JP3299503B2 - Method for controlling fungal plant diseases - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for controlling fungal plant diseases.

[0002]

2. Description of the Related Art As a method for sterilizing microorganisms and bacteria, chemical sterilization by chemicals and physical sterilization by heating are generally used. General.

It is also known to use acidic electrolyzed water as food-related sterilization. The acidic electrolyzed water is an aqueous solution generated on the anode side by electrolyzing a saline solution or the like. Sterilization with acidic electrolyzed water is mainly used for bacteria, mainly Escherichia coli, and for the sterilization of filamentous fungi, its bactericidal effect has been reported for food-contaminating filamentous fungi such as Aspergillus and Penicillium. Yes (J. Antibact. Anti
fung. Agents Vol. 25, No. 7, pp. 387-39
1, 1997).

[0004] However, the sterilization of filamentous fungi using the acidic electrolyzed water reported above is applied only to pure filamentous fungi, and a method for controlling the disease of plants carrying the filamentous fungi is known. Not.

[0005] In the control of plant diseases, it is particularly difficult to control filamentous fungi in grasses, and the fir carrying the filamentous fungi develops during seedling after germination, and causes blast and stunt seedling diseases. appear.

[0006]

When controlling plant diseases using an agricultural fungicide, there is a problem that the agricultural fungicide remains in the environment and causes environmental pollution.

[0007] In addition, there is also a problem that a resistant bacterium appears due to a large amount of agricultural germicides used, and the agricultural germicides are invalidated. When the agricultural germicide is invalidated, it becomes necessary to use a new agricultural germicide, and a vicious cycle occurs in which environmental pollution is further expanded.

On the other hand, for the purpose of reducing the amount of agricultural germicide to be used, there is known a control method in which an aqueous solution obtained by mixing acidic electrolyzed water and agricultural germicide is sprayed on plants. However, when using an aqueous solution obtained by mixing the acidic electrolyzed water and the agricultural germicide, the reduction amount of the agricultural germicide cannot be said to be sufficient, and the agricultural germicide is further reduced from the viewpoint of environmental pollution and weather-resistant bacteria. There is a need for an effective control method with an agent. Also,
The method of mixing the acidic electrolyzed water and the agricultural germicide involves the problem that hypochlorous acid in the acidic electrolyzed water may react with germicidal components and the like in the agricultural germicide to form harmful substances. are doing. There is also a problem that hypochlorous acid, which is a main sterilizing component of the acidic electrolyzed water, is consumed by the agricultural germicide, and the sterilizing activity of the acidic electrolyzed water is reduced.

[0009] In addition, there is no known method of controlling a gramineous plant which carries a filamentous fungus, which has a small effect on the environment and works effectively.

Therefore, the present invention solves the conventional problems,
An object of the present invention is to provide a method for controlling a plant disease caused by a filamentous fungus which does not cause environmental pollution due to residual agricultural fungicide and does not cause a problem of resistant bacteria.

[0011]

The method for controlling a fungal plant disease according to the present invention is characterized in that acidic electrolyzed water and an agricultural disinfectant are separately used in combination with each other for a plant that carries the filamentous fungus. It kills the filamentous fungus or suppresses the growth and proliferation of the filamentous fungus, thereby controlling plant diseases caused by the filamentous fungus.

The acidic electrolyzed water applied to the control method of the present invention is an aqueous solution generated on the anode side in the electrolysis of an aqueous solution containing chlorine, and hypochlorous acid in the acidic electrolyzed water is a phytopathogenic fungi. Has the effect of killing. Hypochlorous acid is highly reactive and has many points of action against diseased bacteria. For this reason, it is considered that bacteria resistant to hypochlorous acid are unlikely to appear, and in fact, there is no report of their appearance.

Further, the control method of the present invention suppresses the growth of filamentous fungi by inhibiting spore formation of filamentous fungi. In general, filamentous fungi take two states, a spore state and a filamentous mycelium formed by germination from spores. In the present invention, spore formation is inhibited by applying acidic electrolyzed water to the spores, and the growth of filamentous fungi is more effectively suppressed.

The control method of the present invention can control, for example, diseases such as rice blast, falcon seedling disease, seedling wilt of flowers, and bulb rot of tulips. Preferably, the target is a disease of a gramineous plant, more preferably, a disease of a rice plant. Here, blast is a disease of a plant that forms a brown spindle-shaped lesion on seedlings, leaves, ears and the like due to the infestation of Pyricularia spp., Which is a type of filamentous fungus and belongs to imperfect fungi, such as rice blast and corn. Blast disease, rice millet blast and the like are known. In addition, frog seedling disease is a kind of filamentous fungus and is a disease in which rice and the like yellow and prolong due to infestation of Gibberella belonging to ascomycetes.

[0015] The gramineous plant is a family of monocotyledonous plants and includes rice, wheat, corn, millet, barnyard millet, sugarcane, bamboo and the like.

The acidic electrolyzed water can be applied in the form of seed disinfection, soil disinfection, spray disinfection during plant growth, or crop disinfection. In these application modes of the acidic electrolyzed water, seed disinfection and crop disinfection are desirable, and seed disinfection is particularly preferable, based on the amount of the acidic electrolyzed water used, the contact conditions with the filamentous fungi, and the growth conditions of the plant.

In the control method of the present invention, as a mode of seed disinfection, soaking in acidic electrolyzed water or immersion in acidic electrolyzed water can be applied. This seed disinfection by soaking involves soaking seeds having filamentous fungi in acidic electrolyzed water for a predetermined time, and desirably soaking for several days before seed germination. Also, in seed disinfection by this soaking,
By exchanging the acidic electrolyzed water every predetermined time, more effective control of filamentous fungi can be performed. By performing seed disinfection, the fungi possessed by the seeds are killed,
The spores of the filamentous fungus can be prevented from germinating and growing into hyphae.

The combined use of the acidic electrolyzed water and the agricultural germicide in the control method of the present invention is carried out in such a manner that the seed is soaked in the acidic electrolyzed water and then the agricultural germicide is soaked, After soaking in water, an embodiment in which a treatment is applied to an agricultural germicide can be applied. Further, in soaking seeds with acidic electrolyzed water, an embodiment in which acidic electrolyzed water is exchanged at predetermined time intervals can be applied.

The combined use of the acidic electrolyzed water and the agricultural germicide enables the use of the agricultural germicide alone,
The use amount of the agricultural disinfectant can be reduced as compared with the case where the mixed aqueous solution of the acidic electrolyzed water and the agricultural disinfectant is used.

In addition, as the agricultural disinfectant used in combination with the acidic electrolyzed water in the present invention, products such as Sportac (manufactured by Nissan Chemical Industry Co., Ltd.), Trifmin (manufactured by Ishihara Sangyo Co., Ltd.) and Hellseed (manufactured by Hokuko Chemical Co., Ltd.) Ergosterol biosynthesis-inhibiting agricultural fungicides known by name can be applied.

[0021]

Embodiments of the present invention will be described below in detail. As the acidic electrolyzed water used in the present invention, an aqueous solution generated on the anode side by electrolyzing an aqueous solution containing chlorine can be used. As a configuration for generating acidic electrolyzed water, for example, electrodes are disposed in two chambers separated by a diaphragm in an electrolytic cell, and a DC power supply is connected to each electrode to form an anode chamber and a cathode chamber. When an aqueous solution containing chlorine is injected into the electrolytic cell and the solution is electrolyzed, acidic electrolyzed water is generated on the anode side, and alkali-reduced water is generated on the cathode side.

The acidic electrolyzed water used in the following tests was 0.1%.
It is formed on the anode side when a 1% aqueous sodium chloride solution is electrolyzed by a batch-type apparatus having a diaphragm. In the method for controlling a fungal plant disease of the present invention, the above-mentioned acidic electrolyzed water is applied to a plant that carries the fungus. In the following, a description will be given using an example in which acidic electrolyzed water is applied to rice infected with the blast fungus as a plant that carries the filamentous fungus.

In the following application examples, a natural blast of rice blast (Hagara Nagano) is used as a plant that carries the filamentous fungus, and the pH of this seed (fir) is 2 and the residual chlorine concentration is 200 ppm. Apply electrolyzed water. An example in which acidic electrolyzed water having a pH of 5 and a residual chlorine concentration of 200 ppm is also shown. Further, an example is shown in which ergosterol biosynthesis-inhibiting Sportac (trade name) is used as an agricultural germicide to be used in combination with acidic electrolyzed water.

The spore formation rate is used as an index for evaluating the control effect. In addition, the measurement of the spore formation rate was performed by the filter paper wet method with reference to the manual of the Japan Plant Control Association.

Hereinafter, description will be made with reference to Tables 1 and 2.
Tables 1 and 2 show two examples of the combined use of acidic electrolyzed water and an agricultural disinfectant. Table 1 shows an example of a first embodiment in which seeds are dipped in acidic electrolyzed water and subjected to a first pretreatment, and then dipped in an agricultural disinfectant to perform a second pretreatment. Fig. 8 shows an example of a second embodiment in which after-soaking in water, post-treatment of soaking in an agricultural fungicide is performed. First, the first embodiment will be described with reference to Table 1.

[0026]

[Table 1] (A) in Table 1 shows a case of no treatment to which the control method of the present invention is not applied. As shown in (a) of Table 1,
The sporulation rate without treatment is 74%. Table 1
(B) in the figure shows the case where the acidic electrolyzed water and the agricultural germicide are used alone.

(B) in Table 1 is a comparative control of the pretreatment. Seeds (fir) were dipped in 0.1% saline for 24 hours in the first pretreatment, and then the seeds (fir) were subjected to the second pretreatment. This shows a case where the pretreatment is performed by dipping in pure water (Milli-Q water). In this case, the spore formation rate is 62%.

On the other hand, in the first pretreatment, the pH was 2 or 5, and the pH was 2 to 5 in acidic electrolyzed water having a residual chlorine concentration of 200 ppm.
After soaked 4 hours, when the processing immersing in pure water (Milli Q water) at a second pre-treatment, 39% respectively, sporulation rate in this case, and 50%.

Further, when a sterilized agricultural fungicide prepared by diluting Sportac's agricultural fungicide to 1/100 of the specified amount is used alone and the diluted agricultural fungicide is treated with a seed (fir) soaked, Has a sporulation rate of 44%.

In contrast to the above-mentioned single use of the acidic electrolyzed water or the diluted agricultural germicide, Table 1 (c) shows the case where the acidic electrolyzed water and the diluted agricultural germicide are used in combination. In (c) of Table 1, after dipping for 24 hours in acidic electrolyzed water having a pH of 2 and a residual chlorine concentration of 200 ppm in the first pretreatment, sportac was reduced to 1/100 of the specified amount in the second pretreatment.
After 24 hours of soaking in a diluted agricultural fungicide diluted to 8%, the sporulation rates in this case are 8% and 2%, respectively.
Becomes

In addition, (c) in Table 1 shows that, after dipping in acidic electrolyzed water having a pH of 5 and a residual chlorine concentration of 200 ppm in the first pretreatment for 24 hours, a specified amount of spore tack was obtained in the second pretreatment. This also shows a case in which a diluted agricultural fungicide diluted to 1/100 of the above is subjected to a soaking treatment for 24 hours. In this case, the spore formation rate is 28%.

Therefore, as the pretreatment before germination, the first pretreatment of soaking the seeds (fir) in acidic electrolyzed water and the second pretreatment of soaking in Sportac's diluted agricultural fungicide are carried out in combination. In addition, sporulation of filamentous fungi can be suppressed. The pH of the acidic electrolyzed water used in the combined treatment is preferably about 2, and the residual chlorine concentration is preferably about 200 ppm. Next, the second embodiment will be described with reference to Table 2.

[0033]

[Table 2] (A) in Table 2, like (a) in Table 1, shows a case of no treatment to which the control method of the present invention is not applied. Table 2
As shown in (a), the spore formation rate in the case of no treatment is 74%. In addition, (b) in Table 2 shows control data that is used in combination with the post-processing according to the second embodiment. In this control data, the spore formation rate when seeds (fir) are soaked with 0.1% saline and then post-treated with pure water (Milli-Q water) is 26%. (Fir)
Is immersed in acidic electrolyzed water having a pH of 2 and a residual chlorine concentration of 200 ppm, and then subjected to post-treatment in pure water (Milli-Q water), the spore formation rate is 6%, and the seeds (fir) Is immersed in a 0.1% saline solution, and then subjected to a post-treatment of dipping Sportac in a diluted agricultural fungicide diluted to 1/100 of the specified amount, the spore formation ratio is 4%. In addition, each immersion was performed for 5 days, and post-treatment was performed for 24 hours.

On the other hand, seeds (fir) having a pH of 2,
After soaking for 5 days in acidic electrolyzed water having a residual chlorine concentration of 200 ppm, the spores are formed at a rate of 2% when subjected to a post-treatment for 24 hours after diluting Spoltac to a diluted agricultural fungicide diluted to 1/100 of the specified amount. . The immersion in the table is at a temperature of 20 ° C.

Therefore, the spore formation of filamentous fungi can be suppressed by performing a combined treatment of soaking seeds (fir) with acidic electrolyzed water and then performing post-treatment with a diluted agricultural fungicide. The pH of the acidic electrolyzed water used for the combined treatment
Is preferably about 2 and the residual chlorine concentration is preferably about 200 ppm.

In each of the above-described embodiments of the acidic electrolyzed water, the pH of the acidic electrolyzed water is preferably about 2.

In soaking seeds with acidic electrolyzed water, an embodiment in which acidic electrolyzed water is exchanged at predetermined time intervals may be applied.

According to the present invention, the combined use of the acidic electrolyzed water and the agricultural germicide enables the use of the agricultural germicide alone or the mixed aqueous solution of the acidic electrolyzed water and the agricultural germicide. It is possible to reduce the use amount of the agricultural germicide as compared with the case where it is performed. In addition, since hypochlorous acid contained in the acidic electrolyzed water has no persistence, the effect on the environment can be suppressed and the appearance of resistant bacteria can be prevented.

[0039]

As described above, according to the present invention,
The plant disease caused by the filamentous fungus can be controlled without causing environmental pollution due to the residual agricultural fungicide and without causing the problem of resistant bacteria.

Continuing from the front page (72) Inventor Tohru Kuda 2-6-1 Sengen, Tsukuba-shi, Ibaraki Co., Ltd. Inside the Functional Water Research Laboratory (72) Inventor Yoji Arata 2-6-1-6 Sengen, Tsukuba-shi, Ibaraki Co., Ltd. Functional Water Research In-house (56) References JP-A-9-308318 (JP, A) JP-A-9-224422 (JP, A) Influence of oxidation potential on plant pathogens-focusing on tobacco mosaic virus- Journal of the Japanese Society of Plant Pathology (Published December 1994), Japan, Vol. 60, No. 6, p. 741. Ritsu, Controlling Bacterial Blight of Rice and Occurring Aqueous Solution in Okayama Prefecture, Japan (1987) ), Japan, No. 156, pp. 33-37 (58) Fields investigated (Int. Cl. ⁷ , DB name) A01N 59/00 A01N 59/08 A01N 25/00 A01N 25/02 A01N 47/38 A01N 43/50 A01M 1/08 JICST file (JOIS)

Claims (3)

(57) [Claims] 1. A plant carrying the blast fungus is treated with acidic electrolyzed water having a residual chlorine concentration of 200 ppm and 1/100 of a specified amount.
A method for controlling filamentous fungal plant diseases, by separately using and applying a two- fold diluted ergosterol biosynthesis-inhibiting agricultural fungicide. 2. The plant according to claim 1, wherein the plant is in a seed state.
The method for controlling fungal plant diseases according to the above. 3. The method for controlling a fungal disease according to claim 2, wherein the seeds are dipped in the order of acidic electrolyzed water and an agricultural fungicide.