LU88502A1 - Treatment of seeds with phosphorous acid or one of its salts and seeds thus treated - Google Patents

Description

Treatment of seeds with phosphorous acid or one of its salts. and seeds thus treated.

The present invention relates to seeds of plants protected against attacks by fungal diseases, as well as antifungal compositions useful for obtaining these seeds thus protected, and the method of treating seeds in order to obtain protected seeds.

More advantageously, the present invention relates to seeds of monocotyledonous plants protected against the attacks of fungal diseases, as well as the antifungal compositions useful for obtaining these seeds thus protected, and the method of treating seeds in order to obtain seeds. protected.

We knew that it was possible to fight against fungal diseases of plants by foliar application of phosphorous acid and its derivatives (British patent 1459539), but this application did not lead in practice because of the phytotoxicity of compositions containing these ingredients (European patent application 230209).

It has now surprisingly been found that compositions having a good protective effect with regard to seeds, and plants resulting from the germination of these seeds, can be obtained, thanks to the protection of seeds using phosphorous acid or its derivatives, without this protection being disturbed by untimely phytotoxicity.

Within the meaning of the present invention, the term seeds designates all the generative parts (propagation material) of the plant that can be used for the reproduction thereof. This includes seeds (seeds in the narrow sense), roots, rhizomes, fruits, tubers, bulbs, parts of plants, sprouted plants, young plants from any method of propagation from seeds, cuttings , cell cultures, artificial seeds such as for example those described in patent applications FR 9305192 or PCT / FR 91/00984 (published under the number WO 92/10087).

The present invention relates more specifically to seeds, natural or artificial, preferably of monocotyledonous 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 triazole 2- (4-chlorobenzylidene) 5,5-dimethyl l- [1-H 1,2,4-triazol-1-ylmethyl] l-cyclopentanol.

Phosphorous acid, also called phosphonic acid, is the product of formula H-P (0) (0H) 2 (H3PO3 for short). Its salts are called phosphites, and can be mono- or di-salts, preferably alkali or ammonium salts, in particular Na2HP03, K2HPO3, NH4H2PO3.

From a practical point of view, the effective quantity 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.

Preferably the seeds are coated in an amount of 1 to 500 g of active material per quintal of seed and preferably 5 to 300 g / quintal.

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

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

Obtaining such seedlings is all the more remarkable since one could expect that the residual phosphorous acid would have a phytotoxic effect on plants resulting from germination, in the same way as it had a phytotoxic effect in foliar treatment.

The invention is particularly advantageous for the protection against fungal diseases of seeds corresponding to crops included in the group comprising cereals, in particular wheat, wheat, barley, rye, barley, oats, triticale; corn, rice.

The invention is particularly advantageous for the protection of seeds against * diseases belonging to the group comprising Pvthium arrhenomanes. Pvthium eraminicola. Pvthium torulosum. Pvthium vanterpoolii. Pvthium mvriotvlum. Pvthium periilum. Pvthium aristosporum. Pvthium aphanidermatum * damping-off, * root necrosis * necrosis of seedling collars.

The invention also relates to antifungal compositions intended for the protection of seeds, preferably of monocotyledonous 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 inert support acceptable in agriculture and, * optionally an acceptable surfactant in agriculture, * the various constituents of these compositions being other than triazole 2- (4-chlorobenzylidene) 5,5-dimethyl 1 - [1-H 1,2,4-triazol-l-ylmethyl] 1-cyclopentanol.

The compositions according to the invention usually contain between 0.5 and 95% (by weight) of active material of phosphorous type. Preferably, the amount of phosphorous-type active material in these treatment formulations is greater than 5% (by weight).

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

By the term "support", in the present description, is meant an organic or mineral, natural or synthetic material, with which the active material is associated to facilitate its application on the seed. This support is therefore generally inert and it must be acceptable in agriculture, in particular on the treated seed. The support can be solid (clays, natural or synthetic silicates, silica, resins, waxes, solid fertilizers, etc.) or, preferably, liquid (water, alcohols, ketones, petroleum fractions, aromatic or paraffinic hydrocarbons, hydrocarbons chlorinated, etc ...). As mentioned above, liquid carriers are preferred, in particular those in which the phosphorous active material is soluble, more particularly water and aqueous solutions.

The surfactant can be an emulsifying, dispersing or wetting agent of ionic or nonionic type. Mention may be made, for example, of salts of polyacrylic acids, salts of lignosulfonic acids, salts of phenolsulfonic or naphthalene sulfonic acids, polycondensates of ethylene oxide on fatty alcohols or on fatty acids or on fatty amines , substituted phenols (in particular alkylphenols or arylphenols), ester salts of sulfosuccinic acids, taurine derivatives (in particular alkyltaurates), phosphoric esters of alcohols or of polyoxyethylated phenols. The presence of at least one surfactant is often required.

These compositions can also contain all kinds of other ingredients such as, for example, protective colloids, adhesives, thickeners, thixotropic agents, penetrating agents, stabilizers, sequestrants, pigments, dyes, polymers .

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

It should be noted in this connection that in the vocabulary of those skilled in the art, the term seed treatment actually refers mainly to the treatment of seeds.

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 film-coating or coating. The coating is preferred in the invention because of its simplicity: it suffices to stir or mix the seed to be treated with the antifungal compositions according to the invention.

Among the compositions, mention may generally be made of solid or liquid compositions.

As forms of liquid compositions or intended to constitute liquid compositions during application, mention may be made of solutions, in particular water-soluble concentrates, emulsifiable concentrates, emulsions, concentrated suspensions, wettable powders (or spray powder).

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

For example, in addition to the solvent, emulsifiable concentrates can contain, when necessary, 2 to 20% of suitable additives such as stabilizers, surfactants, penetrating agents, corrosion inhibitors, dyes or the previously mentioned adhesives.

From these concentrates, emulsions of any desired concentration can be obtained by dilution with water, which are particularly suitable for application to seeds.

Wettable powders (or spray powder) are usually prepared so that they contain 20 to 95% of active ingredient, and they usually contain, in addition to the solid support, 0 to 5% of a wetting agent, 3 to 10% of a dispersing agent, and, when necessary, from 0 to 10% of one or more stabilizers and / or other additives, such as pigments, dyes, penetrating agents, adhesives, or anti-caking agents, etc.

As has already been said, aqueous dispersions and emulsions, for example the compositions obtained by diluting with water a wettable powder or an emulsifiable concentrate according to the invention, are included in 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".

Among these compositions, the skilled person will advantageously choose the one or those suitable according to the conditions of implementation.

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

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

Example 1 100 g of barley seeds were treated with 1.5 ml of an aqueous solution of phosphorous acid. The particular concentration of the treatment solution was calculated so as to obtain, on the seed, the dose (in g / q) of products indicated 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-mixing, for lmn, so as to obtain seeds comprising various concentrations of phosphorous acid as indicated in the table below.

These seeds were placed in pots containing a mixture of peat and pozzolan. One milliliter of Pythium mycelium ground material was inoculated into each pot by sprinkling the soil. There were about 20 seed seeds per pot.

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

The results are as follows:

Example 2

Barley seeds were treated, as in Example 1, with an aqueous solution of potassium diphosphite. To obtain a dose of 240 g / q of product on the seeds, 100 g of seeds were treated with 1.5 ml of a solution comprising 180 g / 1 of K2HPO3.

The seeds were treated so as to put 240 g / q of phosphite on these seeds.

The seeds thus treated were sown in the field and the state of the culture was observed 72 days after sowing compared to an untreated control.

All these cultures were affected by fungal attacks of Pvthium cirrhenomanes.

It was observed that, compared to the untreated plants, the plants resulting from the treatment according to the invention had 2.8 times more roots, than the plants themselves were 24.3% more numerous. The dry matter weight of the roots of treated plants compared to untreated plants was 39% higher.

Claims (14)

1 Plant seeds characterized in that they comprise, on or inside the grains, a fungicidal effective amount of an active material chosen from the group consisting of phosphorous acid or its salts, in l absence of triazole 2- (4-chlorobenzylidene) 5,5-dimethyl 1- [1-H 1,2,4-triazol-1-ylmethyl] 1-cyclopentanol. 2 Seeds of monocotyledonous plants characterized in that they comprise, on or inside the grains, a fungicidal effective amount of an active material chosen from the group consisting of phosphorous acid or its salts, in the absence of triazole 2- (4-chlorobenzylidene) 5,5-dimethyl 1- [1-H 1,2,4-triazol-1-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 or ammonium salts. 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 characterized in that the phosphorous active material is in an amount between 1 g / q and lkg / q, preferably between 5 and 500 g / q. 6 seeds according to one of claims 2 to 5 characterized in that the monocotyledonous plant is chosen from the group comprising cereals, in particular wheat, wheat, barley, rye, barley, oats, triticale; corn, rice. 7 Seeds according to one of claims 1 to 6 characterized in that they are protected against attacks by diseases of the group consisting of * diseases belonging to the group comprising Pvthium arrhennmanes. Pvthium çrciminicola. Pvthium torulosum. Pvthium vanterpoolii. Pvthium mvriotvlum. Pvthium periilum. Pvthium aristosporum. Pvthium aphanidermatum * damping-off, * root necrosis * necrosis of seedling collars. 8 Seeds according to one of claims 1 to 7 characterized in that they comprise a second active material chosen from the group consisting of captan, thiram, guazatine, copper oxyquinoleate, 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 comprise a second active material chosen from the group consisting of aspirin or its salts and esters, salicylic acid or its salts and esters. 10 seedlings characterized in that they come from the germination of seeds according to one of claims 1 to 9. 11 Process for the protection against fungal diseases of seeds, preferably of monocotyledonous plants, characterized in that an effective quantity of phosphorous active material is applied to said seeds included in the group consisting of phosphorous acid and its salts. 12 Antifungal compositions intended for the protection of seeds, preferably of monocotyledonous 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 support, inert acceptable in agriculture and, * optionally a surfactant acceptable in agriculture, * the various constituents of these compositions being other than triazole 2- (4-chlorobenzylidene) 5,5-dimethyl 1- [1-H 1,2,4-triazol-1-ylmethyl] 1-cyclopentanol. 13 Compositions according to claim 12 characterized in that they contain between 0.5 and 95% of active material of phosphorous type. 14 Compositions according to one of claims 12 or 13 characterized in that they are liquid and, preferably aqueous.