JP4456900B2 - Rice seed disinfection method - Google Patents

Description

  The present invention relates to a method for disinfecting rice seeds.

  In paddy rice cultivation, rice seeds are sterilized with chemicals (seed sterilization treatment) before seeding, followed by soaking treatment and sprouting treatment in order to align germination and control seed-borne diseases.

JP 2000-86414 A JP-A-6-227930

However, even if rice seeds are sterilized with chemicals, there are multiple causes such as the fact that the chemicals are inferior in bactericidal activity compared to antibacterial activity, or the presence of pathogenic bacteria resistant to the chemicals. In some cases, the occurrence of sexually transmitted diseases cannot always be sufficiently suppressed.
In addition, it has long been known that components such as eggplant and yam and acetic acid have antibacterial activity, but these components and acetic acid have properties such as extremely strong irritation and strong phytotoxicity to plants. Therefore, the utilization method is limited, and there has been no report about the use of rice seeds as a seed disinfectant.

  Under such circumstances, the present inventors have made various studies on the method of disinfecting rice seeds to suppress the occurrence of seed infectious diseases during the rice seedling stage. It has been found that the occurrence of seed infectious diseases during the rice seedling stage can be sufficiently suppressed by using the rice at a limited time, and the present invention has been achieved.

That is, the present invention
1. Rice seed disinfection method characterized by immersing rice seeds after soaking in an acetic acid solution containing a vegetable spice having an irritating pungent component (hereinafter sometimes referred to as the method of the present invention). );
2. The method for disinfecting rice seeds according to item 1, wherein the acetic acid concentration in the acetic acid aqueous solution is 0.001 to 0.2% by weight;
3. Disinfection of rice seeds according to item 1 or 2, characterized in that the time of soaking the seeds after soaking is 12 to 48 hours in an acetic acid aqueous solution containing a vegetable spice having an irritating pungent component Method;
4). The method for disinfecting rice seeds according to item 1, 2 or 3, wherein the vegetable spice having an irritating pungent component is a vegetable spice derived from eggplant;
5). The method for disinfecting rice seeds according to item 1, 2 or 3, wherein the vegetable spice having an irritating pungent component is a vegetable spice derived from yam;
6). The method for disinfecting rice seeds according to item 4 above, wherein the vegetable spice derived from coconut is powdered mustard or pasty mustard;
7). 6. The method for disinfecting rice seeds according to item 5 above, wherein the vegetable spice derived from yam is powdered wasabi, pasty wasabi, or dried wasabi juice;
8). Rice seed disinfectant solution comprising an aqueous acetic acid solution containing a vegetable spice having an irritating pungent component (hereinafter sometimes referred to as this solution);
9. Disinfecting powder of rice seed characterized by containing a powdery vegetable spice having an irritating pungent component and powdered acetic acid (hereinafter sometimes referred to as the present powder);
Etc. are provided.

  By the method of the present invention, seed infectious diseases that occur during the rice seedling raising stage can be sufficiently suppressed.

  The method of the present invention is characterized by immersing rice seeds after soaking in an acetic acid aqueous solution containing a vegetable spice having an irritating pungent component.

  Rice seeds used in the method of the present invention are those that have been subjected to soaking treatment. Rice seed soaking treatment may be a commonly performed soaking treatment. Usually, the rice seed is soaked in water having a water temperature of about 10 to 30 ° C. for the number of days in which the accumulated water temperature (cumulative daily water temperature) is about 80 to 120 ° C. This is a treatment for immersing seeds.

  The aqueous acetic acid solution used in the method of the present invention may be a liquid containing acetic acid, and examples thereof include an aqueous solution of glacial acetic acid and an aqueous diluted solution of vinegar (synthetic vinegar, brewed vinegar). The acetic acid concentration of the acetic acid aqueous solution is usually in the range of 0.001 to 0.2% by weight, preferably 0.005 to 0.15% by weight, more preferably 0.005 to 0.05% by weight.

Examples of the “plant spice having an irritating pungent component” used in the method of the present invention (hereinafter also referred to as the present plant spice) are plant spices derived from eggplant, yam, and the like. be able to. Examples of the kind of the eggplant include Japanese mustard (Brassica juncea), black mustard (Brassica nigra), and western mustard (Sinapis alba). In addition, examples of the types of yam include Japanese wasabi (Wasabia japonica) and horseradish (Armoracia rusticana).
As plant spices derived from eggplant, yam, etc., for example, powdered or paste-like ones can be used, and these may be used by uniformly suspending or dissolving them in water. Examples of the powdered material include lyophilized products, dried products such as commercially available powdered wasabi or powdered mustard. Examples of the paste-like material include those that have been ground down and those that have been processed after being kneaded with water. Furthermore, for yam, the soup obtained after grinding root wasabi may be used as a vegetable spice having an irritating pungent component.
The vegetable spicy material having an irritating pungent component may contain at least one kind of the above-mentioned vegetable spices, but may be a mixture of a plurality of kinds.
The vegetable spice having an irritating pungent component used in the method of the present invention contains an appropriate amount of a surfactant such as polyoxyethylene sorbitan monolaurate or polyoxyethylene sorbitan monooleate as necessary. May be.

  The acetic acid aqueous solution containing a vegetable spice having an irritating pungent component used in the method of the present invention is usually a vegetable spice in an acetic acid aqueous solution, for example, 0.01 to 4 wt. It is good to make it contain in the ratio of%. When using a powdery thing, it is usually good to contain a vegetable spice in the acetic acid aqueous solution, for example in the ratio of 0.02 to 2 weight%, Preferably it is 0.05 to 1 weight%. When using a paste-like material, a vegetable spice is usually added to the acetic acid aqueous solution, for example, a ratio of 0.04 to 4% by weight, preferably 0.05 to 1% by weight, based on the amount of the acetic acid aqueous solution. It is good to contain. In the case of using rooted wasabi juice, the vegetable spice is contained in the acetic acid aqueous solution in an amount of 0.01 to 2% by weight, preferably 0.05 to 1% by weight, based on the amount of the acetic acid aqueous solution. It is good.

  As a method for preparing an acetic acid aqueous solution containing a vegetable spice having an irritating pungent component used in the method of the present invention, for example, a vegetable spice is added to a predetermined concentration of an acetic acid aqueous solution so as to have a predetermined concentration as described above. In addition to the above, there is a method of mixing well, but there is also a method of once preparing a highly concentrated mixture and then re-preparing it by diluting with water.

  In this invention, the temperature at the time of immersing a rice seed in this liquid agent is the range of 25-40 degreeC normally, Preferably it is the range of 28-35 degreeC from the point which promotes germination more.

  In this invention, the quantity of this liquid agent at the time of immersing a rice seed in this liquid agent should just be the quantity which a rice seed can immerse, and is about 1-3 times amount with respect to the weight of a rice seed normally. The soaking time for immersing rice seeds in this solution depends on the temperature at which the rice seeds are soaked, but is usually in the range of 12 to 48 hours until the rice seeds are uniformly pigeon-chested. . For this reason, sprouting is usually performed at the same time.

Rice seeds germinated simultaneously with seed disinfection by the method of the present invention are sown immediately. The seeding is usually performed in an amount within a range of 80 g to 250 g as a drought amount dried in a 30 cm × 60 cm rice seedling box. Usually, the germinated rice seeds are sown on the soil surface and covered with soil so that the rice seeds are hidden.
The seeded rice seeds germinate when left under high humidity conditions at about 30 ° C. for 2 to 3 days. The seedling box is grown at a temperature of about 20 to 30 ° C. for about 2 to 4 weeks to grow into a transplantable seedling. The growth stage of rice seedlings at the time of transplantation varies greatly from region to region, but about 1.5 leaf stage for breast seedling transplantation, about 2.5 leaf stage for medium seedling transplantation, and about 3.5 leaf stage for adult seedling transplantation. is there. The period from the emergence to the transplantable period is a period called the seedling raising period.

  In the case of rice seed sterilized by the method of the present invention, the occurrence of seed infectious diseases that occur during the rice seedling period is sufficiently suppressed. Such seed infectious diseases include brown streak disease, seedling bacterial disease, stupid seedling disease, seedling blight, seedling blast, sesame leaf blight, seedling rot caused by a rice blight bacterial bacterium, and the like.

  Hereinafter, the present invention will be described in more detail with reference to test examples and the like, but the present invention is not limited to these examples.

  First, manufacture of this liquid agent is shown in the following manufacture examples.

Production Example 1
After weighing 1 g of vinegar and 0.25 g of powdered wasabi in a container, water is added to make a total of 100 ml. Thereafter, the mixture is sufficiently stirred and mixed to obtain this liquid preparation containing 0.25% yam and 1% vinegar (the concentration of acetic acid is about 0.04%).

Production Example 2
1 g of vinegar and 0.25 g of powdered mustard are weighed in a container, and then water is added to make a total of 100 ml. Thereafter, the mixture is sufficiently stirred and mixed to obtain this liquid preparation containing 0.25% coconut and 1% vinegar (the concentration of acetic acid is about 0.04%).

Production Example 3
After weighing 1 g of vinegar and 0.25 g of pasty wasabi in a container, water is added to make a total of 100 ml. Thereafter, the mixture is sufficiently stirred and mixed to obtain this liquid preparation containing 0.25% yam and 1% vinegar (the concentration of acetic acid is about 0.04%).

Production Example 4
1 g of vinegar and 0.25 g of paste mustard are weighed in a container, and then water is added to make a total of 100 ml. Thereafter, the mixture is sufficiently stirred and mixed to obtain this liquid preparation containing 0.25% coconut and 1% vinegar (the concentration of acetic acid is about 0.04%).

Production Example 5
100 g of root wasabi is ground down and then filtered through gauze to obtain the juice as ground down wasabi juice. Weigh 1 g of vinegar and 0.25 ml of mashing juice into a container, and then add water to make a total of 100 ml. Thereafter, the mixture is sufficiently stirred and mixed to obtain the present liquid preparation containing 0.25% vinegar (the concentration of acetic acid is about 0.04%).

Production Example 6
25 parts by weight of powdered wasabi, 10 parts by weight of powdered acetic acid (containing 41% acetic acid), 4 parts by weight of Solpol 5060, 2 parts by weight of Emar 10 powder, 59 parts by weight of Katsumiyama SP clay are mixed to obtain a wettable powder.

  Next, the test example about disease control using this liquid agent is shown.

Test example 1
Rice seeds contaminated with rice blast fungus (spreading about 10 ⁸ cfu / ml of pathogenic bacteria on rice flowers at the flowering stage of rice to about 40 L / 10a, artificially infecting the pathogenic bacteria, Rice seeds harvested based on the usual rice harvesting method were used as contaminated straw.) 7 g was soaked in water equivalent to twice the weight (g) of rice seeds (water temperature 15 ° C.) for 4 days processing). Next, the rice seeds were allowed to germinate by immersing them at 34 ° C. for 24 hours in this liquid preparation prepared by adding commercially available powdered wasabi to a predetermined concentration in cereal vinegar diluted to a predetermined concentration. Processing). For comparison, a method of germinating rice seeds after pre-soaking treatment (that is, a method of immersing rice seeds in chemicals without causing germination) was also performed. Rice seeds thus sprouting are sown in a seedling box and then left to stand for 3 days at 34 ° C., and further grown for 20 days in a glass greenhouse at about 20 to 30 ° C. to grow into seedlings. It was. At the time of the survey, the grown rice seedlings were observed, the number of dead seedlings, the number of severe seedlings (in the diseased seedlings, the plant height was less than half of the healthy seedlings), the number of mild seedlings (in the diseased seedlings, the plant height was healthy The number of diseased seedlings) and the number of disease-free seedlings were counted, the disease severity was determined by the following formula, and the control value was calculated.

[Formula 1]
Disease severity (%) = 100 × {3 × (number of dead seedlings) + 2 × (number of severe seedlings) + 1 × (number of mild seedlings)} / [3 × {(number of dead seedlings) + (number of severe seedlings) + (mild Number of seedlings) + (number of diseaseless seedlings)}]

[Formula 2]
Control value (%) = 100 × [1-{(Disease level in treated area) / (Disease level in untreated area)})

  The results are shown in Table 1. As is apparent from Table 1, it was confirmed that the method of the present invention has a high control effect against seedling rot caused by a rice wilt disease.

＊無処理における防除価（％）の欄にあるカッコ内の数値は、発病度を示した。＊＊酢酸濃度として

* The numerical value in parentheses in the column of the control value (%) without treatment indicates the severity of the disease. ** As acetic acid concentration

Test example 2
Rice seeds contaminated with rice blast fungus (spreading about 10 ⁸ cfu / ml of pathogenic bacteria on rice flowers at the flowering stage of rice to about 40 L / 10a, artificially infecting the pathogenic bacteria, Rice seeds harvested based on the usual rice harvesting method were used as contaminated straw.) 7 g was soaked in water equivalent to twice the weight (g) of rice seeds (water temperature 15 ° C.) for 4 days processing). Next, the rice seeds were allowed to germinate by immersing them at 34 ° C. for 24 hours in this liquid preparation prepared by adding commercially available powdered wasabi to a predetermined concentration in cereal vinegar diluted to a predetermined concentration. Processing).
Rice seeds thus sown are sown in a seedling box and then left to stand at 34 ° C. for 3 days to germinate, and further grown in a glass greenhouse at about 20 to 30 ° C. for 27 days to grow into seedlings. It was. At the time of the survey, the grown rice seedlings were observed, the number of dead seedlings, the number of severe seedlings (in the diseased seedlings, the plant height was less than half of the healthy seedlings), the number of mild seedlings (in the diseased seedlings, the plant height was healthy More than half of the seedlings) and the number of disease-free seedlings were counted, the disease severity was determined by the above formula ([Formula 1], [Formula 2]), and the control value was calculated. The expected value was calculated from Colby's formula (see [Formula 3]: A and B represent the respective control values (%) of the two compounds).

[Formula 3]
Calculation formula of Colby: Expected value (%) = A + (100−A) B / 100

The results are shown in Table 2. As is clear from Table 2, it was confirmed that the method of the present invention has a high control effect against seedling rot caused by a rice wilt bacterial bacterium. Moreover, it was also confirmed that by adding powdered wasabi to the cereal vinegar solution, a control effect that was unpredictable from the control effect of the single agent treatment of powdered wasabi or cereal vinegar was extracted.

＊無処理における防除価（％）の欄にあるカッコ内の数値は、発病度を示した。＊＊酢酸濃度として

* The numerical value in parentheses in the column of the control value (%) without treatment indicates the severity of the disease. ** As acetic acid concentration

Test example 3
7 g of naturally infected seeds of rice contaminated with the seedling fungus were immersed in water equivalent to twice the weight (g) of rice seeds (water temperature 15 ° C.) for 3 days (seeding treatment). Next, the rice seeds were diluted to a predetermined concentration in grain vinegar and soaked in this solution prepared by adding commercially available powdered horseradish to a predetermined concentration at 30 ° C. for 24 hours (germination). Processing). Rice seeds thus sprouting are sown in a seedling box, then left to stand at 30 ° C. for 3 days to germinate, and further grown in a glass greenhouse at about 20 to 30 ° C. for 17 days to grow into seedlings. It was. During the survey, the grown rice seedlings were observed, the number of diseased seedlings and the number of diseaseless seedlings were counted, the diseased seedling rate was determined by the following formula, and the control value was calculated.

[Formula 4]
Disease seedling rate (%) = [(number of diseased seedlings) / {(number of diseased seedlings) + (number of diseaseless seedlings)}] × 100

[Formula 5]
Control value (%) = 100 × [1-{(emergency seedling rate in treated area) / (emergency seedling rate in untreated area)}]

  The results are shown in Table 2. As is clear from Table 2, it was confirmed that the method of the present invention has a high control effect against ridiculous seedling diseases.

＊無処理における防除価（％）の欄にあるカッコ内の数値は、徒長苗率を示した。
＊＊酢酸濃度として

* The value in parentheses in the column of control value (%) without treatment indicates the ratio of the chief seedlings.
** As acetic acid concentration

Test example 4
Rice seeds contaminated with rice brown streak fungi (by spreading about 10 ⁸ cfu / ml of pathogenic fungi on rice flowers at about 40 L / 10a during the flowering period of rice, artificially infecting the pathogenic fungi, Rice seeds harvested based on the usual rice harvesting method were used as contaminated pods.) 7 g of rice seeds was placed in water equivalent to twice the weight (g) of rice seeds (water temperature 15 ° C.) for 3 days. Immersion (immersion treatment). Next, the rice seeds were germinated by dipping for 24 hours at 32 ° C. in this liquid preparation prepared by adding commercially available raw mustard to a predetermined concentration in cereal vinegar diluted to a predetermined concentration.
Rice seeds thus sprouting are sown in a seedling box, then left to stand at 30 ° C. for 4 days to germinate, and further grown for 21 days in a glass greenhouse at about 20-30 ° C. to grow into seedlings. I let you. At the time of the survey, the grown rice seedlings were observed, the number of diseased seedlings and the number of diseaseless seedlings were counted, the diseased seedling rate was calculated by the following formulas ([Formula 6], [Formula 7]), and the control value was calculated. Calculated.

[Formula 6]
Diseased seedling rate (%)% = [(number of diseased seedlings) / {(number of diseased seedlings) + (number of diseaseless seedlings)}] × 100

[Formula 7]
Control value (%) = 100 × [1- (emergency seedling rate in treated area) / (emergency seedling rate in untreated area)]

The results are shown in Table 4. As apparent from Table 4, it was confirmed that the method of the present invention has a high control effect against rice brown stripe disease.

＊無処理における防除価（％）の欄にあるカッコ内の数値は、発病度を示した。＊＊酢酸濃度として

* The numerical value in parentheses in the column of the control value (%) without treatment indicates the severity of the disease. ** As acetic acid concentration

Test Example 5
Rice seeds 15 g contaminated with the following test bacteria were immersed for 5 days in water (water temperature 18 ° C.) three times the rice seed weight (soaking treatment). Next, this liquid preparation was prepared by diluting the wettable powder produced in Production Example 6 to a predetermined concentration.
The seeds after the soaking treatment were allowed to germinate by being immersed in the prepared liquid preparation at 34 ° C. for 24 hours (germination stage treatment). The rice seeds thus sprouting were sown in a plastic cup having a diameter of 9 cm, covered with this, and grown in a glass greenhouse at about 20 to 26 ° C. for about 3 weeks to grow into seedlings. At the time of the survey, the number of diseased seedlings and the number of diseaseless seedlings were counted, and the diseased seedling rate was determined by the above formulas ([Formula 6], [Formula 7]), and the control value was calculated.
The contaminated rice seeds were prepared by immersing uncontaminated fir in a test bacterial culture (about 10 ⁸ cfu / ml) and then drying the fir while reducing the pressure with an aspirator. The contaminated rice seeds used in each test were prepared after mixing so as to have the following contamination rate by mixing uncontaminated fir.
(1) Brown streak disease test and bacterial blight disease test: contamination rate of 50%
(2) Seedling bacterial disease test: 5% contamination rate
The results are shown in Table 5. As is clear from Table 5, it was confirmed that the method of the present invention has a high control effect against brown streak disease, blight blight disease and seedling blight disease.

＊無処理における防除価（％）の欄にあるカッコ内の数値は、発病苗率を示した

* The value in parentheses in the column of control value (%) without treatment indicates the diseased seedling rate.

By the method of the present invention, seed infectious diseases that occur during the rice seedling raising stage can be sufficiently suppressed.

Claims (7)

A rice seed disinfection method characterized by immersing rice seeds after soaking in an aqueous acetic acid solution containing plant spices derived from eggplant or plant spices derived from yam.   The method for disinfecting rice seeds according to claim 1, wherein the acetic acid concentration in the aqueous acetic acid solution is 0.001 to 0.2 wt%. The time to immerse the rice seeds after soaking in an acetic acid aqueous solution containing plant spices derived from eggplant or plant spices derived from yam is 12 to 48 hours. 2. Rice seed disinfection method. The method for disinfecting rice seeds according to claim 1, 2 or 3, wherein the vegetable spices derived from eggplant or the vegetable spices derived from yam are powdered mustard or pasty mustard. The method for disinfecting rice seeds according to claim 1, 2 or 3 , characterized in that the vegetable spice derived from eggplant or the vegetable spice derived from yam is powdered wasabi, pasty wasabi or ground wasabi juice. . A rice seed disinfectant comprising an aqueous acetic acid solution containing a vegetable spice derived from eggplant or a vegetable spice derived from yam . Disinfection powders rice seed, characterized in that it contains powdered vegetable spice product derived from mustard or powdered vegetable spice product derived from wasabi and a powdered acid.