JPS608207A - Herbicide composition - Google Patents

Abstract

PURPOSE:A herbicide composition capable of wilting various kinds of weeds of problem sately and effectively with a small application amount by synergistic effects, obtained by using both a specific oxadiazoline derivative (herbicide for paddy fields) and a specific novel pyrazole derivative. CONSTITUTION:A herbicide composition containing (A) 5-tertiary-butyl-3-(2,4-dichloro-5-isopropoxyphenyl)-1,3,4-oxadiazolin -2-one, well-known as a herbicide for paddy fields and (B) a novel substance shown by the formula (A is lower alkylene; X is halogen, NO2, or lower alkyl; n is 0-5 integer) as active ingredients in a ratio of 1pt.wt. component A to 0.1-20pts.wt. component B. The composition has a wide application width, controls weeds ranging from annual weeds to perennial weeds, can destroy all weeds completely by one application, and yet has extremely high safety to paddy rice plants, men and beasts.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to 5-tert-butyl-3-(2,4-dichloro-5-isopropoxyphenyl)-1,44-oxadiazolin-2-one.

General formula (■): (In the formula, A is a lower alkylene group, X is a halogen atom,
It represents a nitro group or a lower alkyl group, and n represents 0 or an integer of 1-5. When n is 2 to 5, X may be the same or different from each other. This mixture is characterized by being blended with a compound selected from the pyrazole derivatives represented by ) to bring about a synergistic effect far beyond what could be expected from the single application of each, and to be able to kill many types of problem weeds with low application starvation. The present invention relates to a herbicide composition.

Currently, many herbicides have been put into practical use as herbicides for paddy fields.
It is widely used as a single agent or as a mixture. However, rice fields? There are many types of weeds, and although there are many herbicides that are effective against young weeds, there are very few herbicides that are effective against perennial weeds.

As a result, the number of perennial weeds has increased, and there is a strong need to control them.

Perennial weeds generally grow vigorously, have a long emergence period, and are a type of harmful grass. Therefore, herbicides are desired to have a broad spectrum of herbicidal properties that can kill many types of weeds.

In addition, in recent years, mechanization and earlier transplantation of rice cultivation have become widespread, providing a more suitable place for weeds to grow than ever before, and complete weed control cannot be expected with only one herbicide application. tend to be unable to do so. For this reason, the same or different herbicides are used several times, but repeated use of such herbicides not only requires a great deal of effort, but also causes undesirable problems such as chemical damage to paddy rice and residue in the soil due to large amounts of herbicides being applied. is being raised.

In order to improve these problems of conventional herbicides, the present inventors have developed a herbicide that completely controls all weeds by multiple spraying, is highly safe for paddy rice, and is highly toxic to humans and animals. As a result of continuing to search for a safe herbicide with a low herbicide, it was discovered that an excellent herbicide that improved these problems could be obtained by combining two types of active ingredients, and the present invention was completed.

That is, the present invention uses 5-tert-butyl-5-(2,4L dichloro-5-isopropoxyphenyl)-1,3°4-oxadiazolin-2-one (hereinafter referred to as ( A>) and the general formula (r
) is a mixed herbicide with a compound selected from novel pyrazole derivatives (hereinafter referred to as two compounds).

To explain the present invention in more detail, (A), which is one of the components of the herbicidal composition, is highly effective against field weeds and also grows against broad-leaved weeds and perennial weeds, which have become a problem in recent years. Although it is active in the initial treatment, the effect becomes weaker as growth progresses.

On the other hand, the present compound is effective against annual grass weeds, broad-leaved weeds, and perennial weeds such as fireweeds, Japanese grass weeds, black grass weeds, Japanese grasshoppers, Japanese cypresses, and weeds, without causing any phytotoxicity to paddy rice in paddy fields. However, if the weeds are treated with chemicals once they have grown to a certain size, the effectiveness of the treatment will decrease, and the effect on the weeds will be insufficient.

However, the herbicidal effect of a mixed application of both.

As a result of studying drug damage, etc., we found that the range of suitable application periods for spraying should be expanded beyond the application periods that were obtained with each previous agent.
, its grass killing range is grass (novie), cyperaceae,
It can be used without compromising the safety of general broad-leaved weeds and perennial weeds such as bulrush, cyperus japonica, porcupine, cypress, and black grub, as well as paddy rice.

It has been found that the effect of expanding the range of suitable spraying periods has been found.

In addition, a single herbicide can be sufficiently effective when mixed at a much lower dose than when used alone, and an increase in the synergistic effect has been observed, resulting in a sufficient herbicidal effect as an n-time treatment agent. The effect is long-lasting.

Examples of compounds having the general formula (1) used as one of the active ingredients in the herbicide of the present invention are shown in Table 1 (compound numbers are referred to in the following description). ).

Incidentally, the compounds of et al. can be produced by the same method as the example described in Japanese Patent Application No. 1983-69551 previously filed by the present applicant.

Formula: The mixture shown in the present invention is a novel combination that has not been described in any literature, and of course, there is no literature that mentions its unique potency enhancement. The mutual effect related to the present invention is observed in a wide range of mixing ratios, and when compound (A) is mixed at a ratio of 1 to 20 parts by weight of the compound represented by general formula (1) to 1 part by weight of compound (A). , can create useful herbicides. The herbicide of the present invention thus completed is effective even when treated before and after weed germination, and is suitable for soil treatment.

High effects can be obtained even with violet leaf and soil treatment. It is useful not only for paddy rice, but also for various grains, beans, cotton, side vegetables, orchards, lawns, pastures, tea plantations, forests, non-agricultural lands, etc.

The mixture of the present invention may be sprayed as the raw material itself, or may be mixed with a carrier and other adjuvants as necessary to form a formulation commonly used as a herbicide, such as powder, coarse powder, etc.
It is used in the form of fine granules, aqueous preparations, emulsions, bath solutions, water solutions, oil suspensions, etc.

When applying the mixtures of the active compounds of the invention as herbicides, suitable carriers are generally used, such as clay, talc, bentonite.

Solid carriers such as diatomaceous earth or liquids such as water, alcohols (methanol, ethanol, etc.), aromatic hydrocarbons, ethers, ketones, esters (ethyl acetate, etc.), acid amides (dimethylformamide, etc.) It can be applied in combination with a carrier, and optionally an emulsifier, a dispersant, @
By adding a clouding agent, a penetrating agent, a spreading agent, a stabilizer, etc., it can be put into practical use in any form such as an emulsion, a wettable powder, or a powder.

In addition, if necessary, other types of herbicides, various insecticides, fungicides, synergists, etc. may be mixed and applied at the time of formulation or spraying.

Next, specific formulation examples of formulations using the compounds of the present invention will be shown. Parts indicate parts by weight. However, the formulation examples of the present invention are not limited only to andn et al.

Formulation Example 1 Granules After uniformly mixing and pulverizing the above ingredients, a small amount of water is added, the mixture is stirred and kneaded, and the mixture is granulated using an extrusion granulator and dried to form granules.

After uniformly mixing and pulverizing the above, a small amount of water was added, the mixture was stirred and kneaded, and the mixture was granulated using an extrusion type granulator.

Dry and make into granules.

Formulation example 3 Hydrating agent The above is uniformly mixed and pulverized to make an irrigation agent.

Formulation example 4 Hydrating agent The above is uniformly mixed and pulverized to make an irrigation agent.

The above is mixed uniformly to form an emulsion.

Next, the effects of the herbicide composition of the present invention will be specifically explained by giving test examples.

Test Example 1 Weeding effect test under flooded conditions 115000
After putting Okiyoshi soil in Earl's Hugnerbot,
Water was added and mixed to create a submerged condition of water depth 20.

Japanese millet, broad-leaved weeds (Japanese cabbage, Japanese azalea, Japanese grass)
, sow yuzu from Hotarui in the above pot,
In addition, I placed a bed of Urikawa clump violet, Mizugaya clump violet, and Kurogwai clump violet. Furthermore, rice seedlings at the 2.5-leaf stage are transplanted, the pots are placed in a greenhouse at 20-25°C, the plants are grown, and 7 days after sowing, when the barnyard grass is at the 1-leaf stage, a predetermined amount of the chemical is administered. The diluted drug solution was added dropwise using a measuring pipette so that the results were as follows.

Six weeks after dropping the chemical solution, the herbicidal effect on various weeds was investigated according to the following criteria.

The results are shown in Table 2.

Judgment Criteria 5: Weed killing rate 90X or higher (almost complete death) 4...
・1 70~90% 3...1 40~70X 2...1 20~40X 1...! 5 to 20X O...l 5X or less (hardly effective) However, the above weed killing rate was determined by measuring the above-ground grass weight in the chemical-treated area and the above-ground grass weight in the untreated area. It is determined by the formula.

Table 2 Test Example 2 A polyethylene pot with an inner diameter of 8 crn was filled with paddy soil, and Japanese millet was grown in the paddy field. At the second leaf stage of barnyard millet, the soil was irrigated with various chemicals formulated as irrigation agents.

The pots were placed in a greenhouse at 25 to 30°C for controlled cultivation, and 60 days after the treatment, the weight of the above-ground grass of the barnyard grass remaining and the weight of the above-ground grass in the untreated area were measured, and the following equation was calculated. The weed killing rate (%) was calculated.

The results are shown in Table 3.

Table 3 Explanation of the E value in Table 3Individual active compounds often exhibit shortcomings in their herbicidal activity, but in such cases, the herbicidal activity of the combination of two active compounds is When the activity of two compounds is greater than the simple sum of their respective activities (expected activity), this is called synergism.

The expected activity of a specific combination of two herbicides is 1.
It can be calculated as follows (0olby,
S, R, Calculation of synergistic and antagonistic reactions of herbicide combinations Wepd J Vol, 15.20-22, 1
967): X: Inhibition rate when herbicide A is treated at an amount of ar/are Y: Inhibition rate when herbicide B is treated at an amount of br/are E: Herbicide A is 1i? /R, and if herbicide B is used by/R, it can be said that the activity of one combination shows a synergistic effect.

Patent applicant: Nissan Chemical Industries, Ltd.

Claims (1)

[Claims] (1) 5-tert-butyl-5-(2,4-dichloro-5-isopropoxyphenyl) -1° with 4-oxadiazolin-2-one. General formula (1): (wherein, A is a lower alkylene group, X is a halogen atom,
It represents a nitro group or a lower alkyl group, and n represents 0 or an integer of 1-5. When n is 2 to 5, X may be the same or different from each other. ) A herbicide composition containing a compound selected from pyrazole derivatives represented by n as an active ingredient.