time.
(2) The control agent for a disease occurring during the rice seedling raising period according to (1), wherein the pathogen causing the disease during the rice seedling raising period is a rice seed infectious pathogen or a soil infectious pathogen.
(3) The pathogenic bacteria causing disease during the rice seedling season are: Gibberella fujikuroi; rice blast fungus (Pyricularia oryzae); rice sesame leaf blight fungus (Cochliobolus miyabeanus); ; Rice seedling blight fungus (Pseudomonas plantarii); Rice brown fungus (Pseudomonas avenae); Rice seedling blight fungus Fusarium spp., Pythium spp., Rhizopus spp. The control agent of the disease which generate | occur | produces at the time of the seedling raising of rice as described in (2) which is at least 1 of (Trichoderma) genus microbe.
(4) The disease control agent according to any one of (1) to (3), wherein the filamentous fungus belonging to the genus Talaromyces is Talaromyces flavus.
(5) The disease controlling agent according to (4), wherein the filamentous fungus belonging to the genus Talalomyces is Talalomyces flavus Y-9401 strain (FERM P-15816).
(6) In the seedling raising time of rice, comprising the step of treating rice seeds, seedlings, seedling soil or seedling culture medium with the disease control agent according to any one of (1) to (5) How to control the diseases that occur.

According to the present invention, a microorganism preparation having the following features can be provided.
・ Highly effective against various diseases that occur at the time of rice seedling raising.
-Safe and has little impact on the environment.
・ There are no or very few restrictions on the number of uses compared to general chemically synthesized pesticides.

Hereinafter, the present invention will be described in detail.
(Disease control agent of the present invention)
The disease control agent of the present invention is a disease control agent that occurs at the time of rice seedling raising. Here, “seedling” means a seedling plant until the planting of rice. Further, “nurturing seedling” means growing seedlings, and “nurturing time” means a cultivation time before planting seedlings. The seedlings at the seedling raising time may indicate the growth time of the seedlings by the number of leaves of the seedlings, such as 1 leaf stage, 2 leaf stage, 3 leaf stage, etc. Speaking of the growing season of seedlings, the seedlings in the growing season are, for example, seedlings up to about four leaf stages including imperfect leaves that are suitable for transplanting in seedling transplanting cultivation.

The disease control agent of the present invention contains a filamentous fungus belonging to the genus Talalomyces as an active ingredient. (1) Filamentous fungi belonging to the genus Taralomyces No particular limitation is imposed on the filamentous fungi belonging to the genus Taralomyces as long as they have an antagonism against pathogenic bacteria causing disease during the rice seedling raising season. Here, the “antagonism” means an action of reducing the number of cells of pathogenic bacteria causing disease during the seedling raising time of target rice or an action of suppressing the growth, that is, an antibacterial action. As a bacterium having an antagonistic action against a pathogenic bacterium causing disease during rice seedling raising season, preferably a bacterium belonging to the species of the genus Talaromyces flavus, and among them, the strain Talaromyces flavus Y-9401 is preferably mentioned. In the disease control agent of the present invention, one of the above microorganisms can be used alone or in combination of two or more unless the disease control effect is affected.

  Talaromyces flavus Y-9401 strain was registered on the patent microorganism deposit center of the Biotechnology Institute of Industrial Technology, Ministry of International Trade and Industry on September 2, 1996 (currently the National Institute of Advanced Industrial Science and Technology patent biological deposit center). Deposited as FERM P-15816.

  The antagonistic action against pathogenic bacteria causing disease at the time of rice seedling is, for example, culturing the test bacteria and pathogenic bacteria causing disease at the time of rice seedling on the same plate for 3 to 14 days at 15 to 35 ° C. Then, it can be confirmed by observing the state of growth suppression of the pathogenic bacteria causing disease during the rice seedling raising period.

  The filamentous fungus belonging to the genus Tallaromyces used in the present invention can be cultured by the same method as that for ordinary filamentous fungi. For example, filamentous fungi belonging to the genus Tallaromyces can be grown by a liquid culture method such as reciprocating liquid culture or jar fermenter culture cultured in a liquid medium, or a solid culture method cultured on a solid medium. In order to produce spores of filamentous fungi belonging to the genus Taralomyces with high yield, a solid culture method is more preferably used. As for the culture conditions of the filamentous fungi belonging to the genus Tallalomyces, it is desirable to carry out under aerobic conditions by methods such as aeration, stirring and shaking, and the culture temperature is preferably 20 to 40 ° C. The culture period is preferably 3 to 60 days, particularly preferably 3 to 20 days. In addition, it is preferable that the microbial cell of the filamentous fungi which belongs to the genus Taralomyces used for this invention is a spore from a viewpoint of the preservability as a product of a disease control agent. Therefore, if necessary, the culture conditions such as the composition of the medium, the pH of the medium, the culture temperature, the culture humidity, and the oxygen concentration at the time of culturing can be used to spore the filamentous fungi belonging to the genus Taralomyces. It is preferable to prepare so as to adapt to the sporulation conditions.

  A potato dextrose culture medium, a Sabouraud culture medium, etc. are used as a liquid culture medium component used when cultivating the filamentous fungi which belong to the Tallaromyces genus. When performing solid culture, grains such as rice, wheat, corn, and soybeans, solid components derived from grains such as bran and soybean meal, and solid carriers such as clay minerals containing nutrient sources, if necessary, sugars Or a medium containing a nitrogen source or the like can be used.

  The culture containing the filamentous fungus belonging to the genus Talalomyces may be used as it is, but if necessary, the culture may be crushed or shredded, and the spores are mainly recovered from this culture with a sieve or the like. You may use what you did. Alternatively, the cells may be separated from the culture with a liquid such as water or oil and used as it is or after concentration.

The disease control agent of the present invention is a culture containing a filamentous fungus belonging to the genus Tallaromyces as a normal colony forming unit, usually 1 × 10 ⁶ to 1 × 10 ¹² cfu / g, preferably 1 × 10 ⁷ to 1 × 10 ¹¹ cfu / g. A product or a pulverized product of a culture is blended into various types of preparations suitable for use and usage.

  In the disease control agent of the present invention, the content of a culture containing a filamentous fungus belonging to the genus Tallaromyces or a pulverized product of the culture is preferably 0.1 to 99.9% by mass, and 1.0 to 50.0. More preferably, it is mass%.

(2) Optional component In addition to the above-mentioned filamentous fungi belonging to the genus Taralomyces, the disease controlling agent of the present invention can be used by adding it as an optional component as long as it does not interfere with the effects of the present invention. Such optional components can be contained as needed for the purpose of formulation, quality stabilization, and the like.

As an arbitrary component used for the disease control agent of this invention, it can use, for example in combination of 1 type, or 2 or more types of the following components.

  For example, as a bulking agent, kaolin clay, pyroferrite clay, bentonite, montmorillonite, diatomaceous earth, synthetic silicon hydroxide, acid clay, talc, clay, ceramic, quartz, sericite, vermiculite, pearlite, Otani stone, anthra Mineral fine powder such as stone, limestone, coal stone and zeolite; inorganic compounds such as salt, carbonate, sulfate, nitrate, urea; rice husk, bran, crab shell, shrimp shell, krill fine powder, rice bran, wheat flour, Corn cob, peanut husk, bone meal, fish meal, rice cake powder, wood powder, charcoal, kun charcoal, bark charcoal, rice husk kun charcoal, grass charcoal, peat moss, attapulgite, dry animal manure, activated carbon, oil cake, starch and hydrolysates thereof Organic fine powders; soluble in D-sorbitol, lactose, maltose, glucosamine, oligosaccharides, etc. It can be used amount agent. As the liquid carrier, water, vegetable oil, animal oil, mineral oil, synthetic water-soluble polymer and the like can be used.

  In addition, natural polysaccharides such as casein, gelatin, gum arabic, alginic acid, celluloses, carboxymethylcellulose, xanthan gum, chitins, chitosans, etc. as necessary are added; polyvinyl alcohols; polyacrylic acids; bentonite, etc. For the purpose of viscosity, fixation, dispersion, etc., it can be contained as required.

  In addition, dihydric alcohols such as ethylene glycol and propylene glycol can be included as necessary for the purpose of preventing freezing.

  Anionic, cationic, and amphoteric surfactants can be included as necessary for the purpose of dispersion stability, prevention of aggregation, emulsification, and the like.

(Method for producing disease control agent of the present invention)
The disease control agent containing the filamentous fungus belonging to the genus Talalomyces of the present invention can be formulated into a form that is actually easy to use. That is, it can be formulated into a wettable powder, a powder, a granule, an emulsion, a flowable agent, a coating agent, and the like together with various optional components as required according to a normal preparation method.

  For example, wettable powders and powders can be produced by mixing or pulverizing and mixing the above-described surfactant and quality-stabilizing components as necessary with the above-described solid carrier.

  For example, the granule can be produced by mixing or pulverizing and mixing the above-described surfactant and quality-stabilizing component with the solid carrier as described above, and further granulating it.

  For example, an emulsion is mixed or pulverized with a liquid carrier such as vegetable oil, animal oil, mineral oil, etc., for the purpose of emulsifying and dispersing the surfactant as described above, as well as with components for stabilizing quality. Can be manufactured.

  For example, the flowable agent is for the purpose of thickening the above-mentioned auxiliary agent in water, for the purpose of preventing the freezing of the above-mentioned dihydric alcohol, etc., and for the purpose of dispersing the above-described surfactant, etc. In addition, it can be produced by mixing or pulverizing and mixing components that stabilize quality.

  For example, the coating agent can be produced by adding an auxiliary agent to a liquid carrier such as water or oil and mixing them to form a sol or gel.

(Method for applying the disease control agent of the present invention)
The disease control agent of the present invention effectively acts to control diseases that occur during the seedling raising period of rice by filamentous fungi, bacteria, microorganism-borne viruses and the like. Moreover, the disease control agent of this invention acts effectively on the control of the disease caused by a rice seed infectious disease fungus or a soil infectious disease fungus, for example. More specifically, the disease control agent of the present invention includes, for example, rice sapling fungus (Gibberella fujikuroi), rice blast fungus (Pyricularia oryzae), rice sesame leaf blight fungus (Cochliobolus miyabeanus), rice blast fungus (Pseudomonas). glumae), rice seed blight fungus (Pseudomonas plantarii), rice brown streak fungus (Pseudomonas avenae), rice seedling fungus (Fusarium spp.), Pythium spp., Rhizopus spp., Particularly effective in controlling diseases caused by Trichoderma spp. The disease control agent of the present invention acts on one or more of the above pathogenic bacteria. Among the pathogenic fungi that cause diseases at the time of rice seedling as described above, there are pathogenic fungi that cause diseases not only at the time of rice seedling raising but also at times other than the time of rice raising. The “causing pathogen” means a pathogenic fungus that causes disease at least at the time of rice seedling raising, and includes both a pathogenic fungus that causes disease at a time other than the seedling raising time and a pathogenic fungus that does not cause a disease at a time other than the time of raising the rice seedling.

  The disease control agent containing a filamentous fungus belonging to the genus Tallalomyces of the present invention is applied to rice seeds, seedlings, seedling soil or seedling culture medium for the purpose of controlling various diseases as described above. The dosage form is appropriately selected depending on the usage form and disease. As such a method, for example, seed soaking treatment, seed dressing treatment, seed application treatment, seed spraying (including spraying) treatment, soil spraying (including spraying) treatment, soil mixing application, soil irrigation application, seedling box irrigation Examples of the method include application, stock application, ground part liquid dispersion, and ground part solid dispersion.

  In addition, when applying disease control agents to rice, do not mix or mix fungicides, insecticides, nematicides, acaricides, herbicides, plant growth regulators, fertilizers, soil improvement materials, etc. Alternate application or simultaneous application is also possible.

The application amount of the disease control agent containing the filamentous fungus belonging to the genus Tallalomyces of the present invention cannot be defined unconditionally depending on the type of disease or the like. For example, in the case of seed immersion treatment, It is preferable to apply after diluting 1000 times (mass), and the bacterial cell concentration is usually 1 × 10 ³ to 1 × 10 ¹⁰ cfu, preferably 1 × 10 ⁴ to 1 × 10 ⁹ cfu per ml of immersion liquid. .

In the case of seed dressing treatment, it is preferable to apply 1 to 20% by mass of the preparation with respect to the seed mass, and the bacterial cell concentration is usually 1 × 10 ³ to 1 × 10 ¹⁰ cfu, preferably 1 g of seed mass. 1 × 10 ⁴ to 1 × 10 ⁹ cfu.

When applying soil spray, if spraying is liquid per seedling box (for example, about 1800 cm ² area) that is usually used for transplanting seedlings, it is preferable to apply 50 to 1000 ml, and the cell concentration is sprayed. Usually 1 × 10 ³ to 1 × 10 ¹⁰ cfu, preferably 1 × 10 ⁴ to 1 × 10 ¹⁰ cfu per ml of liquid.

When applying to soil, it is preferable to apply 0.1 to 100 g of a seedling box (for example, an area of about 1800 cm ² ) usually used for transplanting seedlings, and the bacterial cell concentration is 1 × 10 ² per 1 ml of soil. ˜1 × 10 ⁹ cfu, preferably 1 × 10 ³ to 1 × 10 ⁸ cfu.

When applying seedling box irrigation, it is preferable to apply 50 to 1000 ml if the spraying is normally liquid per seedling box normally used for transplanting seedlings (for example, an area of about 1800 cm ² ). Usually 1 × 10 ³ to 1 × 10 ⁹ cfu, preferably 1 × 10 ⁴ to 1 × 10 ⁸ cfu per ml of liquid.

  Although there is no restriction | limiting in particular about the application frequency of the disease control agent of this invention, By using at the frequency of 1-5 times at the time of rice seedling raising with respect to the pathogenic microbe which causes a disease at the time of rice seedling raising, for example. This makes it possible to suppress the occurrence of diseases during the rice seedling season.

  Before and after using the disease control agent of the present invention, rice seedlings and rice can be cultivated by ordinary methods.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, it goes without saying that the present invention is not limited to these examples.

<Production Example 1>
(Manufacture of spores)
A bran was used as a medium, and an inoculum of the Tallalomyces flavus Y-9401 (FERM P-15816) strain was inoculated therein, followed by solid culture at 30 ° C. for 10 days. After completion of the culture, the culture was dried, and the dried culture was sieved to remove the residue of the bran to obtain a Talalomyces flavus Y-9401 spore-containing powder (4 × 10 ⁹ cfu / g).

<Formulation example 1>
(Production of preparation)
Using Talaromyces flavus Y-9401 spore-containing powder obtained in Production Example 1, 10% by mass of this spore-containing powder, 5% by mass of SORPOL5082 (manufactured by Toho Chemical Industries) as a surfactant, and clay mineral as an extender (K clay: manufactured by Katsumiyama Mining Co., Ltd.) The raw materials were mixed so as to have a ratio of 45% by mass and glucosamine (produced by Yaizu Suisan Chemical Co., Ltd.), 40% by mass, and mixed and pulverized using a mill pulverizer. One formulation (4 × 10 ⁸ cfu / g) was obtained.

<Example 1>
(Rice seedling disease control test)
(1) Preparation of Infected Seeds Rice (variety: Akitakomachi) seeds were harvested from paddy rice, where ridiculous seedling diseases frequently occur in Honda. This seed was used as a seed infected with an idiotic fungus.

(2) Drug treatment The preparation produced in the above Preparation Example 1 was diluted 200 times (mass) with water, and 5 g of the seeds infected with larvae were introduced into 15 ml of this solution. For 48 hours to obtain drug-treated seeds. In addition, the seeds infected with the fungal seedling fungus were similarly immersed in water to obtain a target (untreated seed).

(3) Growth of test plant After the above immersion treatment, the seeds infected with the seedling fungus were seeded in a 100 cm ² plastic pot filled with the soil for raising rice seedlings. The area where the chemical-treated seeds were sown was designated as the chemical-treated area, and the area where the untreated seeds were sown was designated as the non-treated area. Three repetitions were made in both the drug-treated group and the non-treated group. After covering with the above paddy rice seedling cultivating medium, the cultivation was controlled in a glass greenhouse according to a standard method.

(4) Pest control effect investigation Two weeks after sowing, the seedlings with the extreme symptom symptoms caused by the stupid seedling disease were used as the seedlings, and the average number of the three seedlings in each treatment area was used as follows. Based on (Formula 1), the diseased seedling rate was calculated. And based on the following (Equation 2) from the calculated diseased seedling rate, the control value of the chemical treatment area was calculated as a control effect.

(5) Results The results of the survey are shown in Table 1. As is clear from Table 1, the disease control agent of the present invention showed a remarkably high control effect against the rice seedling disease.

<Example 2>
(Rice blast control trial)
(1) Preparation of Infected Seeds Rice (cultivar: Akitakomachi) seeds were harvested from paddy rice with a high blast disease in Honda. This seed was used as a seed infected with blast fungus.

(2) Drug treatment The preparation produced by the above Preparation Example 1 was diluted 200 times (mass) with water, 4 g of blast-infected seeds were introduced into 15 ml of this solution, and in the dark at 48 ° C in an artificial meteorological apparatus at 30 ° C. Time immersion treatment was performed to obtain drug-treated seeds. The seeds infected with blast fungus were similarly immersed in water and used as the target (untreated seeds).

(3) Growth of test plant After the immersion treatment, seeds infected with blast fungus were sown in a 100 cm ² plastic pot filled with soil for raising rice seedlings. The area where the chemical-treated seeds were sown was designated as the chemical-treated area, and the area where the untreated seeds were sown was designated as the non-treated area. Three repetitions were made in both the drug-treated group and the non-treated group. After covering with the above paddy rice seedling cultivating medium, the cultivation was controlled in a glass greenhouse according to a standard method.

(4) Investigation of control effect Two weeks after sowing, a seedling in which a blast disease spot is expressed on the leaf surface is used as a diseased seedling, and the average value of the number of diseased seedlings in three iterations of each treatment section is used. Based on the above, the diseased seedling rate was calculated. And the control value of the chemical treatment area was calculated from the calculated diseased seedling rate as a control effect based on the above (Formula 2).

(5) Results The survey results are shown in Table 2. As is apparent from Table 2, the disease control agent of the present invention showed a remarkably high control effect against rice blast.

<Example 3>
(Rice blight disease control test)
(1) Preparation of infected seeds Rice (variety: Fusaotome) seeds were put into a solution containing a rice blast fungus and forcedly inoculated into the seeds under reduced pressure. After air-drying, the seed pods were used as seeds infected with bacterial wilt.

(2) Drug treatment The preparation produced by the above preparation example 1 was diluted 200 times (mass) with water, and 5 g of seeds infected with Bacterial fungus were introduced into 15 ml of this solution. And soaked for 48 hours to obtain drug-treated seeds. The seeds infected with bacterial wilt disease were similarly immersed in water to give untreated seeds.

(3) Growth of test plant After the above immersion treatment, the seeds infected with Bacterial bacterium were sown in a 100 cm ² plastic pot filled with a soil for raising rice seedlings. The area where the chemical-treated seeds were sown was designated as the chemical-treated area, and the area where the untreated seeds were sown was designated as the non-treated area. Three repetitions were made in both the drug-treated group and the non-treated group. After covering with the above paddy rice seedling cultivating medium, the cultivation was controlled in a glass greenhouse according to a standard method.

(4) Pest control effect investigation Two weeks after sowing, the average number of diseased seedlings in 3 treatments in each treatment area was treated with the seedlings with the symptoms of bacterial wilt disease such as rot, wilting and whitening. Based on the above (Formula 1), the diseased seedling rate was calculated using the value. And the control value of the chemical treatment area was calculated from the calculated diseased seedling rate as a control effect based on the above (Formula 2).

(5) Results Table 3 shows the survey results. As is apparent from Table 3, the disease control agent of the present invention showed a remarkably high control effect against bacterial wilt disease.

<Example 4>
(Rice Bacterial Disease Control Test)
(1) Preparation of infected seeds Rice (variety: Fusaotome) seeds were put into a solution containing a seedling bacterial bacterium and forcibly inoculated into the seeds under reduced pressure conditions. After air drying, the seed pods were used as seeds infected with the seedling blight disease.

(2) Drug treatment The preparation produced in Formulation Example 1 above was diluted 200 times (mass) in water, and 5 g of seedling-infected bacterial disease-infected seeds that had been absorbed at 15 ° C. for 5 days were added to 15 ml of this solution. In the dark, it was immersed in a 30 ° C. artificial meteorological device for 24 hours to obtain drug-treated seeds. Seeds with seedling bacteriomycetes were similarly immersed in water and used as the target (untreated seeds).

(3) Growth of test plant After the above-mentioned immersion treatment, seedlings infected with bacterial wilt of seedlings were sown in a 100 cm ² plastic pot filled with soil for growing rice seedlings. The area where the chemical-treated seeds were sown was designated as the chemical-treated area, and the area where the untreated seeds were sown was designated as the non-treated area. Three repetitions were made in both the drug-treated group and the non-treated group. After covering with the above paddy rice seedling cultivating medium, the cultivation was controlled in a glass greenhouse according to a standard method.

(4) Pest control effect investigation Two weeks after sowing, the number of diseased seedlings in 3 treatments of each treatment area was determined by using the seedlings with the symptoms of seedling bacterial disease such as rot, wilting and whitening as the diseased seedlings. Based on the above (Formula 1), the diseased seedling rate was calculated using the average value. And the control value of the chemical treatment area was calculated from the calculated diseased seedling rate as a control effect based on the above (Formula 2).

(5) Results Table 4 shows the survey results. As is clear from Table 4, the disease control agent of the present invention showed a remarkably high control effect against rice seedling bacterial diseases.

<Example 5>
(Rice brown stripe control test)
(1) Preparation of infected seeds Rice (cultivar: Fusaotome) seeds were put into a solution containing brown stripe fungus and forcibly inoculated into the seeds under reduced pressure conditions. After air-drying, this seed pod was used as a brown streak-infected seed

(2) Drug treatment Formulation Example 1 produced as described above was diluted 200 times (mass) in water, and 5 g of brown streak-infected seeds that had been absorbed at 15 ° C. for 5 days were introduced into 15 ml of this solution. Immersion treatment was carried out for 24 hours in an artificial meteorological device at 0 ° C. to obtain drug-treated seeds. The seeds infected with brown streak fungus were similarly immersed in water and used as the target (untreated seeds).

(3) Growth of test plant After the immersion treatment, seeds infected with brown streak fungus were sown in a 100 cm ² plastic pot filled with paddy rice seedling culture soil. The area where the chemical-treated seeds were sown was designated as the chemical-treated area, and the area where the untreated seeds were sown was designated as the non-treated area. Three repetitions were made in both the drug-treated group and the non-treated group. After covering with the above paddy rice seedling cultivating medium, the cultivation was controlled in a glass greenhouse according to a standard method.

(4) Control effect investigation Two weeks after sowing, the average value of the number of diseased seedlings in three iterations of each treatment area was set as the seedlings with the symptoms of brown streak disease such as rot, wilting and browning of the seedlings. Based on the above (Equation 1), the diseased seedling rate was calculated. And the control value of the chemical treatment area was calculated from the calculated diseased seedling rate as a control effect based on the above (Formula 2).

(4) Results Table 5 shows the survey results. As is clear from Table 5, the disease control agent of the present invention showed a remarkably high control effect against brown rot of rice.

<Example 6>
(Control of rice seedling blight with Fusarium fungus)
(1) Inoculation with pathogenic fungus The Fusarium fungus and culture of Fusarium cultivated in the paddy rice seedling culture medium were uniformly mixed with the paddy rice seedling culture medium to obtain a rice seedling blight-contaminated soil by Fusarium fungus.

(2) Chemical treatment Rice (variety: Koshihikari) was sown in a 100 cm ² plastic pot filled with the seedling blight-contaminated soil by the Fusarium fungus. And the solution which diluted the formulation manufactured by the formulation example 1 1000 times (mass) with water was uniformly spray-processed on the said soil surface (25 ml), and it was set as the chemical treatment section. Moreover, the pot which used the said chemical | medical agent solution as water was produced, and it was set as the object (non-processing section). Two repetitions were made for both the drug-treated group and the non-treated group.

(3) Growth of test plant After covering the pot subjected to the above treatment with soil for raising rice seedlings, cultivation was controlled in a glass greenhouse according to a standard method.

(4) Pest control effect investigation Two weeks after sowing, seedlings with the symptoms of seedling blight caused by Fusarium fungi such as spoilage, wilting, and browning of seedlings were used as diseased seedlings, and the diseased seedlings in two iterations of each treatment area Based on the above (Equation 1), the diseased seedling rate was calculated using the average number. And the control value of the chemical treatment area was calculated from the calculated diseased seedling rate as a control effect based on the above (Formula 2).

(5) Results Table 6 shows the survey results. As is apparent from Table 6, the disease control agent of the present invention showed a remarkably high control effect against rice seedling blight caused by Fusarium fungi.

<Example 7>
(Riceps fungus control test for rice seedlings)
(1) Inoculation of pathogenic fungi Rice bran seedling culture medium was uniformly mixed with bran and Rhizopus fungus cultures cultured in paddy rice seedling culture medium, to obtain rice seedling blight-contaminated soil by Rhizopus bacteria.

(2) Chemical treatment Rice (variety: Koshihikari) was sown in a 100 cm ² plastic pot filled with the seedling blight-contaminated soil with Rhizopus. Then, a solution obtained by diluting Formulation Example 1 1000 times (mass) with water was uniformly sprayed (25 ml) on the soil surface to obtain a chemical treatment section. Moreover, the pot which used the said chemical | medical agent solution as water was produced, and it was set as the object (non-processing section). Two repetitions were made for both the drug-treated group and the non-treated group.

(3) Growth of test plant After covering the pot subjected to the above treatment with soil for raising rice seedlings, cultivation was controlled in a glass greenhouse according to a standard method.

(4) Investigation of control effect Two weeks after sowing, the seedlings with the symptoms of seedling blight caused by Rhizopus bacteria such as seed rotting, wilting, root growth inhibition, etc. are used as diseased seedlings, and repeated twice in each treatment section. Based on the above (Formula 1), the diseased seedling rate was calculated using the average number of diseased seedlings. And the control value of the chemical treatment area was calculated from the calculated diseased seedling rate as a control effect based on the above (Formula 2).

(5) Results Table 7 shows the survey results. As is apparent from Table 7, the disease control agent of the present invention showed a remarkably high control effect against rice seedling blight caused by Rhizopus.

<Example 8>
(Trial derma bacterium rice seedling blight control test)
(1) Inoculation of pathogenic fungi Rice bran seedling culture medium was uniformly mixed with bran and Trichoderma fungus culture cultivated in paddy rice seedling seedling culture medium to obtain rice seedling blight-contaminated soil by Trichoderma fungus.

(2) Chemical treatment Rice (cultivar: Koshihikari) was sown in a 100 cm ² plastic pot filled with the soil that caused seedling blight caused by Trichoderma bacteria. Then, a solution obtained by diluting Formulation Example 1 in water 1000 times (mass) was uniformly sprayed (25 ml) on the soil surface to obtain a chemical treatment section. Moreover, the pot which used the said chemical | medical agent solution as water was produced, and it was set as the object (non-processing section). Two repetitions were made for both the drug-treated group and the non-treated group.

(3) Growth of test plant After covering the pot subjected to the above treatment with soil for raising rice seedlings, cultivation was controlled in a glass greenhouse according to a standard method.

(4) Pest control effect investigation Two weeks after sowing, a seedling having a disease symptom of seedling blight caused by Trichoderma fungi such as seed rot, wilting, root growth inhibition, etc. is regarded as a diseased seedling, and repeated twice in each treatment section. Based on the above (Formula 1), the diseased seedling rate was calculated using the average number of diseased seedlings. And the control value of the chemical treatment area was calculated from the calculated diseased seedling rate as a control effect based on the above (Formula 2).

(5) Results Table 8 shows the survey results. As is apparent from Table 8, the disease control agent of the present invention showed a remarkably high control effect against rice seedling blight caused by Trichoderma fungi.

Claims (6)

  An agent for controlling a disease occurring during the seedling raising period of rice, comprising a filamentous fungus belonging to the genus Talaromyces having an antagonistic action against a pathogen causing a disease at the time of rice seedling raising.   The control agent of the disease which generate | occur | produces at the time of the seedling raising of rice of Claim 1 whose pathogenic microbe which causes a disease at the time of rice seedling raising is a rice seed infectious pathogen or a soil infectious pathogen. The pathogenic fungi that cause disease during the rice seedling season are: Gibberella fujikuroi; rice blast fungus (Pyricularia oryzae); rice sesame leaf blight fungus (Cochliobolus miyabeanus); Pseudomonas
plantarii); rice brown streak fungus (Pseudomonas avenae); at least one of Fusarium spp., Pythium spp., Rhizopus spp., Trichoderma spp. The control agent of the disease which generate | occur | produces at the time of the seedling raising of rice of Claim 2 which is one.   The disease control agent according to any one of claims 1 to 3, wherein the filamentous fungus belonging to the genus Talaromyces is Talaromyces flavus.   The disease control agent according to claim 4, wherein the filamentous fungus belonging to the genus Talalomyces is Talalomyces flavus Y-9401 strain (FERM P-15816).   A disease occurring at the time of rice seedling raising, comprising a step of treating rice seed, seedling, seedling soil or seedling culture medium with the disease controlling agent according to any one of claims 1 to 5. Control method.