IE940516A1

IE940516A1 - Seed treatment using phosphorous acid or one of its salts,¹and seeds thus treated

Info

Publication number: IE940516A1
Application number: IE051694A
Authority: IE
Inventors: Maurice Chazalet; Jacques Mugnier
Original assignee: Rhone Poulenc Agrochimie
Priority date: 1993-06-23
Filing date: 1994-06-22
Publication date: 1994-12-28
Also published as: CH688601A5; BE1008436A5; RO113936B1; RU2140728C1; ITMI941312A1; CN1098253A; HUT67998A; FR2706736B1; PL303948A1; ES2070792A1; KR100353181B1; NL9401039A; AU679738B2; UA39171C2; SK283983B6; SI9400260B; TW292964B; HU9401897D0; GB2279252B; LU88502A1

Abstract

The invention relates to a coating for seeds to protect them from fungal diseases which contains an inert and acceptable in agriculture carrier and at least one active substance chosen from the group consisting of a phosphorous acid and its salts and a method for applying this coating to seeds. The coating provides a good protective effect.[BY4699C1]

Description

The present invention relates to plant seeds protected against attacks from fungal diseases, to the fungicidal compositions useful for obtaining these thus protected seeds and to the process for treating the seeds with a view to obtaining protected seeds.

More advantageously, the present invention relates to monocotyledon plant seeds protected against attacks from fungal diseases, to the fungicidal compositions useful for obtaining these thus protected seeds and to the process for treating the seeds with a view to obtaining protected seeds.

It was known that it was possible to control fungal diseases of plants by foliar application of phosphorous acid and its derivatives (Patent GB 1,459,539) hut this application has not emerged in practice due to the phytotoxicity of the compositions containing these ingredients (European Patent Application 230,209).

It has now been surprisingly found that it was possible to obtain compositions having a good protective effect with respect to seeds, and plants resulting from the germination of these seeds, by virtue of the protection of the seeds using phosphorous acid or its derivatives, without this protection being disturbed by excessive phytotoxicity.

OPEN TO PUBLIC INSPECTION UNDER SECTION 28 AND RULE 23 JNL. No.

Within the meaning of the present invention, the term seeds denotes any generative part (propagation material) of the plant which can be used for the reproduction of the latter. This includes seed grains (seeds within the narrow meaning), roots, rhizomes, fruits, tubers, bulbs, plant parts, germinated plants, young seedlings resulting from any method of propagation from seed grains, cuttings, cell cultures or artificial seeds such as, for example, those described in Patent Applications PR 9305192 or PCT/FR 91/00984 (published under the number WO 92/10087).

The present invention more specifically relates to natural or artificial seeds, preferably of monocotyledon plants, characterized in that they comprise, on or inside the grains, an effective amount of an active material chosen from the group consisting of phosphorous acid or its salts, in the absence of the triazole 2- (4-chlorobenzylidene)-5,5-dimethyl-l- (1H20 1,2,4-triazol-l-ylmethyl)-1-cyclopentanol.

Phosphorous acid, also known as phosphonic acid, is the product of formula H-P(O)(OH)3 (abbreviated as H3POj) . Its salts are known as phosphites, and can be mono- or disalts, preferably alkali metal or ammonium salts, in particular Na3HPO3, K3HPO3 or NH4H3PO3.

On a practical level, the effective amount of active material of phosphorous type which is retained is generally between 1 g/q and 1 kg/q (q is the abbreviation of quintal = 100 kg), preferably between 5 and 500 g/q.

The seed grains are preferably coated in a proportion of 1 to 500 g of active material per quintal of seed grain and preferably 5 to 300 g/quintal.

The active material of phosphorous type is preferably chosen such that its solubility in water at 20°C is greater than 0.1 g/1, more preferentially still greater than 0.5 g/1 and more preferentially still greater than 50 g/1. Active materials of lower solubility can also be used but it is then necessary to use fairly complicated formulations, for example wettable powders or aqueous suspensions. The use of active materials of sufficiently high solubility as it has just been defined is advantageous in that it makes it possible to treat seeds using simple solutions, which is extremely economic.

According to a first variant, the invention further relates to young plants resulting from the germination of the seeds which have just been defined, these young plants being at the one- or two-leaf stage.

That such young plants are obtained is all the more remarkable since it could be expected that the residual phosphorous acid has a phytotoxic effect with respect to plants resulting from the germination, in the same way that it had a phytotoxic effect in foliar treatment.

The invention is particularly advantageous in protecting, against fungal diseases, seeds corresponding to crops included in the group comprising cereals, in particular wheat, barley, rye, winter barley, oats, triticale, maize or rice.

The invention is particularly advantageous in protecting seeds against * diseases belonging to the group comprising Pvthium arrheaoaaaes, Pythiwa artunioicola. Pvthiun torulosua. Pvthium vanterpoolii, Pvthium mvrlotvlum. Pvthium Deriilum. Pvthium arietoaporum.

Pvthiva aphanideraatum * damping-off, * root rot, * young plant collar rot.

The invention further relates to fungicidal compositions intended for protecting seeds, preferably of monocotyledon plants, against fungal diseases, characterized in that they contain: * at least one active material chosen from the group consisting of phosphorous acid or its salts, * at least one inert vehicle which is acceptable in agriculture and, * optionally a surface-active agent which is acceptable in agriculture, * the various constituents of these compositions being other than the triazole 2-(4chlorobenzylidene)-5,5-dimethyl-1- (1H-1,2,4-triazol-1ylmethyl)-1-cyclopentanol. 940316 The compositions according to the invention commonly contain between 0.5 and 95% (by weight) of active material of phosphorous type. Preferably, the amount of active material of phosphorous type in these treatment formulations is greater than 5% (by weight) .

The present invention also relates to a process for protecting seeds, preferably of monocotyledon plants, against fungal diseases, characterized in that an effective amount of fungicidal active material and/or of fungicidal compositions as defined above is applied to the said seeds. According to this process of the invention, application of the fungicidal active material of phosphorous type is carried out using compositions comprising at least 5% of active material of phosphorous type, preferably at least 10%.

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

As has been said above, liquid vehicles are preferred, in particular those in which the phosphorous active material is soluble, more especially water and aqueous solutions.

The surface-active agent can be an 5 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 often required.

These compositions can also contain any kind of other ingredients such as, for example, protective colloids, adhesives, thickening agents, thixotropic agents, penetrating agents, stabilizing agents, sequestering agents, pigments, dyes or polymers.

More generally, the compositions according to the invention can be combined with all the solid or liquid additives corresponding to the conventional formulating techniques for application of seed treatment in particular.

While on this subject, it will be noted that, in the vocabulary of those skilled in the art, the term Ί seed treatment in fact mainly relates to the treatment of seed grains.

The application techniques are well known to those skilled in the art and they can be used without disadvantage in the context of the present invention.

Mention may be made, for example, of filmcoating or coating. Coating is preferred in the invention because of its simplicity; it is sufficient to stir or mix the seed to be treated with the fungicidal compositions according to the invention.

Among the compositions, solid or liquid compositions may generally be mentioned.

There may be mentioned, as forms of liquid compositions or those intended to constitute liquid compositions at the time of application, solutions, in particular water-soluble concentrates, emulsifiable concentrates, emulsions, suspension concentrates or wettable powders (or powder to be sprayed).

The emulsifiable or soluble concentrates most often comprise 10 to 80% of active material while emulsions or solutions ready for application contain, for their part, 0.01 to 20% of active material.

For example, in addition to the solvent, the emulsifiable concentrates can contain, when this is necessary, 2 to 20% of suitable additives such as stabilizing agents, surface-active agents, penetrating agents, corrosion inhibitors, dyes or the abovementioned adhesives. - 94 G ο 1 6 From these concentrates, it is possible to obtain, by dilution with water, emulsions of any desired concentration, which are particularly suitable for application to seeds.

The wettable powders (or powder to be sprayed) are generally prepared so that they contain 20 to 95% of active material, and they generally contain, in addition to the solid vehicle, from 0 to 5% of a wetting agent, from 3 to 10% of a dispersing agent and, when this is necessary, from 0 to 10% of one or more stabilizing agents and/or other additives, such as pigments, dyes, penetrating agents, adhesives, antidumping agents, and the like.

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, are contained within the general scope of the present invention. Emulsions can be of the water-in-oil or oil20 in-water type and they can have a thick consistency, like that of a mayonnaise.

Among these compositions, a person skilled in the art will advantageously choose that or those which are suitable depending on the conditions of use.

In the invention, the phosphorous derivative can be used alone or as a mixture, in particular with fungicides or insecticides, especially captan, thiram, aspirin or its salts and esters, salicylic acid or its i. 94 0 5 1 6 salts and esters, guazatine, oxine-copper, tefluthrin, anthraquinone or metalaxyl, and insecticides such as imidacloprid, lindane and endosulfan, as well as mixtures of these various products.

The following examples, given without implied limitation, illustrate the invention and show how it can be used.

Example 1 100 g of barley seed grains were treated with 1.5 ml of an aqueous phosphorous acid solution. The specific concentration of the treatment solution was calculated so as to obtain, on the seed, the dose (in g/q) of products shown in the table below. In the case of a dose of 100 g/q, the concentration of phosphorous acid in the water was 75 g/1.

The treatment was carried out by simple mixing/stirring, for 1 min, so as to obtain seeds comprising various concentrations of phosphorous acid as shown in the table below.

These seed grains were deposited in pots containing a mixture of peat and pozzolana. A millilitre of Pythium mycelium ground preparation was inoculated into each pot by spraying the earth. There were approximately 20 seed grains per pot.

The seed grains germinated and, 15 days after sowing, the state of the plants was observed with respect to control seed grains not treated with phosphorous acid and with respect to control seed grains not inoculated with Pythium. All the plants which had germinated had two leaves. No phytotoxicity was observed in any case.

The resulte are the following: Fungicidal agent Dose in g/q efficiency expressed as percentage Pythium arrhenomanes Pythium myriotylum Phosphorous acid 50 60 40 100 100 60 Sodium 100 75 20 monophosphite 200 100 70 400 100 100 800 100 100 Untreated control 0 0 0 Example 2 Barley seed grains were treated, as in Example 1, with an aqueous dipotassium phosphite solution. In order to obtain a dose of 240 g/q of products on the seeds, 100 g of seeds were treated with 1.5 ml of a solution comprising 180 g/1 of K3HPO3.

Treatment of the seeds was carried out so as to place 240 g/q of phosphite on these seeds.

The seed grains thus treated were sown in an open field and the state of the crop was observed 72 days after sowing with respect to an untreated control. All these crops were affected by fungal attacks of 1.940516 Pvthium arrhenojnanea .

It was observed that, with respect to the untreated plants, the plants resulting from the treatment according to the invention contained 2.8 times more roots and that the plants themselves were greater in number by 24.3%. The weight of dry matter of the roots of the treated plants with respect to the untreated plants was greater by 39%.

Claims

1. Plant seeds, characterized in that they comprise, on or inside the grains, an effective amount, from the fungicidal viewpoint, of an active material 5 chosen from the group consisting of phosphorous acid or its salts, in the absence of the triazole 2-(4chlorobenzylidene)-5,5-dimethyl-l-(1H-1,2,4-triazol-lylmethyl) -1-cyclopentanol.

2. Monocotyledon plant seeds, characterized in 10 that they comprise, on or inside the grains, an effective amount, from the fungicidal view point, of an active material chosen from the group consisting of phosphorous acid or its salts, in the absence of the triazole 2-(4-chlorobenzylidene)-5,5-dimethyl-l-(1H15 1,2,4-triazol-l-ylmethyl)-1-cyclopentanol.

3. Seeds according to claim 1 or 2, characterized in that the phosphorous active material comprises phosphorous acid or one of its alkali metal or ammonium salts. 20

4. Seeds according to claim 1 or 2, characterized in that the phosphorous active material is chosen so that its solubility in water at 20°C is greater than 0.1 g/1, preferably greater than 0.5 g/1.

5. Seeds according to one of claims 1 to 4, 25 characterized in that the phosphorous active material is in an amount between 1 g/g and 1 kg/g, preferably between 5 and 500 g/g.

6. Seeds according to one of claims 2 to 5, characterized in that the monocotyledon plant is chosen from the group comprising cereals, in particular wheat, barley, rye, winter barley, oats, triticale, maize or rice.

7. Seeds according to one of claims 1 to 6, characterized in that they are protected against the attacks of diseases from the group consisting of * diseases belonging to the group comprising Pvthlvua arrhennm/tnes. Pvthlum gramiziicola, Pvthiuin toruloBVtt. Pvthiuin vanfcerpoolii. Pvthiuin mvriotvlum. Pvthium Oerlilum. Pvthium ariatosoorum. or Pvthium aphenidermatum * damping-off, * root rot, * young plant collar rot.

8. Seeds according to one of claims 1 to 7, characterized in that they contain a second active material chosen from the group consisting of captan, thiram, guazatine, oxine-copper or metalaxyl as well as insecticides such as imidacloprid, lindane and endosulfan.

9. Seeds according to one of claims 1 to 7, characterized in that they contain a second active material chosen from the group consisting of aspirin or its salts and esters or salicylic acid or its salts and esters.

10. Young plants, characterized in that they have resulted from the germination of seeds according to one 9405-6 of claims 1 to 9.

11. Process for protecting seeds, preferably of monocotyledon plants, against fungal diseases, characterized in that an effective amount of 5 phosphorous active material included in the group consisting of phosphorous acid and its salts is applied to the said seeds.

12. Fungicidal compositions intended for protecting seeds, preferably of monocotyledon plants, 10 against fungal diseases, characterized in that they contain: * at least one active material chosen from the group consisting of phosphorous acid or its salts, * at least one inert vehicle which is 15 acceptable in agriculture and, * optionally a surface-active agent which is acceptable in agriculture, * the various constituents of these compositions being other than the triazole 2-(420 chlorobenzylidene)-5,5-dimethyl-l-(lS-l,2,4-triazol-lylmethyl)-1-cyclopentanol.

13. Compositions according to claim 12, characterized in that they contain between 0.5 and 95% of active material of phosphorous type. 25

14. Compositions according to either of claims 12 and 13, characterized in that they are, preferably aqueous, liquids.

15. A composition according to claim 12, substantially as hereinbefore described.