JPS59128306A - Fungicide for agricultural purpose - Google Patents

Abstract

PURPOSE:A fungicide for agricultural purpose that contains one of isoxazole derivatives bearing a halogenoacetamide group, a part of which are novel, as an active ingredient, thus showing powerful fungicidal action against fungi causative crop diseases and being suitable for controlling gray mold in cucumber and other diseases. CONSTITUTION:A compound of the formula (R<1> is H, alkyl, phenyl which may be substituted, thienyl, furyl; R<2> is H, alkyl, alkoxy, halogen; R<3> is H, alkyl, alkenyl, alkanoyl, phenylalkyl; X is Cl, Br, I), a part of its analogues are novel compounds, is included to give the objective fungicide for agricultural purpose. It is applied to, e.g., seeds, shoots, flower buds, flower bunches, trees, branches, leaves, fruits, soil to control gray mode, Sclerotium, Downy mildew, Anthracnose, powdery mildew or damping-off in cucumber and rice blast.

Description

[Detailed description of the invention] This invention relates to agricultural fungicides containing

A relatively large number of isoxazole derivatives having a halochenoacetamide group at the 3-position are known. For example, anti-inflammatory, antispasmodic, and antifungal effects have been found for compounds in which a phenyl, chenyl, or furyl group is present at the 5-position (Kogen Patent No. 2, 01, !j'l-lI specification). It is known that 3-haloatomidoisoxaburu having a t-butyl group at the 5-position has a herbicidal action (Patent Publication No. 50-31039). In addition, 3-haloacetamido-5-methylisoxazole is used as an intermediate for anti-inflammatory agents (Patent Publication No. 33-/θ
g9 Otsu9).

However, it is not known that a series of haloacetamidoisoxazole derivatives exhibit strong bactericidal activity against pathogenic fungi on agricultural crops. The present inventor studied this effect in detail and completed the invention related to an agricultural fungicide described below.

The agricultural fungicide according to the present invention contains a compound represented by the following general formula as an active ingredient.

(In the formula, R1 represents hydrogen, alkyl, or phenyl, chenyl, or furyl which may have a substituent,
R'! represents hydrogen, alkyl, alkoxy or haloken; RJ represents hydrogen, alkyl, alkenyl, alkanoyl or phenylalkyl; t) L, X are chlorine;
Represents bromine or iodine. ) In this specification, alkyl refers to a straight or branched carbon chain having 7 to 7 carbon atoms, such as methyl, ethyl, propyl, isopropyl,
Butyl.

Examples include isobutyl, t-butyl, pentyl, hexyl, and the like. Alkoxy is an oxy group having the above-mentioned alkyl group, such as methoxy, ethoxy, propoxy, isopropoxy, and phthoxy.

Includes isobutoxy, pentoxy, etc. Alkenyl is a group containing a double bond in the above-mentioned alkyl group having one to two carbon atoms, and examples thereof include vinyl, allyl, phthynyl, and pentenyl. Alkanoyl is a group having carbon numbers from j to acetyl.

Examples include propionyl, phthyryl, isobutyryl, valeryl, and isovaleryl. Halogens include chlorine, bromine, iodine, and fluorine. Phenylalkyl is an alkyl group substituted with seven phenyl groups. Examples of substituents that may be present on the phenyl, chenyl, or furyl group as 4 R' include alkyl, alkoxy, and halogen.

The compound ■ used in the present invention is! It has a haloacetamide group at the 5- or 5-position. Most of Compound 1 is a known compound, and a small number of unknown compounds can also be synthesized according to the following reaction formula by the method described in the specification of the Basic Patent No. λ, θ Oto Peg/f.

(In the formula, R', R% and R3 have the same meanings as above.

X' represents chlorine or bromine. ) That is, a 3-(or group or 3-)aminoisoxazole having a desired substituent is reacted with a monohalogenoacetyl compound in the presence of pyridine. If acetylaminoisoxazole iodide is desired, sodium iodide is further reacted to obtain the desired iodinated compound.

Next, the melting points or nuclear magnetic resonance spectra of representative compounds used in the present invention are shown.

3 (blank below) 7%: MO=methyl, Et-ethyl, 1-Pr-isoproyl.

1-Bu=isobutyl, t-BIl=tcr t
-Butyl.

Pc-pentyl, Ph=phenylrn-1P-9, etc. mean that a substituent is substituted at the meta-position or para-position of phenyl. (Similarly below) Table (blank below) The agricultural fungicide according to the present invention can be used as a fungicide in the fields of agriculture, forestry, and horticulture.1 For example,9 disinfection of seeds, seedlings, flower buds, flower clusters, trees, branches, leaves, fruits, soil, etc. Can be used for sterilization.

Next, the results of tests on the control effects of the agricultural fungicide of the present invention on botrytis blight, sclerotium, downy mildew, anthracnose, powdery mildew, seedling blight, and rice blast of cucumbers will be described. .

■Test method (1) Cucumber gray mold control effect test In a greenhouse with a diameter of 9
A test chemical solution at a predetermined concentration was applied to cucumber seedlings (variety: Makkase), which were cultivated in soil in a c1n hinyl chloride cup, at the 7th true leaf stage.2. It was distributed to jml. After spraying, the temperature was kept at 2.5' to 2°C for 7 days, and 5 pieces of absorbent cotton with a diameter of 2°C were placed on the 7th true leaf.
ytis cinerca) (7) The spore suspension was inoculated dropwise onto absorbent cotton. The inoculated cucumber seedlings were kept at room temperature (
2θ°C) for 3 days and then investigated.

[Survey criteria] ■ 0... No disease ■ j... Slight discoloration on the underside of the leaves ■ 10...
^・ I Slightly softened ■20...Inoculated area softened I7. (2) Cucumber Sclerotinia Disease Control Efficacy Test (1) Spreading in a water-soaked manner A test chemical solution of a predetermined concentration was sprayed at 2.3 mt onto cucumber seedlings grown in the same manner as in (1). After spraying, the temperature was maintained for 1 day at a temperature of 23°C to
niasclerotiorum) with a diameter of 1A1 were inoculated on the first true leaf at three locations, and 704 drops of PDprop) were added. After the inoculated seedlings were kept in a greenhouse (2θ°C) for 2 days, the infected diameter was measured using a vernier caliper.

/) PD broth-potato-dextrose medium (3) Cucumber and disease control effect test Cucumber seedlings grown in the same manner as in (1) were sprayed with 1.3 vtl of the test chemical solution at a predetermined concentration. After spraying, temperature 25-2
Otsu was kept under 0C conditions for 7 days to remove Pseudop.
A suspension of zoospores of P. eronos PDracubcnsis was dropwise inoculated onto the seventh true leaf at three locations. The inoculated cucumber seedlings were kept in a greenhouse for 7 days and then investigated.

[Survey criteria] ■ 0 No disease ■ j Slight onset of disease at the inoculated area ■/θ Lesions the same size as the inoculated area (not expanding) ■λθ Control rate where the lesions have expanded beyond the inoculated area The calculation method is the same as (1).

(4) Cucumber anthracnose disease control efficacy test 2. Cucumber seedlings grown in the same manner as in (1) were treated with a test chemical solution of a predetermined concentration. ! ; Spread to ynl. After spraying, temperature, 2
The anthrax pathogen (Colle
totrichuml agena r i urr+
) (7) A filter paper disk with a diameter of 4 cranes was sufficiently soaked with conidia-suspended solution M (/× 10' CO old mountain a/ml), and j pieces were inoculated onto the first leaves of the tree. The inoculated cucumber seedlings were 25
After being kept in the greenhouse at 'C for 3 days, the filter paper disc was removed and again 2! ;' It was kept under C for 3 days and investigated.

[Survey criteria] Same as test method (3).

(5) Cucumber was kept for 7 days for powdery mildew control efficacy test. After that, powdery mildew fungus (5phae ro tl+
ccafulig! A/X/θ' conidia//
1lIt) Spray inoculated cucumber seedlings (2!; ml/
20 CIII)). After inoculation, cucumber seedlings were kept at 23°C.
The specimens were kept in a greenhouse for λ weeks and then investigated.

[Survey criteria] The control rate calculation method is the same as (1). (6) Cucumber seedling damping-off control effect test Pour 130 ml of sterilized soil into a pot with a diameter of 9 m, and sow cucumber seeds/needle number f) 2θ grains. did. The mixture was mixed with damping-off sterilized soil and cultured again for 2 days. After covering and inoculating the seeded surface with this painting bed nourishing soil, 3θtnl per pot was irrigated with a test chemical solution of a predetermined concentration, and Pythi
um bacteria, Rhi zoctonia bacteria / week.

The Fusariurn bacteria were kept for 2 weeks and the degree of attack was investigated, and the degree of attack and control rate were calculated using the following formula.

Disease severity: ■・・・No germination ■・・・Sickness and death ■・・・The onset of symptoms below ■・・・The onset of symptoms below ■・・・Healthy The method for calculating the control rate is the same as in (1).

(7) Rice blast control effect test Rice seedlings (variety: Aichi Asahi) grown in a greenhouse for /θ days were transplanted into vinyl chloride cups with a diameter of /2 CTn.

A day after transplantation, spray the test drug solution at a predetermined concentration.

Spraying/Day and night, Pyricularia o.
ryzae) spore suspension was spray-inoculated onto the surface of the rice plant at a temperature of 27°C and a humidity of 93°C. The seeds were kept in an inoculation chamber of J% for 2 hours, then kept in a greenhouse at a temperature of 9 degrees Celsius and a humidity of 9 degrees 9 degrees, and the number of lesions per attack was investigated, and the control rate was calculated using the formula below. ■ Test results The test results are Shown in the table.

(Left below) As is clear from the above test results, the compound represented by formula 1 has bactericidal activity against plant pathogenic fungi.

Compounds that were not subjected to the above test also have similar effects,
It can be used as a fungicide for agriculture, forestry, and horticulture.

When compound (1) is used as an agricultural fungicide, a suitable solid or liquid carrier is used, and if necessary, suitable adjuvants such as surfactants, diluents, spreading agents, and synergists are added. , and others may be added.

Solid carriers include talc, clay, and kaolin.

Diatomaceous earth, silica, etc. are exemplified, and water as a liquid carrier,
Examples include methanol, ethanol, acetone, dimethylformamide, and ether.

The surfactant is a nonionic surfactant (so to speak).

Ho IJ oxyethylene alkyl phenyl ether.

polyoxyethylene fatty acid ester), anionic interface R
A-agents (eg, alkylbensene sulfonates, lignin sulfonates, dinaphthyl methanesulfonates), polyvinyl alcohol, CMC.

Gum arabic etc. are used. Powders, hydrating agents.

Agricultural fungicides containing compound (I) formulated into granules, emulsions, suspensions, solutions, etc. are suitable for use on agricultural and horticultural crops.

It can be used not only to sterilize seedlings, but also to sterilize soil. It is also possible to add insecticides, fungicides, and fungicides. Furthermore, the fungicide containing compound (I) can also be used in various industrial fields as a fishery or industrial fungicide.

For example, when spraying the above agricultural fungicides on agricultural crops,
;θ~! ; Used at a concentration of 00 PF'.

Embodiments of the present invention are shown below in Examples.

However, this 1. These Examples do not limit the present invention in any way.

Example/ 5 parts of compound Ia-, 2 (weight ratio, same below).

θ parts of propylene alcohol, j parts of polyoxyethylene alkyl phenyl ether, and 7 θ parts of water are mixed and dissolved to prepare an aqueous solvent. Compound Ia-2 is diluted to an effective concentration of 5θ to Sθθ and sprayed on nine leaves and stems.

Example 1: 50 parts of compound Ia-9, 1 part of sodium alkylbenzenesulfonate, 1 part of sodium ligninsulfonate,
Mix and grind the clay qθ part [・Use it as a hydrating agent. Dilute to give an effective concentration of compound Ia-9 of 5θ to jθθppm,
Spray on fruit.

Example 3 5 parts of Compound Ia-, 2θ, 9θ parts of compound a of bentonite and talc in equal amounts, and j parts of sodium alkylbenzenesulfonate were mixed and pulverized and then molded into granules.

Example 23 parts of compound IC-J', polyoxyethylene alkylphenylnitrate, 2 parts of sodium alkylbensene sulfonate, and 45 parts of xylene were mixed and dissolved to prepare an emulsion stock solution. The effective concentration of compound IC, -f is jθ~oθθ
Dilute to vPI [1] and spray on 9 leaves and stems.

Example j 1 part of compound IC-, 2θ is added to 99 parts of talc to form a powder.

Claims (1)

[Claims] An agricultural fungicide containing a compound represented by the following general formula as an active ingredient. (In the formula, R' is hydrogen, alkyl, or has a substituent and represents phenyl, chenyl, or furyl.
B2 represents hydrogen, alkyl, alkoxy or halokene, R3 represents hydrogen, alkyl, alkenyl, alkanoyl or phenylalkyl, and X represents chlorine, bromine or iodine. )