RU2731472C1 - N-terpenyl-substituted benzimidazoles as fungicides - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: invention relates to agriculture, specifically to use as fungicides of N-terpenyl-substituted benzimidazoles of formula (I)

,

where

and their mixtures are 1:1 as fungicides.

EFFECT: disclosed benzimidazoles suppress a wide spectrum of causative agents of cereals and fruits and vegetables, exhibit high activity and expand the range of fungicides.

1 cl, 2 tbl

Description

The invention relates to agriculture, more precisely, to chemical agents for protecting plants from fungal diseases, specifically to the use of N-terpenyl-substituted benzimidazoles of the formula

as fungicides.

The invention can be most effectively used for the prevention and treatment of plant diseases during pre-sowing treatment of seeds and planting material, leading to an increase in yield.

Compounds Ia and Ib, related to terpene derivatives of benzimidazole of irregular structure, are known: they are formed during telomerization of isoprene with benzimidazole [Petrushkina EA, Bregadze V.V. Metal complex telomerization of isoprene and benzimidazole. Metal organ. Chemistry, 1991, 4 (2), 473-474; Petrushkina E.A., Gavrilenko V.V., Oprunenko Yu.F., Akhmedov N.G. Control of regioselectivity of isoprene telomerization with benzimidazole catalyzed by palladium complexes. J. total chem., 1996, 66 (11), 1864-1870] or in the allylation of benzimidazole [Petrushkina EA, Polonik N.B. Allyl alkylation of benzimidazole catalyzed by palladium complexes. Izv. Acad. sciences. Ser. chemistry., 1999, (2), 357-360] and are environmentally friendly insecticides (juvenoids) used to protect plants, in particular grain stocks, from insect pests of the Tenebrio Molitor L. [Petrushkina E.A., Polonic N.B., Ivanova G.B. Synthesis and juvenile hormone activity of benzimidazolylterpenes possessing a 2,7-dimethyloctane skeleton. Pestic. Sci. 1999,55 (6) 650-652].

The priority trend in the production of modern pesticides is the use of preparations with complex activity. Thus, Celest Top, manufactured by Syngenta, consists of a mixture of an insecticide (thiamethoxan) and two fungicides (difenoconazole and fludioxonil) and ensures the fight against both the most important insect pests and a wide range of fungal diseases - rhizoctoniosis, silvery scab, fusarium, phomosis, alternaria, anthracnose.

In connection with the tightening of environmental requirements for pesticides, the use of compounds with binary activity and, moreover, not having a harmful effect on the environment seems promising.

To protect cereals, fruit and vegetable crops in agriculture, fungicides are widely used, which contain carbamate derivatives of benzimidazoles (carbendazim and benomyl) and 2-heteroaryl-substituted benzimidazoles (thiabendazole and fuberidazole). They are systemic drugs (characterized by both protective and therapeutic effects) and according to GOST 121.007-76 belong to the 3rd class "Moderately hazardous substances" [Popov S.Ya., Dorozhkina L.A., Kalinin V.A. Fundamentals of chemical plant protection. M .: Art-Lyon, 2003 .-- 208 s; Golyshin N.M. Fungicides. M .: Kolos, 1993. - 319 s]. However, the known benzimidazole fungicides do not act on the polymerization enzymes of insects, which are responsible for the biosynthesis of chitin, and therefore cannot act as insecticides.

On the other hand, recently there has been an increase in the number of studies devoted to various terpene derivatives as fungicides, insecticides and other pesticides, since terpene compounds do not have a damaging effect on plants and other participants in the biocenosis and do not cause the formation of terpene-resistant insect lines or strains. bacteria, or spores of harmful fungi (see, for example, [Pizzolitto RP, Herrera JM, Zaio YP, Dambolena JS, Zunino MP, Gallucci MN, and Zygadlo JA Bioactivities of Ketones Terpenes: Antifungal Effect on F. verticillioides and Repellents to Control Insect Fungal Vector, S. Zeamais. Microorganisms, 2015, 3 (4), 851-865]). With regard to terpene derivatives of benzimidazole, it is known that, for example, 1-geranyl-2-methylbenzimidazole inhibits chitin synthase extracted from the culture of soil pathogenic fungi Sclerotium rolfsii, which infect the root system of plants [Cohen E, Kuwano E. and Eto M. The Use of a Tribalium Chitin Synthetase Assay in Studying the Effects of Benzimidazoles with a Terpene Moiety and Related Compounds. Agric. Biol. Chem., 1984, 48 (6), 1617-1620], which, apparently, determines its insecticidal activity. In addition, as noted above, compounds Ia and Ib have growth-regulating activity against insects - pests of grain stocks [Petrushkina EA, Polonic N.B., Ivanova G.B. Synthesis and juvenile hormone activity of benzimidazolylterpenes possessing a 2,7-dimethyloctane skeleton. Pestic. Sci. 1999,55 (6) 650-652].

However, no data on the fungicidal activity of terpene derivatives of benzimidazoles were found in the literature, as well as data on the insecticidal activity of the known fungicidal preparations of benzimidazole.

The object of the present invention is to detect fungicidal activity of compounds with insecticidal action in order to obtain dual-use pesticides.

The problem is solved by using well-known N-terpenylbenzimidazole insecticides of the formula

and their 1: 1 mixtures as fungicides.

The technical result consists in expanding the range of fungicides capable of suppressing pathogens of cereals and fruits and vegetables, due to the detection of fungicidal activity in known compounds with insecticidal action.

Laboratory tests for fungicidal activity in vitro were carried out by treating the culture medium with compounds Ia, Ib and their 1: 1 mixture at a dose of 20 mg / l (note that in an aqueous solution of 1 mg / l ~ 1 ppm) similar to that described in [EP 0551048 A1 , 1993] and the subsequent use of the treated nutrient medium for growing phytopathogenic fungi in it for 5 days at 20 ° C. The results were evaluated as a percentage of the reduction in the growth of the fungal culture in the treated medium compared to the untreated one. Compounds showing high activity were tested at lower doses: 10, 5 and 2 mg / L.

The following mycocultures were used:

PIOR - Pyricularia oryzae (causes rice blast);

BOCI - Botrytis cinerea S. (provokes the formation of gray rot in many cultivated plants);

FUOM - Fusarium oxysporum (causes fusarium wilt in many cultivated plants);

FURO - Fusarium roseum (provokes fusarium poisoning in humans and animals);

RHS4 - Rhizoctonia solani AG4 (causes rhizoctonia, or black scab, potato tubers);

HELG - Helminthosporium gramineum (causes striped spotted barley, or helminthosporium);

CERH - Pseudocercosporella herpotrichoides (causes cercosporella root rot of wheat);

PCIT - Phytophthora citrophthora (provokes citrus late blight);

ALAL - Alternaria alternata (provokes alternaria, the main losses on potatoes);

USNU - Ustilago nuda (causes the dusty smut of barley, in which the ear turns into a black dusty panicle);

SENO - Septoria nodorum (causes septoria disease, affects wheat, rye, barley);

PCIV - Phytophthora cinnnamomi (provokes cinnamon late blight, causes root rot and death).

The results of determining the fungicidal activity in vitro of compounds Ia, Ib and their 1: 1 mixture are presented in table. 1.

Tests for the fungicidal activity in vivo of benzimidazoles Ia, Ib and their 1: 1 mixture at a dose of 1000 ppm were carried out on plants in greenhouses as described in [EP 0551048 A1, 1993; US 5246954 A, 1993; EP 0486409 A1, 1992]. Compounds showing 75% and higher activity in disease suppression were also tested at lower doses: 333 and 111 ppm.

Investigated the fungicidal action against the following fungal diseases:

gray rot of tomatoes caused by BOCI - Botrytis cinerea;

powdery mildew of barley provoked by ERGH - Erysiphe graminis;

brown rust of wheat provoked by PURE - Puccinia recondita;

potato phytophthora provoked by PINF - Phytophthora infestans;

rice black leg, provoked by PIOR - Pyricularia oryzae.

The results of determining the fungicidal activity in vivo of compounds Ia, Ib and their 1: 1 mixture are presented in table. 2.

Data on the decrease in the growth of mycocultures in vitro (Table 1) show that benzimidazole Ia is a more active fungicide than Ib. When using compound Ia at a concentration of 20 mg / l, suppression of the growth of mycoculture up to 80-90% is observed for blast, rhizoctonia, helminthosporium, cercosporeal rot, cinnamon and citrus late blight (high activity remains at a lower concentration of the active substance), alternariosis, septoria. Benzimidazole Ia is moderately active against fusarium and is completely inactive against late blight of tomatoes. Benzimidazole Ib shows moderate activity against all tested mycocultures, with the exception of fusarium, late blight of tomatoes and the pathogen Ustilago nuda, which causes barley smut, which it does not affect at all. A 1: 1 mixture of compounds Ia and Ib has a synergistic, rather than additive, effect on mycocultures. At the same time, in the case of blast, cinnamon and citrus late blight at a concentration of 20 mg / l, the growth of mycultura is suppressed by 100%. In relation to late blight of tomatoes and the pathogen Ustilago nuda, a mixture of benzimidazoles Ia and Ib is inactive.

When tested on plants (Table 2), on the contrary, benzimidazole Ib exhibits higher activity: at a dose of 1000 ppm it inhibits the development of blast blight by 90%, and wheat brown rust by 50%, while benzimidazole Ia at a dose of 1000 ppm has a fungicidal effect only for brown rust of wheat (reduces growth by 75%). A 1: 1 mixture of benzimidazoles Ia and Ib acts synergistically: at a dose of 1000 ppm, it suppresses the development of blast by 90%, maintaining high activity (about 75%) even when the concentration is reduced to 111 ppm, and the development of wheat brown rust by 75%. Moreover, a 1: 1 mixture of compounds Ia and Ib suppresses the development, albeit moderately (by 25% when using a dose of 1000 ppm), of such harmful fungal diseases as potato late blight and powdery mildew of barley, against which the components of the mixture do not show activity at all. The claimed invention is illustrated by the following examples.

Laboratory tests for fungicidal activity in vitro.

Each test is carried out as follows: a nutrient medium consisting of potatoes, glucose and gelose (PDA medium) is introduced in a supercooled state into a series of Petri dishes (100 ml per dish) after they are sterilized in an autoclave at 120 ° C. A solution of the claimed compound in acetone is introduced into a supercooled medium in an amount necessary to obtain the desired final concentration. The control consists of Petri dishes similar to those described above, which are filled with culture medium (100 ml per dish), which does not contain the test substance. After 24 h, a fragment of the crushed mycelium of a particular test fungus obtained from its previous culture is introduced into each Petri dish and grown for 5 days at 20 ° C, after which the growth of the fungus in dishes containing the test material is compared with the growth of the same fungus in cup used as a control. The degree of inhibition of each studied mycoculture is determined for an individual test compound Ia or Ib by the example of four doses at 20, 10, 5 and 2 mg / l, for a 1: 1 mixture of compounds Ia and Ib - by the example of two doses at 20 and 10 mg / l , i.e. 120 experiments are carried out in the laboratory.

Tests for fungicidal activity in vivo on plants in greenhouses.

1. The effect of compounds Ia and Ib and their 1: 1 mixture on wheat when infected with the pathogen Puccinia reconduct (wheat brown rust) PURE.

The test compounds are used as concentrated aqueous emulsions having the following composition:

test compounds 90 mg;

10% aqueous solution of surface-active agent Tween 80 - 0.45 ml;

water - 90 ml.

These original emulsions are then diluted with water to obtain the desired test substance concentration: 1000, 333 and 111 ppm.

Wheat, sown in pots with soil, is treated at the stage when the seedling size reaches 10 cm, by spraying with the prepared emulsion of compounds Ia, Ib or their 1: 1 mixture at various concentrations. After 24 hours, the wheat is sprayed with an aqueous spore suspension (50,000 units / cm ³ ) obtained from the infected plants. The treated wheat is placed for 48 h in insulated boxes, which are maintained at 18 ° C and 100% relative humidity. Thereafter, the relative humidity is reduced to 60%. The condition of the plants is assessed between the 11th and 15th day from the moment of infection and compared with the control samples. The experiments are repeated twice for each concentration of the test compounds.

2. The effect of compounds Ia and Ib and their 1: 1 mixture on barley when infected with the pathogen Erysiphe graminis (barley powdery mildew) ERGH.

The test compounds are used as concentrated aqueous emulsions having the following composition:

test compounds 90 mg;

10% aqueous solution of surface-active agent Tween 80 - 0.45 ml;

water - 90 ml.

These original emulsions are then diluted with water to obtain the desired test substance concentration: 1000, 333 and 111 ppm.

Barley, sown in pots with soil, at the stage when the sprouts reach 10 cm, are sprayed with an emulsion of compounds Ia, Ib or their 1: 1 mixture. After 24 hours, the plants are pollinated with pathogen spores obtained from diseased plants. The condition of the barley sprouts is assessed between the 8th and 12th day from the moment of infection and compared with the control samples. The experiments are repeated twice for each concentration of the test compounds.

3. The action of compounds Ia and Ib and their 1: 1 mixture in rice upon infection with the pathogen Pyricularia oryzae (black rice leg) PIOR.

The test compounds are used as concentrated aqueous emulsions having the following composition:

test compounds 60 mg;

10% aqueous solution of surface-active agent Tween 80 - 0.3 ml;

water - 60 ml.

These original emulsions are then diluted with water to obtain the desired test substance concentration: 1000, 333 and 111 ppm.

Rice, sown in pots with soil, is processed at the stage when the seedling size reaches 10 cm, by spraying with the prepared emulsion compounds Ia, Ib or their 1: 1 mixture at various concentrations. After 24 hours, the rice is sprayed with an aqueous suspension of Pyricularia oryzae spores obtained from a 15-day culture and suspended to a concentration of 100,000 U / cm ³ . Plants are placed for 24 h in insulated boxes, which are maintained at 25 ° C and 100% relative humidity. The condition of the plants is assessed under the same conditions after 6 days from the moment of infection and compared with the control samples. The experiments are repeated twice for each concentration of the test compounds.

4. Effect of compounds Ia and Ib and their 1: 1 mixture on tomatoes infected with the pathogen Botrytis cinerea (gray rot) BOCI.

The test compounds are used as concentrated aqueous emulsions having the following composition:

test compounds 60 mg;

10% aqueous solution of surface-active agent Tween 80 - 0.3 ml;

water - 60 ml.

These original emulsions are then diluted with water to obtain the desired test substance concentration: 1000, 333 and 111 ppm.

Tomatoes (variety Marmande), grown in a greenhouse, at the age of 30 to 40 days, are sprayed with water emulsions of compounds Ia, Ib or their 1: 1 mixture in various concentrations. After 24 or 48 hours, the leaves are cut and placed in two Petri dishes (14 cm in diameter), the bottom of which is pre-filled with a wet filter paper disc. Then, using a syringe, a suspension of Botrytis cinerea spores obtained from a 15-day culture and suspended in a nutrient solution to a concentration of 100,000 units / cm ³ is applied to the leaves (3 drops per leaf). Leaf condition is assessed 3 and 6 days after infection and compared to untreated controls. The experiments are repeated twice for each concentration of the test compounds.

5. The effect of compounds Ia and Ib and their 1: 1 mixtures on tomatoes infected with the pathogenic oomycete Phytophthora infestans (potato late blight, Irish famine, or tomato late rot) PINF.

The test compounds are used as concentrated aqueous emulsions having the following composition:

test compounds 60 mg;

10% aqueous solution of surface-active agent Tween 80 - 0.3 ml;

water - 60 ml.

These original emulsions are then diluted with water to obtain the desired test substance concentration: 1000, 333 and 111 ppm.

Tomato plants (variety Marmande) grown in pots at the age of 1 month (from 5 to 6 leaves, height from 12 to 15 cm) are treated by spraying aqueous emulsions of compounds Ia, Ib or their 1: 1 mixture at various concentrations of the tested substances. After 24 hours, each plant is infected by spraying with an aqueous spore suspension (30,000 units / cm ³ ) Phytophthora infestans. After incubation for 7 days at a temperature of about 20 ° C. in an atmosphere saturated with moisture, the condition of the plants is assessed and compared with the results obtained on untreated control plants. The experiments are repeated twice for each concentration of the test compounds.

Claims (5)

Use of N-Terpenyl-Substituted Benzimidazoles of Formula (I)

, Where

and mixtures thereof 1: 1 as fungicides.