Pesticides containing metals

Abstract

A composition for fertilizing crops and for mitigating crop diseases. The composition includes two nutritive cations solubilized is water: zinc and potassium. The nutritive elements are solubilized concentrated in an aqueous solution at pH above 7 devoid of any inorganic cations.

Description

[0001] PESTICIDES CONTAINING METALS

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] The present application claims the benefit of priority to US Provisional Patent Application Serial Number 63 / 291899, filed 20-DEC-2021 , entitled "PESTICIDES CONTAINING METALS." The aforementioned application is hereby incorporated herein by reference.

[0004] TECHNICAL FIELD

[0005] The present invention generally relates to chemical formulations for benefitting crops, first providing nutrients to crops and second for the control of plant infecting microorganisms.

[0006] BACKGROUND ART

[0007] Various publications disclose compositions that utilize different types of metals to combat plant pests, such as bacteria and or fungi by applying to infected crops various formulations containing metals. Such metals typically include free ions or various complexes thereof, including chelates. In WO 2006 / 135445 A2 the inhibitory effect of zinc chelates on a diverse species of bacteria as well as fungi is disclosed, the scenario in which this activity is observed is within a medical context and or in food preservation context. Another aspect of the pesticidal activity associated with various metals is the essential effect of low pH in such a scenario. For example, in US 8,282,949 B2 the combination of chelated zinc and chelated copper having a pesticidal effect, is ascribed to the association of the metals or metal complexes with a low pH of the solution in which the metals are dissolved and applied. Also in US 2015 / 0342195 A 1 a mixture in solution featuring acid pH in which chelated or non chelated metal ions are disclosed, demonstrating a significant antimicrobial effect. An opposing approach as regards the effect the pH has on the effectivity of metal bearing pesticides exists, which uses inorganic formulations consisting of alkali metal such as potassium together with bicarbonate ions (promoting a higher pH) to mitigate plant diseases, for example Palmer, C.L., Horst, R.K. & Langhans, R.W. (1997), use inorganic bicarbonates to inhibit in vitro colony growth of Botrytis cinerea. Plant Disease 81 : 1432-1438.

[0008] SUMMARY OF THE INVENTION

[0009] In accordance with the present invention a chemical composition is provided that promotes growth, vigor, and quality in, of agricultural crops,

[0010] The composition in accordance with the present invention includes a high concentration of two plant nutritive metal anions, zinc (a transition metal) and potassium (a non transition metal), devoid of inorganic anions, forming an aqueous solution at a pH above 7.

[0011] The composition in accordance with the present invention when applied to crops typically by spraying onto the plant canopy, but also by irrigating the composition into the root environment. Surprisingly the composition when applied to plants, induced a significant reduction in some important plant diseases, caused at least by oomycetes and ascomycetes.

[0012] BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Fig. 1 is a diagram describing the process for preparing a composition in accordance with the present invention.

[0014] DISCLOSURE OF THE INVENTION

[0015] In accordance with the present invention, an aqueous mixture of chelated zinc ions containing also dissolved therein a hefty amount of potassium ion, forms a clear solution. This solution is made having a basic pH. The composition in accordance with the present invention uses water, potassium hydroxide as a source of potassium, zinc oxide as zinc source, and one or more chelating organic acids, typically a combination of citric acid and lactic acid. There are other known chelating organic acid, such as gluconic acid but they were not used. This way a high concentration of solubilized potassium combined with zinc can be obtained. A composition without any lactic acid is possible, but tends to be less stable in storage, as precipitation may start after finalizing the formulation, typically between weeks or months after. A composition without any citric acid can be obtained using enough lactic acid to chelate the zinc. The combination of citric acid and lactic acid as acidifiers and chelators allows to provide a stable solution of specific gravity of almost 1 .5. The pH is brought to a level above 7, for example 8. Such resulting composition (referred to hereinafter as composition A) can be implemented both as a compound fertilizer of zinc and potassium, as well as a pesticide as will be described below. Such a composition as will be described in more detail below, surprisingly demonstrates an activity as an agent for mitigating some notorious plant pathogens causing diseases. Typically, composition A is made out of 38.75 g (grams) water, 19.76 g KOH (90%); 9.68 g ZnO; 26.18 g citric acid monohydrate, and lactic acid (88%) 5.63 g. To describe the production process graphically attention is drawn to Fig. 1. In step 22 water (the entire amount required) is poured to a cooled reactor, in step 24 KOH is added (the entire amount) cooling may be required. In step 26 zinc oxide, (the entire amount) is added while stirring. In step 28 chelating organic acids (one or more) are carefully added while cooling in step 30 mixing and cooling is continued until the solution is clear and transparent. In step 32 pH is adjusted by adding either KOH or acid, conveniently lactic acid. This product contains a high concentration of potassium and zinc in solution.

[0016] If only one type of organic acid is used, the molarity of the acid used should be brought to a level that would compensate for the lack of the additional organic acid. However, the presence of organic acid / s in the compositions in accordance with the invention, is necessary to compensate for the high pH provided by the potassium hydroxide used as a source of potassium. The chelation of the zinc ions with acids (one or both) is necessary in order to keep the zinc ions solubilized in the relatively high pH environment of the composition as described above.

[0017] Field studies

[0018] Tomato plants were grown in a test facility of GEP managed by RES AGRARIA in TERAMO, ITALY The plants exhibited infection by Phytophthora infestans. The test plants treated (by spraying) using two agents to separate group of plants. The agents were Cumeta flow (a product of Diachem, Italy) on the one hand and composition A as described above. Cumeta flow is a commercial product containing a combination of metalaxil-m (at 24 grams / litre) and copper as tribasic copper sulfate (at 200 g / litre). Spraying the commercial product on the tomato plants was performed at a rate of 400 ml per 100 litres, and the spraying of composition A was applied at a rate o1 litre or 2 litres per hectare. The applications were made to compare the two products so equal number of repetitions was carried out. The result of spraying show that both Cumeta flow and composition A are able to suppress the disease as compared to the non treated control, with some advantage to Cumeta flow over composition A. However the rates of application were not optimized and performed in this comparative study for the first time. When measuring the marketable crop yield, the effects of both agents were similar and the well above the yield of the non treated control.

[0019] In Table 1 : some more details of controlled experiments performed in 2022 comparing composition A with the conventional agent (except for the case of hazel nuts in which no conventional agent was used) are reported as compared to conventional pesticides. In Table 2: some more details of non controlled observations demonstrating pesticidal activity, crops are not specified for each pest. However trials were performed on peppers, tomato, eggplant and cucumber and results as observed were described as acceptable in each case.

[0020] Advantages of the use of compositions in accordance with the present invention as pesticides

[0021] The results of the application of the product on the diseased crops were surprisingly efficient. Yet there are no apparent reasons for its strong activity. It should be mentioned that both potassium and zinc, including zinc chelates are used often in agricultural practice as foliar fertizers. At present, as the awareness of the public and plant protection authorities to the toxic effects of pesticides continues, the registering authorities are set to rule out more and more existing pesticides which ere proved to be toxic or dangerous. Also the metabolites of several pesticides have proven to be so. (M. U. Mustapha et al., Pertanika J. Sci. & Technol. 27 (2): 547 - 563 (2019)

[0022] The products in accordance with the present invention can hardly be suspected to contain toxic or environment disrupting components. Even the breakdown products of the organic acids described above which are ubiquitous in the nature, can hardly be suspected as turning into objectionable elements.

[0023] The composition of the invention as a foliar fertilizer

[0024] Potassium and zinc are rwo nutritive metals that are wekk known in the art of agriculture, Although a fertilizer for providing only zinc and potassium is not commonly found in the market, the reason for dispensing such elements to crops or plants in general is obvious. Composition A described above exemplified an embodiment of a fertilizer containing no anionic nutritive element. Usually potassium source is employed as a component of a fertilizer in the form of salt which includes as the anionic part, phosphate, sulfate, chloride, or nitrate. In the fertilizer of the present invention no inorganic anion is included, rather, chelating organic acid / s are included in the composition. These one or more acids are utilized as ligand / s for complexing (or in other words chelating) the zinc of the fertilizer of the invention. To provide a zinc source to the fertilizer of the invention, zinc oxide is used, thereby obviating mineral anions. The raising of the pH of the composition is facilitated by the presence of the ligands which prevent, if well balanced, the precipitation of the zinc. The resulting composition in accordance with the present invention, devoid of any inorganic anions, utilizes the organic anions as acidifiers, providing a high concentration of potassium and zinc in a stable solution. Thus the large amount of foliar fertilization experiments carried out by Seferssa in Mexico in the year 2020 on tomato (open field), and on greenhouse on two varieties of pepper, cucumber and egg plant exhibited a high quality of the agricultural product, never exhibiting phytotoxic effect in the context of foliar application. The company that carried out the experiments in Mexico carried out in addition to my recommendation, soil application with apparently good results. The composition of the invention facilitates the utilization of a high concentration of zinc and potassium, and spraying the combination without the extra burden of cationic minerals.

Claims

CLAIMS A composition for benefitting crops, said composition includes two nutritive cations solubilized is water, comprising:• zinc ions;• at least one organic acid ligand for chelating said zinc ions, and• potassium ions, and wherein said solution has a pH higher than 7, and wherein said composition is devoid of inorganic anions. A composition as in claim 1 for fertilizing plant crops wherein said at least one organic acid ligand is citric acid and lactic acid. A pesticidal composition for mitigating plant pathogens comprising the composition of claim 1 . A pesticidal composition for mitigating plant pathogens as in claim 3 wherein said pathogens belong to the taxonomic groups of Oomycetes, Ascomycetes, and Deuteromycetes. A pesticidal composition for mitigating plant pathogens as in claim 4 wherein said pathogen is Phytophthora infestans. A pesticidal composition for mitigating plant pathogens as in claim 4 wherein said pathogen is Cytospora corylicola.

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