RO113936B1 - Process for treating barley seeds against pythium attack - Google Patents

Description

The invention relates to a method of treating barley seeds against Pythium attack, namely, diseases of Pythium arrhenomanes, Pythium graminicola, Pythium torulosum, Pythium vaterpoolii, Pythium myriotylum, Pythium periilum, Pythium aristosporum, Pythium aphanidermat.

It is known that it is possible to control fungal diseases of plants by folic application of phosphoric acid and its derivatives (GB 1459539), but this application was not practically due to the phytotoxicity of the compositions containing these ingredients (European patent application EP 230209).

Numerous fungicidal compositions containing phosphoric acid or a salt thereof, along with other well-defined components, are known in the patent literature. Thus, in the publication EP-A0230209 above is described a microbicidal composition containing an acylaniline derivative and phosphorous acid or its salts, composition having increased synergetic activity against some plant diseases. Also, EP-A-0280348 describes a fungicidal composition containing phosphorous acid or a salt thereof. A method for controlling the fungal diseases of cultivated plants (EP 466612 B), which consists in applying on their leaves the compound 4- (4-chlorobenzylidene) - 5,5 - dimethyl-1- (1 H-1, 2,4-triazol-1-ylmethyl) -1-cyclopentanol and one or more acids suitable for protection against said diseases.

It has been found that an appropriate protection effect of the seeds and plants from the germination of these seeds can be achieved, without this protection being affected by an accidental phytotoxicity.

The method of treating barley seeds against the attack of Pythium consists in the fact that the seeds apply an amount of 5 ... 500 g / q of phosphorous active material, selected from the group of phosphorous acid and its alkaline or ammonium salts.

The invention has the advantage of performing a phytotoxicity-free method for treating seeds against Pythium attack or other diseases, such as seed rust (cast iron), root necrosis, necrosis of the demarcation between root and seedling strain.

For the purpose of the present invention, the term seeds "means all the generative parts, ie the propagating material of the plant, which can be used for its reproduction. It includes seeds in the restricted sense, roots, rhizomes, fruits, tubers, bulbs, parts of plants, germinated plants, young seedlings resulting from any propagation method from seeds, cuttings, cell cultures, artificial seeds, as described, for example , in patent applications FR 9305192 or PCT / FR 91/00934 (published WO 92/10087).

Phosphoric acid, also called phosphonic acid, is the product of the formula HP (0] (0H] ₂ (H ₃ P0 ₃ , abbreviated). Its salts are called phosphites and may be mono- or di-salts, preferably alkaline salts. or ammonium, in particular Na ₂ HPO ₃ , K ₂ HP0 ₃ , NH ₄ H ₂ P0 ₃ .

The effective amount of phosphorus active material, which is retained, is generally between 1 g / q and 1 kg (q is the abbreviation from quintal = 100 kg), preferably between 5 and 500 g / q. preferably, the seeds are coated with about 1 to 5DD g of active matter per quintal and preferably 5 to 300 g / q.

The phosphorous active material is preferably chosen so that its solubility in water is, at 20 ° C, above 0.1 g / l and, in particular, above 0.5 g / l. Active materials with lower solubility may also be used, but in this case sufficiently elaborate formulations, such as wettable powders or aqueous suspensions, should be applied. The use of active materials with sufficiently high solubility, as defined above, is advantageous because it allows the treatment of seeds with simple solutions, which is especially economical.

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The invention relates to seedlings (embryos) resulting from the germination of the seeds that have been defined above, these seedlings being in the one-two leaf phase, obtaining such seedlings is all the more remarkable, because the residual phosphoric acid was expected to have a phytotoxic effect on the plants resulting from germination, by having a phytotoxic effect in the foliar treatment.

The invention also relates to antifungal compositions intended for the protection of seeds, preferably of monocotyledonous plants, of fungal diseases and which contain at least one active material, selected from the group consisting of phosphoric acid or its salts, at least an inert support acceptable in agriculture and, possibly, an acceptable surfactant in agriculture, 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.

These compositions usually contain between 0.5 and 95% by weight of phosphorus active material. Preferably, the amount of phosphorus active material in these treatment formulations is greater than 5% by weight.

A process can also be carried out for the protection of diseases of the seeds, preferably of the monocotyledonous plants, which consists in that an effective amount of antifungal active matter and / or antifungal composition defined above is applied to the respective seeds. By this process, the application of the phosphorus-active / fungal material is accomplished by means of compositions comprising at least 5% phosphorus-active material, preferably at least 10%.

By the term "support" in this presentation is designated an organic or mineral matter, natural or synthetic, with which the active matter is associated, to facilitate the application on seeds. This support is therefore generally inert and it must be acceptable in agriculture, especially on the treated seed. The support may be solid (clays, natural or synthetic silicates, silica, resins, waxes, fertilizers, etc.) or, preferably, liquid (water, alcohols, ketones, petroleum fractions, aromatic or paraffinic hydrocarbons, liquid hydrocarbons, more especially those in which the phosphorous active matter is soluble, especially water and aqueous solutions.

The surfactant may be an emulsified, dispersing or bleaching agent, ionic or non-ionic. Examples include lignosulphonic acid salts, phenolsulphonic or naphthalenesulphonic acid salts, ethylene oxide polycondensates on fatty alcohols or fatty amines, substituted phenols (especially alkylphenols and arylphenols), salts of the esters of acrylic sulfuric acids. especially alkyl derivatives), phosphoric ethers of polyoxyethylated alcohols or phenols. The presence of at least one surfactant is often required.

These compositions may also contain all kinds of other ingredients, such as, for example, protective colloids, adhesives, penetrating agents, stabilizers, sequestrants, pigments, dyes, polymers. Generally speaking, the respective compositions may be associated with any additives, solids or liquids, corresponding to the usual formulation techniques for applying seed treatment, in particular.

It should be noted that in the vocabulary of specialists, the term of treatment of seeds refers in fact mainly to the treatment of the seeds themselves. The application techniques are known to the skilled person and they can be used without any problems in the present invention. You can cite, for example, filming or dressing. The coating is preferred in the invention because of its simplicity: it is sufficient to mix the seed to be treated with the antifungal compositions, among which solid or liquid compositions can generally be cited.

As forms of liquid compositions, or intended to constitute liquid compositions, upon application, solutions, especially concentrated suspensions, can be cited as powdered powders. Emulsifiable or soluble concentrates most commonly comprise 10 to 80% active material, emulsions or solutions ready for

The application contains, as far as they are concerned, □, □ 1 to 20% active matter. For example, in addition to the solvent, the emulsifiable concentrates may contain, when necessary, 2 to 20% additives suitable as 5 stabilizers, surfactants, penetrating agents, corrosion inhibitors, dyes or adhesives mentioned above. From these concentrates, by dilution with water, emulsions of any desired traction concentration can be obtained, especially suitable for application on seeds. The wettable powders (or spray powders) are usually prepared so that they contain 20 to 95% active material and they contain, in the usual 15, in addition to the solid support, up to 5% a grinding agent, 3 to 10% dispersing agent, and when up to 10% one or more stabilizers and / or other additives are required, such as 20 pigments, dyes, penetrating agents, adhesives or anti-caking agents, etc. As mentioned above, the 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 within the general scope of the present invention.

The emulsions may be of the water-in-oil or oil-in-water type and may have the consistency of a "mayonnaise". between these compositions the specialist will advantageously choose the one or the ones that are suitable depending on the conditions of application.

In the invention, the phosphorus derivative may be used alone or in combination, especially with fungicides or insecticides, in particular with captan, thiram, aspirates or its salts or esters, salicylic acid or its salts and esters, guazatin, oxycinoleate. copper, teflurine, anthracinone, metalaxyl, as well as insecticides, such as imidacloprid, indan, endosulfan, as well as mixtures of these various products.

Two concrete examples of embodiment of the invention are given below.

Example 1. 100 g barley grains are treated with 1.5 ml aqueous phosphorous solution. The particular concentration of the solution to be treated was calculated in order to obtain the seed 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 water was 75 g / l. The treatment was performed by simple mixing-rotation, for 1 min, in order to obtain seeds comprising different concentrations of phosphoric acid, as indicated in the following table. These grains were deposited in pots containing a mixture of peat and powders. In each pot, 1 ml of Pythium mite slurry was inoculated, by sprinkling the soil. There were about 20 seeds per pot. The seeds germinated and, 15 days after sowing, the state of the plants was observed in relation to the control seeds not treated with phosphorous acid and in relation to the control seeds not inoculated with Pythium. All the plants that germinated had two leaves.

No phytotoxicity was observed in either case.

The results are as follows:

Antifungal agent Dose in g / q Efficiency expressed as Pythium Pythium percentages arrhenomanes myriotylum Phosphorous acid 50 60 40 100 100 60 Sodium monophosphite 100 75 20 two hundred 100 70 400 100 100 800 100 100 Untreated witness 0 0 0

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Example 2. Barley seeds were treated, as in example 1, with a potassium diphosphite solution. To obtain a dose of 240 g / q of seed products, 100 g of seeds were treated with 1.5 ml solution containing 180 g / l K ₂ HPO ₃ .

The seed treatment was performed so that 240 g / q of phosphite was applied to these seeds. io

The seeds thus treated were sown in the field, and the condition of the crop was observed 72 days after sowing, in relation to an untreated control. All these cultures were reached by fungal attack of Pythium arrhenomanes.

It was observed that, compared to the untreated plants, the plants resulting from the treatment according to the invention comprise 2.8 times more roots and were in one

The chairman of the examination committee: dr inc. Examiner: ing. Lonescu Bucura increased number by 24.3%. The dry matter weight of the roots of the treated plants compared to the untreated plants is 39% higher.

Claims (2)

claims 1. Method of treating barley seeds against the attack of Pythium, characterized in that 5 to 500 g / q of phosphorous active material, selected from the group of phosphorous acid and its alkaline salts or ammonium. Seed treatment method according to claim 1, characterized in that the phosphorous active material is chosen so that its solubility in water at 2G ° C is above 0.1 g / l, preferably 0.5 g / l.