ITMI941312A1 - TREATMENT OF SEEDS WITH PHOSPHORIC ACID OR WITH ONE OF ITS SALTS AND SEEDS SO TREATED - Google Patents

Description

DESCRIPTION OF THE INDUSTRIAL INVENTION

The present invention relates to plant seeds protected against the attacks of diseases caused by fungi, and also relates to anti-fungal compositions useful for obtaining these protected seeds and relates to the procedure for treating the seeds in order to obtain protected seeds.

More advantageously, the present invention relates to seeds of monocotyledonous plants protected against the attacks of diseases caused by fungi and also relates to the antifungal compositions useful for obtaining these protected seeds and the process of treating the seeds in order to obtain protected seeds.

It was known that it was possible to fight against diseases caused by plant fungi by applying phosphorous acid and its derivatives to the leaves (British patent 1459539), but this application did not have a practical development due to the phytotoxicity of the compositions containing these ingredients. (European patent application 230209).

It has now been found in a surprising way that compositions could be obtained having a good protective effect towards the seeds and plants grown from the germination of these seeds, protecting these seeds with phosphorous acid or with its derivatives, without however this protection being rendered problematic from an untimely phytotoxicity.

For the purposes of the present invention, the term seed indicates all the generative parts (propagation material) of the plant that can be used for its reproduction. It includes seeds (seeds in the strict sense), roots, rhizomes, fruits, tubers, bulbs, parts of plants, sprouted plants, young plants obtained by any method of propagation starting 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 number W0 92/10087).

The present invention relates, more particularly, to seeds, natural or artificial, preferably of monocotyledonous plants.

characterized by the fact of containing, on the seeds or inside the seeds, an effective quantity of an active substance chosen from the group consisting of phosphoric acid or its salts, in the absence of tn azole 2- (4-chlorobenzylidene) 5,5 -dimethyl 1- [1-H 1,2,4-triazol-1-ylmethyl] 1-cyclopentanol.

Phosphorous acid, also called phosphonic acid, is the product of the formula Η-Ρ (O) OΗ) 2 (H3PO3 for abbreviated). Its salts are called phosphites and can be mono-salts or di-salts, preferably alkali salts or ammonium salts, in particular Na2HPO3, K2 HPO3, NH4H2PO3.

From a practical point of view, the effective amount of phosphorous type active substance that is retained is generally between 1 g / q and 1 kg / q (q is the abbreviation for quintal = 100 kg), preferably between 5 and 500 g / q.

Preferably, the seeds are coated with an amount of active substance comprised between 1 and 500 g per quintal of seeds, and preferably between 5 and 300 g / q.

The active substance of the phosphorous type is preferably chosen so that its solubility in water at 20 ° C is higher than 0.1 g / l, even more preferably it is higher than 0.5 g / l and even more preferably it is higher than 50 g / l. It is also possible to use active substances having a lower solubility, but then it is necessary to use very elaborate formulations, for example wettable powders or aqueous suspensions. The use of active substances having a sufficiently high solubility, as has now been defined, is advantageous in that it allows the seeds to be treated with simple solutions and this is most economical.

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

The obtaining of these particles is all the more remarkable that the residual phosphorous acid could be expected to have a phytotoxic effect on the plants coming from the sprouting, just as it had a phytotoxic effect in the treatment of the leaves.

The present invention is particularly advantageous for the protection against diseases caused by fungi of the seeds corresponding to crops included in the group consisting of cereals, in particular wheat, wheat, barley, rye, early barley, oats. , triticum, corn, rice.

The present invention is particularly advantageous for protecting seeds against

* diseases belonging to the group including Pythium arrhenomanes, Pythium graminicola, Pythium torulosum, Pythium vanterpoolii, Pvthium myriotylum, Pythium periilum, Pythium aristosporum, Pythium aphanidermatum

* the destruction of the sown,

* root necrosis

* necrosis of the seedling collars.

The present invention also relates to anti-fungal compositions intended for the protection of seeds, preferably for the protection of monocotyledonous plants, against diseases caused by fungi, characterized by the fact that they contain:

* at least one active substance selected from the group consisting of phosphorous acid or its salts,

* at least one inert support, acceptable in agriculture, e

* possibly a surfactant acceptable in agriculture,

* the different constituents of these compositions being different from triazole 2- (4-chlorobenzylidene) 5,5-dimethyl 1- [1-H 1,2,4-triazol-1-ylmethyl] 1-cyclopentanol.

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

The present invention also relates to a process for protecting seeds, preferably monocotyledonous plant seeds, against diseases caused by fungi, characterized in that, on said seeds, an effective amount of antifungal active substance and / or antifungal compositions such as previously defined. According to this process of the present invention, the application of the phosphorous-type fungicidal active substance is carried out using compositions which contain at least 5% of phosphorous-type active substance, preferably at least 10%.

In the present description, the term "support" indicates an organic or mineral substance, natural or synthetic, with which the active substance is associated to facilitate its application on the seed. This support, therefore, is generally inert and 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, it can be liquid (water, alcohols, ketones, petroleum fractions, aromatic or paraffinic hydrocarbons, chlorinated hydrocarbons, etc ...). As indicated above, liquid supports are preferred, in particular those in which the phosphorous active substance is soluble, more particularly water and aqueous solutions.

The surfactant can be an emulsifier, a dispersant or a wetting agent of the ionic or non-ionic type. For example, salts of polyacrylic acids, salts of lignosulfonic acids, salts of phenolsulfonic or naphthalenesulfonic acids, polycondensation products of ethylene oxide on fatty alcohols or fatty acids, or on fatty amines, substituted phenols (in particular alkylphenols or arylphenols), salts of esters of sulphosuccinic acids, derivatives of taurine (in particular alkyltaurates), phosphoric esters of alcohols or polyoxyethylated phenols. The presence of at least one surfactant is often required.

These compositions can also contain any type 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 present invention can be associated with all the solid or liquid additives corresponding to the usual formulation techniques, in particular for the application of the seed treatment.

In this regard, it will be noted that, in the vocabulary of those skilled in the art, the term seed treatment is actually primarily concerned with seed treatment.

The application techniques are well known to those skilled in the art and can be adopted without drawbacks within the scope of the present invention.

For example, the introduction into films or the coating could be mentioned. The coating is preferred in the present invention because of its simplicity: it is sufficient to treat or mix the seed to be treated with the antifungal compositions according to the present invention.

Among the compositions, solid or liquid compositions can be mentioned in general.

As forms of liquid compositions or those intended to obtain liquid compositions at the time of application, solutions can be mentioned, in particular water-soluble concentrates, emulsifiable concentrates, emulsions, concentrated suspensions, wettable powders (or powders to be pulverized ).

Emulsifiable or soluble concentrates contain, more often 10% to 80% of active substance, emulsions or ready-to-use solutions contain 0.01 to 20% of active substance.

For example, in addition to the solvent, the emulsifiable concentrates can contain, if necessary, from 2% to 20% of suitable additives, such as stabilizers.

the surfactants, penetrating agents, corrosion inhibitors, dyes or adhesives mentioned above.

Starting from these concentrates, by dilution with water, it is possible to obtain emulsions having any desired concentration which are particularly suitable for application on seeds.

The wettable powders (or powders to be pulverized) are usually prepared so that they contain from 20% to 95% of active substance and they usually contain, in addition to the solid support, from 0% to 5% of a wetting substance, to be 3% to 10% of a dispersant and, if necessary, 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 indicated, the aqueous dispersions and emulsions, for example, the compositions obtained by diluting a wettable powder or an emulsifiable concentrate according to the present invention with water, are included in the general scope of the present invention. The emulsions may be of the water-in-oil type or of the oil-in-water type and may have a thick consistency.

like that of a "mayonnaise".

Among these compositions, those skilled in the art will advantageously choose the one or those which are suitable according to the manufacturing conditions.

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

The following examples, given without limitation, illustrate the present invention and indicate how it can be realized.

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 in order to obtain, on the seed, the dose (in g / q) of products indicated in the following table. In the case of a dose of 100 g / q, the concentration of phosphorous acid in the water was 75 g / l.

The treatment was carried out by simple mixing-mixing for 1 minute, in order to obtain seeds that have different concentrations of phosphorous acid as indicated in the following table.

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

The seeds sprouted and, 15 days after sowing, the state of the plants was observed with respect to reference seeds not treated with phosphorous acid and with respect to reference seeds not inoculated with Pythium. All the plants that had sprouted had two leaves. In no case was any phytotoxicity observed.

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 seed products, 100 g of seeds were treated with 1.5 ml of a solution containing 100 g / l of K2HPO3.

The treatment of the seeds was carried out in order to apply 240 g / q of phosphite on these seeds.

The seeds thus treated were sown outdoors and the state of the crop was observed 72 days after sowing with respect to an untreated reference. All of these crops were attacked by Pythium arrhenomanes fungi.

As regards the untreated plants, it was observed that the plants obtained by the treatment according to the present invention had a number of roots 2.8 times higher and the plants themselves were 24.3% higher. The dry matter weight of the roots of the treated plants, referred to untreated plants, was 39% higher.

Claims (14)

CLAIMS 1. Plant seeds characterized by the fact that they contain, on the seeds or inside the seeds, an effective quantity, from a fungicidal point of view, of an active substance 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. 2. Seeds of monocotyledonous plants characterized by the fact that they contain, on the seeds or inside the seeds, an effective quantity, from a fungicidal point of view, of an active substance chosen from the group consisting of phosphorous acid or its salts, in the absence triazole 2- (4-chlorobenzylidene) 5,5-dimethyl 1- [1-H 1,2,4-triazol-1-ylmethyl] 1-cyclopentanol. Seeds according to claim 1 or 2, characterized in that the phosphorous active substance contains phosphorous acid or one of its alkali salts or its ammonium salts. 4. Seeds according to claim 1 or 2, characterized in that the phosphorous active substance is selected so that its solubility in water at 20 ° C is greater than 0.1 g / l, preferably greater than 0.5 g /L. Seeds according to one of claims 1 to 4, characterized in that the phosphorous active substance is in a quantity comprised between 1 g / q and 1 kg / q, preferably between 5 and 500 g / q. Seed according to one of claims 2 to 5, characterized in that the monocotylenedone plant is selected from the group comprising cereals, in particular wheat, wheat, barley, rye, early barley, oats , Triticum, corn, rice. 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 including Pythium arrhenomanes, Pythium graminicola, Pythium torulosum, Pythium vanterpoolii, Pythium myriotylum, Pythium periilum, Pythium aristosporum, Pythium aphanidermatum * the destruction of the sown, * root necrosis * necrosis of the seedling collars. 8. Seeds according to one of claims 1 to 7, characterized in that they contain a second active substance selected from the group consisting of captan, thiram, guazatin, copper oxyquinolate, metalaxyl, and also insecticides such as for example imidacloprid, lindane and endosulfan. Seeds according to one of claims 1 to 7, characterized in that they contain a second active substance selected from the group consisting of aspirin or its salts and esters, salicylic acid or its salts and esters. 10. Seedlings characterized in that they have developed from the sprouting of seeds according to one of claims 1 to 9. 11. Process for the protection against diseases caused by seed fungi, preferably of monocotyledonous plants, characterized in that an effective quantity of phosphoroselected active substance is applied to said seeds in the group consisting of phosphorous acid and its salts. 12. Antifungal compositions intended for the protection of seeds, preferably for the protection of monocotyledonous plants, against diseases caused by fungi, characterized by the fact that they contain: * at least one active substance selected from the group consisting of phosphorous acid or its salts, * at least one inert support, acceptable in agriculture, and * possibly a surfactant acceptable in agriculture, * the different constituents of these compositions being different from 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 substance of the phosphorous type. 14. Compositions according to one of claims 12 or 13, characterized in that they are liquid and preferably aqueous.