GB2315218A

GB2315218A - Synergistic triazole-based fungicidal compositions containing bromuconazole in conjunction with either tebuconazole and epoxiconazole

Info

Publication number: GB2315218A
Application number: GB9714972A
Authority: GB
Inventors: Carole Aubert; Patrice Duvert
Original assignee: Rhone Poulenc Agrochimie SA
Current assignee: Bayer CropScience SA
Priority date: 1996-07-16
Filing date: 1997-07-16
Publication date: 1998-01-28
Anticipated expiration: 2017-07-16
Also published as: CZ222797A3; HU9701205D0; HUP9701205A2; DE19730134A1; SK284515B6; NL1006531C2; CZ293674B6; GB2315218B; FR2751173B1; RU2165701C2; RO116858B1; SK95697A3; DE19730134B4; HUP9701205A3; PL321120A1; UA58490C2; FR2751173A1; BE1010505A3; PL187142B1; GB9714972D0

Abstract

Fungicidal compositions comprising bromuconazole (B) [which is 1-[(2RS, 4RS : 2RS, 4SR)-4-bromo-2-(2, 4-dichlorophenyl) tetrahydrofurfuryl]-1H-1, 2, 4-triazole] and another triazole (A) chosen from tebuconazole [which is (RS)-1-(4-chlorophenyl)-4, 4-dimethyl-3-(1H-1, 2, 4-triazol-1-ylmethyl) pentan-3-ol] and epoxiconazole [which is (2RS, 3SR)-1-[3-(2-chlorophenyl)-2, 3-epoxy-2-(4-fluorophenyl) propyl]-1H-1, 2, 4-triazolel are useful in controlling fungal attacks on crops, eg cereals, such as barley, wheat, rye or triticale.

Description

2315218 Fungicidal composition based on 2 compounds of triazole type The

subject of the present invention is a fungicidal composition, based on bromuconazole and on another triazole compound, which is useful in the treatment of fungal attacks on crops. It also relates to a process for the treatment of crops having the same aim.

The effectiveness of bromuconazole in controlling eyespot of cereals is known. This disease, due to the fungus Pseudocercosporella herpotricholdes, is the cause of significant damage, mainly on winter cereals. However, the effectiveness of bromuconazole with respect to controlling certain other diseases of is cereals and in particular in controlling brown rust (disease due to the fungus Puccinia recondita) and septoria disease (disease due to the fungus Septoria tritici) is unsatisfactory, in particular when the active material is applied at the so-called "final foliar treatment" stage. This term is understood to mean the agrochemical treatment employed when the cereals have reached the stage of development corresponding to the development of the final leaf of the stalk. In particular, the persistence of the bromuconazole must be improved. Persistence is understood to mean the period of time during which the agrochemical product, after it has been applied, is 2 capable of retaining its effectiveness.

The effectiveness of certain triazoles, such as tebuconazole, in controlling rusts and septoria diseases of cereals is known, in particular from the Pesticide Manual, loth edition, by Clive Tomlin, published by the British Crop Protection Council and the Royal Society of Chemistry.

However, it is always desirable to improve this effectiveness, in particular by decreasing the dose of tebuconazole necessary for controlling this disease or alternatively by widening the possibilities of choice offered to the farmer, in order for the latter to find the solution which is best suited to his particular problem.

An aim of the invention is thus to supply a new fungicidal composition which is useful for the problem described above.

Another aim of the invention is to provide a new fungicidal composition comprising bromuconazole which is useful in the treatment of brown rust and/or of septoria diseases of cereals and/or of diseases of the ear (fusarium diseases), in particular of wheat.

Another aim of the invention is to provide a new fungicidal composition comprising bromuconazole which has an improved persistence.

It has now been found that these aims could be achieved in all or in part by virtue of the fungicidal composition according to the present 3 invention.

The fungicidal composition according to the invention is characterized in that it comprises bromuconazole (B) and another triazole (A) chosen from tebuconazole and epoxiconazole in association with a fungicidally acceptable carrier and/or surface active agent.

Bromuconazole and the triazole (A) which are specified above are active materials which are well known to the person skilled in the art and which are described in the work: "The Pesticide Manual", 10th edition, by Clive Tomlin, published by the British Crop Protection Council. Bromuconazole is 1-[(2RS,4RS:2RS, 4SR)-4-bromo-2-(2,4dichlorophenyl)tetrahydrofurfurylj-lH-1,2,4-triazole; tebuconazole is (RS)-l-(4-chlorophenyl)-4,4-dimethyl-3(lH-1,2,4-triazol-1-ylmethyl)pentan-3-ol; and epoxiconazole is (2RS,3SR)-l-[3-(2-chlorophenyl)-2,3epoxy-2-(4-fluorophenyl)propyll-lH-1,2,4-triazole.

The B/A ratio by weight in the composition according to the invention is generally from 0.1 to 20, preferably from 0.5 to 10. The composition according to the invention is advantageous by reason of the spectrum of activity and the low doses which can be used for the active materials, the latter quality being particularly advantageous for easily understandable ecological reasons.

The composition according to the invention also 4 makes it possible to obtain notable synergic effects.

These synergic effects are in particular evidenced by application of the Tammes method, "Isoboles, a graphic representation of synergism in pesticides", Netherlands Journal of Plant Pathology, 70(1964), p. 73-80.

The triazole A is preferably is tebuconazole.

In this case, the B/A ratio by weight is advantageously from 0.5 to 5, preferably from 1 to 3.

The fungicidal composition according to the invention usually contains from 0.05 to 95-. of the mixture of bromuconazole and triazole A.

It can be a concentrated composition, that is to say a commercial product combining the two active materials. It can also be a dilute composition ready to be sprayed on the crop to be treated. In this latter case, dilution with water can be carried out either from a commercial concentrated composition containing the two active materials (this mixture is known as "ready mix") or by means of a mixture prepared at the time of use (known as "tank mix") of two commercial concentrated compositions each containing one active material.

The composition according to the invention can additionally comprise the usual additives or adjuvants of plant-protection compositions, especially vehicles, surface- active agents, adhesion agents and flow-improving agents.

In the present account, the term "vehicle" denotes a natural or synthetic, organic or inorganic material with which the active materials are combined to facilitate their application on the plant. This vehicle is thus generally inert and it must be acceptable in agriculture, especially on the treated plant. The vehicle can be solid (eg. clays, natural or synthetic silicates, silica, resins, waxes, solid fertilizers) or liquid (eg. water, alcohols, ketones, petroleum fractions, aromatic or paraffinic hydrocarbons, chlorinated hydrocarbons, liquefied gases).

The surface-active agent can be an emulsifying, dispersing or wetting agent of ionic or nonionic type. There may be mentioned, for example, salts of polyacrylic acids, salts of lignosulphonic acids, salts of phenolsulphonic or naphthalenesulphonic acids, polycondensates of ethylene oxide with fatty alcohols or with fatty acids or with fatty amines, substituted phenols (especially alkylphenols or arylphenols), salts of esters of sulphosuccinic acids, taurine derivatives (especially alkyltaurates) or phosphoric esters of polyoxyethylenated phenols or alcohols. The presence of at least one surface-active agent is desirable to promote dispersion of the active 2S materials in water and their ready application on the plants.

The composition can also contain other ingredients such as, for example, protective colloids, 6 adhesives, thickening agents, thixotropic agents, penetrating agents, stabilizing agents, sequestering agents, pigments, dyes or polymers.

More generally, the composition according to the invention can include the solid or liquid additives corresponding to the usual techniques for the formulation of plant-protection products.

The composition according to the invention can be in solid, gel or liquid form and, in the latter case, in the form of solutions or suspensions or emulsions or emulsifiable concentrates. Liquid compositions are preferred, due both to their convenience of use and to their simplicity of manufacture.

is There may be mentioned, as forms of solid compositions, powders for dusting or dispersion (with an active compounds content which can range up to 100%), wettable powders and granules for dry spreading, as well as dispersible or soluble granules.

Wettable powders (or powders to be sprayed), as well as dispersible granules, generally contain 20 to 95% of active materials and, in addition to the solid vehicle, from 0 to 5% of a wetting agent, from 3 to 10% of a dispersing agent and, when necessary, from 0 to 106 of one or more stabilizing agents and/or other additives, such as pigments, dyes, penetrating agents, adhesives, or anticlumping agents. It is well understood that some of these compositions, such as 7 wettable powders or dispersible granules, are intended to constitute liquid compositions at the time of application.

There may be mentioned, as forms of liquid compositions, solutions, in particular water-soluble concentrates, emulsifiable concentrates, emulsions, suspension concentrates, aerosols or pastes.

The emulsifiable or soluble concentrates generally comprise 10 to 80% of active materials, the emulsions or solutions ready for application containing, for their part, 0.01 to 20% of active materials. In addition to the solvent, the emulsifiable concentrates can contain, when necessary, 2 to 20% of suitable additives such as the stabilizing agents, is surface-active agents, penetrating agents, corrosion inhibitors, dyes or adhesives mentioned above. From these concentrates, it is possible to obtain, by dilution with water, emulsions of any desired concentration, which are particularly suitable for application on the aerial parts of the plant to be treated. As has already been said, aqueous dispersions and emulsions, for example the compositions obtained by diluting a wettable powder or an emulsifiable concentrate according to the invention with water, come within the general scope of the present invention. The emulsions can be of the water-in-oil or oil-in-water type and they can have a thick consistency, like that of a "mayonnaise".

8 The suspension concentrates, also applicable by spraying, are a stable fluid product, which does not thicken or form a sediment after storage, and they generally contain from 10 to 750-. of active materials, from 0.5 to 15'-. of surface-active agents, from 0.1 to 100-o of thixotropic agents and from 0 to 100-. of suitable additives, such as pigments, dyes, antifoaming agents, corrosion inhibitors, stabilizing agents, penetrating agents and adhesives and, as vehicle, water or an organic liquid in which the active materials are insoluble or nearly insoluble: certain organic solid materials or inorganic salts can be dissolved in the vehicle to aid in preventing sedimentation or as antigels for water.

The composition according to the invention is prepared according to processes known per se.

Thus, to obtain powders to be sprayed or wettable powders, the active materials are intimately mixed, in suitable mixers, with the additional substances and the mixture is milled with mills or other grinders. Powders to be sprayed are thereby obtained with advantageous wettability and suspensibility; they can be suspended in water at any desired concentration and these suspensions can be used very advantageously, in particular for application on the aerial parts of the plants.

Pastes or suspension concentrates can be produced in place of wettable powders. The conditions 9 and modes of production and use of these pastes are similar to those of wettable powders or powders to be sprayed, part of the milling operation necessary simply being carried out in a liquid medium.

The dispersible granules are generally prepared by agglomeration or extrusion or compacting, in suitable granulation systems, of compositions of wettable powder type. The granules for dry spreading are generally obtained by impregnating a granulated vehicle with a solution or an emulsion of the active materials.

The invention also relates to a method of treatment intended to control or prevent fungal attacks on crops, characterized in that bromuconazole (B) and another triazole (A) chosen from tebuconazole and epoxyconazole or a composition according to the invention is applied to the aerial parts of the crops.

It will be understood that the amount of (A) and (R) in combination will be effective and non-phytotoxic.

The composition is advantageously used so that the bromuconazole dose applied is from 100 to 300 g/ha, preferably from 150 to 250 g/ha, and the triazole A dose is from 50 to 250 g/ha, preferably from 75 to g/ha. This dose is a function of the nature of the disease, the stage of development of the plant treated, the degree of infestation and the weather conditions.

When, according to a preferred alternative form of the composition according to the invention, the compound A is tebuconazole, the tebuconazole dose is generally from 75 to 250 g/ha, preferably from 100 to 150 g/ha.

The fungal attacks are mainly those caused by septoria diseases (Septoria tritici, Septoria nodorum), rusts (Puccinia striiformis, Puccinia recondita) and fusarium diseases of the ears (Fusarium culmorum, Microdochium nivale).

Crops which are suitable for the treatment process according to the invention include cereals, in particular barleys, wheat, rye or triticale, preferably wheat.

The invention also provides a product comprising bromuconazole (B) and another triazole (A) chosen from tebuconazole and epoxiconazole for simultaneous, separate or sequential use in controlling fungal attacks on crops.

The following Examples illustrate the invention.

In the figures appended to the present text, the dose of each active material, used in isolation, required for controlling the phytopathogenic fungus at the level indicated is compared with that of the 2 active materials used as a mixture. The effective dose of each active material, used in isolation, is indicated on the axis of the abscissae and of the ordinates and a straight line is drawn cutting these two axes and connecting these 2 doses. As regards the 2 11 active materials used as a mixture, the dose of the mixture at a given ratio is indicated by a point.

Example 1: Test under glass of a composition comprising a mixture of bromuconazole and of tebuconazole on Puccinia recondita responsible for brown rust of wheat:

Use is made either of a composition comprising bromuconazole, in the form of a 200 g/l suspension concentrate, or of a composition comprising tebuconazole, in the form of a 250 g/l emulsifiable concentrate, or alternatively of a composition according to the invention, obtained by mixing the 2 above compositions.

In the case of active materials as a mixture, the bromuconazole/tebuconazole ratio by weight is 1, 1.5, 2, 2.5 and 3.

Wheat seedlings (variety Talent) are grown in pots. When these seedlings are 14 days old, which corresponds to the Zadoks stage 11, they are treated by spraying with each of the above compositions.

The Zadoks scale is defined in the article which appeared in Phytiatrie phytopharmacie [Plant Pathology and Plant Pharmacology], 1977, 26, pages 129140, entitled "A decimal code for the growth stages of cereals", by Zadoks J. C., Chang T. T. and Konzak C. F.

24 hours after the treatment, each seedling is infected by spraying with an aqueous suspension of Puccinia recondita spores (100,000 sp/cm').

12 After this infecting, the wheat seedlings are incubated at 200C and 100% relative humidity for 24 hours and are then transferred under glass at 180C and 70% relative humidity.

12 days after the infecting, the percentage of leaf area infected is quantified. The percentage of destruction of the phytopathogenic fungus is calculated by comparison with a control wheat seedling which has not been treated with an active material but which has been infected with Puccinia recondita.

The results obtained are shown in the form of points, corresponding to 80% destruction of the parasite, placed in a Tammes diagram which contains, on the abscissa, the tebuconazole doses expressed in g/ha and, on the ordinate, the bromuconazole doses, also in g/ha.

The diagram of Figure 1 is obtained in which it appears that the addition of a tebuconazole dose of less than 28 g/ha (which corresponds to the dose of tebuconazole alone which it is necessary to apply in order to obtain the destruction of 80% of the parasite) makes it possible, in an entirely unexpected way, to lower the bromuconazole dose necessary for the destruction of 80% of the parasite well below 337 g/ha (this value corresponding to the dose of bromuconazole alone which it is necessary to apply in order to obtain this same percentage of destruction of 80%).

The arrangement of the points obtained 13 therefore indicates a bilateral effect, described according to the Tammes method mentioned above as a "two-sided effect". This arrangement corresponds to a type-III isobole according to the said method (page 75 of the corresponding bibliographical reference already mentioned) and is characteristic of a synergy.

ExamT)le 2: Test under glass of a composition comprising a mixture of bromuconazole and of epoxiconazole on Septoria tritici responsible for septoria disease of wheat:

Use is made either of a composition comprising bromuconazole, in the form of a 200 g/l suspension concentrate, or of a composition comprising epoxiconazole, in the form of a 125 g/l suspension concentrate, or alternatively of a composition according to the invention, obtained by mixing the 2 above compositions.

In the case of active materials as a mixture, the bromuconazole/epoxiconazole ratio by weight is 1, 3, 4, 5 and 6.

Wheat seedlings (variety Darius) are grown in pots. When these seedlings are 14 days old, which corresponds to the Zadoks stage 11, they are treated by spraying with each of the above compositions.

24 hours after the treatment, each seedling is infected by spraying with an aqueous suspension of Septoria tritici spores (250,000 Sp/CM3).

After this infecting, the wheat seedlings are 14 incubated at 181C and 100% relative humidity for 4 days and are then transferred under glass at 180C and 90% relative humidity.

days after the infecting, the percentage of leaf area infected is quantified. The percentage of destruction of the phytopathogenic fungus is calculated by comparison with a control wheat seedling which has not been treated with an active material but which has been infected with Septoria tritici.

The results obtained are shown in the form of points, corresponding to 50% destruction of the parasite, placed in a Tammes diagram which contains, on the abscissa, the epoxiconazole doses expressed in g/ha and, on the ordinate, the bromuconazole doses, also in is g/ha.

The diagram of Figure 2 is obtained in which it appears that the addition of an epoxiconazole dose of less than 7 g/ha (which corresponds to the dose of epoxiconazole alone which it is necessary to apply in order to obtain the destruction of 50% of the parasite) makes it possible, in an entirely unexpected way, to lower the bromuconazole dose necessary for the destruction of 50% of the parasite well below 101 g/ha (this value corresponding to the dose of bromuconazole alone which it is necessary to apply in order to obtain this same percentage of destruction of 50%).

The arrangement of the points obtained, in particular that corresponding to the ratios 3, 4, 5 and is 6, therefore indicates a bilateral effect, characteristic of a synergy.

Claims

16 CLAIMS

1. Fungicidal composition, characterized in that it comprises bromuconazole (B) which is 1-[(2RS,4RS:2RS,4SR)-4-bromo-2-(2,4dichlorophenyl)tetrahydrofurfuryll-lH-1,2,4-triazole and another triazole (A) chosen from tebuconazole which is (RS)-l-(4-chlorophenyl)-4,4dimethyl-3-(lH-1,2,4triazol-i-ylmethyl)pentan-3-ol and epoxiconazole which is (2RS,3SR)-l-[3-(2-chlorophenyl)-2,3-epoxy-2-(4fluorophenyl)propyl]-lH-1,2,4-triazole in association with a fungicidally acceptable carrier and/or surface active agent.

2. Fungicidal composition according to Claim 1, characterized in that the B/A ratio by weight is from 0.1 to 20.

3. Fungicidal composition according to claim 2 in which the B/A ratio is from 0.5 to 10.

4. Fungicidal composition according to either of Claims 1 and 2, characterized in that the triazole A is tebuconazole and the B/A ratio by weight is from 0.

5 to 5.

S. Fungicidal composition according to claim 4 in which the B/A ratio is from 1 to 3.

6. Fungicidal composition according to any one of Claims 1 to 3, characterized in that it contains from 0.05 to 950-. of mixture of bromuconazole and of the triazole A.

17

7. Fungicidal composition according to claim 1 substantially as hereinbefore described in Example 1 or 2.

8. Method intended to control or prevent fungal attacks on crops, characterized in that bromuconazole (B) which is 1-[(2RS,4RS:2RS,4SR)-4 bromo-2-(2,4-dichlorophenyl)tetrahydrofurfuryll-1H- 1,2,4-triazole and another triazole (A) chosen from tebuconazole which is (RS)-1-(4-chlorophenyl)-4,4 dimethyl-3-(1H-1,2,4-triazol-l-ylmethyl)pentan-3-ol and epoxiconazole which is (2RS,3SR)-1-[3-(2-chlorophenyl)- 2 3 -epoxy-2- (4-f luorophenyl) propyll -1H-1, 2, 4-triazole or a composition according to any one of Claims 1 to 7 is applied to the aerial parts of the crops.

is

9. Method according to Claim 8, characterized in that the bromuconazole dose applied is from 100 to 300 g/ha, and the triazole A dose is from to 250 g/ha.

10. Method according to claim 9 in which the bromuconazole dose is from 150 to 250 g/ha and the triazole (A) dose is from 75 to 200 g/ha.

11. Method according Claim 9 or 10, characterized in that the compound A is tebuconazole and the tebuconazole dose is from 75 to 250 g/ha.

12. Method according to claim 11 in which the tebuconazole dose is from 100 to 150 g/ha.

13. Method according to any one of Claims 8 to 12, characterized in that the fungal attacks are 18 caused by septoria diseases, rusts or fusarium diseases of the ears.

14. Method according to any one of Claims 8 to 13, characterized in that the crops are cereals.

15. Method according to claim 14 in which the crop is barley, wheat, rye or triticale.

16. Method according to claim 15 in which the crop is wheat.

17. Method according to claim 8 substantially as hereinbefore described in Example 1 or 2.

18. A product comprising bromuconazole (B) which is 1-[(2RS,4RS:2RS,4SR)4-bromo-2-(2,4dichlorophenyl) tetrahydrofurfuryl I -1H-1, 2,4-triazole is and another triazole (A) chosen from tebuconazole which is (RS)-1-(4chlorophenyl)-4,4-dimethyl-3-(1H-1,2,4triazol-l-ylmethyl)pentan-3-ol and epoxiconazole which is (2RS,3SR)-1-[3-(2-chlorophenyl)-2,3-epoxy-2(4fluorophenyl)propyll-1H-1,2,4-triazole for simultaneous, separate or sequential use in controlling fungal attacks on crops.