The present invention relates to a synthesis process of iron-bearing compositions and additional essential elements for treating nutritional deficiencies in plants, in particular for the prevention and treatment of physiological alterations or nutritional unbalances in plants due to a deficiency of iron and other essential elements.

STATE OF THE ART

Some of the iron-bearing compositions object of the present invention have already been described by the Applicant in patent application W02007/003388 for use as siderophores in the agronomic field. These compositions in WO'388 are prepared according to the following scheme;

Copolymer + Element Element- Supplier wherein Copolymer refers to the class of compounds defined as "aery lie -saccharide copolymers" described in EP0289895, WO9517442, WO9401476 and in the patents cited therein, and Element refers to an acid, a base or a salt of an essential element selected from nitrogen, potassium, iron, calcium, magnesium, manganese, copper, zinc, molybdenum and boron.

According to WO'388, the reaction can be carried out in water, at a temperature ranging from 0 to 80°C, in the presence or absence of an inorganic base, such as, for example, ammonium hydroxide, potassium hydroxide, sodium hydroxide, depending on the element or elements to be used for the preparation of the composition.

With respect to the preparation of the above-mentioned iron-bearing compositions, the synthesis strategy used in WO'388 provides for mixing the copolymer, for example the commercial copolymer "Beixon AB200%" sold in aqueous solution at 44% weight/weight (which will be indicated hereafter as w/w) and previously basified with a large excess of ammonium hydroxide at 30% w/w, with the solution obtained by solubilization in water of iron ammonium sulfate dodecahydrate, also called iron alum. Said mixing is effected by means of suitable vigorous stirring, also with the use of a Turrax homogenizer, in order to appropriately manage the various thickening and redissolving phases of the iron- bearing composition, according to scheme 1: Scheme 1 supplier +

The use of this synthesis process therefore involves the preparation in separate reactors of two solutions, the Beixon AB200% polymer solution with the addition of ammonium hydroxide and the iron ammonium sulfate solution, with subsequent transfer. During the mixing step of the two solutions according to the synthesis process in accordance with WO'388, there is a significant thickening of the reaction mixture consisting of the iron-bearing composition. This thickening creates a criticality that can only be mitigated by using an impeller with a powerful driving force or by operating with a greater dilution of the two solutions in water. Furthermore, during the neutralization reaction between the basic solution of the copolymer and the acid solution of the iron salt and the formation of the iron-based complex, the temperature spontaneously reaches high values which are such as to remove the excess ammonium hydroxide used initially, in the form of ammonia vapours, with the consequent necessity, especially from an industrial perspective, of controlling the ammonia emissions into the atmosphere by means of an additional abatement or recovery system for said vapours.

In addition, the operation as described in patent application WO'388, does not allow, unless there is a forced removal of part of the water with additional costs, lengthy operating times and energy consumption, a reaction mixture to be obtained with a final iron concentration greater than 2.5% w/w with respect to the total weight of the final iron-bearing composition.

Reaching higher iron concentrations, on the other hand, is of great interest from an agronomic point of view for improving the effectiveness of the product obtained.

Consequently, although the above-mentioned methodology described in WO'388 provides an iron-bearing composition, it does not allow this process to be carried out industrially in an effective and optimal way. The need is therefore particularly felt for identifying a new synthesis process of iron-bearing compositions (indicated for the sake of simplicity as Fe-Comp) which, thanks to an optimization of the different steps and stoichiometry of the process, using controlled reaction conditions and a more careful use of the reagents, allows compositions to be obtained bearing essential elements having a better agronomic efficacy and a broader spectrum of application in terms of crops.

The objective of the present invention is therefore to identify a new synthesis process according to the following scheme:

Copolymer + Fe salt Comp which overcomes the drawbacks of the processes according to the state of the art previously indicated.

A further objective of the present invention is to identify a new synthesis process with an easy industrial applicability and capable of providing a new and enhanced product in biological effectiveness, both as a siderophore and as a biostimulant, with a preventive and curative action of physiological alterations or nutritional unbalances of plants, increasing their resistance to pathogenic attacks and having numerous advantages with respect to the known art

DESCRIPTION

The Applicant has now surprisingly found that it is possible, by using a new process having an easy industrial applicability, to obtain iron-bearing compositions enhanced in their biological effectiveness, both as siderophores and as biostimulants and having a preventive and curative action of the physiological alterations of plants or their nutritional unbalances.

The present invention therefore relates to a synthesis process of iron-bearing compositions according to the following reaction:

Fe salt + Copolymer + NFEOHaqu Fe-Comp + (NFU SCU comprising the following steps: i) preparation of an aqueous solution of an Fe salt, said iron salt being an iron (II) sulfate or an iron (III) sulfate, soluble in water, preferably a salt consisting of the sulfate anion and a double cation, more preferably the double cation is Fe ³⁺ and ammonium NH ⁴⁺ ; ii) preparation of a suspension by adding an aqueous solution to the solution obtained in step i), at a concentration ranging from 30% to 70% w/w, of an acrylic - saccharide copolymer with a weight ratio between the iron ion and the copolymer solution which varies within the range of 1:5 to 1:50, preferably equal to 1:10, at a temperature ranging from 20°C to 40°C, preferably at a temperature of 35°C; iii) addition of an aqueous solution of NH4OH at 30-33% w/w to the suspension obtained at the end of step ii) and simultaneous dissolution by heating to a temperature within the range of 35 °C to 60°C; iv) conditioning of the reaction mixture obtained at the end of step iii) for a time ranging from 1 to 4 hours, preferably for 2 hours, at a temperature within the range of 60°C to 70°C, until complete homogenization; v) pH regulation within the range of 7.5 to 8.0 at a temperature ranging from 20°C to 75°C, preferably at a temperature of 50°C; vi) possible addition of further salts or chelates or complexes of essential elements and finally the possible addition of water in a quantity ranging from 0 to 4% w/w with respect to the weight of the final iron-bearing composition (Fe-Comp).

More specifically, at an industrial level, the synthesis process according to the present invention is particularly advantageous, as it is a synthesis process of iron-bearing compositions, having only synthesis steps in sequence, characterized by a reduced use of ammonium hydroxide, with a high and efficient control of the rheology of the system and of the heat exchange that allows a final product to be obtained directly, i.e. an iron-bearing composition and possibly additional essential elements, ready for use. This process is in fact capable of providing a new product that is already formulated, with concentrations of iron and ammonium sulfate higher than the state of the art, enhanced in agronomic application and with simple administration and the possibility of extensive foliar application on a much greater number of crops thanks to the total absence of phytotoxic effects.

Furthermore, the iron-bearing compositions (Fe-Comp), obtained with the process according to the present invention, are highly stable under conditions of alkaline pH, which is not unusual in soils poor in organic matter or rich in carbonates, allowing a constant prompt and effective bioavailability of the metal. In addition, these compositions, compared to commercial products, have the advantage of not leaving residues on the vegetation, thus not altering the colour.

Said compositions, obtained with the process according to the present invention, are also capable of reaching higher iron concentrations within the range of 3-5%, allowing a saving in the dosage of use with respect to that described in WO'388 and with comparable or superior agronomic effects with respect to commercial products thanks to the balanced contribution of their components and the specific way of complexing the metal.

The iron (II) or iron (III) salt can optionally be prepared in situ according to the following scheme 2:

Scheme 2

The synthesis process according to the present invention is characterized in that the quantity of ammonium hydroxide that is added in step iii) is the exact minimum quantity necessary for bringing the product formed in reaction at the end of step ii) into solution.

Furthermore, in the synthesis process according to the present invention, step v) is characterized in that the excess of ammonium hydroxide, with respect to the stoichiometry of the process necessary for bringing the product formed at the end of step ii) into solution, is neutralized by adding an aqueous solution diluted at 10% w/w of sulfuric acid or lactic acid or citric acid or sorbic acid, carefully maintaining the pH within the range of 7.5 to 8.

Thanks to step v) and the correction of the pH up to a value of 7.5 to 8.0, at the end of the synthesis process according to the present invention, vapours and ammonia residues are completely absent and, if an aqueous solution of sulfuric acid is used for neutralization, at the end of step vi) an iron-bearing composition is obtained containing a further quantity of ammonium sulfate which is approximately 4% w/w higher than the quantity present in the compositions according to the state of the art. This increased concentration of ammonium sulfate proves to agronomically characterize the iron-bearing composition, i.e. the final agronomic preparation, guaranteeing further positive biostimulation effects.

In the synthesis process according to the present invention, all the steps are carried out in sequence without the need for isolating or transferring any intermediate, the synthesis operating temperature ranges from 20°C to 70°C with a rigorous control of the same in each step and the possible rheological criticalities found using the processes of the state of the art are mitigated/eliminated. In particular, the final product, i.e. the iron-bearing composition, thus obtained, thanks to the stoichiometry and the dilutions used, appears to have a higher concentration of iron than similar compositions known in literature, with a total absence of the formation of iron oxides which on the contrary, they are easily formed when the synthesis is carried out in a basic environment.

Examples of acrylic-saccharide copolymers are the copolymers obtained by reaction of acrylic acid, methacrylic acid and acrylamide and their sulfonated derivatives, such as for example 2-acrylamido-2-methyl- 1 -propane sulfonic acid, with mono or disaccharides such as glucose, sucrose, fructose, leucose, palatinose, maltose, mannose, sorbitol, mannitol, gluconic acid, glucuronic acid, alkyl ethers, hydroxyalkyls and carboxyalkyls of saccharides.

Examples of particularly preferred acrylic-saccharide copolymers are those obtained by the reaction of acrylic acid with glucose, fructose and sucrose.

Even more preferred is the acrylic-saccharide copolymer obtained by the reaction of acrylic acid with glucose, which is also a commercial product referred to as Beixon AB200% sold in 44% w/w aqueous solution.

More generally, possible examples of acrylic-saccharide copolymers are the compounds defined as "acrylic-saccharide copolymers" described in EP0289895, WO95 17442, WO9401476 and in the patents cited therein.

Examples of iron salts are ferrous sulfate, ferric sulfate, iron (II) ammoniumsulfate, iron (III) ammonium-sulfate, wherein said salts should be considered as being in any of their available forms, such as hydrated forms, in the solid state or already in aqueous solution. In step vi) of the synthesis process according to the present invention, the addition of further essential elements (indicated as Elem.2, Elem 3.) is optionally provided, such as for example zinc, manganese, potassium, boron, calcium, magnesium, copper and molybdenum, in the form of water-soluble salts or in the form of chelates or complexes.

Particularly preferred essential elements are zinc, manganese and boron.

Examples of salts, chelates or complexes of said further essential elements are zinc sulfate, manganese sulfate, sodium borate, calcium nitrate, ammonium molybdate, copper sulfate or EDTA-Zn, EDTA-Mn, EDDHA-Zn , EDDHA-Mn EDDHSA-Mn, EDDHSA-Zn and EDDHMA-Mn or EDDHMA-Zn, wherein EDTA is ethylenediaminotetra-acetic acid, EDDHA is ethylenediamino-di-(o- hydroxyphenyl) acetic acid, EDDHSA is ethylenediamino-di-(o-hydroxy-4-sulfo- phenyl) acetic acid and EDDHMA is ethylenediamino-di-(o-hydroxy-4-methyl- phenyl) acetic acid and EDDHMA is ethylenediamino-di-(o-hydroxy-4-methyl- phenyl) acetic acid.

The synthesis process according to the present invention is therefore also characterized by the further advantage of allowing the synthesis of iron-bearing compositions possibly enriched with further elements, depending on the deficiency pathophysiology of the crops to be treated.

The iron-bearing compositions obtained with the synthesis process described above are therefore a further object of the present invention.

Schematically, the iron-bearing compositions according to the present invention can be obtained with the synthesis process shown in Figure 1.

As previously indicated, the synthesis process of iron-bearing compositions according to the following reaction:

Fe salt + Copolymer + bTEOHaqu Fe-Comp + (bTU SCE comprising the following steps: i) preparation of an aqueous solution of an Fe salt, said iron salt being an iron (II) sulfate or an iron (III) sulfate, soluble in water, preferably a salt consisting of the sulfate anion and a double cation, wherein the double cation is Fe ³⁺ and ammonium NH ⁴⁺ ; ii) preparation of a suspension by adding an aqueous solution to the solution obtained in step i), at a concentration ranging from 30% to 70% w/w, of an acrylic - saccharide copolymer with a weight ratio between the iron ion and the copolymer solution which varies within the range of 1:5 to 1:50, preferably equal to 1:10, at a temperature ranging from 20°C to 40°C, preferably at a temperature of 35°C; iii) addition of an aqueous solution of NH4OH at 30-33% w/w to the suspension obtained at the end of step ii) and simultaneous dissolution by heating to a temperature within the range of 35 °C to 60°C; iv) conditioning of the reaction mixture obtained at the end of step iii) for a time ranging from 1 to 4 hours, preferably for 2 hours, at a temperature within the range of 60°C to 70°C, until complete homogenization; v) pH regulation within the range of 7.5 to 8.0 at a temperature ranging from 20°C to 75°C, preferably at a temperature of 50°C; vi) possible addition of further salts or chelates or complexes of essential elements and finally the possible addition of water in a quantity ranging from 0 to 4% w/w with respect to the weight of the final iron-bearing composition (Fe-Comp).

In an embodiment of the process according to the present invention for the synthesis, by way of example, of a 3% w/w iron-bearing composition, the synthesis process according to the present invention comprises a step i) for the preparation of a solution of iron (III) ammonium sulfate in water, also called iron alum, wherein the FeNH4(SO4)2 salt contains the quantity of Fe (III) ions necessary for obtaining the iron-bearing composition at 3% w/w.

Said solution of iron (III) ammonium sulfate in water can be obtained alternatively using the following methods a) -e): a) Iron (III) ammonium sulfate dodecahydrate, commercial crystalline solid FeNH ₄ (SO ₄ )2*12H ₂ O; b) Iron sulfate pentahydrate Fe2(SO4)3*5H2O, solid, mixed with an equimolar quantity of ammonium sulfate in the solid state; c) Iron sulfate pentahydrate Fe2(SO4)3*5H2O, solid, mixed with sulfuric acid diluted at 10% w/w and, subsequently, with a calculated quantity of aqueous ammonia at 30-33% w/w in order to form the ammonium sulfate salt in situ, necessary for the subsequent formation of iron (III) ammonium sulfate; d) Iron sulfate Fe2(SO4)3, in concentrated aqueous solution (commercially available at approximately 46% w/w), mixed with an equimolar quantity of ammonium sulfate, solid; e) Iron sulfate Fe2(SO4)3, in concentrated aqueous solution (commercially available at about 46% w/w), mixed with sulfuric acid diluted at 10% w/w and, subsequently, with a calculated quantity of aqueous ammonia at 30-33% w/w in order to form the ammonium sulfate salt in situ, necessary for the subsequent formation of iron (III) ammonium sulfate.

The components used in methods a) - e) are weighed, dissolved and/or diluted in water in order to obtain an aqueous solution of iron (III) ammonium sulfate at a concentration ranging from 30% to 60% w/w.

The mixture thus obtained is stirred and slightly heated to 35-40°C until completely dissolution, resulting in a clear, dark red, strongly acid solution (pH = 0.80 as such, pH = 1.50 if diluted in water at 10% w/w).

In this embodiment of the process according to the present invention for the synthesis, for example, of an iron-bearing composition at 3% w/w, step i) described above is followed by a step ii) for the preparation of a suspension by the addition to the solution obtained in step i) of an aqueous solution, at a concentration ranging from 30% to 70% w/w, of the acrylic-saccharide copolymer, for example by adding an aqueous solution at 44% w/w of commercial copolymer Beixon AB200%.

The commercial solution of Beixon AB200%, aqueous liquid at 44% w/w of active substance, i.e. of acrylic-saccharide copolymer, used in a ratio 10 times higher than the content of iron ions of the solution obtained in step i), is progressively added to said solution previously obtained in step i), under very vigorous stirring to allow homogenization of the resulting viscous suspension. The temperature is kept at about 40°C to facilitate this operation.

In this embodiment of the process according to the present invention for the synthesis, for example, of an iron-bearing composition at 3% w/w, step ii) described above is followed by step iii) in which an aqueous solution of NH4OH at 30-33% w/w is added to the suspension obtained at the end of step ii) and at the same time the suspension is dissolved by heating to a temperature ranging from 35°C to 65°C.

More specifically, the concentrated aqueous solution of NH4OH at 30-33% w/w is added slowly under vigorous stirring. The reaction already exothermic in itself, is favoured by applying external heating so as to reach, at the end of the addition of ammonia, a temperature ranging from 58 °C to 65 °C.

The reaction mixture, initially viscous, passes through a further thickening phase, but the quantity of concentrated aqueous solution of NH4OH, corresponding to a slight excess with respect to the stoichiometry of the process, allows a sudden and almost complete dissolution of the agglomerates formed in the reaction mixture during the first step of the addition, to be reached.

The final solution obtained at the end of step iii) has a pH equal to 8.5-9.2.

The quantity of the ammonia solution added ranges from 10 to 15% w/w with respect to the weight of the final iron-bearing composition, based on the concentration of the NH4OH solution used; for example, using an aqueous solution of NH4OH at 30% w/w, the quantity added is 12.4% w/w with respect to the weight of the iron-bearing composition.

In this embodiment of the process according to the present invention for the synthesis, for example, of an iron-bearing composition at 3% w/w, step iii) described above is followed by a step iv) for conditioning the reaction mixture obtained at the end of step iii) under stirring, at a temperature within the range of 60°C to 70°C, for about 2 hours, until complete homogenization.

In this embodiment of the process according to the present invention for the synthesis of an iron-bearing composition at 3% w/w, step iv) described above is followed by a step v) for adjusting the pH within the range of 7.5 to 8.0 at a temperature equal to 50°C by the addition of acid components.

More specifically, after having brought the temperature back to about 50°C, an additive having a biocidal action is added in a quantity ranging from 0.1 to 1% w/w with respect to the weight of the final iron-bearing composition and then diluted sulfuric acid at 10% w/w, in a quantity equal to 3.5-4% w/w with respect to the weight of the final iron-bearing composition, to bring the final pH within the range of 7.5-8.0.

The additive having a biocidal action is selected from green biocides, such as, for example, Purac Sanilac®80, (lactic acid in an 80% aqueous solution) Sovinol®P540 (mixture of 1,2-dihydroxy -pentane and 3 -phenyl- 1 -propanol within a range of 30-70%), Sovinol®P740/O (Cinnamaldehyde within a range of 30-60%).

In this embodiment of the process according to the present invention for the synthesis, for example, of an iron-bearing composition at 3% w/w, step v) described above is followed by a step vi) for the possible addition of further essential elements (Elem. 2, Elem 3) and finally the possible addition of water, within a range of 0 to 4% w/w with respect to the weight of the final iron-bearing composition (Fe- Comp).

More specifically, after the temperature has reached environmental values (about 25°C), the necessary amount of water is added and the reaction mixture is discharged, passing it through an on-line filtering system to retain any undissolved particulate, thus obtaining the desired 3% w/w iron-bearing composition.

If additional essential elements (Elem.2, Elem 3) are to be added, salts or chelates or complexes of these additional elements (Elem.2, Elem 3) are added, dissolved or diluted in a quantity of water ranging from 0 to 4% w/w with respect to the weight of the iron-bearing composition.

The final solution thus obtained at the end of step vi), i.e. the iron-bearing composition (Fe-Comp), is analyzed for the following parameters:

• iron content, with the spectrophotometric method

• pH

• density and is packaged in HDPE (High-density polyethylene) containers in which it is kept without alterations as confirmed by accelerated stability tests, keeping the product in a stove at 54 °C for 14 days and then verifying its perfect integrity and conservation with respect to the starting situation.

The quantitative method for the determination of total iron is based on the treatment of a diluted sample of the final mixture with the reagent kit (sodium metabisulfite + sodium dithionite + 1.10-phenanthroline) and the reading of its absorbance at a wavelength of 525 nm. (Adaptation of the method 3500-Fe B, Iron by Phenanthroline, Standard Methods for the Examination of Water and Wastewater, 23rd Edition).

The product obtained at the end of step vi), i.e. the iron-bearing composition (Fe-Comp), is characterized in its elemental composition and its values are included in the range specified in Table 1 where they are compared with the corresponding values of the compound of Example 55 of WO'388.

Table 1

From the data in the previous table, the higher concentration of iron and sulfate ion of the iron-bearing composition (Fe-Comp) and total nitrogen according to the present invention are evident with respect to the compounds of the state of the art.

The pH of the final product, i.e. of the iron-bearing composition (Fe-Comp), and also that of the intermediates of each step of the synthesis process according to the present invention, is monitored on line with a probe pH-meter when the solution is clear or the suspension is homogeneous, or it is measured on samples diluted in water at 10% w/w, by means of an electronic pH-meter with a combined glass membrane electrode.

The final product obtained through the synthesis process described above, i.e. the iron-bearing composition (Fe-Comp) at 3% w/w, is characterized by pH values within the range of 7.5 ± 0.5. The density of the final product, i.e. of the iron-bearing composition (Fe- Comp), can be determined either by means of an immersion densimeter or measured by weighing 100 ml of finished product solution in a volumetric flask.

The final product obtained through the synthesis process described above, i.e. the iron-bearing composition (Fe-Comp) at 3% w/w, is characterized by a density equal to 1.2 g/ml.

Should the synthesis process also provide for the addition of further essential elements, their quantity, in the product obtained through the synthesis process described above, i.e. in the iron-bearing composition (Fe-Comp) at 3% w/w, is determined by the maximum permissible solubility of the salt, chelate or complex of each single element added.

The iron-bearing composition and any further essential elements, obtained with the synthesis process according to the present invention, is consequently not only enriched with the iron element (as evident from the previous table 1), but, with respect to what is described in the known art, is also more balanced and formulated so as to allow its use in the agronomic field with a reduction in the dosage of iron to be applied and with the same or even improved ability to provide nutritional elements useful for the well-being of the plant and to counteract its physiopathies.

Furthermore, the presence of the acrylic-saccharide copolymer gives the iron- bearing composition a biostimulating effect that favours the growth of the plant, positively influences its state of health and contributes to making it more resistant to attacks by pathogens, offering numerous advantages compared to the known art.

The present invention further relates to the use of said iron-bearing composition and of any further essential elements, obtained with the synthesis process according to the present invention, as a nutritional product for preventing and treating physiological alterations or nutritional unbalances in plants, such as, for example, iron deficiency, or as a biostimulating product for modulating the physiological processes of plants or as an inducer of defensive and innate responses specific to each crop.

Said iron-bearing compositions and any additional essential elements, subject of the present application, can be applied, for example, on vegetables, fruit trees (pome fruit and stone fruit), citrus fruits, grapevines, strawberries, kiwis, tobacco, legumes, cereals, floral and ornamental plants, nurseries, golf courses, sports fields, trees, soil and turf.

The Applicant has, again, surprisingly found that this iron-bearing composition and any other essential elements, object of the present patent application, is characterized by excellent compatibility with the absence of phytotoxic effects with other biocidal active ingredients such as fungicides, resistance inducers, plant regulators, antibiotics, herbicides, insecticides and other fertilizers and biostimulants as well as with the microflora and microfauna of the soil, thus also associating the protective action of the agropharmaceutical product with the beneficial effects of the iron-bearing composition and any other essential elements.

These biocidal active ingredients can be introduced into the iron-bearing composition obtained with the synthesis process according to the present invention by adding them during the pH regulation step v) within the range of 7.5 to 8.0.

Examples of fungicides that can be added to the iron-bearing composition and any other essential elements, object of the present patent application, for also associating a biocidal action against pathogenic fungi with the nutritional properties of said composition are, for example, copper oxychloride, copper hydroxide, Airone (mixture 1:1 copper oxychloride: copper hydroxide), Bordeaux mixture (copper sulfate neutralized with lime), Fosetil-Aluminum, Micronized sulfur, Dodina, Azoxystrobin, Dimetomorph, Tetraconazole, Benalaxyl-M Benalaxyl, Fenexamide, Captan, Fludioxonil, Cyprodinil, Tebuconazole, Fluazinam, Epoxiconazole, Prothioconazole, Fluindapyr, Oxathiopiprolin.

Examples of insecticides are: Acetamiprid, Spirotetramat; Deltamethrin; Fosamet, Cypermethrin, Etofenprox.

Examples of other biostimulants are: Ergostim (N-acetylthiazolidin-4- carboxylic acid and thiazolidine-carboxylic acid), humic acids, plant extracts, animal and vegetable amino acids, Siapton (amino acids and peptides obtained from the chemical hydrolysis of animal epithelium). Examples of microflora and microfauna of the soil are: Bacillus thuringiensis,. Bacillus subtilis, Bacillus amyloliquefaciens, Trichoderma harzianum, Trichoderma viride.

The present invention further relates to a method for preventing and treating possible nutritional unbalances of plants, in order to modulate their physiological processes by applying an iron-bearing composition and any additional essential elements obtained with the synthesis process previously described.

More specifically, said iron-bearing compositions and any other essential elements can be applied at different stages of the vegetative development, for example, for tree crops, starting from the vegetative restart until the falling of the leaves and for horticultural crops from the moment of post-transplantation with subsequent applications at regular intervals.

Said application can be foliar, or to the soil by fertigation even in soils with an alkaline pH and, in a particular and effective way, by means of micro-irrigation systems such as hoses and driplines, without any phenomenon of phyto toxicity, or said application can be effected through seed tanning or in the solution of hydroponic crops.

The quantity of compound to be applied for obtaining the desired effect can vary depending on various factors such as, for example, the compound used, the crop to be protected, the climatic conditions, the characteristics of the soil, the method of application, and so forth.

Dosages of iron compositions and any other elements ranging from 1 1 to 1.5 1 per hectare in foliar application and from 5 1 to 10 1 per hectare in soil application generally provide an effective solution for supplying the various elements to the crops and therefore for the control of the various physiopathies.

Due to their physico-chemical characteristics, these iron-bearing compositions and any possible other elements can also find application in organic farming.

Some examples are now provided which should be considered as being descriptive and non-limiting of the present invention.

EXAMPLE 1 Preparation of the copolymer of acrylic acid with glucose

A mole of glucose is dissolved in a 30% sodium hydroxide solution (3 moles) under stirring at 0°C. 0.07 moles of H2O2 are then added, maintaining the temperature at 0°C. 3 moles of acrylic acid are then dripped into the alkaline solution of sugar and hydrogen peroxide with a consequent increase in the temperature to about 75°C. The mixture is further heated to 85°C, triggering the exothermic reaction which brings the temperature to 105 °C. As soon as the maximum temperature has been reached, the reaction mixture is immediately cooled to 20°C, obtaining an extremely viscous solution. The content of active substance in the solution is 48%, determined by acidification.

EXAMPLE 2

Preparation of a 3% w/w iron-bearing solution by means of method b (Fe- Comp)

132.9 g of iron sulfate pentahydrate, 35.9 g of ammonium sulfate and 321 g of H2O were charged into a jacketed reactor of 1 1 and the temperature was brought to 35°C until complete dissolution, with a resulting pH equal to 1.2 (measured on a sample 10% diluted in H2O).

Maintaining the temperature at 35°C, 300 g of Beixon AB200% copolymer, sold as aqueous solution at 44% w/w of active substance, were added dropwise and under vigorous stirring, obtaining a well-stirred brick-red suspension. At this point, 124 g of aqueous ammonia at 30% w/w were added again dropwise and under vigorous stirring, allowing the temperature to rise to 58-60°C by spontaneous exothermic reaction and applying a mild external heating. The brick-red suspension gradually thickened and then re-liquefied becoming a reddish-brown solution. This was followed by a conditioning step of about 2 hours, to allow the total dissolution of the mass, keeping the temperature at around 65-70°C by applying a mild external heating. The pH reached the value of 8.4-8.9.

The external heating was stopped and when the temperature had reached about 50°C, 10 g of the biocidal agent Purac Sanilac 80 (80% w/w lactic acid) and 38 g of 10% w/w H2SO4 were added. The resulting solution has a pH of approximately 7.5. The solution was brought to volume with the remaining 38.2 g of H2O and 1 kg of final product was obtained.

Elemental analysis:

Fe = 3.21%; Na = 1.31%; C = 4.47%; N = 3.59%; S = 3.69%; SO ’: 10.58% EXAMPLE 3

Preparation of a 3% w/w iron-bearing solution by means of method d (Fe- Comp)

756.8 g of a 46% w/w solution of iron sulfate, 116.2 g of ammonium sulfate and 716.0 g of H2O were charged into a 5 1 jacketed reactor and the temperature was brought to 35°C until complete dissolution, with a resulting pH equal to 1.2 (measured on a sample diluted at 10% in H2O).

Maintaining the temperature at 35°C, 972.0 g of Beixon AB200% copolymer, sold as aqueous solution at 44% w/w of active substance, were added dropwise and under vigorous stirring, obtaining a well-stirred brick-red suspension. At this point, 401.8 g of ammonia, in aqueous solution at 30% w/w, were added again dropwise and under vigorous stirring, allowing the temperature to rise to 58-60°C by spontaneous exothermic reaction and applying a mild external heating. The brick- red suspension gradually thickened and then re-liquefied becoming a reddish-brown solution. This was followed by a conditioning step of about 2 hours to allow the total dissolution of the mass, keeping the temperature at around 65-70°C by applying a mild external heating. The pH reached the value of 8.4-8.9.

The external heating was stopped and when the temperature had reached about 50°C, 32.4 g of the biocidal agent Purac Sanilac 80 (80% /w lactic acid) and 123.1 g of H2SO4 in a 10% w/w solution, were added. The resulting solution has a pH of about 7.5. The solution was brought to volume with the remaining 121.7 g of H2O and 3240.0 g of final product were obtained.

Elemental analysis:

Fe = 2.95%; Na = 1.51%; C = 4.44%; N = 3.29%; S = 3.45%; SO?’: 10.13% EXAMPLE 4

Effectiveness test of iron chlorosis on tobacco in sand. Table 2 Bryght cultivar tobacco (first two actual leaves) was transplanted into plastic cups having a volume of 161 cm ³ , filled with 180 g of sand. After overcoming the transplant crisis, samples 2 and 3 were treated respectively with 20 ml and 10 ml of solution of the compound described in Example 55 of W02007/003388 (Ref 1) and sample 4 with 10 ml of Fe-Comp every 10 days (three applications). The samples were sprayed every three days with 50 ml of demineralized water. This quantity is calculated so that there is never any leakage of liquids from the vessel. The samples were placed in a greenhouse at a temperature of about 24°C - 60-65% R.H. - 16H of light. 10 days after the last treatment each sample was visually evaluated with respect to the leaf and/or root development and the chlorophyll content indices (SPAD values) carried out on the last three leaves (average of 5 surveys per leaf) were recorded, using the Minolta instrument “Chlorophyll Meter - SPAD 502”.

Table 2:

* average of the three leaves

** overall visual judgment (range 0-10)

Ref 1 = Compound 55 of WO 2007/003388

EXAMPLE 5

Effectiveness test of iron chlorosis on tobacco in a basic medium. Table 3

Bryght cultivar tobacco was transplanted into plastic cups having a volume of 855 cm ³ , filled with 600 g of soil at pH 8.0/8.2. After 20 days, samples 2 and 3 were treated respectively with 25 ml and 12.5 ml of solution of the compound described in Example 55 of W02007/003388 (Ref 1) and sample 4 with 12.5 ml of Fe-Comp, every 10 days (three applications). The samples were sprayed every three days with 50 ml of demineralized water. This quantity is calculated so that there is never any leakage of liquids from the vessel. During the first two applications, together with iron, the mineral fertilizer compound NPK at 3g/L was administered to all samples. The samples were placed in a greenhouse at a temperature of about 24°C - 60-65% R.H. - 16H of light. 10 days after the last treatment each sample was visually evaluated with respect to the leaf and/or root development and the chlorophyll content indices (SPAD values) carried out on the last three leaves (average of 5 surveys per leaf) were recorded, using the Minolta instrument “Chlorophyll Meter - SPAD 502”.

Table 3:

* average of the three leaves

** overall visual judgment (range 0-10)

Ref 1 = Compound 55 of WO 2007/003388

EXAMPLE 6

Effectiveness test of iron chlorosis on a tomato plant in sterile soil with application to the soil. Table 4

A Marmande cultivar tomato plant (first two actual leaves) was transplanted into plastic cups having a volume of 855 cm ³ , filled with 600 g of sterile soil (extremely sandy). After overcoming the transplant crisis, samples 2 and 3 were treated respectively with 20 ml and 10 ml of solution of the compound described in Example 55 of W02007/003388 (Ref 1) and sample 4 with 10 ml of the Fe-Comp compound, thus applying half of the amount of Fe with the second compound, every 10 days (three applications). The samples were sprayed every three days with 50 ml of demineralized water. This quantity is calculated so that there is never any leakage of liquids from the vessel. The samples were placed in a greenhouse at a temperature of about 24°C - 60-65% R.H. - 16H of light. 10 days after the last treatment each sample was visually evaluated with respect to the leaf and/or root development and the chlorophyll content indices (SPAD values) carried out on the last three leaves (average of 5 surveys per leaf) were recorded, using the Minolta instrument “Chlorophyll Meter - SPAD 502”.

Table 4:

* average of the three leaves

Ref 1 = Compound 55 of WO 2007/003388

EXAMPLE 7

Effectiveness test of iron chlorosis on a strawberry plant in a basic medium, soil application. Table 5

A remontant variety of strawberry plant was transplanted in plastic pots having a diameter of 15 cm, filled with 1,500 g of soil at pH 8.0/8.2. In the pre- flowering stage, samples 2 and 3 were treated respectively with 150 ml and 75 ml of solution of the compound described in example 55 of W02007/003388 (Ref 1) and sample 4 with 75 ml of Fe-Comp compound every 10 -14 days (three applications). The samples were sprayed every three days with 100 ml of demineralized water. This quantity is calculated so that there is never any leakage of liquids from the vessel. During the first two applications, together with iron, the mineral fertilizer compound NPK at 3g/L was administered to all of the samples. The samples were placed in a greenhouse at a temperature of about 24°C - 60-65% R.H. - 16H of light. Starting from the second treatment, each sample was evaluated considering the number of fruits produced (the average of 7 collections is indicated) and the chlorophyll content indices (SPAD values) carried out on the last three leaves were recorded (average of 5 surveys per leaf), using the Minolta instrument “Chlorophyll Meter - SPAD 502'7

Table 5:

Ref 1 = Compound 55 of WO 2007/003388

EXAMPLE 8

Effectiveness test of iron chlorosis on a strawberry plant in a basic medium, foliar application. Table 6

A remontant variety of strawberry plant was transplanted in plastic pots having a diameter of 15 cm, filled with 1,500 g of soil at pH 8.0/8.2. In the pre- flowering stage, samples 2 and 3 were treated respectively with 100 ml and 50 ml of solution of the compound described in Example 55 of W02007/003388 (Ref 1) and sample 4 with 50 ml of Fe-Comp compound every 10-14 days (three applications). The samples were sprayed every three days with 100 ml of demineralized water. This quantity is calculated so that there is never any leakage of liquids from the vessel. During the first two applications, together with iron, the mineral fertilizer compound NPK at 3g/L was administered to all samples. The samples were placed in a greenhouse at a temperature of about 24 °C - 60-65% R.H. - 16H of light. Starting from the second treatment, each sample was evaluated considering the number of fruits produced (the average of 7 collections is indicated) and the chlorophyll content indices (SPAD values) carried out on the last three leaves were recorded (average of 5 surveys per leaf), using the Minolta instrument “Chlorophyll Meter - SPAD 502'7

Table 6: * average of the three leaves

Ref 1 = Compound 55 of WO 2007/003388

EXAMPLE 9

Effectiveness test of iron chlorosis on a tomato plant in sterile soil with foliar application. Table 7

A Marmande cultivar tomato plant (first two actual leaves) was transplanted into plastic cups having a volume of 855 cm ³ , filled with 600 g of sterile soil (extremely sandy). After overcoming the transplant crisis, samples 2 and 3 were treated respectively with 50 ml and 25 ml of solution of the compound described in Example 55 of W02007/003388 (Ref 1) and sample 4 with 25 ml of Fe-Comp compound, every 10 days (three applications). The samples were sprayed every three days with 20 ml of demineralized water. This quantity is calculated so that there is never any leakage of liquids from the vessel. The samples were placed in a greenhouse at a temperature of about 24°C - 60-65% R.H. - 16H of light. 10 days after the last treatment, each sample was visually evaluated with respect to the leaf and/or root development and the chlorophyll content indices (SPAD values) carried out on the last three leaves (average of 5 surveys per leaf) were recorded, using the Minolta instrument “Chlorophyll Meter - SPAD 502”.

Table 7:

* average of the three leaves

Ref 1= Compound 55 of WO 2007/003388

EXAMPLE 10

Effectiveness test of iron chlorosis on basil in sterile soil with foliar application.

Table 8 Classic Italian cultivar basil was sown in plastic cups having a volume of 855 cm ³ , filled with 600 g of sterile soil (extremely sandy). At the stage of 2 actual leaves, samples 2 and 3 were treated respectively with 50 ml and 25 ml of solution of the compound described in Example 55 of W02007/003388 (Ref 1) and sample 4 with 25 ml of the Fe-Comp compound, every 7 days (two applications). The samples were sprayed every three days with 50 ml of demineralized water. This quantity is calculated so that there is never any leakage of liquids from the vessel. The samples were placed in a greenhouse at a temperature of about 24 °C - 60-65% R.H. - 16H of light. 10 days after the last treatment, each sample was evaluated considering the fresh weight of the seedlings and the chlorophyll content indices (ND VI values) were recorded, using the Trimble "Greenseeker" instrument.

Table 8:

Ref 1= Compound 55 of WO 2007/003388

EXAMPLE 11

Effectiveness test of iron chlorosis on basil in sterile soil with soil application. Table 9

Classic Italian cultivar basil was sown in plastic cups having a volume of 855 cm ³ , filled with 600 g of sterile soil (extremely sandy). At the stage of 2 actual leaves, samples 2 and 3 were treated respectively with 100 ml and 50 ml of solution of the compound described in Example 55 of W02007/003388 (Ref 1) and sample 4 with 50 ml of the Fe-Comp compound, every 7 days (two applications). The samples were sprayed every three days with 50 ml of demineralized water. This quantity is calculated so that there is never any leakage of liquids from the vessel. The samples were placed in a greenhouse at a temperature of about 24 °C - 60-65% R.H. - 16H of light. 10 days after the last treatment, each sample was evaluated considering the fresh weight of the seedlings and the chlorophyll content indices (NDVI values) were recorded using the Trimble "Greenseeker" instrument.

Table 9:

Ref 1= Compound 55 of WO 2007/003388 EXAMPLE 12

Effectiveness test of iron chlorosis in field tests. Tables 10-14

The Fe-Comp compound was tested in field tests carried out in various Italian regions on crops sensitive to iron chlorosis: pears, vines, kiwis, plums, citrus fruits. It was compared with commercial products, applying it to the soil for fertigation or spraying it on the leaves. The effectiveness was assessed by detecting the chlorophyll content indices (SPAD values) and measuring the increase compared to the values detected at the beginning of the experiment. Some examples of the results obtained are provided hereunder.

Table 10: Test on table grapes (Puglia) soil and foliar application Vanguard and Sequestrene are commercial products

Table 11: Test on Pear trees (Emilia Romagna) application to the soil and leaves

Vanguard and Sequestrene are commercial products

Table 12: Test on Pear trees (Emilia Romagna) foliar application

Sequestrene is a commercial product

Table 13: Test on Kiwis (Emilia Romagna) soil and foliar application Libfer and Chelated iron ellesei are commercial products

Table 14: Test on Kiwis (Emilia Romagna) soil and foliar application

Vanguard and Chelated-Fe are commercial products The previous tables 10-14, which show the results of the field tests conducted by applying the Fe-Comp composition on crops sensitive to iron chlorosis, compared with the results of the field tests conducted by applying commercial products, reveal the greater effectiveness of the iron-bearing composition according to the present invention.