RU2563665C1 - Herbicidal composition in form of oil dispersion for weed control - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: composition comprises active compounds, a nonionic surfactant, diluents, and a thickener. The active compounds are imazamox and chlorimuron-ethyl. The nonionic surfactant is a mixture of polyethylene glycol esters of fatty acids or alkoxylated fatty alcohols. The thickener is used as silica or bentonite. The diluent is vegetable oil. The mass concentration of the composition is following, g/l: imazamox 10-100, chlorimuron-ethyl 1-40, surfactant 100-400, thickener 10-30, vegetable oil - the rest up to 1 l.

EFFECT: increase in maximum wettability of leaf surface and more rapid and deep penetration of the preparation into the plant by creating oil dispersion with a dispersion of the active substance of not more than 3 micron, which enhances the biological efficacy of the preparation.

Description

The invention relates to a herbicidal composition containing, as the main active substance, a compound belonging to the class of imidazolinones (imazamox), and as another herbicidal compound belonging to the class of sulfonylureas (chlorimuron-ethyl), and may find application in agriculture for weed control, for example, in soybean crops, and having a stable herbicidal effect, safe for crops.

In recent years, various studies have been carried out to obtain mixed compositions of pesticides that stably exhibit a positive herbicidal effect, do not adversely affect the culture, and can be used safely.

To enhance the herbicidal effect, compositions of several active substances are used that exhibit a synergistic effect with respect to each other, increasing the effectiveness of the formulation due to the correct selection and combination of excipients.

Known active ingredient Imazamox is (R, S) -2- (4-isopropyl-4-methyl-5-oxo-Δ ¹ -imidazolin-2-yl) -5-methoxymethyl-nicotinic acid. Belongs to the class of imidazolinones. It is used to control weeds in crops of sunflower, soybeans and other legumes. The consumption rate is 35-45 g / ha. Selectivity is due to the difference in metabolic rate in cultivated and weed plants. Imazamox, an inhibitor of ALS (acetolactate synthase), exhibits a herbicidal effect through inhibition of the biosynthesis of plant amino acids.

Chlorimuron-ethyl ethyl ester of 1- (4-chloro-6-methoxypyrimidin-2-ylcarbamoylsulfamoyl) benzoic acid belongs to the group of herbicides, whose action is due to the mechanism of absorption of the active compound through the leaves. It is produced mainly in mixed preparations (Melnikov N.N. et al. Pesticides and plant growth regulators. Handbook. - M., 1995). Destroys annual dicotyledonous weeds in soybean crops.

From the publications, in addition, it is known that preparations containing sulfonylureas, to which chlorimuron belongs, are problematic with regard to the stability of the active substance, since the active substance may decompose under unfavorable conditions. Then the desired herbicidal action is not provided.

Preparations containing chlorimuron-ethyl exhibit high biological effectiveness, activity when applied in an effective dose, but can have a phytotoxic effect on the protected crop and adversely affect the development of subsequent crops - sugar beets, sunflowers, corn, sorghum, rice. Elevated doses are often applied involuntarily and accidentally, since the edge zones overlap when spraying with strips due to wind exposure or due to incorrect spray rating along the front of the spray device. Climatic conditions or soil conditions can influence so that the recommended amount of herbicides for normal conditions will act as an excess dose. In order to counter this problem, it is proposed to use various excipients, as well as reduce the dose of chlorimuron-ethyl by using synergistic amounts of another herbicide.

Various synergistically active combinations of imazamox with other herbicides are known, for example, with substituted thien-3-ylsulfonylaminocarbonyl triazolinone (US Pat. RF 2303872), derivatives of arylsulfonylamino-carbonyl triazolinone (US Pat. RF 2240691).

Known aqueous dispersion of polymers containing one of the possible pesticides: chlorimuron-ethyl or imazamox (US Pat. RF 2369093).

Known water-soluble granular composition based on imidazolinone herbicide, for example imazamox, and the second herbicide salt of dicamba (US Pat. RF 2152151).

Known 2-composition mixture of chlorimuron-ethyl with imazamox in the form of a solid granular form (US Pat. RF 2187933).

The closest technical solution is an oil-based herbicidal dispersion, including imazamox with chlorimuron-ethyl as active compounds, as a nonionic surfactant, their group selected from an alkoxylated sorbitol or sorbitan fatty acid ester, vegetable oil as a diluent, and as a thickener silica (US Pat. RF No. 2418410).

The disadvantages of the known composition is the lack of dispersion of the oil emulsion (droplet size 17-23 microns), as a result of which the target properties of the herbicidal active substances are not fully used and low stability of the working solution of the drug is observed.

The technical task of the proposed composition is to increase the maximum wettability of the leaf surface and more rapid and deeper penetration of the drug into the plant by creating an oil dispersion with a dispersion of the active substance of not more than 3 microns, which ensures an increase in the biological effectiveness of the drug.

Under these circumstances, the inventors conducted extensive research to solve the above problems.

To solve the technical problem, it is necessary to use a herbicidal composition for the suppression of dicotyledonous and cereal weeds in the form of an oil-based herbicidal dispersion, including imazamox and chlorimuron-ethyl, nonionic surfactant as a diluent, vegetable oil as a diluent, silica or bentonite as a thickener, while as a nonionic surfactant use a mixture of polyethylene glycol fatty acid esters or alkoxylated fatty alcohols with the following amounts of components, g / l:

Imazamox 10-100 Chlorimuron ethyl 1-40 Surfactant 100-400 Thickener 10-30 Vegetable oil The rest is up to 1 liter

The proposed herbicidal composition is applicable to soy.

The invention is illustrated by the following examples.

EXAMPLE OF PREPARATION OF THE STATED COMPOSITION

In a bead mill with stirring, the calculated amount of vegetable oil, surfactant, thickener is loaded. All components are mixed at a reaction temperature of 20 ° C and high stirrer speeds. The calculated amount of imazamox and chlorimuron-ethyl is added, everything is mixed, ground until an average particle size of not more than 3 μm is reached (see Table 1).

EXAMPLE BIOLOGICAL TEST

A seedling pot with a surface area of 1/1000000 ha is filled with soil from a plot of elevated territory, sown with milkweed seeds (Euphorbia htlioscopia L.) and grown in an artificial climate laboratory. When euphorbia reaches the stage of development of 3 leaves, a certain amount of a preparation containing (imazamox + chlorimuron-ethyl) as active ingredients is diluted with water in an amount corresponding to a consumption rate of 200 l / ha, followed by treatment of the deciduous surface with the use of the obtained working fluid. On the 7th day after the application of the herbicidal composition, milkweed growth is evaluated visually: the degree of growth inhibition 100% is complete defeat. For comparison, the plant in the second pot is treated with a similar preparation with the same content of active substances (imazamox with chlorimuron-ethyl) at the same flow rate, but the reference preparation did not contain the claimed surfactants. The effectiveness of the drug in comparison with the standard was determined. Test conditions: spraying plants in the early phase of development. Sowing seeds into the soil to a depth of 3 cm, 4 repetitions per variant. Cultivation at 22-23 ° C and a lighting mode of 10,000 lux at a 16-hour daylight.

Similar test results were obtained when treating the following weeds: bonfire, species (Bromus spp) - growth inhibition rate of 91%, quinoa, species (Atriplex spp) - growth inhibition rate of 87%, tenuous (Galium aparine L) - growth inhibition rate of 96% , wormwood, species (Artemisia spp) - the degree of growth inhibition of 91%. From the obtained results it is obvious that the claimed composition increases the herbicidal effect by expanding the spectrum of suppression of malicious weeds and reducing the time of manifestation of the herbicidal effect.

EXAMPLE OF DETERMINATION OF THE DROP SIZE IN THE OIL COMPOSITION

Each of the oil suspension concentrates obtained in the examples was diluted before testing with water and placed in an apparatus equipped with a circulation bath and measuring particle size (MICROTRAS HRA, model 9320 x 100, HONEYELL) for 5 minutes. The size of the droplets of the emulsion in the working solution diluted 1500-2000 times was measured. The results are shown in table. 2. The size of the solid particles of the active substance in the preparation was measured using a microscope.

The oil suspension concentrate prepared in comparative example 6 corresponds to the formulation described in RF patent No. 2418410 (prototype). These oil suspension concentrates were in some emulsifiable state, while the oil dispersion concentrates, which were the herbicidal dispersions of the invention prepared in Examples 1-3, were in a finer emulsifiable state, which is exceptional.

Storage Stability Assessment

The storage stability of the suspension of the invention was evaluated at various temperatures for various periods of time. The following physicochemical properties were determined:

- appearance: color, physical condition and smell,

- pH (determined potentiometrically),

- density (measured using a vibrating density meter KEM DA-110),

- dynamic viscosity (measured using a Brookfield DV-III-axis SC4-18 rotational viscometer).

Storage stability was observed under the following temperature conditions:

- accelerated stability test during storage in a thermostatically controlled chamber at 54 ° ± 2 ° C for 14 days in accordance with CIPAC MT 46.1 (CIPAC = Collaborative International Pestisides Analitical Council / Council for international cooperation in the field of pesticide analysis),

- cold stability at 0 ° C in accordance with CIPAC MT 39. After cooling the sample in a thermostatic chamber at 0 ° ± 1 ° C, an imazamox seed crystal was added. Then the sample was stored at 0 ° ± 1 ° C for 7 days,

- stability during freezing / thawing when the temperature changes cyclically between -5 ° C and + 45 ° C for 24 hours for 7 days,

- cold storage at -20 ° ± 2 ° C for 3 weeks,

- storage at room temperature (22.5 ° ± 2.5 ° C) for 6 weeks,

- storage at 40 ° ± 2 ° C for 6 weeks.

The suspension of the preparation of example 2 was tested in the above experiments on storage stability. The appearance of the specified suspension at the beginning of each test for storage stability was an opaque and homogeneous liquid, which is almost odorless. This state remained unchanged in all experiments during storage in the cold and no precipitation or sedimentation of the active compounds was observed in the experiments during storage in the cold. Samples stored at -20 ° ± 2 ° C for 3 weeks showed only slight phase separation, which was reversible with gentle stirring.

The remaining parameters (pH, density, dynamic viscosity) remained unchanged in all experiments on storage stability.

Based on these tests on storage stability, it can be argued that the shelf life of the oil suspension of the preparation of example 2 is 2 years.

In the proposed herbicidal composition, the goals are achieved. The range of weeds intended for destruction has been expanded, the time interval at which the maximum effect of the herbicidal composition on weeds is observed, the herbicidal activity is enhanced. Active substances are present in these dispersions in the form of small particles having sizes in the micrometer range up to 3 μm.

Improving the biological activity is achieved by the joint use of active compounds mixed with excipients, as indicated in the proposed composition.

Claims (1)

A herbicidal composition in the form of an oil dispersion for the suppression of dicotyledonous and cereal weeds, including imazamox and chlorimuron-ethyl, nonionic surfactants as active compounds, vegetable oil as a diluent, silica or bentonite as a thickener, characterized in that a mixture is used as a nonionic surfactant polyethylene glycol fatty acid esters or alkoxylated fatty alcohols with the following amounts of components, g / l:
Imazamox 10-100 Chlorimuron ethyl 1-40 Surfactant 100-400 Thickener 10-30 Vegetable oil The rest is up to 1 liter