JPH01175907A - Herbicidal composition - Google Patents

Abstract

PURPOSE:To obtain a herbicidal composition, containing three kinds of specific active compounds used in combination and capable of synergistically enhancing herbicidal effects and exhibiting precise controlling effects even by using in any period from the initial emergence of weeds just after rice transplanting to the season without phytotoxicity to paddy rice. CONSTITUTION:A herbicidal composition, obtained by blending (A) 3-chloro-4- methyl-6-(N-2-chloro-2-propenyl-N-phenylamino)pyridazine with (B) methyl 2-[3-(4,6-dimethoxypyrimidin-2-yl)ureidosulfonylmethyl]benzoate and (C) 3,7- dichloro-8-carboxyl-quinoline as active ingredients at 1:0.02-0.2:0.03-0.5 weight ratio (A:B:C) and useful as a herbicide for paddy field having the above- mentioned effects favorable from the view point of environmental pollution, since all the weeds can be controlled at a time by spraying small amounts of the chemicals which are incapable of controlling the weeds at all using the individual chemicals.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to 3-chloro-4-methyl-6-(N-2-chloro-2-propenyl-N-phenylamino)pyridazine (hereinafter abbreviated as compound 1lffA). ), methyl-2-(3-(
4,6-dimethoxypyrimidin-2-yl)ureidosulfonylmethyl]benzoate (hereinafter abbreviated as compound B) and 3,7-dichloro-8-carboxy-quinoline (
A herbicidal composition is characterized in that it contains a compound (hereinafter abbreviated as compound C) as an active ingredient.

The herbicidal composition according to the present invention is agriculturally useful as a herbicide for paddy fields.

[Prior art]

Herbicides for paddy fields in Japan are roughly divided into three categories based on the timing of use: initial herbicides, -all-treatment herbicides, and mid-term herbicides, but the first two account for the majority of the amount used.

Early stage herbicides include 2,4,6-)dichlorophenyl-4-nitrophenyl ether and 2,4-dichlorophenyl-4-nitro-3-methoxyphenyl ether, and mid-stage herbicides include S-( 4-chlorobenzyl) -N,N-diethylthiol carbamate and 2
-methylthio-4,6-bis(ethylamino)-S-)
Mixture with riazine, S-ethyl N,N-hexamethylenethiol carbamate and 2-methylthio-4,6-bis(ethylamino)-3-triazine and T-(2-methyl-4-chlorophenoxy)butyric acid A mixture with ethyl ester, or as a total treatment agent, 2-chloro-2',6'
-Mixture of diethyl-N-(butoxymethyl)-acetanilide and 4-(2,4-dichlorobenzoyl)-1゜3-dimethylpyrazol-5-yl-P-)luenesulfonate, 2-(2-naphthoxy ) A mixture of propionanilide, 2-benzothiazol-2-yloxy-N-methylacetanilide, and N-(1,1-dimethylbenzyl)-2-promo-tert-butylacetamide, etc.

Furthermore, these herbicides are not sufficiently effective against perennial weeds, and depending on conditions such as temperature, soil, and water management, they often reduce their effectiveness or cause chemical damage to paddy rice. In recent years, from the perspective of saving labor in agricultural work, there has been a desire for a herbicide that can control all weeds, including perennial weeds, in two treatments, has a wide range of suitable periods for use, and is harmless to paddy rice. However, existing herbicides cannot be said to satisfy these requirements.

[Problem that the invention seeks to solve]

The present invention meets these demands and provides a herbicidal composition that can be used at any time from the onset of weed emergence immediately after rice planting to the growing season, has an accurate control effect, and is harmless to paddy rice. purpose.

[Means and actions for solving the problems] Compound A is described in JP-A-60-185768, compound B is described in JP-A-57-112379, and compound C is described in JP-A-57-112379.
It is disclosed in Japanese Patent No. 165368. When these active compounds are used alone, their herbicidal activity is not always fully satisfactory, and the types of vehicles and suitable periods for which they can be used are limited, and when the dosage is set high to control weeds, chemical damage to paddy rice is often observed. . In other words, Compound A has a high effect on firefly and cypress,
Next, it is effective against Japanese grasshopper and Japanese cyperus, but it is not effective against Omodaka and Urikawa. Compound B has a high herbicidal effect on annual broad-leaved weeds, porphyry, and staghorn weeds, but has a low herbicidal effect on pine weeds, bulrushes, and cypresses.

Compound C has a high herbicidal effect on Japanese millet, but has a low herbicidal effect on Japanese grasshopper, Japanese cypress, and broad-leaved weeds. Furthermore, it is known that the effectiveness of any compound decreases rapidly as the leaf stage of the weed advances. Furthermore, with each single agent, there is a concern that it may cause chemical damage to paddy rice depending on when it is used.

As a result of intensive studies to solve the above problems, the present inventors found that when compounds A, B, and C are used in combination, they not only complement each other against weeds that are difficult to control with the individual active compounds, but also synergize with each other. Due to its targeted herbicidal effect, each active compound can be used in small doses that would not be able to control the lateral side by itself, and has a remarkable control effect on not only annual weeds but also perennial weeds, which have recently become more common, even when they are quite advanced in leaf age. We have completed the present invention by discovering that it exhibits an unexpected and surprising effect of not causing chemical damage to paddy rice over the entire period from immediately after rice planting to the growing season.

That is, the present invention provides 3-chloro-4-methyl-6-(N
-2-chloro-2-propenyl-N-phenylamino)
Pyridazine, methyl-2-(3-(4,6-dimethoxypyrimidin-2-yl)ureidosulfonylmethyl)
Benzoate and H3,7-dichloro-8-carboxy-
This is a herbicidal composition characterized by containing quinoline as an active ingredient.

Although the herbicidal compositions according to the invention exhibit a particularly strong synergistic effect in certain composition ratios, the mixing proportions of the three active compounds may vary within a fairly wide range.

Specifically, compound 80102 to 1 part by weight of compound A
~0.2 part by weight, 0.3 to 0.5 part by weight of compound CO, and 80.04 to 0.1 part by weight of compound A to 1 part by weight of compound A.
More preferably, the amount is 3 parts by weight, and the amount of the compound CO is 06 to 0.3 parts by weight.

The herbicidal composition according to the present invention is usually used by adding and mixing a carrier and other adjuvants as necessary to form a formulation such as granules, powders, wettable powders, flowables, etc. . Examples of carriers include inorganic substances such as clays, talc, bentonite, diatomaceous earth, white carbon, calcium carbonate, zeolite, and silicic anhydride; vegetable organic substances such as wheat flour, soy flour, starch, and crystalline cellulose; polyvinyl chloride, Polymer compounds such as petroleum resins and polyalkylene glycols; urea; waxes and the like can be mentioned.

In addition, examples of the liquid carrier include various oils, organic solvents, water, and the like.

Furthermore, auxiliary agents required for formulation include various surfactants, gelatin, albumin, sodium alginate,
Examples include polymeric compounds such as methylcellulose, carboxymethylcellulose, polyvinyl alcohol, and xanthan gum, and other auxiliary agents. Examples of the surfactant include various nonionic and anionic surfactants, but cationic and amphoteric surfactants are sometimes used [Example] Next, the herbicidal composition according to the present invention The present invention will be described with reference to examples, but the present invention is not limited thereto.

In addition, all the mixing ratios in the examples are weight ratios.

Example 1 Granule Compound A 4z, Compound 80.17! , compound C1z
, mixture of bentonite and talc (7:3) 91.8
After mixing 3χ, alkylnaphthalene sulfonic acid condensate 2z, and dioctyl sulfosuccinate 1χ, an appropriate amount of water was added and kneaded, and the mixture was granulated using a granulator in a conventional manner to obtain granules.

Example 2 Granules Compound A5χ, Compound B0.25K, Compound co, sy
t, mixture of bentonite and talc (7:3) 92
．． After mixing 95χ and sodium ligninsulfonate 1χ, an appropriate amount of water was added and kneaded, and the mixture was granulated using a granulator in a conventional manner to obtain granules.

Example 3 Granules Compound A 6z, Compound 80.17χ, Compound C0,5
! , clay 89.33χ, sodium alkylbenzenesulfonate 2χ and carboxymethylcellulose 2χ were uniformly ground and mixed, then kneaded with an appropriate amount of water, and granulated using a granulator in a conventional manner to obtain granules.

Hereinafter, the herbicidal effect of the herbicidal composition according to the present invention will be specifically explained using test examples.

Test Example 1 Weeding test at the beginning of weed germination Paddy soil was placed in a 1/2.0007-Lugnerbont, and the entire layer was fertilized with a chemical fertilizer containing 1 g each of N, P, O5, and KzO, and an appropriate amount of water was added. Add water and stir thoroughly to make it submerged. Paddy rice seedlings grown in advance in a greenhouse (leaf age 2.
5) are considered as one plant, and the two plants per pot are placed at a depth of 3c.
1! I planted seedlings, and then sowed seeds of Japanese cabbage, firefly, and Konagi. In addition, tubers of Omodaka, Kurogwai, and Urikawa were transplanted to this, and grown in a greenhouse while being maintained at submergence method 3CI11.

After 10 days from the seedlings, at the beginning of weed emergence, a predetermined amount of the test compound was treated using granules prepared according to the method shown in the above example. After treatment, water leakage of 1 cm per day was allowed. One month after the chemical treatment, the herbicidal effect and chemical damage to paddy rice were investigated. The results are shown in Table 1 below.

In this table, the herbicidal effects and phytotoxicity of each grass species are expressed using a 10-level numerical value from "0" to "9" according to the following evaluation criteria.

Evaluation criteria 0 Remaining grass amount to no treatment ratio 85 or more (weight%) 1
71-84 2 56-70 3 41-55 4 31-40 5 21-30 6 11-20 7 6-10 8 1-5 The classification of chemical damage to paddy rice is "fungal infection" and "human damage"
There were six levels: ``, nakayori'', ``small book'', ``minor'', and ``harmless''.

Harmless: No drug-induced symptoms Minor symptoms: ``Recovery: Expected decrease in yield g 5% or less Medium-sized: 〃 6-15χ Human damage: 〃 16-30χ Bacterial infection: 〃 31% or more The following is clear from the results in Table 1. It is. Commercially available pesticides cannot control Omodaka and Kurogai at the beginning of weed emergence, while compounds A, B, and C alone cannot completely control Omodaka, Kurogwai, and Urikawa at dosages A/B.
/C3 compounds can control all plant species.

In addition, the combination of compounds B/C has an insufficient herbicidal spectrum and leaves harmful weeds such as firefly, omodaka, and black weed, but the mixture of A/B/C3 compounds of the present invention can control all plant species.

Table 1 Drug Compound Dosage
Wow Harmful Compound A 2 022020 No 5
196090 Compound B0.113
5222 0.3478668 Compound C2402000 5 918100 Compound B/C
O, 1/2 3 3 5 2 2 4
〃0.315 9 7 9
6 6 8 Compound A/B
/C210,1/2 9 9 9 9 9
9 〃1 store U yen D Toribe%
9 8 9 4 2
8 Commercially available agent: 2-chloro2',6''-diethyl-N-(butoxymethyl)acetanilide 2.5
χ,4-(2,4-dichlorobenzoyl)-1,3-dimethyl-5-pyrazolyl-P-)luenesulfonate
6χ Test Example 2 Field Test Paddy Field A paddy field in which general weeds are naturally mixed was plowed and fertilized in the usual way (N, PKO5 + KtO, each IKg)
/ R), plowing and leveling the land, - Ward 10 Ho (2,
5sX4a+), and two paddy rice seedlings of leaf age 2.5 are placed as one plant with a row spacing of 30C11 and a horizontal spacing of 15C1.
I transplanted it with 1. After transplanting, keep the waterlogging method at 3 to 5 [at the beginning of weed germination (3 days after rice planting) and 3.0 to 3.0 for Japanese millet.
At the 3.5 leaf stage (15' days after rice planting), a mixture or single granule of the test compound prepared according to the method shown in the above example was spread by hand. The amount of weeds one month after sowing and the yield of paddy rice four months later were investigated, and the results are shown in Table 2.

From the results in Table 2, the commercially available agent has a dosage of 300g/a and a rice transplant rate of 5.
After a day's treatment, the amount of grasses that account for less than 5% of Japanese grasshopper, firefly, Konagi, and Urikawa can be almost completely controlled, but Black-capped Gray Wig and Omodaka cannot be controlled. However, the three-compound mixture of the present invention contains 2 g/a of compound A and 8 g/a of compound A.
Even a combination of 0.05 g/a and Compound 01 g/a can completely control weeds that cannot be controlled with a single agent.

When treated 15 days after rice planting, when the growth of weeds is considerably advanced, commercially available pesticides are hardly able to control weeds; Although there are some weeds that cannot be controlled with chemical agents, it is clear that the combination of A/B/C3 compounds shows a surprisingly high control effect and can control not only annual weeds but also perennial weeds.

〔Effect of the invention〕

As is clear from the above results, the herbicidal composition according to the present invention is harmless to paddy rice even when used at any time from the beginning of weed germination to the peak of weed growth immediately after rice transplantation, and is effective against three types of chemical agents. Due to the synergistic effect of the two, it is possible to control all weeds in a single application using a dosage that cannot be controlled by each individual agent, making it a preferable herbicide from the standpoint of environmental pollution, compared to the herbicides commonly used in the past. It is extremely superior.

Claims (2)

[Claims] (1) 3-chloro-4-methyl-6-(N-2-chloro-2-propenyl-N-phenylamino)pyridazine,
Methyl-2-[3-(4,6-dimethoxypyrimidine-
A herbicidal composition comprising 2-yl)ureidosulfonylmethyl]benzoate and 3,7-dichloro-8-carboxy-quinoline as active ingredients. (2) 3-chloro-4-methyl-6-(N-2-chloro-2-propenyl-N-phenylamino)pyridazine,
Methyl-2-[3-(4,6-dimethoxypyrimidine-
2-yl)ureidosulfonylmethyl]benzoate and 3,7-dichloro-8-carboxy-quinoline in a ratio of 1:0.02 to 0.2:0.03 to 0.5 (weight ratio) The herbicidal composition according to claim 1.