JPS61189208A - Seed disinfectant - Google Patents

Abstract

PURPOSE:A seed disinfectant that contains a combination of a specific benzimidazole (fungicide for agricultural purposes) with dichlofluanid (a fungicide for agricultural purposes), thus showing improved disinfectant effect against rice plant BAKANAE-causative microorganism which is difficult to combat, because strains resistant to chemicals have appeared. CONSTITUTION:The objective seed disinfectant contains, as active ingredients, (A) at least one selected from compounds of formulas I-IV such as benomyl, MBC, TBZ, thiofanate methyl and (B) a compound of formula V (dichlofluanid). The disinfectant manifests synergism to completely control rice plant BAKANAE-causative microorganism resistant and sensitive to ingredient (A), which could not be controlled by single application of the ingredients. The ratio of thee active ingredients may be varied according to application conditions, however, it is preferred that 0.5-3.0pts.wt. of component B is used per 1pt.wt. of ingredient A.

Description

Detailed Description of the Invention The present invention disinfects the seeds of various crops such as rice, wheat, and vegetables before sowing, and kills harmful plant pathogens that parasitize the seeds. The present invention relates to a seed disinfectant that can grow healthy seedlings and increase the yield of various crops by protecting seeds from soil-borne diseases that attack young seedlings. More specifically, the present invention relates to methyl-1-(n-butylcarbamoyl)-2-penzimitazolecarpamer, which is represented by the chemical structural formula below.
) (hereinafter abbreviated as benomyl), methyl-2-benzimidazole carbamate (hereinafter abbreviated as MBC), 2-(4-
:f-azolyl)benzimidazole (hereinafter abbreviated as TBZ) and one selected from 1,2-bis(3-methoxycarbonyl-zene (hereinafter abbreviated as thiophanate methyl)), and N-(dichlorofluoromethylthio)- N',
The present invention relates to a novel mixed seed disinfectant characterized by containing a mixture of two types of N'-dimethyl-N-phenylsulfamide (hereinafter abbreviated as dichlorofluanid) as an active ingredient. Therefore, the present invention can be effectively used in the fields of pesticide manufacturing and agriculture and horticulture.

0=CNHC4H9n H Thiophanate methyl dichlorofluanido
Z and thiophanate methyl are known as agricultural fungicides, and are used as spraying agents to control various diseases of vegetables, fruit trees, and cereals, and as seed disinfectants. These drugs have a wide spectrum of control activity;
It is also an excellent drug with no chemical toxicity. These are described in Japanese Patent Publication No. 11q45-19078 (thiophane i methyl), pages 190 to 191 of "Pesticide Handbook, 1981 Edition" (Japan Plant Protection Association, published July 2011, 1981) (benomyl). ), pages 188-190 (thiophanate methyl), etc.

In addition, the use of a mixture containing one of these as a seed disinfectant has been reported, for example, in Japanese Patent Publication No. 56-3844 (Mixture of Benomyl and Polyoxin Group Antibiotics), Japanese Patent Publication No. 56-3845 ( thiophanate methyl and polyoxin group antibiotics), JP-A-52-130917 (mixture of benomyl and procymidone), JP-A-52-130917 (mixture of benomyl and procymidone)
6-81510 (mixture of 3 types of kasugamycin, benomyl and TMTD), JP-A-47-1598 (mixture of thiophanate methyl and TMTD), etc. (Drug names in parentheses are: [This is the common name listed in the Pesticide Handbook 1981 Edition].

On the other hand, dichlorofluanid is also known as an agricultural fungicide, and is used to control gray mold and downy mildew on various vegetables.
, is used as a 4i agent. This is described on pages 185 to 186 of the "Pesticide Handbook 1981 Edition". In addition, as a mixture containing dichlofluanid, JP-A-57-16805 (mixture of dichlofluanid and procymidone) is known, but benzimidazole compounds (benomyl, MBC, T
BZ, thiophanate methyl) and its use as a seed disinfectant are not known.

(To date, the use of systemic fungicides benomyl, thiophanate methyl, MBClTBZ, or mixtures of these with TMTD or gyabutane has been widely used as seed disinfectants. However, As a result of continuous use of benomyl, thiophanate methyl, and MBClTBZ, which has a similar action, drug-resistant bacteria have developed in Inakanae disease, resulting in a decrease in control effectiveness.However, Currently, there are no effective alternatives to these chemicals, and it has been pointed out that there is an urgent need for control measures.

Under these circumstances, the present invention aims to provide a new drug for disinfecting seeds of rice blight, which is difficult to control due to the appearance of drug-resistant bacteria.

In view of the current situation, the present inventors have conducted extensive research in order to develop a seed disinfectant that is particularly effective against rice grains infected with rice blight-resistant bacteria. As a result, we found that a mixture of two benzimidazole compounds selected from benomyl, MBC, TBZ, and thiophanate methyl to which dichlorofluanid is added meets the purpose and is extremely effective. .

The seed disinfectant of the present invention is effective in disinfecting the seeds of various crops such as rice, wheat, and vegetables.It is particularly effective in disinfecting rice seeds, and is particularly effective against the emergence of drug-resistant bacteria. It is highly effective against rice baka seedling disease, which is difficult to control. Preferred disinfection methods include diluting the seed disinfectant of the present invention with water and immersing the rice seeds in this solution, or coating the rice seeds with a powdered hydrating agent as is. If the seed disinfectant of the present invention is used according to this method, it will not only show a high seed disinfection effect on paddy infected with Inaka Nae disease that is sensitive to benomyl, MBC, TBZ, and thiophanate methyl, but also show a high seed disinfection effect against these agents or Existing mixed seed disinfectants containing one of these (e.g., a mixture of benomyl and TMTD) have a particularly high level of effectiveness against paddy infected with rice blight-resistant bacteria, for which practical seed disinfection effects cannot be sufficiently demonstrated. Shows seed disinfection effect. What should be noted is that, as shown in the test examples below, when dichlorofluanid is used alone, rice plants that are susceptible to benomyl, MBC, TBZ, or thiophanate methyl are affected, and rice plants that are resistant are Although no practical seed disinfection effect was observed on paddy infected with Bakanae fungus, when dichlofluanid was mixed with one of benomyl, MBC, TBZ, or thiophanate methyl, dichlofluanid was found to be more effective than benomyl, MBC, or thiophanate methyl. , TBZ and methyl thiophanate to exhibit a synergistic seed disinfection effect, making it possible to completely control both sensitive and resistant rice fungi.

(3'''-(Hi) The seed disinfectant of the present invention can be formulated into a wettable powder, emulsion, flowable, etc. by a conventional method together with the active ingredient, a carrier, and various auxiliary agents. Examples include clay, talc, bentonite, kaolin, diatomaceous earth,
Solid carriers such as silica, sucrose, etc., or benzene, xylene, [luene, kerosene, alcohols (methanol, ethanol, isopropanol, n-butamel, etc.), ketones (acetone, methyl ethyl ketone, cyclohexanone, etc.)] A liquid carrier is 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, by weight, 1 part of benomyl, MBClTBZ or thiophanate methyl to 0.5 to 0.5 to 1 part of dichlorofluanid.
It is appropriate to mix it in a proportion of 3.0 parts. However, the blending ratio can be changed as appropriate depending on the conditions at the time of application. Further, other fungicides, insecticides, herbicides, plant growth regulators, etc. can also be mixed and used.

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

20 parts of benomyl, 40 parts of dichlorofluanid, 3 parts of white carbon, 2 parts of calcium ligninsulfonate and 20 parts of clay are mixed and thoroughly ground to obtain a wettable powder.

1'・Se 2(-]) 20 parts of MBC, 20 parts of dichlorofluanid, 15 parts of white carbon, 3 parts of polyoxyethylene alkylaryl ether, 2 parts of sodium lignin sulfonate and 40 parts of clay were mixed and thoroughly ground. Obtain a hydrating powder.

20 parts of TBZ, 15 parts of dichlorofluanid, 15 parts of white carbon, 3 parts of polyoxyethylene alkylaryl ether, 2 parts of calcium lignin sulfonate and 45 parts of diatomaceous powder were mixed and pulverized to obtain a wettable powder.

-″- 4 (11 parts of water, 20 parts of thiophanate methyl, 30 parts of dichlorofluanid)
15 parts of white carbon, 3 parts of polyoxyethylene alkylaryl ether, 2 parts of sodium ligninsulfonate, and 30 parts of clay were mixed and ground for 1 minute to obtain a wettable powder.

” - The hydrating agents of Examples 1 to 4 are diluted 20 to 1000 times with water, and 10 to 10% of the seed rice is added to a welfare solution 1 to 2 times the volume of the seed rice.
Seed-borne diseases such as Inabaka Nae Disease can be controlled by soaking the rice for ~48 hours or coating the seed rice with a hydrating agent equivalent to 0.1 to 1.0% by weight of the rice seed. can.

Two Loaves Saki Ribe 11 The disease control effect of the seed disinfectant of the present invention will be explained using test examples.

Ward pod 11 Benomyl-resistant Inaka Nae disease fungus and susceptible Inaka Nae disease fungus (Gibberella Fujikuroi) cultured in steam-sterilized rice straw medium
uroi) was made into a spore suspension and sprayed and inoculated to rice (variety: Nipponbare) at the flowering stage twice each to obtain paddy infected with Inabaka Nae bacterium (two types: paddy infected with #sexual fungus and susceptible paddy). .

1.1.1 -: Infected rice grains obtained by the distribution method were added to a predetermined concentration dilution solution of each drug prepared according to the wettable powder of Example 1 at a seed rice to drug solution ratio (V/ V) in a ratio of 1 to 2
It was soaked at 0°C for 24 hours. The next day [1, the chemical solution was discarded, tap water was newly added at a ratio of 1:2 (V/V) to the rice seed, and the seeds were soaked at 20°C for 3 days. Then at 30°C
4 o'clock bud treatment, Kumiai granular culture ± (1 section 180rn
') was sown at 5g per plot. After budding treatment at 32°C for 2 days, they were transferred to a glass greenhouse and cultivated.

To investigate the onset of the disease, 30 days after sowing, we investigated the number of diseased bacteria that exhibited symptoms of Inabaka Nae Disease such as elongation and withering, as well as the number of healthy bacteria (total number of bacteria per area was approximately 200), and determined the rate of diseased seedlings ( %) was calculated. From this, as shown by the following formula, the diseased seedling rate in the untreated area (
The seed disinfection rate (%) was calculated in comparison with the seed disinfection rate (%). Regarding phytotoxicity, germination rate, growth level, etc. were observed and expressed using the phytotoxicity index below.

Phytotoxicity index 0 = No phytotoxicity 1 - Little 2 - Medium 3 = High 4 = Jinmoto test was conducted with 1 treatment and 3 effects, average seed disinfection rate (%)
I asked for The results are shown in Table 1.

Table 1, i): 1) The numbers in parentheses indicate the rate of diseased seedlings (%) in the untreated plot.

is larger than L\L example LZ ′I −-′
-J--W Pod 11 The same seed rice as in Test Example 1 was used.

11 Shion L Using each water use agent prepared according to Example 1, seed rice was washed with salt water, then lightly drained and placed in a plastic bag, and 0.25 to 0.5% of the seed rice type chemicals were uniformly applied. Dressed in powder. This treated form was air-dried indoors for about 3 hours and then soaked in water at 20° C. for 4 days. Subsequent sowing, sprouting treatment, cultivation management,
The disease onset investigation was conducted in the same manner as in Test Example 1. In addition, drug damage was also investigated using the same criteria as Test Example 1. The results are shown in Table 2.

Table 2

Claims (1)

[Claims] Methyl-1-(n-butylcarbamoyl)-2-benzimidazole carbamate, methyl-2-benzimidazole carbamate, 2-(4-thiazolyl)benzimidazole and 1,2-bis(3-methoxycarbonyl-2-thioureido) One type selected from benzene,
A seed disinfectant characterized by containing a mixture of two types of N-(dichlorofluoromethylthio)-N',N'-dimethyl-N-phenylsulfamide as an active ingredient.