RU2206204C1 - Seed treating composition and method for controlling plant diseases - Google Patents

Abstract

FIELD: agriculture. SUBSTANCE: composition is used in the form of aqueous suspension concentrate comprising components used in the following ratio, wt%: Diniconasol 2.0-15; Thiabendasol 2.0-15; Rhodasurph 860/P 0.02-1.0; Soprophore FL 1.0-7.0; Rhodopol 23 0.08-0.3; water the balance. Composition may additionally comprise anti-freeze such as propylene glycol in an amount of 10-24 wt%, anti-frothing agent such as polydimethylsiloxane in an amount of 0.02-0.8 wt%, preservative such as Cobate C in an amount of less than 0.045 wt%, cationic dye 2C in an amount of less than 4.0 wt%. Method involves providing presowing treatment of seeds with said composition. Composition and method provide for increased biological activity against seed mold agents, Fusarium mold, Fusarium-Cercosporella rot, bacteriosis and various kinds of cereals, corn and oats smut. EFFECT: increased efficiency in controlling plant diseases and provision for obtaining preparation having prolonged storage time. 6 cl, 17 tbl, 5 ex

Description

 The present invention relates to a composition for seed dressing containing as active active substances (E) -1- (2,4-dichlorophenyl) -4,4-dimethyl-2- (1,2,4-triazol-1-yl) -1-penten-3-ol (diniconazole) and 2- (4'-thiazolyl) benzimidazole (thiabendazole), more precisely, to a new formulation in the form of an aqueous suspension concentrate containing the aforementioned active active substances in a weight ratio of 1-2: 1 -2 in combination with other necessary components, providing stability and high efficiency of the claimed composition.

 Diniconazole is a systemic fungicide that suppresses the biosynthesis of ergosterone and disrupts the biosynthesis of gibberilins in pathogens of plant fungal diseases, it is known, in particular, from the publications EPO applications 0121284 and 0175278 (priority application from Sumitomo of Japan from 15.12.80).

 It is known that the (-) isomer of the aforementioned triazolylpentenol has a fungicidal effect, while the (+) isomer is active as a herbicide or plant growth regulator. Therefore, in the composition of the present invention, (E) -1- (2,4-dichlorophenyl) -4,4-dimethyl-2- (1,2,4-triazol-1-yl) -1-penten-3 is used -ol containing 80% by weight of the (-) E isomer.

 Thiabendazole - a contact fungicide that inhibits DNA synthesis in the cells of pathogenic fungi and stops the growth of mycelium, is known, in particular, from UK patents 1071421, cl. A 5 E, Merck & Co., France 2014326, USA 3017415 dated 01.16.1962.

 It is known that both diniconazole and thiabendazole alone are effective against a limited spectrum of pathogens of fungal and bacterial diseases of plants, in addition, many pathogens have already acquired resistance to these fungicides. Therefore, in recent years, various mixtures of fungicides have been used more and more, allowing to expand the spectrum of action of the drug and reduce the degree of resistance.

 As for the combined preparations containing diniconazole and thiabendazole as active substances, they are also known. In patent EPO 0092961, cl. A 01 N 47/38, from Sumitomo, describes a fungicidal composition based on diniconazole and fungicides based on benzimidazole and thiophanate derivatives, including thiabendazole, in a weight ratio of 1: 0.1 to 1:10.

 In the application EPA 0274839 C. A 01 N 43/653, Sumitomo company describes a composition for disinfecting seeds based on diniconazole with a content of (-) E enantiomer of not less than 50% by weight, preferably not less than 80% by weight, and comprising at least one of benzimidazole thiophanate fungicides , including thiabendazole, with a component ratio of 1-50: 1-50, preferably 1-20: 1-20.

 It is shown that the combined use of these fungicides results in a synergistic effect.

Examples of formulations include examples of the preparation of water-suspension concentrates. Nonionic polyoxyethylene monooleate was used as a surfactant in the formulation, and carboxymethyl cellulose was used as a suspension stabilizer (thickener). The ratio of the components in the VSK formulations in accordance with the cited source, wt.%:
Active ingredient - 1,1-30,5
Nonionic surfactant - 3
Carboxymethyl cellulose - 3
Water - the rest is up to 100
Water-suspension concentrate is a relatively new formulation, which has several advantages over other known formulations: it does not dust, does not contain toxic or flammable solvents, has high efficiency due to its small particle size, and has a small packaging volume. The necessary characteristics of VSC are stability during long-term storage (absence of sediment), preservation of fluidity and sufficiently low viscosity, subject to storage terms and conditions (optimal viscosity limits from 500 to 1500 MPa • s), as well as high stability of the diluted suspension during use. These qualities can be ensured by the optimal selection of surfactants, fine grinding of the active substance and stabilization of the drug using a thickener.

 It turned out that the water-suspension concentrate prepared according to the recipe of the prototype based on diniconazole (A) and thiabendazole (B) with an A: B ratio of 1: 20 and 1: 1.3 does not satisfy the above requirements. If, immediately after preparation, the water-suspension concentrates have satisfactory values according to the main physicochemical parameters, then even with short storage, separation and precipitation of a white loose precipitate was observed. During the accelerated storage test (CIPAC MT 46), stratification and precipitation also quickly occurred. Thus, the VSK formulation according to the prototype is suitable only for laboratory tests, it is unsuitable for use in a production environment.

 The object of the present invention is a composition for seed dressing, in the form of VSK, containing as an active substance a mixture of diniconazole (A) and thiabendazole (B) in a ratio of 1-2: 1-2 with the content of active active substance from 4.0 to 30 weight. %

 As a surfactant, the composition contains a mixture of nonionic and anionic surfactants. Nonionic surfactant acts as a wetting agent, which helps to achieve optimal results during wet grinding. Anionic surfactant acts as a dispersant, i.e. prevents agglomeration of finely dispersed particles and ensures stabilization of the dispersed composition during storage and when the drug is diluted with water during use.

 As a nonionic surfactant, the composition contains in an amount of 0.02-1 weight. % Rodasurf 860 / P, developed by Rodia, a polyethoxylated fatty alcohol, more specifically [poly (hydroxy-1,2-ethan-di-yl) tridecyl-oxo-hydroxy] α-isodecyl-ω-hydroxyisodecyl alcohol (see, for example, international application WO 01 / 30147A1).

 As a dispersant, 1.0-7.0% by weight of the already widely known Soprofor FL, which is a triethanolamine salt of tristyrylphenylpolyglycol ether of phosphoric acid, was introduced into the composition (see, for example, EPB 0357553A2).

The next main component of the composition is the anionic heteropolysaccharide Rodopol 23, registered in many countries of the world under the name “Xantangum” as a dietary supplement (LD ₅₀ for rats> 5000 mg / kg) (see WHO Food additives Series 6, 1976, as well as Cosmetic SC., 4, 53, 1982). Rhodopol 23 has a high molecular weight (~ 2500000) and is used in the formulation as a thickener in the form of a 2% aqueous solution in an amount of 0.08-0.3 weight. % The thickener provides the so-called gravitational stabilization of the concentrate, helps to avoid sedimentation during long-term storage of VSK.

Thus, the composition for seed treatment in the form of VSK includes the following components ensuring its effectiveness and stability, i.e. the main characteristics of VSK as a preparative form, wt.%:
Diniconazole - 2.0-15
Thiabendazole - 2.0-15
Rodasurf 860 / P - 0.02-1.0
Soprofor FL - 1.0-70
Rhodopol 23 - 0.08-0.3
Water - up to 100
This composition has high stability during storage and use, good biological activity, however, it has a freezing point of -1.5 ^o C, which creates problems during storage of the drug, especially in Russia. Therefore, to increase frost resistance to minus 15 ^o C - minus 24 ^o C, propylene glycol is introduced into the composition in the amount of 10.6-24 wt.%, Which is a well-known antifreeze.

 To avoid the formation of foam during the preparation of the suspension, as well as during dilution with water during the use of the drug, antifoam can be added to its composition. Recently, organosilicon compounds have been widely used as antifoams, effectively suppressing foam at low concentrations. Polydimethylsiloxane in an amount of 0.02-0.8 wt.% Can be added to the composition.

 To prevent microbiological decomposition of the thickener, a preservative can be introduced into the composition, and a dye, most often red, can be used to stain pickled seeds.

 To obtain a composition, metered amounts of diniconazole, thiabendazole, water, surfactants with or without propylene glycol are mixed and wet milled in a bead mill to achieve the required dispersion composition (international standards <5 μm for 85% particles). To the resulting suspension are added a separately prepared thickener solution (with or without preservative added) and dye, the mixture is thoroughly mixed, after which the preparation is poured into closed containers. The viscosity of the drug changes over time: first it increases during the day, then it slowly drops and maintains its value within the specified limits.

For the preparations obtained, the most important physicochemical characteristics were determined: viscosity, stability of the working suspension during use, dispersion, density, pH value. Test for accelerated storage of drugs (CIPAC MT46) showed that all parameters retain their value after storage at 54 ^o C for 2 weeks, which corresponds to a 2-year shelf life under normal conditions. Storage of drugs at 0 ^o C for 1 week also did not affect their basic physico-chemical characteristics.

 The drug is practically non-toxic to warm-blooded, toxicological characteristics are shown in table 1.

 Biological tests showed that the VSK seed dressing developed by the applicant based on a mixture of diniconazole and thiabendazole shows a higher activity compared to the preparations described in EPA 0274839. Using the performance indicators for all mixtures of diniconazole and thiabendazole presented in tables 1-9 of the description to the above application, you can calculate the coefficient of joint action (KSD) for these drugs, shown in relation to various pathogens of seed diseases. The calculation can be carried out according to the formula given in the application on pages 5-6, as well as the method of P. Popov ("Chemistry in agriculture", 1976, 11, p. 54-56; "Chemistry in agriculture", 1965, 10, pp. 72-79), which is practically the same. The results are presented in table 2.

 The seed dressing composition of the present invention has been shown to be highly effective against seed mold activators (Rhizopus spp., Aspergillus spp, Penicillium spp, Trichothecium thecium spp), Fusarium snow mold (Fusarium culmorum, F. oxysporum F. avenacium), fusarium-cercosporellosis rot (Fusarium Link, Cercosporella spp.), Bacterial diseases (Pseudomonas spp., Xhanthomonas spp., Corynebacterium spp.), Smut diseases (Ustilago laevis, Ustilagoethealacetae zeae, Sorosporium reilianum) cereals, corn, and millet. In terms of synergistic effect, the new composition exceeds the composition of the prototype 3-4.5 times.

 The experiments also showed the beneficial effect of the new composition on the size and quality of the wheat and barley crops. The following are examples illustrating but not limiting the invention.

 Example 1. Obtaining a composition for seed treatment.

In a reactor heated to a temperature of 30-35 ^o With mixed dosage amounts of propylene glycol, Soprofor FL, Rodasurf 860 / P and polydimethylsiloxane and mix thoroughly. To the resulting mixture was added diniconazole, thiabendazole, water and also thoroughly mixed. The resulting mixture is ground in a bead mill to achieve a particle size of <5 μm. The ground suspension is poured into a container, the mass of the product obtained is determined, after which a calculated amount of a 2% aqueous solution of Rhodopol 23 is added to it, to which a preservative and dye can be added. After adding all the components, the mixture is again thoroughly mixed. Table 3 presents some formulations of the resulting composition
Example 2. Assessment of the stability of drugs during storage.

I. To compare the stability of the drugs during storage prepared according to example 1, sample 8 and two samples according to the recipe of the prototype. After determining the main characteristics, the preparations were placed in a thermostat for testing accelerated storage (54 ^° C, 2 weeks, CIPAC MT46 technique). Sample 8 remained stable throughout the storage period, while both samples prepared according to the prototype exfoliated on the second day of storage in a thermostat with the formation of a white flocculent precipitate. The results are presented in table 4.

II. According to the same CIPAC MT46 method, storage stability of samples 3 and 4 was evaluated. Additionally, storage stability of samples at t 0 ^o C for 1 week was evaluated (CIPAC MT 46). At the end of the storage period, a re-evaluation of the physicochemical parameters was carried out. The results are presented in table 5.

 As can be seen from table 5, physico-chemical parameters after storage under standard conditions remained unchanged.

Biological tests were carried out both in the laboratory and in the field. All obtained experimental data were processed by the method of mathematical statistics. Confidence limits on the arithmetic mean value of SC ₅₀ or the percentage of disease suppression are calculated at a probability level of P = 0.05. They are respectively 4-5% and 2-6%.

 Example 3. The study of biological activity in experiments in vitro (in pure cultures).

 The experiments were carried out with respect to such pathogens of cereal diseases as Fusarium culmorum, Fusarium oxysporum, Fysarium graminearum, Fusarium avenacium, Pseudomonas atrofociens, Xantomonas translucens, Corynebacterium mickiganense.

где Т - торможение (подавление) роста по сравнению с контролем,
Д_к - диаметр колоний в контроле,
Д₀ - диаметр колоний в опыте.Petri dishes with the test objects seeded in them were kept in the thermostat for 3-5 days at 25 ^° C. At the end of the aging, the linear growth (diameter) of the colonies of fungi or bacteria was measured, and the growth of the colonies in the control and on the medium was compared with the preparation . Inhibition of colony growth was calculated by the Abbot formula:

where T is the inhibition (suppression) of growth compared with the control,
D _to - the diameter of the colonies in the control,
D ₀ - the diameter of the colonies in the experiment.

By varying the concentrations of the active substances and making the appropriate measurements, we plot the concentration – death dependence and, by interpolation, determine the values of CK ₅₀ — the concentration that causes 50% inhibition of the growth of fungal colonies. SK ₅₀ is a universal characteristic of the fungicidal activity of compounds and preparations, which allows one to compare the effectiveness of their action in relation to various pathogens.

 To characterize the intensity and type of joint action of the components, the coefficient of joint action (KSD) was determined as the quotient of dividing the calculated value of SC by the corresponding experimental value.

где Т - аддитивная токсичность, выраженная в тех же единицах, что и показатель токсичности;
А, В, С - доли препаратов в смеси;
а, в, с, - показатели токсичности препаратов.In turn, the calculated (additive) value of the toxicity indicator of the drug (CK ₅₀ or the percentage of suppression) was determined by the formula

where T is the additive toxicity expressed in the same units as the toxicity indicator;
A, B, C - the proportion of drugs in the mixture;
a, b, c, - indicators of toxicity of drugs.

 (See Golyshin N.M. Fungicides in agriculture, M .: Kolos, 1970, p. 161-170, and Popov P.V. Chemistry in agriculture, 1976, 11, p. 54-56).

 The results of the experiments are presented in tables 6, 7, 8, 9, 10.

 As can be seen from tables 6 and 10, a mixture of diniconazole and thiabendazole in the form of VSK at a ratio of 1: 1; 1: 2; 1: 1.3; 1.6: 1 and 2: 1 had a synergistic effect on the pathogens Rhizoctonia spp, Aspergillus Mich, Penicillium link and Trichoclerma lignorum, causing moldy seeds of grain crops. KSD depending on the kind of pathogen ranged from 2.0 to 12.0.

 A mixture of diniconazole + thiabendazole in the form of VSK at a ratio of 1: 1; 1: 2; 1: 1.3; 1.6: 1 and 2: 1 (tables 7 and 9) had a synergistic effect for the fungi F. culmorum, F. oxysporum, F. graminearum and F. avenacium, causing fusarium snow mold of cereal grains. KSD ranged from 2.5 to 17.

 A diniconazole + thiabendazole mixture in the form of BSC at a ratio of 1: 1.3 (Table 8) showed a synergistic effect with bactericidal activity for bacteria of the genus Pseudomonas spp, Xantomonas spp and Corynebacterium spp, which cause bacterioses of cereal crops. KSD ranged from 7.0 to 9.0.

 Example 4. Evaluation of biological activity against root rot and smut diseases in small plot experiments.

We studied the effectiveness in small-scale experiments of samples of a new formulation, including diniconazole and thiabendazole in different ratios, as a dressing agent for winter wheat seeds (S. Kupava) against fusarium-cercospolose root rot (Fusarium graminearum, Fusarium culmorum, Cercospores her) Astor) - covered smut (Ustilago laevis), spring barley (village Zazersky) - dust smut (Ustilago nuda), spring wheat (village Spectrum) - hard smut (Tilletia caries), winter wheat (village Albatros) - dusty smut (Ustilago tritici), spring wheat (L503) - dusty bare down (Ustilago tritici). The laying and conducting of experiments was carried out according to the "Methodological guidelines for state testing of fungicides, antibiotics and seed dressers for agricultural crops", M., 1985; "Guidelines for conducting greenhouse-field testing of seed dressers, fungicides and bactericides", Cherkasy, 1996, "Methods for the study of seed dressers", M., 1980. Infected and pickled seeds were sown in open ground to a depth of at least 3 cm in size plots of 2-3 m ³ , the repetition of experiments - 4 times. Seeds were treated either by wet dressing (immersion) or by spraying with a HBGB-11 pickling machine.

Accounting for the defeat of Fusarium-cercosporellosis rot was carried out in the tillering phase and in the ripening phase, digging up the plants and assessing the degree of damage according to the point system:
0 - no diseases on the seedlings;
1 - weak rooting in the form of strokes or spots on the roots or in the basal part of the seedlings;
2 - on the roots or in the basal part of the seedlings, a distinct browning is noted in the form of strokes or spots;
3 - a strong browning in the form of strokes or spots is noted on the roots or in the basal part of the seedlings;
4 - rootlets of seedlings, rotten or dead.

где Р - степень развития болезни, %;
а - число растений с одинаковыми признаками поражения;
b - соответствующий этому признаку общий балл поражения;
n - число учтенных растений;
4 - высший балл учетной шкалы.The degree of development of root rot was calculated by the formula

where P is the degree of development of the disease,%;
a - the number of plants with the same signs of damage;
b - the total score of the lesion corresponding to this attribute;
n is the number of registered plants;
4 - the highest score on the score scale.

где А - пораженность головни, %;
В - число больных колосьев, штук;
С - число здоровых колосьев при уборке, штук.Accounting for the defeat of the smut smut was carried out from phase F 51-55 (the beginning of heading) with an interval of 9-10 days. The total smut lesion was determined by the formula

where A is the smut affection,%;
In - the number of sick ears, pieces;
C is the number of healthy ears during harvesting, pieces.

Coefficient of joint action was determined by the method described in example 3. When analyzing the data obtained, we used one-way analysis of variance, determining the smallest significant difference at a probability level of 95% - NDS ₀₅ (Dospekhov B.A., Method of field experiment, M., 1979). The results are presented in tables 11, 12, 13, 14.

 It was found that the mixture of diniconazole (A) + thiabendazole (B) with a ratio of 1: 1; 1: 2; 1: 1.3; 1.6: 1 and 2: 1 in the form of VSC shows a high synergistic effect for pathogens of fusarium-cercosporellosis rot of cereal crops (CSD = 6-10.5); covered oat smut (KSD = 7.0), dusty smut of barley (KSD = 5.0), hard (KSD = 4.0) and dust smut (KSD = 7.0) of spring wheat.

Example 5. Evaluation of the effect of the drug on the size and structure of the crop
The experiments were carried out on winter wheat (v. Kupava) in the southern foothill zone of the Krasnodar Territory; oats, spring wheat and barley - in the Moscow region and winter wheat (s. Albatros) - in the Republic of Moldova.

 The experiments were carried out according to the "Methodological guidelines for conducting greenhouse-field testing of seed dressers, fungicides and bactericides", Cherkasy, 1996, p.24-35. The results are presented in tables 15, 16, 17. It was found that the formulation of the VSA formulation developed on the basis of diniconazole + thiabendazole has a positive effect on crop formation, surpassing Sumi-8 (diniconazole), 2% Flo, Raxil (tebuconazole) 6% CS, Vincit (flutriafol + thiabendazole 1: 1), 5% SC and Premis (200 g / l triticonazole).

 The mixture (diniconazole + thiabendazole 1: 1.3) of 14% VSA in the consumption rate of 0.5 l / t of seeds exceeded Sumi-8 in efficiency against smut diseases of cereals, 2% Flo with the consumption rate of 2 l / t and Vincit 5% SK with a consumption rate (1.5-2 l / t).

Thus, based on the data given in examples 3-5, it was found:
- the composition of the VSK formulation enhances the synergistic effect of the fungicidal mixture of diniconazole + thiabendazole (1: 1; 1: 2; 1: 1.3; 1.6: 1 and 2: 1) for the pathogens Rhysopus spp., Aspergillus spp, Penicillium spp, Trichoderma spp, causing moldy cereal seeds 2-15 times; Fusarium culmorum, F. oxysporum, F. graminearum, F. avenacium, causing fusarium-cercosporellosis rot - 2.5-17 times; causative agents of smut diseases (U. laevis, U. nuda, T. tritici) - 4-7 times, superior according to EPA N0274839 cells. A01N 43/653, a mixture of diniconazole + thiabendazole (1: 2; 2: 1; 1: 5; 1:10; 10: 1) in terms of synergistic effect 3-4.5 times;
- the composition of the VSK formulation enhances the bactericidal synergistic effect of the mixture of diniconazole + thiabendazole for bacterioses (Pseudomonas spp., Xhanthomonas spp, Corynebacterium spp) of cereal crops. KSD ranged from 7 to 9.0;
- the composition of the VSK formulation positively affects the economic efficiency of the mixture of diniconazole + thiabendazole (1: 1.3):
a) increases the mass of 1000 grains by 25%;
b) grain weight in the ear of 73%;
c) wheat productivity by 40-72%, oats 30%, barley 42%;
d) 13% greenery.

Claims (5)

1. A composition for dressing seeds in the form of a water-suspension concentrate, containing as an active substance a synergistically effective mixture of diniconazole and thiabendazole, a surfactant, a suspension stabilizer (thickener) and water, characterized in that it contains diniconazole and thiabendazole in a ratio of 1-2: 1-2, as a surfactant mixture of a nonionic polyoxyethylated higher fatty alcohol (Rodasurf 860 / P) and the anionic triethanolammonium salt of the tristyrylphenylpolyglycolic ester of phosphoric acid lots (Soprofor FL), and as a stabilizer suspension (thickener) heteropolysaccharide Rodopol 23 in the following ratio of components, wt.%:
Diniconazole - 2.0-15
Thiabendazole - 2.0-15
Rodasurf 860 / P - 0.02-1.0
Soprofor FL - 1.0-7.0
Rhodopol 23 - 0.08-0.3
Water - The rest is up to 100%
2. The etching composition according to claim 1, which further comprises propylene glycol as antifreeze in an amount of 10-24 wt.%.  3. The composition for seed dressing according to claims 1 and 2, which additionally contains as antifoam agent polydimethylsiloxane in an amount of 0.02-0.8 wt.%. 4. The composition for seed dressing according to claims 1 to 3, which additionally contains a preservative Cobate C ^® in an amount of not more than 0.045 wt.%.  5. The composition for seed dressing according to claims 1 to 4, which further comprises a cationic red dye 2C in an amount of not more than 4.0 wt.%.  6. A method of combating plant diseases by pre-sowing treatment (dressing) of seeds, characterized in that the seeds are treated with an effective amount of a composition according to claims 1-5.

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