JPS61172803A - Seed disinfectant - Google Patents

Abstract

PURPOSE:A seed disinfectant, containing a mixture of kasugamicin with 2- bromo-2-bromomethylglutaronitrile as an active constituent, capable of exhibiting remarkable effect particularly on control of seed and seedling rot caused by Pseudomonas glumae, and effective against bakane disease and helminthosporium leaf spot. CONSTITUTION:A seed disinfectant containing a mixture of kasugamycin or a salt thereof with 2-bromo-2-bromomethylglutaronitrile incorporated at 1:1-15 weight ratio as an active constituent. This disinfectant is used by formulating the above-mentioned active constituent with a soilid carrier, e.g. clay or talc, liquid carrier, e.g. benzene or alcohol, and an adjuvant, e.g. surfactant, stabilizer or spreader, into wettable powder, dust, emulsion or flowable, etc., diluting the resultant formulation with water to prepare a chemical solution in a low or high concentration, dipping seed rice therein or powder coating the seed rice directly with the powdery wettable powder, etc.

Description

Detailed Description of the Invention The seed disinfectant of the present invention disinfects the seeds of various crops such as rice, wheat, and vegetables before sowing, and kills any plant pathogenic bacteria that may be parasitic on the seeds. ■A new mixture that makes it possible to grow healthy seedlings and increase the yield of various crops by protecting seeds from soil-borne pathogens that live in the soil and invade and damage seeds and young seedlings after seeding. The present invention relates to a seed disinfectant.More specifically, the present invention uses kasugamycin or its salts (hereinafter referred to as KSM) and 2-bromo-2-bromomethylglutaronitrile (hereinafter referred to as BBMG) represented by the following chemical structural formula as active ingredients, The present invention relates to a seed disinfectant characterized by containing the following: Therefore, the present invention can be effectively used in the agrochemical manufacturing industry and the agricultural and horticultural fields.

r BBMG NC-CH2CH2-C-CNH2Br KSM, which is one of the active ingredients of the present invention, is known as an agricultural fungicide. In addition, it has low toxicity to humans, livestock, fish and shellfish, and there is no concern about chemical damage, so it is effective against rice blast disease.
It is widely used as a spray agent to control diseases in vegetables.

Recently, KSM has also been used to control seedling rot caused by rice blight bacterium, which occurs on rice in seedling boxes and causes great damage.
A technology for mixing granules containing granules with seedling growing soil has been established and is being put into widespread use. These things were explained in
Publication No. 818, Special Publication No. 41-21757, "Pesticide Handbook 1981 Edition" (Japan Plant Protection Association, published July 20, 1981) No. 162-1
It is described in JP-A-57-42611, page 64, etc. Also.

It is also known to have seed disinfection activity against cucumber bacterial spot disease (Japanese Patent Publication No. 32053/1983 [2003])9 However, seed disinfection activity against bacterial rice blight disease is not known.

On the other hand, BBMG is a compound that is used as a preservative and antimagnetic agent for industrial applications such as paint, wood, textiles, cosmetics, leather, tobacco, latex emulsions, and cutting oil, as described in U.S. Patent No. 3,833,731. be.

However, it has not been used as an agricultural seed disinfectant.

is trying. In recent years, seedling rot caused by rice blight bacteria has been occurring frequently in rice nursery box cultivation, but there is no effective seed disinfectant to control this, which has become a problem.

Up until now, benomyl, thiophanate methyl, or a mixture of these and TMTD have been widely used as seed disinfectants (the chemical name is from the ``Pesticide Handbook 1981'').
These seed disinfectants are highly effective against filamentous fungal diseases such as rice blight and sesame leaf blight, but they are not effective against bacterial diseases. KSM used in the present invention, on the other hand, is effective against seedling rot caused by certain rice blight bacteria, as mentioned above. A method of controlling the disease by mixing its granules into the soil for raising seedlings is becoming popular. However, the effectiveness of this method is unstable depending on the type of seedling growing soil, and it also requires a larger amount of chemicals than normal foliage spraying.

Further, there are problems such as complicated work.

Therefore, the development of effective seed disinfectants is one of the important issues in raising rice seedlings.

In view of these circumstances, the present invention is highly effective in controlling seedling rot caused by rice blight bacterium, for which the use of conventional seed disinfectants could not be expected to be effective. An object of the present invention is to provide a novel mixed seed disinfectant that is also effective against sesame leaf blight.

In order to achieve the above object, the present inventors have intensively studied a large number of drugs. As a result, it was found that a mixture of KSM and BBMG met the purpose and exhibited an extremely high seed disinfection effect.

The seed disinfectant of the present invention is particularly effective against seedling rot caused by rice bacterium blight, and is also effective in disinfecting seeds against other rice diseases and various crop diseases such as wheat and vegetables. .

As a disinfection method, the seed disinfectant of the present invention is diluted with water to prepare a low concentration chemical solution (100-1000 ppm) or a high concentration chemical solution (1000-1010000 ppm), and the rice seeds are immersed in this solution. It is preferable to coat the hydrating powder as it is (wet powder coating). In this case, in the former method, seeds are immersed in a low concentration chemical solution for a long time (6 to 48 hours), similar to the general seed disinfection method. ) or immersion in a highly concentrated chemical solution for a short period of time (10 to 30 minutes).If the seed disinfectant of the present invention is used by these methods, rice wilt, which cannot be controlled with conventional seed disinfectants, can be prevented. It exhibits a high specific control effect on seedling rot caused by bacterial pathogens, and moreover, this effect is exhibited as a synergistic effect that could not be obtained by treatment with each agent alone.

In addition, the seed disinfectant of the present invention can be used against the use of benomyl, thiophanate methyl, or a mixture of these and TMTD, which belongs to the strain of pathogenic bacteria that are resistant to the use of benzimidazole-based seed disinfectants. It is highly effective against paddy infected with Inaka-seedling-resistant bacteria, which is not sufficiently effective, and is also effective against Inaka-seedling leaf blight infection, which is a major seed-borne disease of rice, similar to Inaka-seedling disease. It exhibits an excellent seed disinfection effect, and this effect was exhibited as a synergistic effect that could not be obtained by using each agent alone, as in the case of seedling rot caused by rice bacterium.

-(1) The seed disinfectant of the present invention has active ingredients KSM and BBM.
G can be formulated into wettable powders, powders, emulsions, flowables, etc. by conventional methods together with carriers and various auxiliary agents. The carriers used include solid carriers such as clay, talc, bentonite, kaolin, diatomaceous earth, and silica, or benzene, xylene, toluene, kerosene, and alcohols (methanol, ethanol, isopropanol, n-butanol, etc.). ), ketones (acetone,
Liquid carriers such as methyl ethyl ketone, cyclohexanone, etc.) are used. These can be formulated with appropriate amounts of surfactants and other auxiliary agents, such as stabilizers and spreading agents, for use.

The blending ratio of the active ingredients in the present invention is 1 weight ratio of KSM
It is appropriate to mix 1 part to 15 parts of BBMG. However, the blending ratio can be changed as appropriate depending on the conditions at the time of application. Benomyl, MBC (methyl 2
-benzimidazole carbamate), TBZ (2-
(4-thiazolyl)benzimidazole] or thiophanate methyl.

Next, examples of the present invention will be shown. In the examples, all parts are by weight.

KSM 4 parts, BBMG 10 parts, white carbon 5 parts, lauryl sulfate 3 parts, naphthalene sulfonic acid soda formalin condensate 2 parts and clay 7
Mix 6 parts and thoroughly grind to obtain a wettable powder.

KSM 5 parts, BBMG 15 parts, white carbon 10 parts, lauryl sulfate 3 parts, naphthalene sulfonic acid sodium formalin condensate 2 parts, clay
65 parts were mixed and thoroughly ground to obtain a wettable powder.

To disinfect rice seed rice using the hydrating agent of Examples 1 and 2 above, dilute the hydrating agent 10 to 1000 times with water and place the seed rice in a solution 1 to 2 times the volume of the seed rice. Soaking for 10 minutes to 48 hours or coating the seed rice with an irrigation agent equivalent to 0.1-1% by weight of the rice seed will prevent seedling rot and other seedling rot caused by rice blight bacteria. can be prevented.

EXAMPLE 1 The seed disinfecting effect of the seed disinfectant of the present invention will be explained using test examples.

Pseudomonas bacterium (Pseudomonas gourmet) was prepared by culturing rice seed (variety Asahi) in a potato decoction liquid medium (30°C for 36 hours) in advance.
glumae) bacterial solution (108 cells/mJL
) for 24 hours to obtain rice infected with bacterial rice blight.

JL method Soaking treatment method 2 The rice grains infected with rice blight bacterial disease obtained by the above method were diluted with a predetermined concentration of a wettable powder prepared according to Example 1.
The rice seed to chemical ratio (V/V) was 1:1 at 20°C.
Soaked for 0 minutes and 24 hours. After disinfecting, throw away the chemical solution,
The seeds were soaked in tap water twice the capacity of the rice seeds at 20°C for 3 days (seed rice soaked for 24 hours) and for 4 days (seed rice soaked for 10 minutes).

Dressing treatment method: The rice seeds were soaked in tap water for 2 minutes, drained, placed in a plastic bag, and uniformly coated with an irrigation agent equivalent to 0.25 to 0.5% of the weight of the rice seeds. Processed paddy is about 3.
After air-drying for an hour, soak the seeds in tap water with an amount twice the capacity of the seeds (20
℃ for 4 days).

After that, all rice treated with one ryo was subjected to 24 hour bud treatment at 30℃.
Seeds were sown in Kumiai granular soil (180 crn' per plot) at sg per plot. After budding treatment at 32°C for 2 days, they were transferred to a glass greenhouse and cultivated.

The disease onset survey was carried out on 200 rice seedlings in each district 14 days after sowing, and the severity of damage was determined by dividing the seedlings into rotten and dead seedlings, severely rotten leaf sheath rot, seedlings with mild leaf sheath rot, and healthy seedlings. From this, the seed disinfection rate (%) was calculated in comparison with the untreated plot. Regarding phytotoxicity to seeds and seedlings, the germination rate, growth level, etc. were observed, and the degree was expressed using the phytotoxicity index below.

3a+2b+c Damage level = xto.

N N: Total number of surveyed seedlings a: Number of dead bacteria b: Number of bacteria with severe leaf sheath rot C: Number of bacteria with mild leaf sheath rot Damage level in treated area Seed disinfection rate = (1-) (%) Damage level in untreated area x 100 Chemical damage Index O = No phytotoxicity l = Low 2 = Medium 3 = High 4 = Jinmoto The test was conducted in three consecutive l treatment concentration groups, and the average seed disinfection rate (%) was determined. The results are shown in Table 1.

Table 1 Note 1) Granules containing neutral calcium hypochlorite.

Note 2) The numbers in parentheses indicate the degree of damage in untreated areas.

Me L thing-Example L? “... to
-Benomyl-resistant Inakanae disease fungus and benomyl-susceptible Inakanae disease fungus (Gibberella fujikuroi: Gibberell) cultured in steam-sterilized rice straw medium
A fujikurai) was used as a spore suspension and sprayed and inoculated twice at 3-day intervals to rice (cultivar Akihikari) during the flowering stage to inoculate paddy infected with Inabaka Nae disease (two types: paddy infected with resistant bacteria and paddy infected with susceptible bacteria). I got it.

The 0-infection investigation was carried out using the same method as in Test Example 1 except for the 1-soil 1-direct disease detection method, and was determined by the mathematical formula of the pathogenic bacteria that showed rice seedling disease symptoms such as elongation and withering of rice seedlings 30 days after sowing. As described above, the seed disinfection rate (%) was calculated by comparing the rate of diseased seedlings in the untreated plot. In addition, the phytotoxicity of rice seedlings was expressed using the same index as in Test Example 1.

In the disease plot number test, the average seed disinfection rate (%) was determined in rows It ~ in three consecutive treatment concentration groups. The results are shown in Table 2.

1. Naturally infected paddy collected from a field where rice sesame leaf blight was common in Sesame seeds (
Variety Nipponbare) was used.

1 Dowata IJ The test was carried out in exactly the same manner as in Test Example 1, which tested the efficacy of seed disinfection against rice seedling rot caused by bacterial bacterium.

The disease onset investigation was conducted 25 days after sowing, and the 0-plant test, which investigated the number of pathogenic bacteria showing rice and sesame leaf blight symptoms and the number of total seedlings, was conducted in three consecutive L treatment concentration zones, and the disease onset was conducted in the same manner as in Test Example 2. The seedling rate was determined and the average seed disinfection rate (%) was calculated. The results are shown in Table 3.

Table 3

Claims (1)

[Claims] A seed disinfectant comprising a mixture of kasugamycin or its salts and 2-bromo-2-bromomethylglutaronitrile as an active ingredient.