JPS61172802A - Seed disinfectant - Google Patents

Abstract

PURPOSE:A seed disinfectant, containing 2-bromo-2-bromomethylglutaronitrile as an active constituent, capable of exhibiting remarkable effect particularly on control of seed and seeding rot caused by Pseudomonas glumae, and effective against bakanae disease and the helminthosporium leaf spot. CONSTITUTION:A seed disinfectant containing 10-30wt% 2-bromo-2- bromomethylglutaronitrile expressed by the formula. This disinfectant is used by formulating the above-mentioned active constitutent with a solid 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., by the conventional method, diluting the resultant formulation with water, dipping seed rice therein or powder coating the seed rice directly with the powdery wettable powder, etc. Any one of generally used benomyl and thiophanate methyl, etc., may be mixed with the above-mentioned seed disinfectant.

Description

DETAILED DESCRIPTION OF THE INVENTION The seed disinfectant of the present invention protects seeds from soil-borne pathogens that invade and cause damage to various seeds such as rice, wheat, vegetables, and young seedlings, thereby cultivating healthy seedlings and This invention relates to a novel seed disinfectant that can increase crop yields. Therefore, the present invention can be effectively used in the agrochemical manufacturing industry and the agricultural and horticultural fields.

2-Bromo-2-bromomethylglutaronitrile (abbreviated as BBMG), which is the active ingredient of the present invention and is represented by the chemical structural formula below.

As described in U.S. Pat. No. 3,833,731,
It is a compound used as a preservative and fungicide for industrial applications such as paint, wood, textiles, cosmetics, leather, tobacco, latex emulsions, and cutting oil. However, it has not been used as an agricultural seed disinfectant.

r BBMG NC-CH2CH2-C-CNH2Br 3 is effective.In recent years, seedling rot caused by rice blight bacterium has been occurring frequently in rice seedling box cultivation, but there is no effective method to control this. There is no seed disinfectant, which is a problem.

Until now, benomyl, thiophanate methyl, or a mixture of these and TMTD have been widely used as seed disinfectants (the chemical name is ``Pesticide Handbook 198
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. It is almost ineffective against seedling rot caused by certain rice blight bacteria.
The development of a seed disinfectant that is effective against wood stalks 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 bacterium blight, 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 new seed disinfectant that is also effective against rice sesame leaf blight.

In order to achieve the above-mentioned object, the present inventors have intensively studied a large number of drugs. As a result, it was found that 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, and is also effective as a seed disinfectant against other rice diseases and various crop diseases such as wheat and vegetables. It is also effective for

As a disinfection method, the seed disinfectant of the present invention is diluted with water,
It is preferable to immerse the rice seeds in this liquid or to coat the powdered irrigation agent as it is (wet coating).If the seed disinfectant of the present invention is used by these methods, it will not be used as a conventional seed disinfectant. It exhibits a high specific control effect on seedling rot caused by rice bacterium, which has been difficult to control.

In addition, the seed disinfectant of the present invention belongs to the strain of pathogenic bacteria that are resistant to the use of benzimidazole-based seed disinfectants, and is a widely used seed disinfectant such as benomyl, thiophanate methyl, or a mixture of these and TMTD. It is also highly effective against paddy infected with rice baka seedling disease-resistant bacteria, which is not sufficiently effective.

Furthermore, it also exhibits excellent seed disinfection effects against paddy infected with Sesame leaf blight, which is a major seed-borne disease of rice, similar to Inabaka seedling disease.

The seed disinfectant of the present invention is prepared by adding BBMG as an active ingredient to a carrier and various auxiliaries in a conventional manner.

It can be used in formulations such as irrigation agents, powders, emulsions, and flowables. The carriers used include solid carriers such as clay, tar, bentonite, kaolin, diatomaceous earth, and silica, or benzene, xylene, toluene, kerosene, and alcohols (methanol, ethanol, impropatol, n-methanol, etc.). Liquid carriers such as ketones (acetone, methyl ethyl ketone, cyclohexanone, etc.) are used. Surfactants and other auxiliary agents suitable for these, such as stabilizers.

It can be formulated and used by adding an appropriate amount of a spreading agent.

(%) is appropriate. However, the addition ratio can be changed as appropriate depending on the situation during seed disinfection. Also, benomyl, MB, which is widely used as a seed disinfectant.
C (methyl 2-benzimidazole carbamate),
It may be mixed with either 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.

20 parts of BBMG, 10 parts of white carbon, 3 parts of lauryl sulfate, 2 parts of naphthalene sulfonic acid soda formalin condensate, and 65 parts of clay are mixed and thoroughly ground to obtain a wettable powder.

30 parts of BBMG, 15 parts of white carbon, 3 parts of lauryl sulfate, 2 parts of naphthalene sulfonic acid soda formalin condensate, and 50 parts of clay 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 first seed rice. If you soak the rice for 10 minutes to 48 hours or apply a hydrating agent equivalent to 1 to 1% by weight of the seed rice as is, it will prevent seed contagious diseases such as seedling rot caused by rice blight bacteria. Diseases can be controlled.

EXAMPLE 1 The seed disinfection 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 (l 08 cells/mu
) for 24 hours to obtain rice infected with bacterial rice blight.

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

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

After that, both treated paddy were subjected to 24 hour sprouting treatment at 30℃.
The seeds were sown in Kumiai granular medium ± (180 crn" per plot) at 5 g per plot. After germination treatment at 32°C for 2 days, they were transferred to a glass greenhouse for cultivation management.

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 rice seedlings, the germination rate, growth level, etc. were observed, and the degree was expressed using the phytotoxicity index shown below.

3a+2b+c Damage degree = Damage degree of treatment area x 100 Harm index 0 = No phytotoxicity 1 = Low 2 = Medium 3 = High 4 = Jinmoto The test was conducted in 3 consecutive l treatment concentration areas, and the average seed disinfection rate (%) was determined. The results are shown in Table 1.

Table 1 Note 1) Granular 2 containing neutral calcium hypochlorite
) The numbers in parentheses indicate the degree of damage in untreated areas.

C1-Do you have an example? “...to
・ -- Benomyl-resistant Inakanae disease fungus and benomyl-susceptible Inakanae disease fungus (Gibberella fujikuroi: Gibberel) cultured in steam-sterilized rice straw medium
la fujikuroi) was made into a spore suspension and inoculated into flowering rice (cultivar Akihikari) twice at 3-plot intervals. ) was obtained.

1 Ball 111 6 The disease investigation was conducted using the same method as Test Example 1 except for the disease detection method. 30 days after sowing, the number of infected bacteria and the number of healthy bacteria that showed rice seedling disease symptoms such as elongation and withering were determined. Let's investigate 1
The total number of bacteria per area was 350 on average) and the rate of diseased seedlings (%) was determined. From this, the seed disinfection rate (%) was calculated in comparison with the diseased seedling rate in the untreated plot, as shown by the following formula. In addition, the phytotoxicity of rice seedlings was expressed using the same index as in Test Example 1.

Number of pathogenic bacteria Diseased seedling rate (%) = -X 100 Total number of surveyed seedlings Rate of diseased seedlings in treated area Seed disinfection rate = (1-> (%) Rate of diseased seedlings in untreated area xio.

This test was conducted in triplicate at 1 treatment concentration, and the average seed disinfection rate (%) was determined. The results are shown in Table 2.

Naturally infected paddy (variety: Nipponbare) collected from a field where sesame leaf blight was prevalent in rice vines was used.

1 Ball 11 Test Example 1 The test was carried out in exactly the same manner as the test for the effectiveness of seed disinfection against seedling rot caused by rice bacterium bacterium in Test Example 1.

Disease onset investigation was carried out 25 days after sowing, and the number of diseased bacteria showing rice sesame leaf blight symptoms and the number of healthy bacteria were investigated.

This test was conducted in triplicate at 1 treatment concentration, the rate of diseased seedlings was determined in the same manner as in Test Example 2, and the average seed disinfection rate (%) was calculated.

The results are shown in Table 3.

Table 3

Claims (1)

[Claims] A seed disinfectant characterized by containing 2-bromo-2-bromomethylglutaronitrile as an active ingredient.