JPH11279015A - Plant growth promoter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a plant growth promoter having a plant growth promotive action, disease control action and no harmful effect on the environment and ecosystem and useful as a harmless microbial material by making the promotor include fungi belonging to the genus Trichoderma. SOLUTION: This promoter is obtained by including fungi belonging to the genus Trichoderma preferably those being in sporulation (e.g. Trichoderma aureoviride IFO 31932) and preferably soil. This promoter has a pest control action for diseases especially caused by pathogenic fungi belonging to pythium family or saprolegnia family (especially fungi belonging to the genus Pythium, Saprolegnia or Aphanomyces) especially damping-off of plants (corn, sweet potatoes, beet, Hibiscus Manihot, grass or the like). The does of the promoter is preferably 10-10<11> CfU (colony forming unit) fungi belonging to the genus Trichoderma based on 100 g culture soil.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a fungus having both a plant growth promoting action and a disease control action. In addition, the present invention relates to a method for promoting plant growth and controlling diseases by applying the fungi to plant growing soil. The invention further relates to plants grown using the method and the crops.

[0002]

BACKGROUND OF THE INVENTION The promotion of plant growth and the control of disease on plants are extremely important issues in the fields of agriculture and horticulture. Much research has been done energetically, and numerous results have been reported. As substances having a plant growth promoting action, plant growth hormones and plant growth regulators produced by plants themselves, and synthetic chemical substances which promote the production of these substances are known. These are all compounds and active researches on them are active. On the other hand, promotion of plant growth using fungi growing in soil has not been studied much. According to the theory, on the surface of plant roots growing in soil, harmful rhizosphere bacteria that inhibit plant growth and plant growth-promoting rhizosphere bacteria that antagonize this bacteria and promote growth are mixed. It is said that there is. Many plant growth-promoting rhizosphere bacteria are fluorescent Pseudomonas, and are said to produce siderophores and suppress the growth of harmful bacteria by competition for iron ions. However, a practical technique for promoting plant growth by increasing the number of plant growth promoting rhizosphere bacteria in soil has not yet been developed. Further, the relationship between filamentous fungi including Trichoderma spp. And the plant growth promoting action of the present invention has not been clarified at all.

On the other hand, most of the plant disease control methods which are carried out today employ pesticides. In particular, the pathogens to be controlled by the present invention are transmitted from the ground to the soil near the ground surface by the movement of zoospores. Pest control is being carried out. However, soil disinfection is not practical because it requires a great deal of labor as a means of disinfecting large-scale soil such as houses and fields. In addition, various fungicides such as chlorpicrin and methyl bromide are concerned about destruction of the environment and ecosystem and adverse effects on the human body, and laws and regulations are being regulated to prohibit use.

[0004] In order to cope with this, microbial materials using bacteria such as Bacillus and Pseudomonas, actinomycetes such as Streptomyces, and filamentous fungi such as Gliocladium have been developed. Most of these microorganisms are antagonistic microorganisms having a deterrent effect on soil-borne pathogenic fungi, and have been confirmed to have a certain effect in reducing soil diseases. However, little research has been done on the effects of these microorganisms on plants themselves, and no effect on plant growth was known.

[0005]

As described above, microbial materials having both a plant growth promoting action and a disease control action have not been developed until now. For this reason, conventionally, a plant growth promoter and a disease control agent had to be prepared and used, respectively, which was costly and complicated.
In addition, depending on the combination of the plant growth promoter and the disease control agent, the mutual effect may be reduced or the plant may be adversely affected, so that the desired effect has not always been obtained.

Therefore, the present invention has been made to solve such a problem of the prior art. In other words, the task to be solved was to develop a safe microbial material that has both a plant growth promoting effect and a disease control effect and does not adversely affect the environment and ecosystem. Another object of the present invention is to develop a microbial material that is easy to use, has low cost, and is expected to be effective.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies in order to solve the above-mentioned problems. As a result, the present inventors have found that Trichoderma spp. They have found that they have a controlling effect, and have provided the present invention. That is, the present invention provides a plant growth promoting agent containing a fungus belonging to the genus Trichoderma. The plant growth promoting agent of the present invention can also be used for the purpose of controlling diseases caused by fungi belonging to the family Phytoaceae or Mycaceae. Above all, it can be used for the control of diseases caused by bacteria belonging to the genera Genus Phytophthora, Exhibitia or Aphanomyces, in particular, damping-off.

[0008] The plant growth promoter of the present invention is preferably a plant selected from the group consisting of corn, sweet potato, sugar beet, trolley mallow, western grass, radish, Chinese cabbage, cabbage, broccoli, spinach, ginger, strawberry, cattleya and dendrobium. Can be applied. In a preferred embodiment of the present invention, Trichoderma sp. Forming spores is used and mixed with soil for application.

[0009] The present invention also provides a method for promoting plant growth, which comprises applying the above-mentioned agent for promoting plant growth to plant growing soil. Further, the present invention provides a method for controlling a disease caused by a fungus belonging to the family Phytoaceae or Mycaceae, which comprises applying the plant growth promoter to a plant growing soil, and also promoting a plant growth. The invention further provides plants grown using these methods and harvests thereof.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the plant growth promoting agent and the method for promoting plant growth of the present invention will be described in detail. For the plant growth promoter of the present invention, fungi belonging to the genus Trichoderma are used as microorganisms having both a plant growth promoting action and a disease control action. The type of fungi used is not particularly limited as long as it is classified into the genus Trichoderma in taxonomic terms.

[0011] For example, Trichoderma Oureobiridi (Trichoderma aureoviride)
IFO 31932, Trichoderma Hazeram ( Tr
ichoderma harzianum ) IFO 3
0543, Trichoderma Koningii ( Tricho
derma koningii ) IFO 9065, Trichoderma Longibrachatium ( Tricho
derma longibrachiatum ) IFO
4847, Trichoderma polysporium ( Tric
holderma polysporium ) IFO 9
322, Trichoderma pseudoconingy ( Tric
hoderma pseudokoningii) IF
O 30545, Trichoderma Lagei ( Trich
derma reese i) IFO 3132, Trichoderma virido ( Trichoderma vir)
ide ) IFO 5720 and the like.

In the present invention, it is preferable to use a bacterium belonging to the genus Trichoderma, but a mutant thereof can also be used. For the mutant strain, for example, spore suspension of Trichoderma sp. Is irradiated with ultraviolet light or treated with a mutagen such as ethyl methanesulfonate or N-methyl-N'-nitro-N-nitrosoguanidine. Can be obtained by In the present invention, any one of these Trichoderma spp. And mutants thereof may be used alone, or two or more may be used in combination.

As the plant growth promoter of the present invention, fungi belonging to the genus Trichoderma may be used as the raw powder, or a culture cultured on a solid medium or liquid medium may be used. In order to effectively exert the effects of the present invention, it is preferable to use Trichoderma spp. In which spores are sufficiently formed. Among them, it is preferable to use thick-membrane spores having a higher germination rate than conidiospores which are extremely sensitive to bacteriostatic action and have a low germination rate in soil. Therefore, it is desirable to use a bacterium cultured to an appropriate growth stage in an appropriate medium for the growth promoter of the present invention.

As a medium for culturing Trichoderma sp.
For example, cornmeal sand medium (cornmeal 3g, bran 2g, glucose 0.5g, mountain sand 150g, tap water 3
0 ml). By culturing Trichoderma spp. In a cornmeal medium at 25 ° C. for 3 weeks, 70% chlamydospores can be formed.

The Trichoderma bacterium can also be cultured using a medium containing a plant-derived solid component and a porous carrier. As the plant-derived solid component, it is preferable to use inexpensive grounds such as cereals and beans, and specifically, bran, rice bran, soybean grounds, okara, red bean grounds, peanut grounds, and the like can be used. These plant-derived solid components can be used alone or in combination of two or more. Examples of the porous carrier to be added to the medium include mineral inorganic porous carriers such as zeolite, montmorillonite, perlite, pumice, charcoal, and coral sand, and vegetable organic porous carriers such as bark and sawdust.
These porous carriers can be used alone or in combination of two or more. The particle size of the porous carrier is 0.2 to 5 m
m, and the compounding amount of the porous carrier is preferably 30 to 70% by weight of the compounding amount of the plant-derived solid component. By culturing Trichoderma cells under such conditions, a sufficient amount of chlamydospores can be formed.

As the medium, a medium other than those described above can be used. For example, a bran / verculite medium (1: 1), a wheat grain medium, and an oat grain medium can also be used. The obtained culture may be used as it is as the plant growth promoter of the present invention, or may be used after drying.

The cells of the genus Trichoderma (including mycelia, conidia, and chorion spores) can be encapsulated and used as the growth promoter of the present invention. For example, Trichoderma cells can be embedded in a gel formed by reacting a cation such as calcium with an aqueous solution of sodium alginate to form granules. Further, granulation can also be carried out using clay as a bulking agent for cells. In addition, a nutrient such as bran can be used as a bulking agent and granulated as a food base for Trichoderma sp.

These Trichoderma cells, cultures and encapsulated materials may be used as they are, or may be used after being mixed with soil in advance. When mixed with soil, sandy to loam soil, soil sterilized by steam at about 70 ° C., natural soil, and the like can be used. The amount of the strain relative to the whole soil is preferably 25% or more, more preferably 30% or more, and 3% or more.
Most preferably, it is 5% or more.

The method for applying the plant growth promoter of the present invention is not particularly limited. Therefore, Trichoderma cells, cultures, encapsulated materials or a mixture of these and soil may be sprayed on plant seeds at the time of sowing, or mixed with seedling soil or placed at the root of seedlings. . Time of application is not particularly limited. Therefore, it can be applied before seeding, at the time of plant germination, at the time of plant growth, at the time of bud formation, at the time of fruiting, and the like. Most preferably, it is applied before sowing. No limit on the number of applications, 1
The application may be applied all at once, or may be applied periodically or irregularly and divided into a plurality of times. Further, it may be applied intensively before a time when a disease is predicted or when a disease occurs. Those skilled in the art can appropriately optimize these application conditions.

The amount of the plant growth promoter of the present invention to be applied is 10 to 10 ¹¹ CFU of Trichoderma per 100 g of soil.
(Colony forming unit).
If this amount is less than 10 CFU per 100 g of cultivation soil, the expression of the plant growth promoting effect tends to be unstable, and if it exceeds 10 ¹¹ CFU, the effect is flattened out and becomes economically disadvantageous.

The types of plants to which the plant growth promoter of the present invention can be applied are not limited. Therefore, agriculture,
The present invention can be applied to any plants useful in the fields of horticulture and medicine. Among them, it can be preferably applied to plants classified as vegetables, fruits, and grains. For example, corn, sweet potato, sugar beet, trolley mallow, western grass, radish, Chinese cabbage, cabbage, broccoli, spinach, ginger, strawberry, cattleya,
It can be preferably applied to dendrobium and the like.
Among them, it can be more preferably applied to Chinese cabbage, cabbage, and broccoli.

By applying the plant growth promoter of the present invention, plant growth can be greatly promoted. As will be apparent from the embodiments and drawings described later, the effects of the present invention are so remarkable that they can be clearly recognized at a glance. The usefulness of the present invention is extremely high because a large growth promoting effect can be obtained by a simple operation of simply applying Trichoderma to soil.

Further, the plant growth promoter of the present invention not only exhibits a growth promoting effect, but also has a controlling effect on diseases caused by fungi belonging to the family Phytoaceae or Mycaceae. Fungi belonging to the family Phytomycetes or Mycetaceae include harmful pathogens belonging to the genus Phthium , the genus Phytophthora and the genus Aphanomyces . In particular, Pythium ultimum belonging to the genus Phythium is known to cause many diseases. For example, maize seedling wilt, sweet potato white rot, sugar beet seedling wilt, trolo-mallow wilt, western sibapicium disease, radish rot, Chinese cabbage seedling wilt, spinach wilt,
Ginger rhizome rot, strawberry fruit rot, cattleya seedling black rot, dendrobium seedling black rot, etc. are caused by infection with picium ultimum. This fungus survives in oospores and has a long lifespan in the soil. For this reason, Chinese cabbage, which has been continuously cultivated due to competition between production areas, is spreading nationwide, and its damage has become a serious problem.

By applying the plant growth promoter of the present invention, such diseases can be effectively controlled. The plant growth promoter of the present invention is different from a conventional product in which soil microorganisms are killed indiscriminately by highly toxic agents such as fumigants, and there is no concern that the balance of soil microorganisms is excessively disrupted. The plant growth promoter of the present invention can germinate and grow seeds without being infected by pathogenic bacteria, especially if applied before sowing. In addition, the disease can be effectively controlled by applying it immediately before the time when the onset of the pathogen is predicted. Further, even when applied after being infected with a pathogenic bacterium, the disease can be minimized. Whether or not a plant is infected with a pathogenic bacterium is determined by a method such as observing the growth state of the plant, placing a diseased tissue fragment of a root or a ground stem on a potato dextrose agar medium and detecting the pathogenic bacterium, or the like. be able to.

The present invention also includes a plant grown using the plant growth promoter of the present invention and a harvest thereof. For example, horticultural plants grown by applying the plant growth promoter of the present invention, vegetables, fruits, cereals, and plants of the present invention harvested from plants grown by applying the plant growth promoter of the present invention All medicinal ingredients obtained from herbs grown by applying a growth promoter are included in the present invention.

[0026]

EXAMPLES The present invention will be specifically described below with reference to examples. Components, amounts, ratios, procedures, and the like described in the following examples can be appropriately changed without departing from the technical idea of the present invention. Therefore, the scope of the present invention is not limited to the specific examples described below.

[0027] Pysium ultimum isolated from tulips in Wakami town, Akita prefecture and confirmed to be pathogenic to Chinese cabbage seedlings was transformed into a V8JS medium [V8 juice 200 m
l, 3 g of calcium carbonate, 20 g of glucose and 800 ml of distilled water, and 15 ml of the resulting mixture
g of sterilized mountain sand] at 25 ° C for 3 weeks. Separately, six kinds of Trichoderma spp. Are cultured in a cornmeal sand medium (3 g of cornmeal, 2 g of bran, 0.5 g of glucose, 150 g of mountain sand, 30 ml of tap water) for 25 minutes.
C. for 2 to 3 weeks. While culturing these bacteria, they were shaken by hand every 2-3 days.

After cultivation, Samples 1 to 8 were prepared by mixing at a ratio of pathogen: Trichoderma: soil = 8 g: 80 g: 160 g per pot. The soil used was a mixture of sterilized mountain sand, vermiculite and perlite at a volume ratio of 1: 1: 1. After adding 30 ml of distilled water per pot, each sample was put in a plastic bag and cultured at room temperature for 3 days.
After that, put them in plastic pots and put 2
0 to 30 seeds were sown, and distilled water of about 8 minutes was put in a saucer and cultivated using an artificial weather machine (27 ° C., 3000 lux illumination for 12 hours).

Two weeks after the sowing, the effect of each sample on promoting plant growth, emergence rate, and the number of dead after emergence were examined.
The plant growth promoting effect was evaluated by measuring the number of leaves and the maximum leaf length (vertical, horizontal). The budding rate was calculated by the following formula (1), considering that the cotyledons having more than half exposed on the ground surface were regarded as budding. In addition, the mortality was calculated by the following equation (2). The results are summarized in Table 1. FIG. 1 shows the state of Samples 1, 2 and 4 two weeks after the seeding.

[Equation 1] Emergence rate (%) = (Number of emergence / Number of seeds) × 100 (1) Death rate (%) = (Number of emergence / Number of emergence) × 100 (2)

[0030]

[Table 1]

The presence of Pycium in the sterile soil greatly reduces the germination rate, and the germination ends when the germination occurs (comparison between sample 1 and sample 2). On the other hand, when Trichoderma sp. Is present (samples 3 to 8), the germination rate and the number of leaves are recovered to the same extent as those in the absence of Pycium fungi, and there is almost no withering after germination. Also, the leaf size is clearly larger than in the absence of P. typhi, with a maximum height of 1.
There is a growth promoting effect of 8 times and 1.6 times in horizontal length. Since such a remarkable growth promoting effect has been confirmed in the presence of P. fungi, it is clear that the plant growth promoting agent of the present invention exhibits a positive growth promoting effect as well as the control of pathogenic bacteria.

[0032]

EFFECT OF THE INVENTION Since the plant growth promoter of the present invention has both a plant growth promoting action and a disease control action, two effects can be expected by applying it once. Therefore, there is no need to separately prepare and apply a plant growth promoter and a disease control agent as in the conventional case, which is useful for cost reduction and work simplification. Further, the plant growth promoter of the present invention has an advantage of high safety because it does not adversely affect the environment and ecosystem.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a photograph showing the growth state two weeks after sowing of Chinese cabbage (see samples 1, 2 and 4 in Examples: the upper and lower rows show the results of performing the same test twice).

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Reiko Honda 241 Kariwano, Nishi-Senboku-cho, Senboku-gun, Akita Co., Ltd. Inside the Fungal Function Development Laboratory (72) Inventor Hiroshi Konno 241 Kariwano, Nishi-Senboku-cho, Senboku-gun, Akita Prefecture Address: Inside the Fungal Function Development Laboratory, Inc. (72) Inventor Isamu Takahashi, 241 Kariwano, Nishi-Senboku-cho, Senboku-gun, Akita Prefecture Inside the Fungal Function Development Laboratory, Inc.

Claims (10)

[Claims] 1. A plant growth promoter comprising a fungus belonging to the genus Trichoderma. 2. The plant growth promoting agent according to claim 1, which has an action of controlling diseases caused by fungi belonging to the family Phytoaceae or Mycaceae. 3. The plant growth promoting agent according to claim 2, wherein the pathogenic bacterium is a bacterium belonging to the genus Phylum, the genus Echibokin or the genus Aphanomyces. 4. The plant growth promoter according to claim 2, wherein the disease is a damping-off of a plant. 5. The plant according to claim 1, wherein the plant is selected from the group consisting of corn, sweet potato, sugar beet, trolley mallow, western grass, radish, Chinese cabbage, cabbage, broccoli, spinach, ginger, strawberry, cattleya, and dendrobium. Item 5. The plant growth promoter according to any one of Items 1 to 4. 6. The plant growth promoting agent according to claim 1, wherein the fungus belonging to the genus Trichoderma forms spores. 7. The plant growth promoter according to claim 1, further comprising soil. 8. A method for promoting plant growth, comprising applying the plant growth promoting agent according to any one of claims 1 to 7 to plant growing soil. 9. A plant growth promoting agent according to any one of claims 1 to 7, which is applied to a plant growing soil for controlling diseases caused by fungi belonging to the family Phytoaceae or Mycobacterium. A method of promoting plant growth. 10. A plant grown using the method according to claim 8 or 9 and a harvest thereof.