Composite microspheres

Abstract

A composite microsphere enhancing the efficacy of an agrochemical active ingredient, characterized by comprising chitosan, with an average molecular weight in the range of 190,000 to 310,000 g / mol; and a crosslinking agent; in the absence of an agrochemical active ingredient. And agrochemical formulations that comprises said composite microsphere.

Description

[0001] COMPOSITE MICROSPHERES

[0002] Cross-reference to related Application

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 621,881, filed on January 17, 2024, which is incorporated by reference herein in its entirety.

[0004] Field of the Invention

[0005] The present invention relates to the field of intelligent materials designed to enhance the efficiency of chemical products used in agricultural processes. Specifically, the present invention refers to a microstructured polymeric compound with tailored chemical composition, charge distribution, and advantageous properties for its application in the dosage and controlled release of agrochemicals for sustainable agricultural processes. In particular, it relates to agrochemical formulations enhanced with composite microspheres. The present invention also includes scalable, high- conversion methods, verified and validated, for their preparation.

[0006] State of the Art

[0007] The use of fertilizers and pesticides has been a fundamental pillar in the development of modern agriculture, enabling improved crop yields to meet the growing global demand for food.

[0008] In general terms, an agrochemical is understood to be any substance or mixture of natural or synthetic substances used to prevent, eliminate, and / or control any pest, disease, or weed in agricultural activity. These substances are commonly known as pesticides or pest control agents— also referred to as crop protection products— and include insecticides, herbicides, fungicides, acaricides, among others. This categorization also includes substances aimed at providing elements that stimulate plant growth, commonly referred to as fertilizers.

[0009] Fertilizers and plant growth regulators are agrochemicals used to enhance the quality and growth of crops. Fertilizers are products that supply essential nutrients to plants, improve root quality in the soil, and facilitate plant growth and development with greater speed and quality. Plant growth regulators are products that regulate plant growth, typically composed of plant hormones (phytohormones), and their primary functions are to stimulate or inhibit the development of roots and aerial parts.

[0010] The term pesticide applies to any substance or mixture of substances intended to prevent, destroy, repel, or mitigate any pest. Pests include insects, fungi, weeds, rodents, bacteria, and other harmful organisms. Pesticides are categorized into specific groups based on the type of pest they target, such as insecticides (insects), herbicides (weeds), fungicides (fungi), and rodenticides (rodents).

[0011] Insecticides are chemical, biological, or natural substances used to eliminate or control insect populations by killing them or interfering with their development and reproduction. Insecticides are commonly applied in agriculture to control diseasetransmitting pests and prevent material damage.

[0012] Herbicides are used to eliminate the main harmful plants for crops, also known as weeds, and are available in various types depending on their characteristics, such as application periods, the extent of plant impact, or the timing of use.

[0013] Fungicides are used to eradicate harmful fungi and molds that affect both plants and animals.

[0014] According to the Food and Agriculture Organization of the United Nations (FAO), up to 40% of global agricultural production is lost due to pests that affect various crops.

[0015] Crops face numerous challenges, including insects, pests, diseases, pesticides, and the toxicity associated with these agrochemicals. Pests cause total losses of 50% in wheat and 80% in cotton worldwide. Other crops that experience significant production losses include soybean (26-29%), corn (31%), rice (37%), and potatoes (40%) [Oerke, 2006]. Pest insects account for approximately 30% of crop losses [Vinutha, 2013], and weeds also cause substantial losses of around 34%. In addition to pests, fungal diseases also affect crops globally. Fungi are responsible for approximately 70% of diseases in major agricultural crops [Agrios, 2005], such as wheat, potato, cotton, tomato, peanut, grapevine, and cotton [Dhekney, 2005], The severity of the situation is underscored by the fact that annual crop losses due to fungal diseases, both in the field and post-harvest, exceed $200 billion in the agricultural industry. In contrast, more than $600 million is spent annually on fungicides in the United States alone [Fernandez-Perez, 2000], Globally, approximately one-quarter of food crops are damaged by fungal toxins such as aflatoxins, ergot toxins, Fusarium toxins, patulin, and tenuazonic acid [Razzaghi- Abyaneh, 2014].

[0016] Weeds compete with crops for light, water, nutrients, and space. This competition can reduce crop growth and impact its development (Segundo Congreso Argentine de Girasol Taller ASAGIR Malezas en Girasol). Depending on the type of weed and its density, yield reduction can range from 10% to 90% in extreme cases. Fallowing involves allowing a plot of land to rest for several months or years before being cultivated again and generally requires weed control between crop cycles. Poor management during fallow periods can promote the emergence of herbicide-resistant weeds, such as Amaranthus spp. (redroot pigweed) and Lolium spp. (ryegrass), which are problematic in the Humid Pampa region of Argentina [Bedmar, 2002],

[0017] The impact of weed competition on soybean yield depends on when they appear and the duration of interference. Specific factors:

[0018] 1. Early Competition (first 4-6 weeks): The most critical stage is the initial phase of the crop (up to V4 or V5), where the soybean establishes its architecture and generates leaves for photosynthesis. Weed competition during this period can reduce yield by 20-50% if not adequately controlled.

[0019] 2. Interference by Problematic Weeds: Weeds such as Echinochloa spp. (barnyard grass) and Conyza spp. (horseweed) are particularly competitive and, if not wellmanaged, can lead to yield losses of up to 80% in cases of high infestation.

[0020] 3. Control Strategies: The use of residual and post-emergent herbicides is key to reducing the impact of weeds during sowing and crop growth. In areas with high pressure from resistant weeds, constant monitoring and combining different herbicide modes of action are essential.

[0021] In soybeans, yield losses due to weed competition during fallow and early growth stages can range from 10% to 70%. In poorly managed fields or areas with resistant weeds, losses can exceed 90% if competition is not controlled promptly. Therefore, weed control during fallow and early crop stages is critical to maximizing soybean yield and avoiding significant economic losses. The difference in crop yield when weed control improves from 85% to 90% may seem small in terms of control percentage, but it can be significant at the agricultural yield level [Green-Tracewicz, 2012],

[0022] Pesticides have been used to combat pests; however, the widespread application of pesticides has had a devastating effect on humans and other living organisms, with an increasing incidence of human poisoning.

[0023] Undesirable effects of agrochemical use on human health can be described, such as the emergence of chronic diseases, acute problems due to accidental exposure to high doses that may cause acute poisoning including symptoms like dizziness, vomiting, respiratory difficulty, and even death. Risks in sensitive populations such as pregnant women and children are particularly susceptible to the neurotoxic and endocrine effects of some agrochemicals, which can affect physical and cognitive development [Islam, 2024],

[0024] The indiscriminate use of agrochemicals has disrupted natural balances, causing harmful effects on various ecosystems, such as soil contamination, which reduces the soil's natural fertility, alters microbiota, and generates salinization or acidification processes. Excessive application of agrochemicals can leach into rivers, lakes, and groundwater, causing water pollution and phenomena such as eutrophication, where excess nutrients in the water promote the proliferation of toxic algae, affecting water quality, aquatic life, and biodiversity. Moreover, the repeated and excessive use of agrochemicals has led to the development of resistance in pests, weeds, and pathogens. The report on the environmental and health impacts of pesticides and fertilizers, prepared in close collaboration and consultation with the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO), highlights the need for transformative actions and better management of pesticides and fertilizers as the demand and use of these products increase globally (URL: https: / / wedocs.unep.org / xmlui / bitstream / handle / 20.500.11822 / 38409 / pesticides.pdf

[0025] There is a critical situation that necessitates the adoption of sustainable procedures to reduce the negative impact of excessive agrochemical use. In recent years, traditional agriculture has been supplemented with alternatives aimed at mitigating these adverse effects, such as precision agriculture, which seeks to optimize agricultural practices by utilizing advanced technologies that allow forthe collection, analysis, and interpretation of data on crops, soil, climate, and other factors to make more efficient decisions. Its main objective is to maximize resource efficiency, such as water, fertilizers, and pesticides, while minimizing environmental impacts and increasing productivity.

[0026] Nanotechnology has provided developments and technologies aimed at addressing these problems by maximizing resource optimization. Nanotechnology is widely used in modern agriculture to realize the concept of precision agriculture [Duhan, 2017], Nanotechnology includes nanoparticles with one or more dimensions in the orderof 100 nm or less. Nanomaterials find applications in plant protection, nutrition, and agricultural practices management due to their small size, high surface-to-volume ratio, and unique optical properties [Auffan, 2009],

[0027] In addition to offering other benefits, such as reduced toxicity, greater stability / shelf life, and improved pesticide solubility, biopolymeric systems are also cost-effective, readily available, biocompatible, biodegradable, and environmentally safe (i.e., they gradually release associated active compounds without endangering the environment) and have a low carbon footprint. Biopolymeric nanoformulations support plant growth while improving soil aeration and microbial activity, which can benefit the environment.

[0028] The development of controlled release formulations (CRFs) is highly desirable from the perspective of meeting international environmental and biodiversity laws. The use of polymers for sustained release began in the early 1970s, due to the greater efficacy of their encapsulated components compared to commercial formulations. To enhance the value of traditional pesticides, many natural biopolymers, such as carrageenan, galactomannans, chitosan, alginate, pectin, cellulose, gum arabic, guar gum, cashew gum, chitin, tamarind seed polysaccharide (TSP), and starch, are processed into nanomaterials for the slow and targeted release of agrochemicals [Salgueiro, 2013; Albuquerque, 2016; Sharma, 2019; Slade, 2019; Rashidipour, 2019; Elabasy, 2020],

[0029] In the state of the art, one of the most widely used polymers is chitosan, which is a polysaccharide composed of repeating units of D-glucosamine and N-acetyl-D- glucosamine. Chitosan is the primary industrial derivative of chitin and can be obtained through the N-deacetylation of chitin. It is sparingly soluble in water, and when the degree of deacetylation reaches at least 50%, it dissolves as a polycation in diluted aqueous acids [Robert, 1992], The degree of deacetylation and molecular weight of chitosan strongly determine its physicochemical and biological properties, such as solubility, hydrophobicity, crystallinity, and cellular response. In recent decades, chitosan has garnered increasing interest in the agricultural sector. For instance, chitosan dissolved in an acidic solution activates its antimicrobial and biostimulatory properties, which enhance plants' defense mechanisms, giving it the potential to become a new class of stress protectors for plants [Bautista-Banos, 2006; Sahariah, 2017],

[0030] The publication by Rychter [Rychter, 2019] evaluates chitosan microparticles encapsulating glyphosate, their herbicidal effect, and controlled release performance.

[0031] Another way to use chitosan in different applications, particularly for agricultural applications, is by forming three-dimensional structures through the crosslinking of chitosan molecules, creating stable structures that enable the nanoencapsulation of active components. These structures are characterized by offering a more controlled release of the encapsulated component. Slow release, protection against degradation, and low solubility of the encapsulated insecticide are the most important characteristics of polymeric nanoformulations, making them the first choice for nanoencapsulation. This valuable information has paved the way for the development and practical application of polymeric nanoinsecticides with enormous potential. Different types of nanoformulations, both polymer-based and non-polymer-based, have been proposed, such as nanospheres, nanocapsules, nanogels, micelles, nanofibers, nanometals, and nanoemulsions, for the encapsulation of insecticides. Among these, nanocapsules are the most widely used for the controlled release of insecticides. Very recently, a novel concept of hybrid nanoformulation (nanoemulsion encapsulation or coating with liposomes) has been suggested for the controlled release of certain insecticides. However, the efficacy of this novel approach needs to be tested across a wide range of insecticides [Das, 2014],

[0032] In the document by Grenha in 2012 [Grenha, 2012], methods for preparing chitosan- based nanostructured systems are described, mainly through emulsification, various types of coacervation, or even slight modifications of both. More specifically, the methods include the coalescence of emulsion droplets [Tokumitsu et al., 1999], solvent diffusion in emulsion [El-Shabouri, 2002], reverse micelle method [Mitra et al., 2001], ionic gelation, polyelectrolytic complexation [Calvo et al., 1997; Sarmento et al., 2006], and desolvation [Tian & Groves, 1999], All these methods involve bottom-up manufacturing processes, which consist of assembling molecules in solution to form defined structures [Chan & Kwok, 2011]. In this case, composite nanomicrobeads. The release systems resulting from bottom-up technologies typically exhibit size polydispersity [Wang et al., 2011], which in some cases limits the utility of nanoparticles. Indeed, it is assumed that, in a polydisperse system, larger nanoparticles may have a greater active ingredient loading capacity, while smaller nanoparticles are expected to be more efficient in delivering agrochemicals to tissues or cells [Fan et al., 2012],

[0033] Chitosan microparticles and nanoparticles have been manufactured through chemical crosslinking with glutaraldehyde, glyoxal, and ethylene glycol diglycidyl ether. Although these are highly effective crosslinking agents, they are not preferred due to their physiological toxicity. Chitosan is polycationic in acidic media (pKa 6.5) and can interact with negatively charged species, such as the crosslinker TPP (sodium tripolyphosphate) and sodium sulfate. This characteristic can be exploited to prepare crosslinked chitosan nanoparticles. The interaction of chitosan with TPP leads to the formation of biocompatible crosslinked chitosan nanoparticles that can be efficiently employed in the delivery of proteins, vaccines, and many other types of compounds. The crosslinking density, crystallinity, and hydrophilicity of crosslinked chitosan allow the modulation of the release of encapsulated drugs and extend their range of potential applications in drug delivery [Bhumkar, 2006],

[0034] Chitosan exhibits a high degree of protonation in its amine functions and has the ability to form hydrogels in the presence of specific polyanions. This process derives from inter- and intramolecular crosslinking mediated by anionic molecules [Janes et al., 2001; Terbojevich & Muzzarelli, 2009] and has been used to produce chitosan-based nanoparticles through ionic gelation or polyelectrolytic complexation. It is important to note that the term ionic gelation is preferred when the gelation of chitosan is induced by small anionic molecules such as phosphate, citrate, or sulfate. On the other hand, it is considered polyelectrolytic complexation when anionic macromolecules are used instead of small molecules [Bhattarai et al., 2010],

[0035] The formation of nanoparticles via ionic gelation is described in the work of Carvalho [Carvalho et al., 2009], Several studies in the state of the art describe chitosan nanoparticles crosslinked with TPP or another biopolymer encapsulating an active compound, where their fungicidal or herbicidal activity is detailed according to the encapsulated compound.

[0036] Additionally, studies in the state of the art have identified chitosan nanoparticles loaded or encapsulated with herbicides. For instance, in a study by Dos Santos Silva and collaborators (2011), alginate / chitosan nanoparticles measuring 635 ± 12 nm with a zeta potential of -22.8 ± 2.3 mV and an association efficiency of 74.2% were prepared as an eco-friendly carrier system for encapsulating the herbicide Paraquat. The nanoparticles conjugated with Paraquat improved the herbicide's release profile and its interaction with the soil, demonstrating that this formulation can effectively reduce the adverse impacts of Paraquat [dos Santos Silva, 2011]. In a similar approach, Grillo and others (2014) conducted a study on chitosan / tripolyphosphate nanoparticles (CSTPP) loaded with Paraquat. An encapsulation efficiency of 62.66 ± 0.77% was achieved, indicating good affinity between the CSTPP NPs and the active herbicide component. Herbicidal activity was evaluated on maize (Zea mays) and mustard (Brassica sp.). Both free and encapsulated forms of Paraquat caused flaccid foliar necrosis within 48 hours, a characteristic effect of this herbicide in both plants. In Z. mays, the use of the nanoherbicide resulted in more significant necrosis, possibly due to better adhesion of the nanoparticles to the leaf, as they have a higher surface-to-volume ratio.

[0037] Mancozeb, a contact protective fungicide belonging to the dithiocarbamate group, is widely used in agricultural crops for controlling fungal diseases (FAO, 2020). In a 2022 publication, Kumar and collaborators demonstrated the fungicidal activity of Mancozeb encapsulated in chitosan nanocapsules. In this study, chitosan and acacia gum nanoparticles crosslinked with TPP were loaded with three concentrations of Mancozeb during the synthesis process, allowing the active ingredient to be encapsulated. The study described that the encapsulated formulations exhibited a controlled release of Mancozeb over an extended period of at least 10 hours compared to the commercial formulation. The nanoparticles loaded with Mancozeb showed an inhibition of at least 85.2% against the fungus Alternaria alternata and 100% against the fungus Stemphylium lycopersici when applied at concentrations of 1.0 and 1.5 ppm, respectively, compared to the commercial Mancozeb control. The same authors presented chitosan and carrageenan nanocapsules containing Mancozeb, demonstrating antifungal effects against the fungi Sclerotinia sclerotiorum and S. lycopersici at concentrations of 1.0 and 1.5 ppm [Kumar, 2022],

[0038] Finally, in a study by Butstraen and collaborators [Butstraen, 2014], chitosan and gum arable microcapsules crosslinked with TPP and loaded with commercial Miglyol 812 N were described. The microcapsules were obtained using the coacervation method, and various chitosa gum arabic mass ratios of 1:4 and 1:5 with TPP as the crosslinker were evaluated in the presence of Miglyol during synthesis. The physicochemical parameters of the microparticles and their encapsulation capacity were assessed, along with the zeta potential of the particles. This document presents research aimed at finding optimal conditions for Miglyol encapsulation but does not describe or suggest a correlation between TPP concentration and the zeta potential of the formed particles. This document suggests an optimal chitosamgum mass ratio of 1:4, whereas the present invention proposes a significantly different range from 5:1 to 20:1, ensuring that the agrochemical formulation containing the composite microspheres of the invention is more readily redispersible in an aqueous agrochemical solution and does not clog spray nozzles in the field.

[0039] None of the prior art discloses or suggests a composite microsphere like that of the present invention, which does not encapsulate agrochemical actives but is instead added to a fungicide formulation to enhance its effectiveness and efficiency while reducing the concentration of fungicide used, maintaining effective activity.

[0040] Furthermore, none of the prior art suggests that the zeta potential of such a composite microsphere can be regulated through the TPP concentration during the synthesis process. None of the prior art has proposed the use of gum, which is a preferred embodiment, to improve the stability of the dispersion of chitosan composite microspheres when combined with fungicide and prevent clogging of applicator spray nozzles. The prior art proposes the use of gums as dispersants in the manufacturing process of natural polymer microparticles, such as chitosan, to regulate dispersion during the synthesis of microparticles. However, the use of gums to improve the stability of redispersion of such particles when added to an agrochemical solution has not been reported.

[0041] The present invention provides composite microspheres that can be used as adjuvants in agrochemical formulations (with herbicidal, fungicidal, insecticidal, and other activities). Together, these properties make the composite microsphere an innovative and promising tool to enhance the efficiency of agricultural inputs, reduce environmental impact, and promote sustainability in modern agriculture.

[0042] The present invention differs from close inventions in the prior art in that it can be combined with a pesticide, herbicide, fungicide, or combinations thereof prior to application and does not require encapsulation of the same duringthe particle synthesis process. Moreover, the present agrochemical formulation contains particles in concentrations that do not exhibit pesticidal effects (herbicidal, fungicidal, insecticidal, etc.) by themselves.

[0043] Surprising evidence has been demonstrated in laboratory and field trials of the agricultural application of the agrochemical formulation of the present invention, which contains a herbicide such as glyphosate in combination with the composite microsphere described herein, showing enhanced herbicidal activity. These trials demonstrate that the chitosan:dispersant:crosslinker particles of the present invention are non-toxic and exhibit increased herbicidal activity by more than 10%, achieving the same herbicidal effect when applied at 48% of the standard dose.

[0044] The present invention provides composite microspheres that can be used as adjuvants in fungicidal formulations, particularly when combined with Mancozeb, enhancing fungicidal activity against fungi by up to 1400%. Collectively, these properties make the composite microsphere an innovative and promising tool to improve the efficiency of agricultural inputs, reduce environmental impact, and promote sustainability in modern agriculture. Therefore, the present invention addresses the technical problem of reducing agrochemical usage with a biocompatible and biodegradable solution that enables the application of lower doses of agrochemical active ingredients, which are generally associated with toxic risks and high commercial costs.

[0045] Consequently, the present invention solves the technical problem posed by reducing the use of agrochemicals with a non-toxic, safe, biocompatible, and biodegradable solution.

[0046] Brief Description of the Invention

[0047] A composite microsphere designed to enhance the efficacy of an agrochemical active ingredient, the principal object of the present invention, comprises chitosan with an average molecular weight ranging from 190,000 to 310,000 g / mol, and a crosslinking agent, in the absence of an agrochemical active ingredient. It exhibits a surface electric charge (zeta potential) in an aqueous medium, adjustable through the concentration of said crosslinking agent, wherein the chitosan-to-crosslinker mass ratio is 1:X, where X is variable within a range from 0.08 to 1.5, preferably within a range from 0.4 to 1.2, more preferably 0.8, and most preferably within a range from 0.08 to 0.4, with 0.08 being most preferred. The crosslinking agent is selected from the group consisting of sodium tripolyphosphate (TPP), sodium hexametaphosphate, and their derivatives, preferably sodium tripolyphosphate (TPP). The zeta potential can be regulated according to the agrochemical to be combined.

[0048] The composite microspheres of the invention exhibit, in an aqueous solution, a zeta potential ranging from +30 mV to -30 mV, adjustable by the concentration of the crosslinking agent. When the crosslinking agent is present at low concentrations, such as 8% of the chitosan mass, the potential is approximately +30 mV. As the TPP concentration increases, the zeta potential decreases, reaching zero when the crosslinking agent constitutes approximately 40% of the chitosan mass. Further increases in the concentration of the crosslinking agent result in progressively more negative zeta potential values, reaching approximately -30 mV at concentrations of crosslinking agent exceeding 80% of the chitosan mass.

[0049] In preferred embodiments of the invention, 8% crosslinking agent relative to chitosan is used, resulting in a microsphere with a zeta potential of approximately +30 mV, whereas synthesizing with 100% crosslinking agent relative to the chitosan mass achieves zeta potentials of approximately -30 mV.

[0050] Preferred embodiments of the present invention include TPP concentrations of 0.08, 0.3, 0.5, 0.8, and 1.2 relative to chitosan.

[0051] In a preferred embodiment, the present invention further includes a dispersant that enhances the redispersion of said microsphere when combined with an aqueous solution containing a fungicidal active ingredient. The dispersant is selected from the group consisting of gum arabic, xanthan gum, guar gum, carrageenan, pectin, alginates, dextrins, cyclodextrins, maltodextrins, tragacanth gum, mesquite gum, polyethylene glycol, and their mixtures, with gum arabic being particularly preferred. The chitosamdispersant mass ratio is Y:l, where Y ranges from 5 to 20. Thus, the gum is incorporated into the microsphere in an amount of up to 20% of the chitosan mass.

[0052] Another principal object of the present invention is an agrochemical formulation comprising an agrochemical active ingredient and composite microspheres of the invention that enhance the agrochemical effectiveness on crops. The composite microsphere is present in a concentration from 2% to 200% w / w relative to said agrochemical active ingredient, more preferably from 2% to 100%, even more preferably from 2% to 20%, and most preferably from 5% to 10%.

[0053] In preferred embodiments of the present invention, said agrochemical active ingredient is selected from the group consisting of fertilizers, phytohormones, biostimulants, pesticides, herbicides, fungicides, nematicides, insecticides, rodenticides, agricultural biocompounds, phytosanitary products, plant hormones, and their mixtures.

[0054] In further preferred embodiments of the agrochemical formulation of the invention, said agrochemical active ingredient is selected from the group consisting of pre-emergent herbicides, contact herbicides, systemic herbicides, residual herbicides, biological herbicides, Glyphosate, Ammonium Glufosinate, Imazapyr, Imazapic, Imazamox, Imazaquin, Atrazine, Simazine, Diuron, Pendimethalin, Trifluralin, Fluorochloridone, Fluazifop-p-butyl, Quizalofop-p-ethyl, Dicamba, Paraquat, Clethodim, Haloxyfop, Fomesafen, Lactofen, 2,4-Dichlorophenoxyacetic Acid (2,4-D), Thiophanate-methyl, Pyraclonil, Diflufenican, Sulfentrazone, S-metolachlor, Flumioxazin, Pyroxasulfone, MCPA, Saflufenacil, Bromoxynil, Chlorantraniliprole, Abamectin, Thiamethoxam, Cypermethrin, Bifenthrin, Imidacloprid, Lambda-cyhalothrin, Deltamethrin, Dimethoate, Flubendiamide, Difenoconazole, Trifloxystrobin, Cyproconazole, Metalaxyl, Prothioconazole, Carbendazim, Isopyrazam, Chlorothalonil, Epoxiconazole, Fluoxastrobin, Mancozeb, Propiconazole, Prothioconazole, Trifloxystrobin Sedaxane, Tebuconazole, Thiram, Azoxystrobin, their derivatives, and their mixtures; insecticides, biological insecticides, Imidacloprid, Thiamethoxam, Acetamiprid, Clothianidin, Dinotefuran, Lambda-cyhalothrin, Cypermethrin, Deltamethrin, Permethrin, Bifenthrin, Chlorpyrifos, Dimethoate, Malathion, Methyl Parathion, Diazinon, Carbaryl, Methomyl, Aldicarb, Propoxur, Chlorantraniliprole, Cyantraniliprole, Diflubenzuron, Novaluron, Lufenuron, Buprofezin, Pyriproxyfen, Abamectin, Spinosad, Spinetoram, Beauveria bassiana, Flubendiamide, Azadirachtin, Mineral Oils, Insecticidal Soaps, their derivatives, and combinations; fungicides, systemic fungicides, biological fungicides, Prothioconazole, Trifloxystrobin, Cyproconazole, Carbendazim, Difenoconazole, Isopyrazam, Chlorothalonil, Epoxiconazole, Fluoxastrobin, Mancozeb, Zineb, Thiram, Tebuconazole, Propiconazole, Azoxystrobin, Pyraclostrobin, Thiabendazole, Metalaxyl, Boscalid, Captan, Folpet, Dithiocarbamates, Triazoles, Strobilurins, Benzimidazoles, Anilides, Organochlorines, Phthalimides, Sedaxane, biological fungicides, their derivatives, and combinations; controlled-release fertilizers, foliar fertilizers, low-biuret urea, potassium nitrate, monoammonium phosphate, monopotassium phosphate, ammonium nitrate, ammonium sulfate, zinc sulfate, zinc chelate (EDTA), zinc chelate (DTPA), zinc chelate (HEDTA), iron sulfate, iron chelate (EDDHA), iron chelate (DTPA), iron chelate (EDTA), copper sulfate, copper chelate (EDTA), manganese sulfate, manganese chelate (EDTA), boron sulfate, sodium borate, boric acid, sodium molybdate, ammonium molybdate, calcium nitrate, magnesium nitrate, magnesium sulfate, potassium silicate, potassium carbonate, potassium bicarbonate, seaweed extracts, amino acid-based fertilizers, protein hydrolysates, humic acid, fulvic acid, plant biostimulants, NPK soluble blends with micronutrients, concentrated nitrogen solutions, concentrated phosphorus solutions, concentrated potassium solutions, chelated micronutrient solutions, complexed calcium solutions, plant polysaccharides, silicon as silicic acid, plant extract-based products, liquid fertilizers with phytohormones, organic liquid fertilizers, alginate-based compounds, binary fertilizers diammonium phosphate (DAP), monoammonium phosphate (MAP), complete phosphate blends triple superphosphate (TSP), DAP, TSP, MAP, Urea, simple superphosphate (SSP), triple superphosphate (TSP), potassium chloride, potassium sulfate, rock phosphate, NPK fertilizers (blends of nitrogen, phosphorus, and potassium), controlled-release fertilizers, foliar fertilizers, animal manure, compost, guano, biofertilizers, iron chelates, zinc chelates, sodium nitrate, wood ash, and their mixtures.

[0055] In even more preferred embodiments of the agrochemical formulation of the invention, said agrochemical active ingredient is selected from the group consisting of Mancozeb, Dicamba, Glyphosate, Glufosinate, insecticides, 2,4-D, Prothioconazole, Trifloxystrobin, Thiamethoxam, Lambda-cyhalothrin, Chlorantraniliprole, biological fungicides, a biofertilizer, and foliar fertilizer.

[0056] In a preferred embodiment of the agrochemical formulation of the invention, said composite microsphere comprises chitosan with an average molecular weight ranging from 190,000 to 310,000 g / mol, a dispersant, and a crosslinking agent, wherein the chitosan:crosslinker mass ratio is 1:X, where X varies within a range from 0.08 to 1.2 and defines the zeta potential in an aqueous solution of said microspheres.

[0057] In a preferred embodiment, said composite microspheres comprise chitosan, gum arable, and tripolyphosphate, in the absence of agrochemical active ingredients. Said composite microsphere has, in an aqueous solution, a zeta potential ranging from +30 mV to -30 mV, adjustable by the concentration of the crosslinking agent.

[0058] In a preferred embodiment, said composite microspheres further comprise a coadjuvant selected from the group consisting of an adhesive, a surfactant, a stabilizer, an antifoaming agent, a pH buffer, a chelating agent, their derivatives, and combinations thereof.

[0059] Preferably, said agrochemical active ingredient is present at a concentration equal to or lower than the recommended field application rate. This allows the agrochemical formulation of the invention to reduce the amount of agrochemical active ingredient used in agriculture.

[0060] A preferred embodiment of the agrochemical formulation of the present invention is an aqueous composition comprising an agrochemical active ingredient and composite microspheres packaged in containers, as it has been mixed at the manufacturing plant and jointly packaged for sale and distribution.

[0061] In another preferred embodiment, the agrochemical formulation of the invention involves the agrochemical active ingredient and composite microspheres being mixed in the field prior to application.

[0062] In another preferred embodiment, the agrochemical formulation of the invention involves the agrochemical active ingredient and composite microspheres being mixed at least 2 hours before application.

[0063] In yet another preferred embodiment, the agrochemical formulation of the invention comprises an aqueous composition of the agrochemical active ingredient and composite microspheres packaged in containers, having been mixed at the manufacturing plant and jointly packaged for sale and distribution.

[0064] In another preferred embodiment, the agrochemical formulation of the invention comprises an aqueous composition of the agrochemical active ingredient and, separately, composite microspheres in powder form to be mixed before use.

[0065] Another object of the present invention is a method for obtaining the agrochemical formulation of the invention, comprising the following steps: a) preparing an aqueous solution of the agrochemical active ingredient at the desired concentration, b) adding the composite microspheres in a dry form at a concentration of up to 100% relative to the agrochemical active ingredient, c) mixing prior to application. Additionally, a coadjuvant may be added.

[0066] Another object of the present invention is a method for preventing and controlling plant diseases caused by fungi, bacteria, insects, and weeds, characterized by applying the agrochemical formulation of the invention to a crop. Said crop is selected from the group consisting of cereals, oilseeds, forest species, fruit trees, ornamental plants, vegetables, wheat, barley, rye, triticale, oats, maize, sunflower, rice, soybeans, peas, beans, peanuts, rapeseed, kale, cotton, potatoes, sugar beet, sugarcane, swiss chard (Beta vulgaris), peppers (Capsicum spp.), garlic and onions (Allium spp.), celery (Apio gravolens), eggplant (Solanum melongena), squash (Cucurbita moschata), chayote (Sechium edule), cabbage (Brassica oleracea), spinach (Spinacia oleracea), green beans (Phaseolus vulgaris), lettuce (Lactuca sativa), maize (Zea mays), peanuts (Arachis hypogaea), tomatoes (Solanum lycopersicum), cucumbers (Cucumis sativus), okra (Hibiscus esculentus), radishes (Raphanus sativus), beets (Beta vulgaris), carrots (Daucus carota), avocado (Persea americana), sugar apple (Annona squamosa), star apple (Chrysophyllum cainito), canistel (Pouteria campechiana), cherry (Malpighia punicifolia), soursop (Annona muricata), guava (Psidium guajava), pomegranate (Punica granatum), lime (Citrus aurantifolium), lemon (Citrus limonum), mamey (Calocarpum mammosum), tangerine (Citrus reticulata), mango (Mangifera indica), passionfruit (Passiflora laurifolia), watermelon (Citrullus vulgaris), sweet orange (Citrus sinensis), pineapple (Ananas comosus), banana (Musa paradisiaca), tamarind (Tamarindus indica), grapefruit (Citrus paradisi), grapes (Vitis vinifera), beans (Phaseolus vulgaris), rice (Oryza sativa), coffee (Coffea arabica), sugarcane (Saccharum officinarum), cucumbers (Melothria guadalupensis), sweet potatoes (Ipomoea batatas), potatoes (Solanum tuberosum), gooseberries (Physalis peruviana), cassava (Manihot esculenta), strawberries (Fragaria spp.), blackberries (Morus spp.), raspberries (Rubus spp.), oil palms (Elaeis guineensis), apple trees, cacao (Theobroma cacao), tree tomatoes (Solanum betaceum), lulo (Solanum quitoense).

[0067] In a preferred embodiment of the agrochemical formulation of the present invention, the composite microsphere enhances agrochemical action by at least 15% compared to the action of the agrochemical agent in the absence of composite microspheres.

[0068] In a preferred embodiment, the agrochemical formulation of the present invention is effective against infections caused by fungi selected from the group consisting of Magnaporthe oryzae, Botrytis cinerea, Puccinia spp., Fusarium spp., Fusarium graminearum, Fusarium oxysporum, Blumeria graminis, Mycosphaerella spp., Mycosphaerella fijiensis, Mycosphaerella graminicola, Colletotrichum spp., Ustilago maydis, Melampsora lini, Phakopsora pachyrhizi, Stemphylium lycopersici, and Rhizoctonia solani.

[0069] In a preferred embodiment, the agrochemical formulation of the present invention enhances the effectiveness of an agrochemical active ingredient by at least 15% and comprises said agrochemical active ingredient and composite microspheres. Said composite microspheres comprise chitosan with an average molecular weight ranging from 190,000 to 310,000 g / mol, and a crosslinking agent, wherein the chitosan:crosslinker mass ratio is 1:X, where X varies within a range from 0.5 to 1.5, and wherein the concentration of said composite microsphere is from 2% to 200% w / w relative to said fungicide in an aqueous phase.

[0070] In a preferred embodiment, the agrochemical formulation of the invention comprises a chitosan-to-dispersant mass ratio of Y:l, where Y ranges from 5 to 20, and the surface electric charge or zeta potential of said composite microsphere is adjustable through the concentration of the crosslinking agent, with X ranging from 0.08 to 0.8, and wherein said crosslinking agent is TPP.

[0071] In a preferred embodiment of the agrochemical formulation of the invention, said agrochemical active ingredient is in an aqueous solution stored in a container, and said composite microsphere is a powder configured to be added to said container.

[0072] In a preferred embodiment, the agrochemical formulation of the invention comprises the following steps: mixing acetic acid, chitosan, and water while stirring; adding said dispersant and stirring; adding the crosslinking agent solution dropwise; allowing the mixture to settle; and drying the obtained microspheres.

[0073] Another object of the present invention is a process for obtaining said composite microsphere, comprising the following steps: a. dissolving chitosan in 1% v / v acetic acid with constant stirring at a temperature of 20°C until no lumps are observed; b. adding dispersant and stirring until complete dissolution to achieve a chitosan-to- dispersant mass ratio of Y:l, where Y ranges from 5 to 20; c. adding dropwise to the mixture a solution of the crosslinking agent, at a chitosamcrosslinker mass ratio of 1:X, where X ranges from 0.08 to 1.2, in the absence of an herbicidal active ingredient; d. adjusting the pH to approximately 6.5; e. drying the composite microspheres; Wherein step e) involves freeze-drying with a 220 V lyophilizer at -45°C and 10 Pa pressure, followed by grinding with a mortar and sieving with a 100-mesh filter for the composite microspheres. Alternatively, step e) involves spray-drying at an inlet temperature of 200°C.

[0074] Another object of the present invention is a process for obtaining the agrochemical formulation of the invention, characterized by comprising the following steps: a) preparing an aqueous solution of fungicide; b) adding dry composite microspheres to the aqueous fungicide solution; c) allowing the mixture to remain in contact for at least 2 hours; d) stirring and applying to the crop.

[0075] In a preferred embodiment, the composite microsphere of the invention is a co- formulator that enhances agrochemical formulations.

[0076] Description of the Figures

[0077] Figure 1. Scanning Electron Microscopy (SEM) images of MCS 0.08-0.1, MCS 0.3-0.1, MCS 0.5-0.1, MCS 0.8-0.1, MCS 1.2-0.1, and MCS 1.5-0.1.

[0078] Figure 2. Transmission Electron Microscopy (TEM) images of MCS 0.08-0.1, MCS 0.3-0.1, MCS 0.8-0.1, and MCS 1.2-0.1.

[0079] Figure 3A. Scanning Electron Microscopy (SEM) images of composite microspheres:

[0080] • Top Left Panel: SEM image of the microspheres formulated with Mancozeb. Magnification 1600x. Composite microspheres MCS 0.8-0.15 added to a Mancozeb suspension and mixed for 24 hours.

[0081] • Top Center Panel: SEM image of the microspheres formulated with Mancozeb. Magnification 6000x. Composite microspheres MCS 0.8-0.15 added to a Mancozeb suspension and mixed for 24 hours.

[0082] • Top Right Panel: SEM image of the microspheres formulated with Mancozeb. Magnification 20000x. Composite microspheres MCS 0.8-0.15 added to a Mancozeb suspension and mixed for 24 hours.

[0083] • Bottom Left Panel: SEM image of the microspheres. Magnification 3050x. The image shows agglomerated microspheres after spray-drying. • Bottom Center Panel: SEM image of the microspheres. Magnification 2760x. The image shows agglomerated microspheres after spray-drying. Concentrated sample.

[0084] • Bottom Right Panel: SEM image of the microspheres. Magnification 18000x. The image shows agglomerated microspheres after lyophilization. Individual microspheres can be observed in this image.

[0085] These images clearly show the reconfiguration of microspheres when combined with an aqueous Mancozeb (MZ) solution for a sufficient time.

[0086] Figure 3B. Scanning Electron Microscopy (SEM) images of composite microspheres:

[0087] • Left Panel: SEM image of Mancozeb. Magnification 1600x.

[0088] • Right Panel: SEM image of the microspheres formulated with Mancozeb. Magnification 6000x. Composite microspheres MCS 0.8-0.15 added to a Mancozeb suspension and mixed for 2 hours. New laminar forms begin to appear.

[0089] Figure 4. Herbicidal activity assay of Glyphosate combined with MCS 0.8-0.1. Representative plants for each treatment are shown.

[0090] Figure 5. Herbicidal activity assay of Glyphosate combined with MCS 0.8-0.1. The bars represent the average fresh foliar biomass in grams for each treatment.

[0091] Figure 6. Herbicidal activity assay of Glyphosate combined with 5% MCS 0.08-0.1 and MCS 0.8-0.1 on foliar biomass in wheat plants grown for 14 days in plates. Plants were treated at 8 days of growth, and observations were made 6 days later (6 DAA). The height of the bars represents the mean of each group.

[0092] Figure 7. Field trials of the herbicidal activity of Glyphosate combined with MCS 0.8-0.1 on the weed Cynodon dactylon (Bermuda grass). The height of the bars represents the mean of each group (n=3). Solid black columns correspond to measurements 7 days after application (7 DAA), and white columns correspond to measurements 14 days after application (14 DAA). Figure 8. Field trials of the herbicidal activity of Glyphosate combined with MCS 0.8-0.1 on the weed Brassica rapa "elongata" (Nobolza elongata). The height of the bars represents the mean of each group (n=3). Solid black columns correspond to measurements 7 days after application (7 DAA), and white columns correspond to measurements 14 days after application (14 DAA).

[0093] Figure 9. Photograph showing herbicide sprayer filters clogged by the microspheres of the invention without gum.

[0094] Figure 10. Scanning Electron Microscopy (SEM) images of MCS 0.8 without gum (left) and with gum arabic (right).

[0095] Figure 11. Fungicidal activity assay of Mancozeb (MZ) combined with MCS 0.8-0.1 on B. cinerea. The height of the bars represents the mean of each group (n=3).

[0096] Figure 12. Fungicidal activity assay of MZ combined with MCS 0.08-0.1 and MCS 0.8-0.1 at different preincubation times (2 hours, 4 hours, and 24 hours) prior to application on B. cinerea. The height of the bars represents the mean of each group (n=3).

[0097] Figure 13. Antifungal activity assay of MZ combined with MCS at different TPP concentrations on B. cinerea. The height of the bars represents the mean of each group (n=6). Two preincubation times (2 hours and 24 hours) were evaluated for each particle with different TPP concentrations (MCS 0.08-0.1, MCS 0.3-0.1, MCS 0.5-0.1, MCS 0.8- 0.1, MCS 1.2-0.1).

[0098] Figure 14. Herbicidal activity assay of Dicamba combined with 5% MCS 0.8 in tomato plants grown for 22 days in substrate. Plants were treated at 8 days of growth, and observations were made 14 days later (14 DAA). The height of the bars represents the mean of each group (n=3).

[0099] Detailed Description of the Invention

[0100] An agrochemical formulation comprising an agrochemical active ingredient in an aqueous solution and composite microspheres that enhance agrochemical efficacy against weeds in crops; wherein said composite microspheres, in powder form, are present in a concentration from 2% to 200% w / w relative to the herbicide when combined with said aqueous solution, and wherein said composite microspheres include chitosan, with an average molecular weight ranging from 190,000 to 310,000 g / mol, and a crosslinking agent. These composite microspheres enhance the efficacy of the agrochemical on crops.

[0101] For the purposes of the present invention, "agrochemical" refers to any substance or mixture of natural or synthetic substances used to prevent, eliminate, and / or control any pest, disease, or weed in agricultural activities, and / or preserve or increase soil fertility, and / or improve the quality and / or yield of crops.

[0102] In the context of this document, agrochemicals include fertilizers, plant growth regulators, biostimulants, pesticides, herbicides, fungicides, nematicides, insecticides, rodenticides, agricultural biocompounds, and phytosanitary products.

[0103] In this document, the term "agrochemical" is used generically to encompass any of the following: fertilizers, plant growth regulators, biostimulants, pesticides, herbicides, fungicides, nematicides, insecticides, rodenticides, agricultural biocompounds, phytosanitary products, or any biological, chemical, natural, or synthetic compound usable to improve agricultural production.

[0104] In this document, "agrochemical active ingredient" refers to any active compoundchemical, biological, synthetic, or natural— used in agriculture to improve yields, eliminate pests, or optimize agricultural tasks.

[0105] In this document, "agrochemical effect" refers to any effect an agrochemical active ingredient has on agricultural activities, such as improving yields, eliminating insects, pests, fungi, or weeds.

[0106] In this document, "agrochemical formulation" refers to a mixture of one or more agrochemical active ingredients with other components that have an agrochemical effect. These formulations can be liquid or solid in the form of powders or aqueous solutions. They may contain adjuvants or co-adjuvants and may be suspensions, solutions, emulsions, etc.

[0107] The agrochemical formulation of the present invention comprises at least one agrochemical active ingredient and the composite microspheres of the present invention. For the purposes of the present invention, "adjuvant," "co-adjuvant," "agricultural adjuvant," or "agricultural co-adjuvant" refers to products of natural or synthetic origin that enhance or facilitate the action of an agrochemical ( phytosa nitary, fertilizer, or biostimulant) by modifying certain characteristics of the solution and whose properties improve the activity of the agrochemical.

[0108] In this document, "herbicide" refers to a chemical product used to control and / or eliminate unwanted plants.

[0109] For the purposes of this document, the terms "unwanted vegetation," "undesirable vegetation," "weed," "herbaceous plants," and "weeds" are used interchangeably.

[0110] In this document, "e.a. ha-1" refers to the amount of glyphosate acid equivalent applied per hectare of land. It is a unit commonly used to specify doses in agricultural applications.

[0111] For the purposes of this document, "fungicide" is defined as a product capable of eliminating fungi harmful to plants.

[0112] For the purposes of this document, "fungicidal active ingredient" is defined as a chemical or biological, natural, modified, or synthetic product with the capacity, either direct or derived, to eliminate, prevent, or control fungi harmful to plants.

[0113] For the purposes of this document, "insecticides" are defined as chemical, biological, or natural substances used to eliminate or control insect populations, either by killing them or interfering with their development and reproduction. These substances are applied to crops in agriculture to control disease-transmitting pests and prevent material damage.

[0114] In this document, "microsphere" refers to particles of micrometric or nanometric sizes, which may be microparticles, microspherules, nanoparticles, or nanospheres, with various shapes. The size of such microspheres is referred to as particle diameter or size.

[0115] For the purposes of the present invention, the term "MCS" refers to the composite microspheres of the invention made with chitosan:dispersant:crosslinker, preferably chitosan:gum:TPP. For the purposes of the present invention, the term "MCS0.08" refers to the composite microspheres of the invention made with chitosan:gum:TPP in a mass ratio of 1:0.1:0.08.

[0116] For the purposes of the present invention, the term "MCS0.3" refers to the composite microspheres of the invention made with chitosan:gum:TPP in a mass ratio of 1:0.1:0.3.

[0117] For the purposes of the present invention, the term "MCS0.5" refers to the composite microspheres of the invention made with chitosan:gum:TPP in a mass ratio of 1:0.1:0.5.

[0118] For the purposes of the present invention, the term "MCS0.8" refers to the composite microspheres of the invention made with chitosan:gum:TPP in a mass ratio of l:0.1:0.8.

[0119] For the purposes of the present invention, the term "MCS1.2" refers to the composite microspheres of the invention made with chitosan:gum:TPP in a mass ratio of 1:0.1:1.2.

[0120] Crosslinking agents are molecules that may contain at least two reactive functional groups, allowing the formation of covalent bonds between polymer chains.

[0121] One of the major challenges associated with agricultural activity is the excessive use of agrochemicals due to their adverse effects on human health, the environment, and the emergence of resistant crops. The present invention provides a solution to this problem described in the state of the art. The present invention provides reticular composite microspheres based on chitosan, preferably in quasi-spherical shapes, with sizes ranging from 100 to 200 nanometers that can aggregate into structures ranging from 200 to 5000 nm. When combined at low concentrations with an agrochemical, these microspheres enhance its efficacy, allowing the application of reduced doses of the agrochemical agent while achieving the same agrochemical effect.

[0122] A composite microsphere, a principal object of the present invention, that reduces the use of agrochemicals in agriculture, comprises chitosan, a crosslinking agent, and preferably a dispersant, wherein said microsphere has a positive, neutral, or negative surface charge, and wherein said surface charge is adjustable by the concentration of the crosslinking agent in the microsphere.

[0123] In preferred embodiments, the microspheres of the present invention comprise medium molecular weight chitosan, ranging from 190,000 to 310,000 g / mol, with a degree of deacetylation greater than 90%. The composite microspheres of the present invention are characterized by being composed of chitosan and a crosslinking agent, and preferably a dispersant, wherein said microsphere has a positive, neutral, or negative surface charge, and wherein said surface charge is adjustable by the concentration of the crosslinking agent in the microsphere.

[0124] In preferred embodiments of the present invention, the crosslinking agent comprises TPP in a chitosan / crosslinker / dispersant weight ratio of 100 / 8 / 15 and 100 / 80 / 10.

[0125] The present invention provides a composite microsphere comprising chitosan and a crosslinking agent, in a preferred embodiment tripolyphosphate (TPP), and in another preferred embodiment a dispersant such as gum. The composite microsphere of the invention can be synthesized by regulating its zeta potential through an adjustable concentration of crosslinking agent, enabling fine-tuning of the zeta potential in aqueous solutions. This feature of the present invention allows the design and selection of the desired composition, enabling combination with different agrochemical compounds. The particle of the present invention, formulated with an herbicidal, fungicidal, or insecticidal agent for its application, enhances the effect of the formulated agrochemical.

[0126] The ability to adjust the zeta potential allows the microspheres to be customized for different pH conditions, salinity levels, and soil types. This capability enables the microspheres to be utilized in a wide variety of crops and agricultural systems. The regulation of the zeta potential through the concentration of the crosslinking agent suggests that the microspheres can control surface charge, which influences the release of active compounds (fertilizers, pesticides, or micronutrients) in aqueous solutions. The control of the zeta potential enables the design of microspheres that selectively interact with specific surfaces or ions, adapting to the needs of the crop and / or soil, facilitating advantages for the targeted delivery of active ingredients to specific sites of action (plant, pathogen, soil), and optimizing the use of agricultural inputs.

[0127] The present invention provides hierarchical composite microspheres manufactured from chitosan with adjustable and precisely defined chemical composition, size, shape, and charge distribution. These microspheres act as co-formulators to reduce the pesticide dose in an agrochemical formulation. The microspheres exhibit a well-defined microstructure with an adjustable surface charge that can be positive, neutral, or negative. The amount of the crosslinking agent, preferably sodium tripolyphosphate, is strategically defined based on the expected charge distribution in the particle, ranging from 3% to 150% w / w relative to chitosan.

[0128] In one embodiment of the present invention, the composition of the microspheres comprises a positive surface charge, and the amount of sodium tripolyphosphate is less than 40% w / w relative to chitosan.

[0129] In another embodiment of the present invention, the composition of the microspheres comprises a negative surface charge, and the amount of sodium tripolyphosphate is at least 50% w / w relative to chitosan.

[0130] The dispersant, generally a natural polymer, imparts rapid dispersibility to the microspheres and allows their use across a wide range of salinity, pH, and temperature conditions. The dispersant is selected from the group consisting of gum arable (and its derivatives), xanthan gum (and its derivatives), guar gum (and its derivatives), triblock copolymers of poly(ethylene glycol)-poly(propylene glycol), polyacrylamide derivatives, microcrystalline cellulose (and its derivatives), carboxymethylcellulose (and its derivatives); and the dispersant comprises up to 20% w / w relative to chitosan.

[0131] The composite microspheres of the present invention differ from those identified in the prior art in that their physicochemical characteristics, particularly their zeta potential or charge distribution, can be adjusted. The inventors have been able to adjust or define the zeta potential of the microspheres ofthe present invention according to the amount of crosslinking agent incorporated during synthesis. Particles were developed such that their crosslinking agent content, varying from 0.02 to 1.5 per unit of chitosan, allows a zeta potential adjustable within the range of +30 mV to -30 mV. This enables the synthesis of particles with optimal physicochemical characteristics to be combined with a wide range of agrochemicals.

[0132] It should be noted that the use concentration of the composite microspheres of the invention can range from 2% to 200% w / w relative to the concentration of the agrochemical active ingredient by weight, with excellent results observed within ranges as low as 5% to 10%.

[0133] From the application perspective, this allows a sustained and efficient supply of agrochemicals / fertilizers, both chemical and biological, as well as phytosanitary products, reducing losses due to leaching or evaporation and increasing availability at the biological targets where they act (plants, fungi, insects). Additionally, the preferred components (chitosan, gum arabic, and TPP) are biodegradable and non-toxic, making the microspheres environmentally friendly. Thus, they reduce the environmental impact compared to synthetic matrices, promote sustainable agriculture, and protect soil biodiversity. Chitosan also has antimicrobial properties that can protect plants against pathogens and fungal diseases.

[0134] Unlike similar particles identified in the prior art, which are characterized by encapsulating the agrochemical active ingredient during the synthesis process, the composite microspheres of the present invention are combined with the active ingredient after synthesis, preferably before field application. The most notable advantages are that they can be applied with a wide variety of agrochemicals and exhibit an enhancing effect on the agrochemical with which they are formulated. Therefore, by enhancing its efficiency, it is possible to recommend lower application doses compared to those commercially recommended on product labels. The fact that the composite microspheres of the invention are dried and combined at the time of application makes it possible to have a product stable under regular environmental conditions with a high shelf life. These composite microspheres, being biodegradable, do not accumulate and therefore do not cause environmental damage. No indices of cytotoxicity in human cells have been detected.

[0135] The inventors of the present invention have formulated these composite microspheres with fungicidal active ingredients, finding that the addition of these microspheres enhances fungicidal effects. Specifically, they have demonstrated that the particles exhibit minimal fungicidal activity when applied at concentrations of 25 pg / ml, as their activity against B. cinerea does not exceed 20%. Furthermore, the inventors have shown that fungicidal formulations composed of 25 pg / ml of Mancozeb combined with the composite microspheres of the invention, with different TPP compositions in a mass ratio of 1:1 (25 pg / ml MZ and 25 pg / ml MCS), enhance the fungicidal activity of Mancozeb between 14X and 16X compared to the activity of free Mancozeb— representing an enhancement of more than 1400%. An unexpected synergistic effect is evidenced by the combination of the agrochemical active ingredient with the particles containing different TPP contents (MCS0.08, MCS0.3, MCS0.5, MCS0.8, MCS1.2).

[0136] Surprising evidence from laboratory trials has been presented regarding the agricultural application of the fungicidal formulation of the present invention, which contains a fungicidal active ingredient such as Mancozeb combined with the composite microspheres described in this document, showing enhanced fungicidal activity. These trials demonstrate that the chitosan:gum:TPP microspheres of the present invention are innocuous and enhance the fungicidal activity of the active ingredient by up to 1400%. Furthermore, it has been demonstrated that such a significant fungicidal effect occurs when the composite microspheres are mixed with the fungicidal active ingredient for more than 2 hours, preferably around 24 hours before applying the agrochemical formulation— in particular, when the agrochemical is a fungicide, more specifically Mancozeb.

[0137] In this document, the enhancement of an agrochemical active ingredient when combined with the composite microspheres of the present invention is calculated as follows:

[0138] ((Effect of the invention - Effect of agrochemical alone) / Effect of agrochemical alone) x 100

[0139] In this case, the effect can be measured by the activity of the agrochemical (e.g., knockdown, reduced biomass, fungal inhibition, etc.). However, it can also be measured by other variables, such as yield per hectare, when it depends on the control exerted by the agrochemical in question. This formula can also be applied when, instead of one agrochemical, the microspheres are combined with another agrochemical, such as an herbicide, insecticide, fungicide, fertilizer, or others.

[0140] In the present invention, the composite microspheres are obtained through the ionic gelation method, where the necessary amounts of chitosan and dispersant (in the embodiments that include it) are mixed, followed by the dropwise addition of crosslinking agent at the desired concentration.

[0141] The composite microspheres of the present invention, compared to those known in the prior art, exhibit the versatility of being combinable with different agrochemicals and can also be handled independently by combining them at the time of use, thereby enhancing particle stability.

[0142] The present invention provides a process for producing said composite microspheres, which involves a physical gelation process employing a strategically designed synthesis, in a preferred embodiment, using three components: chitosan, a crosslinking agent, and a dispersant.

[0143] The production process has been successfully scaled up to a reaction volume of 20 liters. Throughout the process, the pH is maintained at 4.5, adjusted with acetic acid, while agitation and temperature are kept constant at 130 rpm and 20°C, respectively. At the end of the process, the pH is raised to 6.5, and the microspheres undergo natural decantation. Subsequently, they are dried using a spray drying process and sieved with a 100-mesh screen.

[0144] The present invention also provides a production process for obtaining the composite microsphere of the invention, which comprises the following steps: a. dissolving chitosan in 1% v / v acetic acid with constant stirring at a temperature of 20°C until no lumps are observed; b. adding dispersant and stirring until complete dissolution is achieved, reaching a chitosan-to-dispersant mass ratio of Y:l, where Y ranges from 5 to 20; c. adding dropwise to the mixture a solution of the crosslinking agent until the desired concentration of the crosslinking agent is achieved, at a chitosan:crosslinker mass ratio of 1:X, where X ranges from 0.03 to 1.2, in the absence of an agrochemical active ingredient; d. adjusting the pH to approximately 6.5; e. d rying the particles; Wherein, in a preferred embodiment of the invention: said step e) involves freeze-drying with a 220 V lyophilizer at -45°C and 10 Pa pressure, followed by grinding with a mortar and sieving with a 100-mesh screen for the composite microspheres; or said step e) involves spray drying at an inlet temperature of 200°C.

[0145] The present invention provides a method for preventing and controlling infections and weeds, which comprises applying the agrochemical formulation of the invention to a crop, wherein said crop is selected from the group consisting of trees, cereals, oilseeds, vegetables, fruits, ornamentals, Swiss chard {Beta vulgaris), chili peppers {Capsicum spp.), garlic and onions {Allium spp.), celery {Apia gravolens), eggplant (Solarium melongena), squash (Cucurbita moschata), chayote (Sechium edule), cabbage (Brassica oleracea), spinach (Spinacia oleracea), green beans (Phaseolus vulgaris), lettuce (Lactuca sativa), corn (Zea mays), peanut (Arachis hypogaea), tomato (Solarium lycopersicum), cucumber (Cucumis sativus), okra (Hibiscus esculentus), radish (Raphanus sativus), beet (Beta vulgaris), carrot (Daucus carota), avocado (Persea americana), sugar apple (Annona squamosa), star apple (Chrysophyllum cainito), eggfruit (Pouteria campechiana), cherry (Malpighia punicifolia), custard apple (Annona reticulata), plum (Spondias dulcis), coconut (Cocos nucifera), papaya (Carica papaya), soursop (Annona muricata), guava (Psidium guajava), pomegranate (Punica granatum), lime (Citrus aurantifolium), lemon (Citrus limonum), apple (Malus domestica), mamey sapote (Calocarpum mammosum), Santo Domingo apricot (Mammea americana), Spanish lime (Melicoccus bijugatus), tangerine (Citrus reticulata), mango (Mangifera indica), passion fruit (Passiflora laurifolia), watermelon (Citrullus vulgaris), bitter orange (Citrus aurantium), sweet orange (Citrus sinensis), pear (Pyrus communis), pineapple (Ananas comosus), banana (Musa paradisiaca), plantain (Musa balbisiana), tamarind (Tamarindus indica), grapefruit (Citrus paradisi), native grapefruit (Citrus grandis), grape (Vitis vinifera), beans (Phaseolus vulgaris), rice (Oryza sativa), coffee (Coffea arabica), sugarcane (Saccharum officinarum), cotton (Gossypium hirsutum), gherkin (Melothria guadalupensis), sweet potato (Ipomoea batatas), potato (Solanum tuberosum), native potato (Solanum phureja), cape gooseberry (Physalis peruviana), cassava (Manihot esculenta), soybean (Glycine max), strawberries (Fragaria spp.), mulberries (Morus spp.), brambles (Rubus spp.), palm trees from the family Arecaceae, oil palm (Elaeis guineensis), cacao (Theobroma cacao), tree tomato (Solanum betaceum), lu Io (Solanum quitoense), and chickpeas (Cicer arietinum), among other species. When said infections are fungal, they are caused by fungi selected from the group consisting of Magnaporthe oryzae, Botrytis cinerea, Puccinia spp., Fusarium spp. (including but not limited to Fusarium graminearum, Fusarium oxysporum), Blumeria graminis, Mycosphaerella spp., Mycosphaerella fijiensis, Mycosphaerella graminicola, Colletotrichum spp., Ustilago maydis, Melampsora lini, Phakopsora pachyrhizi, and Rhizoctonia solani, among others.

[0146] The present invention also provides an agrochemical formulation, particularly a herbicide, containing the composite microspheres of the invention combined with a herbicide, wherein said composite microspheres, incorporated at low concentrations and showing no herbicidal activity per se, enhance the effect of the herbicide, allowing for reduced application doses by up to 52% compared to the recommended doses of the free herbicide while maintaining similar effectiveness. Compelling and surprising evidence has demonstrated that formulations of glyphosate combined with the composite microspheres of the invention exhibit herbicidal activity between 15% and 21% higher than glyphosate applied alone in laboratory plant trials. It should be noted that the usage concentration of the composite microspheres of the invention can range from 2% to 100% w / w relative to the herbicide concentration by weight, with excellent results observed in ranges as low as 5% to 10%.

[0147] Field trials have demonstrated that the agrochemical formulation of the present invention, incorporating the composite microspheres at a ratio of 5% w / w relative to the active ingredient, allows for a reduction in the application dose of glyphosate by up to 52%, while achieving herbicidal activity comparable to glyphosate applied alone at the recommended dose.

[0148] The formulation of the present invention comprises an agrochemical active ingredient formulated in a container and the microspheres of the invention in powder form, to be added prior to application to the field or crops.

[0149] In another embodiment, the formulation of the present invention contains the agrochemical active ingredient and the microspheres of the invention combined in an aqueous solution within the same container. The present invention is further described by the following examples, which should not be considered as limiting the scope of the invention. The invention is not limited by the illustrative examples provided below.

[0150] Examples

[0151] Example 1: Method of Synthesis and Production of Chitosan:Arabic Gum:Tripolyphosphate (TPP) Microspheres at Laboratory Scale

[0152] Materials Used: Chitosan (degree of deacetylation 95%, Mw 275,000), Arabic gum (Mw 70,000), TPP, 1% acetic acid, IM sodium hydroxide, distilled water, 600 mL and 250 mL beakers, Dragon Lab mechanical stirrer, peristaltic pump, pH meter, 100 and 450 mesh sieves.

[0153] Microspheres of Chitosan, Arabic Gum, and Tripolyphosphate (TPP) were obtained using the ionic gelation method in reactors of 0.6 and 20 liters, fol lowing the procedure below: a) For a 600 mL Reactor:

[0154] • Prepare a 200 mL solution of 1% w / v acetic acid (10 mL / L) and add 4 g of chitosan, stirring constantly at 1300 RPM with the Dragon Lab mechanical stirrer until the solution becomes completely dissolved, achieving a uniform and clear color without visible lumps, for 10 minutes (maintain temperature between 19- 24°C).

[0155] • Add 0.4 g of Arabic gum (10% or 15% relative to chitosan) and stir for 10 minutes until completely dissolved.

[0156] • Prepare a 1.6% w / v aqueous solution of tripolyphosphate (TPP).

[0157] • Using a peristaltic pump, slowly add TPP dropwise into the beaker at a rate of 0.55 L / h until 200 mL of TPP is added to the reactor (23-25 minutes). Then maintain stirring for 30 minutes after the addition is complete. Keep the reactor stirring at 1300 RPM.

[0158] • Measure and adjust the pH to 6.5 using IM sodium hydroxide.

[0159] • Centrifuge for 10 minutes at 1200 RPM and discard the supernatant. • Freeze the microspheres in a freezer for at least 24 hours.

[0160] • Dry the microspheres using a PeetLab BK-FD10PT lyophilizer at -10°C and 10 Pa pressure.

[0161] • Grind and sieve the microspheres first through a 100-mesh sieve and then through a 450-mesh sieve. b) For a 20 L Reactor: The same procedure was followed, adjusting the quantities of materials to the dimensions of the 20 L reactor with a Dragon Lab 4-blade mechanical stirrer (Figmay). The drying step was modified as follows:

[0162] In a 20 L borosilicate glass reactor (Figmay) with a 4-flat-blade stirrer and no heating, 5 L of 1% acetic acid (10 mL / L) and 100 g of chitosan (degree of deacetylation 95%, Mw 275,000) were added, stirring at 130 RPM for 10 minutes. The reactor temperature was maintained at 21 ± 2°C. Complete dissolution was achieved, resulting in a uniform and clear solution without visible lumps. Subsequently, 10 or 15 g of Arabic gum was added as a dispersing agent (depending on the case) and stirred for 10 minutes.

[0163] In a second 10 L reactor, a 16 g / L TPP (tripolyphosphate) solution was prepared by adding 5 L of distilled water and 80 g of TPP, stirring until completely dissolved for 5 minutes at room temperature.

[0164] The 20 L reactor with the chitosan solution was stirred at 130 RPM, and using two peristaltic pumps, TPP was added dropwise at a rate of 2 L / h. TPP was added according to the desired final concentration, and stirring was maintained for 30 minutes. Finally, the pH was adjusted to 6.5 with IM NaOH.

[0165] The reactor contents were then discharged into a 20 L container and left to stand overnight (12 hours) at room temperature. The supernatant liquid was discarded. Using a JISL LSD-48 benchtop spray dryer with a drying capacity of 1 L / h, the microspheres were dried at 200°C with a 60% feed rate. The microspheres were kept suspended by agitation during the drying process. Example 2: Preparation of Chitosan Microspheres with Variable Proportions of Arabic Gum and Tripolyphosphate (TPP)

[0166] Microspheres were obtained following the procedures described in Example 1, adjusting the amounts of Arabic gum relative to the grams of chitosan, and adjusting the volumes of TPP added dropwise relative to the amount of chitosan to achieve microspheres with different chitosa Arabic gum:TPP mass ratios.

[0167] The following microspheres were prepared with mass ratios as shown in Table 1.

[0168] Table 1. Microspheres with Mass Ratios of Arabic Gum and TPP per Unit of Chitosan

[0169] Example 3: Preparation of Composite Chitosan Microspheres with Sodium Hexametaphosphate (HMP) as a Crosslinking Agent and Xanthan Gum and Polyethylene Glycol as Dispersants

[0170] In a 20 L glass reactor (Figmay) made of borosilicate glass 3.3, equipped with a 4-flat- blade stirrer without heating, 5 L of a 15% citric acid solution (10 ml_ / L) and 100 g of chitosan (degree of deacetylation 92%, Mw 210,000) were added. The mixture was stirred at 150 RPM for 10 minutes, maintaining the reactor temperature at 21 ± 2°C. Complete dissolution was achieved, resulting in a uniform solution with a clear color and no visible lumps. Subsequently, 5 g of xanthan gum and 10 g of polyethylene glycol were added as dispersants, and the mixture was stirred for an additional 10 minutes.

[0171] In a second 10 L reactor, a 25 g / L solution of sodium hexametaphosphate (HMP) was prepared by adding 5 L of distilled water and 125 g of HMP, stirring until completely dissolved for 10 minutes at room temperature.

[0172] The 20 L reactor containing the chitosan solution was stirred at 150 RPM, and using a peristaltic pump, HMP was added dropwise at a rate of 0.5 L / h (10 hours). Stirring was maintained for an additional 60 minutes after the complete addition of HMP.

[0173] The reactor contents were discharged into a 20 L container and allowed to settle overnight (12 hours) at room temperature. The supernatant was carefully transferred to another container, ensuring no material was lost during the process. The mixture was then centrifuged for 15 minutes at 1500 RPM using a "Rolco MOD.CM-2036" laboratory centrifuge. The samples were frozen for 24 hours at -24°C. Using a tabletop multi- collector laboratory freeze dryer, the samples were freeze-dried for 72 hours. Finally, the samples were ground and sieved through a 450-mesh sieve.

[0174] Example 4: Determination of the Size and Morphology of Chitosan:Arabic Gum:Sodium Tripolyphosphate Microspheres

[0175] An exhaustive physicochemical characterization of the composite microspheres obtained according to the procedure in Example 1 and the chemical composition described in Example 2 was performed to define their structure and properties.

[0176] Three techniques were used to study and define the size and morphology of the composite microspheres:

[0177] 1. Dynamic Light Scattering (DLS). Three measurements of 60 seconds each were performed with 10-second intervals at 25°C using a Malvern Zetasizer NanoS90. The Brownian motion of the composite microspheres in suspension was analyzed. The light scattered by the composite microspheres provided information about the diffusion coefficient, allowing determination of the hydrodynamic radius and size distribution of the material. Table 2 shows the sizes of the composite microspheres (MCS) with varying amounts of TPP.

[0178] Table 2. Physicochemical parameters of composite microspheres (MCS) for different TPP:CS ratios, all samples containing 10% arabic gum.

[0179] 2. Transmission Electron Microscopy (TEM). This technique was performed using a JEOL JEM 2100, operating at 200 kV with a B6La filament. Images were captured at magnifications of 50,000x or higher to analyze the morphology and size of the composite microspheres.

[0180] 3. Scanning Electron Microscopy (SEM). (FESEM) ZEISS Model Crossbeam 350. Samples were prepared with Cr or Au coating. Images were captured at magnifications of 30x, 500x, 1500x, 6000x, 20,000x, and 40,000x. General appearance, size, and morphology of the composite microspheres were analyzed.

[0181] The DLS characterization of the composite microspheres' sizes concluded the existence of populations with different size distributions (Table 2). In many cases, up to three different hydrodynamic diameter sizes were observed, typically around 200-300 nm, 600-1000 nm, and 2000-5000 nm. Using more precise techniques such as SEM and TEM to study the morphology and size of the composite microspheres, spherical particles approximately 20-30 nm in diameter were observed interacting with each other to form larger aggregates, some amorphous and others spherical (Figures 1 and 2). These aggregates ranged from several hundred nanometers to micrometers, confirming the size distribution results obtained via DLS for the composite microspheres synthesized in the process.

[0182] Example 5: Determination of the Charge Distribution of Chitosan:Arabic Gum:Tripolyphosphate Particles

[0183] To determine the zeta potential, three measurements of 100 seconds each were performed at 25°C, with 10-second intervals between measurements, using a Horiba SZ- 100 analyzer. The average of these measurements is reported. The results for the different composite microspheres (MCS) containing 10% Arabic gum and varying TPP concentrations are shown in Table 2. The characterization results indicate that composite microspheres with Arabic gum and a TPP:CS ratio between 0.08 and 0.3 exhibit positive zeta potential values, whereas those with a TPP:CS ratio between 0.5 and 1.5 show negative values (Table 2). The inflection point appears to correspond to a TPP:CS ratio of 0.4, where the surface charge of the composite microspheres approaches neutrality, as the zeta potential value is around zero, considering the measurement error (±5 to ±10 mV). These results demonstrate that increasing TPP concentrations alters the zeta potential of the particle, thereby enabling the design of composite microspheres with a desired zeta potential by adjusting the TPP content.

[0184] Example 6: Morphological Characterization of Composite Microspheres Combined with Mancozeb

[0185] The morphology of composite microspheres combined with Mancozeb was characterized using electron microscopy techniques. The upper panels of Figure 3A display composite microspheres (MCS0.8-0.15) formulated with Mancozeb at different magnifications after 24 hours of contact between the two components. These images reveal a morphological transformation of the system, forming laminar structures resembling flower petals.

[0186] The lower panels of Figure 3A depict images of MCS0.8-0.15 composite microspheres obtained through different drying methods (lyophilization or spray drying). Figure 3B illustrates SEM images of Mancozeb alone (left panel) and MCS0.8-0.15 composite microspheres formulated with Mancozeb after 2 hours of contact (right panel). The latter image highlights how the microstructure of Mancozeb evolves in the presence of the particles, displaying a laminar microstructure (flower petal-like) alongside an intermediate microstructure (worm-like).

[0187] Example 7: Study of the Interaction Between Composite Microspheres and Agrochemicals

[0188] Additionally, studies were conducted to evaluate the interaction capacity of the composite microspheres with various agrochemicals in aqueous solution, aiming to determine the amount of active ingredient associated with the material. Nuclear Magnetic Resonance (NMR): Following the method described in "Probing interactions by means of pulsed field gradient nuclear magnetic resonance spectroscopy" by S. Cozzolino et al., Magn. Reson. Chem. 2008, 46, S16-S23, DOI: 10.1002 / mrc.2345, diffusion coefficients were calculated using NMR techniques. These coefficients allow the calculation of the association percentages (physico-chemical) of various analytes with the composite microspheres (MCS).

[0189] An analyte and a particle have unique diffusion coefficients in their free state, reflecting molecular weight and shape. When a complex forms, with strong binding between the analyte and particle, they share the same diffusion coefficient, as they diffuse as a single molecular entity. In cases of weak or negligible association, the diffusion coefficients remain unchanged. For other cases, assuming rapid exchange on the NMR timescale, the observed diffusion coefficient is a weighted average of the free and bound diffusion coefficients, enabling calculation of the bound fraction.

[0190] Diffusion coefficients were determined using a PFGSTE26 sequence on a Magritek Spinsolve80 Ultra, placing membrane strips in a 5-mm tube and operating at 26°C.

[0191] 1. Interaction with Glyphosate

[0192] For this study, samples MCS0.8-0.1 (with gum), MCS0.8-0 (without gum) from Example

[0193] 2, and glyphosate were used to evaluate the association percentage. Components were mixed in a laboratory test tube with distilled water and stirred manually for 1 minute. Suspensions were prepared for individual components and mixtures of each microparticle with glyphosate in a 1:5 mass ratio of glyphosate to microspheres.

[0194] In a second study, mixtures of glyphosate with MCSO.08-0.1, MCSO.8-0.1, and MCS1.2- 0.1 microspheres from Example 2 were prepared in a 10:1 mass ratio of glyphosate to microspheres.

[0195] Table 3. Association Percentages of Glyphosate (Negative Charge) with Composite Microspheres (MCS) Obtained via NMR Diffusion Coefficients

[0196] The results highlight that the highest association rate occurs with composite microspheres exhibiting a positive zeta potential, attributable to glyphosate's negative charge. It is also evident that the presence of gum decreases the association capacity between glyphosate and the microspheres, limiting the amount of gum that can be used. 2. Interaction with Mancozeb

[0197] Studies were conducted to evaluate the interaction capacity between composite microspheres and Mancozeb (MZ) in aqueous solution to determine the association percentage between the two materials.

[0198] For this study, samples MCSO.8-0.1 (with gum), MCS0.8-0 (without gum) from Example 2, and Mancozeb were used. Components were mixed in a laboratory test tube with distilled water and stirred manually for 1 minute. Suspensions were prepared for individual components and mixtures of each microparticle with Mancozeb in a 1:5 mass ratio of Mancozeb to microspheres.

[0199] Since Mancozeb is paramagnetic, the NMR signal reflects only the solvent, not Mancozeb's diffusion coefficient. By mixing it with the particles, the association percentage of microspheres with Mancozeb can be determined.

[0200] Table 4. Association Percentages of Composite Microspheres (MCS) with Mancozeb (MZ) Obtained via NMR Diffusion Coefficients

[0201] The results in Table 4 show that the presence of gum does not alter the association capacity between Mancozeb and the composite microspheres. Additionally, it was determined that the maximum effective amount of microspheres interacting positively with Mancozeb corresponds to a 2:1 mass ratio of microspheres to Mancozeb, as approximately 40% of the microspheres associated with Mancozeb (40% x 5:1 = 2:1 p / p).

[0202] Example 8: Herbicidal Activity Assay of Glyphosate Combined with Composite Microspheres (MCS) on Lettuce Plants {Lactuca sativa)

[0203] To evaluate whether chitosan:gum arabic:TPP composite microspheres enhance the herbicidal effect when formulated with Glyphosate, an assay was conducted where various concentrations of commercial herbicide were combined with composite microspheres and applied to lettuce plants under the following experimental protocol:

[0204] Lettuce plants (Lactuca sativa var. manteca) were grown for two weeks in pots measuring 7 x 9.5 x 4 cm, using commercial GrowMixMultipro substrate (25 g per pot) under controlled conditions of light (16:8 photoperiod), temperature (25°C), and humidity (60% relative humidity). After 14 days of growth, the plants were divided into five experimental groups, each containing 10 plants (5 x 10). Foliar spray treatments were applied as described in Table 5. Each plant received 0.2 mL of spray. Spray quality and calibration were verified using a hydrosensitive card. A plastic sprayer (PVC-EPA) was used for application.

[0205] Table 5. Treatments to Evaluate Herbicidal Efficacy of Different Glyphosate Concentrations Combined with MCS 0.8-0.1

[0206] For the application solutions, a stock solution of 5 mg / mL MCS was prepared. The required amount of MCS solution for the Glyphosate herbicide was calculated to maintain a 5% weight ratio of composite microspheres (MCS) relative to the acid equivalents (e.a.) of Glyphosate active ingredient present in the mixture. The application solutions were prepared in 15 mL or 50 mL Falcon tubes (Bio-Plast) depending on the required volume and agitated for 2 hours in an orbital shaker (Vicking, model: M23) before application.

[0207] Ten days after treatment application (10 DDA), 10 plants from each experimental group were analyzed, and their fresh leaf biomass was measured using an analytical balance (OHAUS, model Traveler TA302).

[0208] Representative plants from each treatment are shown in Figure 4, and the average weight (with standard deviation) of 10 plants per treatment is presented in Figure 5.

[0209] Results and Analysis:

[0210] • Applying the full dose of herbicide (1 L ha-1Glyphosate) reduced fresh biomass by 62% relative to the water control (H2O).

[0211] • Plants treated with 0.5 L ha-1Glyphosate showed a 30% reduction in biomass compared to the control (Figure 5).

[0212] • Plants treated with 0.5 L ha"1Glyphosate + 5% MCS 0.8-0.1 exhibited a 51% reduction in biomass compared to the control. This represents a 21% increase in herbicide efficacy compared to the same concentration of Glyphosate without MCS 0.8-0.1. In percentage terms, the use of the invention's formulation with 5% chitosan composite microspheres (MCS) enhanced the herbicidal power of Glyphosate by 70%. The formula for calculating the enhancement is as follows:

[0213] Enhancement (%)=( Effect with MCS-Effect without MCS)Effect without MCSxlOO lOOEnhancement (%)=Effect without MCS(Effect with MCS-Effect without MCS)xl00

[0214] Using this formula: (51-30) / 30xl00=70%

[0215] Control plants treated with 5% MCS 0.8-0.1 without Glyphosate did not show visible phytotoxic effects or biomass reduction.

[0216] Conclusion:

[0217] This assay demonstrates that adding MCS 0.8-0.1 at a 5% concentration (which has no herbicidal activity per se) significantly increases herbicidal efficacy, allowing the Glyphosate application dose to be reduced by up to 50%. This is evidence of a surprising and unprecedented synergistic effect.

[0218] Example 9: Herbicidal Activity Assay of Glyphosate Combined with Composite Microspheres of Different TPP Concentrations on Wheat (Triticum aestivum) Used as a Target Plant (Simulating Weeds)

[0219] The study evaluated whether the surface charge (zeta potential) of the chitosan composite microspheres differentially affects the efficacy of glyphosate on wheat plants grown in petri dishes under controlled environmental conditions.

[0220] The experimental design was as follows: wheat seeds were sterilized with 20% (v / v) bleach and evenly sown in sterile petri dishes (90 mm x 15 mm, Bio-Plast) containing filter paper moistened with 5 ml of sterile water. The seeds were germinated and grown for 8 days under controlled light, temperature, and humidity conditions. After this period, the treatments were applied via foliar spray using the solutions described in Table 6. A PVC-EPA sprayer was used for application, with a spray volume of 0.8 ml per dish. Table 6. Treatments to evaluate the potentiating effect of composite microspheres MCS 0.8-0.1 and MCS 0.08-0.1 on the herbicidal efficacy of glyphosate applied to wheat plants.

[0221] An aqueous solution of 5 mg / ml MCS was initially prepared. The required amount of MCS solution (depending on the treatment) was combined with the tested doses of glyphosate. The solutions were placed on an orbital shaker (Vicking, model: M23) for 2 hours. Six days after treatment (6 DDA), the plants were harvested and weighed using a precision balance (OHAUS, model Traveler TA302) to quantify the fresh biomass of the aerial part. The average foliar biomass per plant was estimated (Figure 6).

[0222] Plants treated with 1 L ha"1glyphosate showed a 28% (w / w) reduction in dry foliar biomass compared to the H2O control (Figure 6). Plants treated with 5% MCS 0.08-0.1 + 1 L ha"1glyphosate exhibited a biomass reduction of 40.56% (w / w) relative to the same control (H2O). In relative terms, the use of the invention's formulation with 5% MCS 0.08-0.1 composite microspheres enhanced the herbicidal power of glyphosate by 45%; the biomass reduction increased from 28% (w / w) without MCS 0.08-0.1 to 40.56% (w / w) with MCS 0.08-0.1. Thus, the MCS boosted the original power of glyphosate by 45%.

[0223] Potentiation: ((40.56-28) / 28) x 100 = 45%

[0224] In this document, we define this indicator of relative enhancement of the herbicide's power as potentiation. Thus, in this assay, the use of MCS 0.08-0.1 potentiated the herbicide formulation by 45% compared to the herbicide alone without the addition of composite microspheres (MCS). In plants treated with 5% MCS 0.8-0.1 + 1 L ha"1Glyphosate, the biomass reduction was 32.24% (w / w) relative to the H2O control. This implies that the combination of 5% MCS 0.08-0.1 with 1 L ha"1Glyphosate showed an absolute difference compared to glyphosate alone of 32.24-28: 4.24%. The addition of 5% MCS 0.8-0.1 to glyphosate increased its herbicidal effect by ((32.24-28) / 28) x 100: 15%.

[0225] In relative terms, the use of the invention's formulation with 5% composite microspheres (with 80% TPP mass relative to chitosan) increased the herbicidal power of glyphosate by 15%.

[0226] In this document, we define this calculation of the relative increase in the herbicide's power as enhancement. Thus, in this assay, the use of MCS 0.8 provided the invention's herbicide formulation with a 15% enhancement.

[0227] It can be observed that MCS with 0.08 TPP, which have a positive zeta potential, generate better enhancement than MCS with 0.8 TPP, which have a negative zeta potential. This could be due to the fact that glyphosate carries a negative charge, which may facilitate a greater loading of the active ingredient onto the composite microsphere, resulting in improved herbicidal efficacy.

[0228] Example 10: Field Trials of Glyphosate Herbicidal Activity Combined with Composite Microspheres for Different Weeds

[0229] Independent field trials were conducted in various locations within Argentina. In all trials, glyphosate was formulated at different concentrations, always combined with composite microspheres MCS 0.8-0.1 dried using the spray-drying method. Different weeds were tested, and measurements were taken at various intervals post-treatment.

[0230] The following general protocol was used for the trials: The experiments were carried out during the summer (2023 / 2024) in Argentina, evaluating glyphosate's herbicidal activity in chemical fallow. The experimental design consisted of microplots of 3 m wide by 8 m long, with three randomized replicates. Different solutions were applied to the fallow using a CO2backpack sprayer at constant pressure. Table 7 describes the treatments evaluated. Treatments were randomly assigned to ensure equal representation of each experimental group (n = 3). Weed control percentage was quantified at different intervals after treatment application (DDA). The percentage of weed control was calculated by comparing treated plots to untreated plots, following periodic assessments as per EWRS (European Weed Research Society) guidelines. Monthly and cumulative precipitation during the growing season were recorded.

[0231] Table 6. Treatments for evaluating the efficacy of Glyphosate combined with composite microspheres MCS 0.8-0.1

[0232] 1. Location: Adolfo Gonzales Chaves

[0233] Plot Coordinates: 38°09'39.93"S / 59°45'42.70"W Application Conditions: Conducted with a CO2backpack sprayer equipped with a 2 m boom, flat fan nozzle, applying 110 L / ha of spray volume at 2 bars of pressure.

[0234] Weeds Tested: Cynodon dactylon (Bermuda grass)

[0235] In Figure 7, the average results for n = 3 per treatment are shown, displaying weed control percentages compared to untreated plots at two intervals post-treatment: 7 and 14 days. Treatments with glyphosate at the full dose of 1500 e.a. ha-1combined with composite microspheres (5% and 10% w / e.a.) showed slightly higher control percentages compared to glyphosate alone at the same dose. On the other hand, treatments with a dose of 900 e.a. ha"1combined with composite microspheres (5% and 10% w / e.a.) (treatments 4 and 5, respectively) achieved control percentages comparable to those of the full dose of glyphosate alone (treatment 1).

[0236] • Brassica rapa "elongated" (Wild turnip)

[0237] In Figure 8, the average results for n = 3 per treatment are shown, with weed control percentages relative to untreated plots at 7 and 14 days post-treatment. Treatments 4, 5, 6, and 7 exhibited herbicidal activity percentages similar to those of treatment 1 (1500 e.a. ha-1glyphosate alone).

[0238] Both trials demonstrated that the combination of composite microspheres with glyphosate allows for at least a 40% reduction in application dose, as the herbicide's efficacy is enhanced to match the levels of the highest doses tested.

[0239] 2. Location: Tres Arroyos

[0240] Plot Coordinates: -38.602085°, -59.960860°

[0241] Application Conditions: Constant-pressure backpack sprayer equipped with a carbon fiber lateral boom with four hollow cone nozzles spaced 52 cm apart, applying a volume of 100 L / ha at 3 bars of pressure.

[0242] Weeds Tested: Datura ferox (Thorn apple)

[0243] Glyphosate was applied per label recommendations (1500 e.a. ha"1Glyphosate) and compared to the following applications of the invention's formulation: o 900 e.a. ha-1Glyphosate + 5% MCS 0.8: At 19 days post-application, the same herbicidal effect was observed, indicating a 40% reduction in glyphosate dose can achieve equivalent herbicidal potency. o 900 e.a. ha-1Glyphosate + 10% w / w MCS 0.8: At 19 and 28 days postapplication, a 15% enhancement of herbicidal effect was observed compared to traditional glyphosate application (#1). o 1500 e.a. ha-1Glyphosate + 10% w / w MCS 0.8: At 19 days postapplication, herbicidal power was enhanced by 40%, and at 28 days, it was enhanced by 15%.

[0244] • Chenopodium album (Lamb's quarters)

[0245] Glyphosate was applied per label recommendations (1500 e.a. ha"1Glyphosate) and compared to the following applications of the invention's formulation: o 720 e.a. ha"1Glyphosate + 5% w / w MCS 0.8: At 7 days post-application, a 5% enhanced herbicidal effect was observed with a glyphosate dose 48% lower than the label recommendation, indicating a 52% dose reduction achieves superior potency. o 1500 e.a. ha"1Glyphosate + 10% w / w MCS 0.8: At 7 days postapplication, herbicidal power was enhanced by 10%.

[0246] 3. Location: 9 de Julio

[0247] Plot Coordinates: 35°23'12.86"S; 61°00'41.64"W

[0248] Application Conditions: Manual constant-pressure CO2backpack sprayer equipped with a boom with four hollow cone nozzles (80015), applying 100 L / ha at 2.5 bars of pressure. Weeds Tested:

[0249] • Eleusine indica (Goose grass)

[0250] Glyphosate was applied per label recommendations (1500 e.a. ha"1Glyphosate) and compared to the following applications of the invention's formulation: o 900 e.a. ha"1Glyphosate + 5% w / w MCS 0.8 o 900 e.a. ha"1Glyphosate + 10% w / w MCS 0.8

[0251] At 14 days post-application, a 24% enhanced herbicidal effect was observed with a glyphosate dose 40% lower than the label recommendation. At 21 days, the control of Eleusine indica was 63% with the label dose of glyphosate alone. Adding 5% (w / e.a. Glyphosate) MCS 0.8 increased weed control to 72%, representing a 9% increase in glyphosate efficacy. Furthermore, adding 5% (w / e.a. Glyphosate) MCS 0.8 to a reduced glyphosate dose (40% lower than the full dose) achieved 70% weed control, demonstrating that MCS allows at least a 40% reduction in glyphosate dose under field conditions.

[0252] Example 11: Field Trial of Herbicidal Activity of Glyphosate and Choline Salt of 2,4-D Combined with Composite Microspheres on Weeds

[0253] Independent field trials were conducted in various locations in Argentina. In all trials, glyphosate and / or choline salt of 2,4-D were formulated at different concentrations, always combined with composite microspheres MCS 0.8-0.15 dried using the spray method. The trials targeted the weed Conyza sumatrensis (Black Horseweed), and measurements were taken at various intervals post-treatment.

[0254] The following general protocol was used: The trials were carried out during the summer in Argentina to evaluate glyphosate's herbicidal activity on chemical fallow. The experimental design consisted of microplots measuring 3 m wide by 8 m long, with three randomized replicates. Different solutions were applied to the fallow using a constantpressure CO2backpack sprayer. Table 7 describes the treatments evaluated. Treatments were randomly assigned to ensure equal representation of each experimental group (n = 3). Weed control percentages were quantified at different intervals after treatment application (DDA). Weed control percentages were calculated relative to untreated control plots, following periodic assessments as per EWRS (European Weed Research Society) guidelines. Monthly and cumulative precipitation during the growing season were recorded.

[0255] Table 7. Treatments to evaluate herbicidal activity in formulations of Glyphosate and Glyphosate combined with Choline Salt of 2,4-D (2,4-D) and composite microspheres MCS 0.8-0.15

[0256] Location: Tres Arroyos

[0257] Plot Coordinates: -38.388612; -60.346111

[0258] Application Conditions: Manual backpack sprayer with a 2 m wide boom, equipped with TeeJet 80015 nozzles, operating at constant pressure of 2.5 bars via CO2, and applying 126 L / ha spray volume. Visual control measurements were taken at 10, 20, 30, and 50 days after application (DDA). Data were analyzed using ANOVA, and means were compared using Fisher's LSD test (p < 0.05).

[0259] Weed Tested: Conyza sumatrensis (Black Horseweed)

[0260] Table 8. Control of Black Horseweed with formulations of Glyphosate and Glyphosate + Choline Salt of 2,4-D (2,4-D) combined with composite microspheres MCS 0.8-0.15

[0261] These results demonstrate the residual power of the present invention.

[0262] Example 12: Field Trial Evaluating the Herbicidal Efficacy of Ammonium Glufosinate

[0263] Combined with Composite Microspheres on Black Horseweed A field trial was conducted to evaluate the herbicidal effect of ammonium glufosinate at different concentrations, both alone and combined with composite microspheres MCS 0.8-0.15 dried using the spray method. The trials targeted the weed Conyza sumatrensis (Black Horseweed), and measurements were taken at various intervals post-treatment.

[0264] The following general protocol was used: The trials were carried out during the summer in Argentina to evaluate the herbicidal activity of ammonium glufosinate on chemical fallow. The experimental design consisted of microplots measuring 3 m wide by 8 m long, with three randomized replicates. Different solutions were applied to the fallow using a constant-pressure CO2backpack sprayer. Table 9 describes the treatments evaluated. Treatments were randomly assigned to ensure equal representation of each experimental group (n = 3). Weed control percentages were quantified at different intervals after treatment application (DDA). Weed control percentages were calculated relative to untreated control plots, following periodic assessments as per EWRS guidelines. Monthly and cumulative precipitation during the growing season were recorded.

[0265] Location: Bragado

[0266] Plot Coordinates: -35.0804.3S; -60.33043.6W

[0267] Application Conditions: Manual backpack sprayer with a 2 m wide boom, equipped with TeeJet 80015 nozzles, operating at constant pressure of 2.5 bars via CO2, and applying 126 L / ha spray volume. Visual control measurements were taken at 7 and 25 days after application (DDA). Data were analyzed using ANOVA, and means were compared using Fisher's LSD test (p < 0.05).

[0268] Weed Tested: Conyza sumatrensis (Black Horseweed)

[0269] Table 9. Control of Black Horseweed with Different Formulations of Ammonium Glufosinate Combined with Composite Microspheres MCS 0.8-0.15. % Control for the Different Treatments Tested.

[0270] The inclusion of the microspheres, respecting the weight-to-weight ratio of microspheres to the active ingredient in each mixture (i.e., p / p MCS / Ammonium Glufosinate), demonstrated higher efficacy, faster weed desiccation, and reduced weed regrowth rates. The treatment that included the composite microspheres of the present invention increased efficacy compared to ammonium glufosinate applied alone, even at a dose lower than the full commercially recommended dose (2 L / ha).

[0271] Example 13: Stability Test of Composite Microspheres During Synthesis and Redispersion of Microspheres Before Application by Adding Gum

[0272] The formulation corresponding to Treatment 3 from Table 7 of Example 10— Glyphosate + 2,4-D Choline Salt in equal parts— was applied along with 5% and 10% of the composite microspheres of the invention defined in Test 4 from Table 1 of Example 2, i.e., MCS 0.8- 0 microspheres with a chitosan:gum:TPP mass ratio of 1:0:0.8 (without gum), using a portable backpack sprayer. It was observed that the spray nozzle filters became clogged by particles, as shown in Figure 9. This clogging was attributed to the low redispersion capability of the microspheres of the invention in the absence of gum.

[0273] When the test was repeated using microspheres from Test 4 of Table 1 of Example 2— MCS 0.8-0.1, containing a gum concentration of 10% relative to the mass of chitosan— the spray nozzles did not clog, and filter cleaning was not required.

[0274] Figure 10 demonstrates that a gum concentration between 5% and 20% improves the formation of the microspheres of the invention. Example 14: Fungicidal Activity Test of Mancozeb Combined with Composite Microspheres on Botrytis cinerea

[0275] In vitro tests were conducted to evaluate the fungicidal activity of Mancozeb, alone or combined with composite microspheres (MCS), on spores of Botrytis cinerea, an agronomically relevant fungus that particularly affects strawberry and grape crops. The B. cinerea spores used in all tests were obtained from a culture grown on potato dextrose agar (15 g / L agar, 20 g / L dextrose, 4 g / L potato extract). The spores were harvested, suspended in water, and quantified using a Neubauer chamber.

[0276] Spores in a suspension of 2 x 105spores / mL were incubated in multiwell plates (30 mm x 100 mm x 6 mm; Marienfield Superior) containing water as a control orthe treatments listed in Table 10: 25 pg / mL Mancozeb (MZ), 25 pg / mL composite microspheres MCS 0.8-0.1, or a combination of 25 pg / mL MZ + 25 pg / mL MCS 0.8-0.1. All incubations were conducted in the dark at 23°C for 24 hours. A sucrose concentration of 2% (w / v) was added to each incubation solution. For the combination of MZ + MCS 0.8-0.1 (Treatment 4), both compounds were pre-incubated together for 24 hours before application to the spores.

[0277] Table 10. Treatments for Evaluating the Fungicidal Efficacy of Mancozeb Formulations

[0278] Combined with MCS 0.8-0.1 on B. cinerea Spores.

[0279] At the time of quantification and analysis, spores subjected to each of the treatments and controls were collected from three independent replicates (three wells per treatment, n = 3) and observed under a light microscope (Eclipse E200, Nikon). For each treatment, the percentage (%) of spore germination was quantified. Spores were considered germinated when the length of the germ tube was greater than half the length of the conidium [Plascencia-Jatomea et al., 2003]. Three independent photographs were taken from each replicate, and the quantified germination percentages were averaged across the replicates. At least 100 spores were counted for each replicate corresponding to each treatment. A value of 100% fungicidal activity for a treatment indicates 0% spore germination after 24 hours of incubation.

[0280] Treatments with 25 pg / mL MZ or 25 pg / mL MCS 0.8-0.1 showed residual fungicidal activity against B. cinerea spores, very similar to that observed in the water control incubation (Figure 11). The combination of 25 pg / mL MCS 0.8-0.1 + 25 pg / mL MZ resulted in a 73% increase in the efficacy of MZ compared to the action of MZ without MCS. The addition of composite microspheres enhanced the fungicidal effect of Mancozeb.

[0281] This result is extraordinary and demonstrates an astonishing synergy between a fungicide like Mancozeb and the composite microspheres of the invention. Considering potentiation as the percentage improvement in the fungicidal action of an active fungicide due to the addition of the microspheres of the invention, this case demonstrates a 1460% potentiation. Since the fungicidal effect of Mancozeb alone is 5%, and the effect of the combination is 78%, the fungicidal effect of Mancozeb is enhanced by the increase divided by the fungicidal effect of the active alone, multiplied by 100. That is:

[0282] Potentiation= ((Effect of the invention - ) / Effect of fungicide alone) X 100

[0283] In this example:

[0284] Potentiation=((78-5) / 5xl00=1460% This is absolutely disruptive.

[0285] Example 15: Fungicidal activity assay of Mancozeb combined with composite microspheres at different preincubation times with the fungicide

[0286] To evaluate the influence of preincubation time or contact between the fungicide and the composite microspheres (MCS), an experimental design was conducted comparing the fungicidal activity of formulations at 2, 4, and 24 hours on B. cinerea. The B. cinerea spores used in all assays were obtained from a culture grown on potato dextrose agar (15 g L“1agar, 20 g L“1dextrose, 4 g L“1potato extract). The spores were harvested, suspended in water, and quantified using a Neubauer chamber. The spores in a suspension of 2 x 105spores / mL were incubated in 30 mm x 100 mm x 6 mm multiwell plates (Marienfield Superior) containing water as a control or the treatments: 25 pg / mL Mancozeb (MZ), 25 pg / mL composite microspheres (MCS), or the combination of 25 pg / mL MZ + 25 pg / mL MCS (in all cases) in darkness at 23°C for 24 hours (Table 11). A 2% w / v sucrose solution was added to each incubation solution. In this experimental setup, different preincubation times of the formulation (MZ + MCS) were tested: 2, 4, and 24 hours before application to the spores. Two composite microspheres with different TPP concentrations, MCSO.08-0.1 and MCS0.8-0.1, were tested.

[0287] Table 11. Treatments to evaluate fungicidal efficacy in formulations of Mancozeb combined with MCS at different preincubation times on B. cinerea spores

[0288] At the time of quantification and analysis, spores subjected to each treatment and control were collected from three independent replicates (three wells per treatment, n = 3) and observed under a light microscope (Eclipse E200, Nikon). For each treatment, the percentage (%) of spore germination was quantified. Spores were considered germinated when the length of the germ tube was greater than half the conidial length [Plascencia-Jatomea et al., 2003], Three independent photographs were taken for each replicate, and the quantified germination percentages were averaged. A minimum of 100 spores per replicate corresponding to each treatment were counted. A value of 100% fungicidal activity for a treatment indicates 0% spore germination after 24 hours of incubation.

[0289] In Figure 12, it can be observed that at short preincubation times (2 and 4 hours) of the composite microspheres MCS0.08-0.1 and MCS0.8-0.1 with Mancozeb, the fungicidal activity does not exceed 20% effectiveness. However, with a preincubation of 24 hours before application, effectiveness increases to approximately 75% and 95% for MCS0.08- 0.1 and MCS0.8-0.1, respectively. This assay demonstrates that the enhanced effectiveness of Mancozeb is surprisingly increased when the particles are preincubated with Mancozeb for at least 24 hours.

[0290] Example 16: Fungicidal activity assay of Mancozeb combined with composite microspheres with different TPP concentrations on B. cinerea spores

[0291] To evaluate whether the TPP content influences the fungicidal enhancing effect of the particles on Mancozeb, formulations of Mancozeb combined with different composite microspheres (MCS0.08-0.1, MCS0.3-0.1, MCS0.5-0.1, MCS0.8-0.1, and MCS1.2-0.1) were tested. The B. cinerea spores used in all assays were obtained from a culture grown on potato dextrose agar (15 g L“1agar, 20 g L“1dextrose, 4 g L-1potato extract). The spores were harvested, suspended in water, and quantified using a Neubauer chamber. The spores in a suspension of 2 x 105spores / mL were incubated in 30 mm x 100 mm x 6 mm multiwell plates (Marienfield Superior) containing water as a control or the treatments: 25 pg / mL Mancozeb (MZ), 25 pg / mL composite microspheres (MCS), or the combination of 25 pg / mL MZ + 25 pg / mL MCS (in all cases) in darkness at 23°C for 24 hours (Table 12). A 2% w / v sucrose solution was added to each incubation solution. In this experimental setup, different preincubation times of the formulation (MZ + MCS) were tested: 2 and 24 hours before application to the spores. Particles with different TPP concentrations— MCSO.08-0.1, MCS0.3-0.1, MCS0.5-0.1, MCS0.8-0.1, and MCS1.2- 0.1— were tested. Table 12. Treatments to evaluate fungicidal efficacy in formulations of Mancozeb combined with MCS at different TPP concentrations on B. cinerea spores

[0292] At the time of quantification and analysis, spores subjected to each treatment and control were collected from three independent replicates (three wells per treatment, n = 3) and observed under a light microscope (Eclipse E200, Nikon). For each treatment, the percentage (%) of spore germination was quantified. Spores were considered germinated when the length of the germ tube was greater than half the conidial length [Plascencia-Jatomea et al., 2003], Three independent photographs were taken for each replicate, and the germination percentages were averaged. A minimum of 100 spores per replicate corresponding to each treatment was counted. A value of 100% fungicidal activity for a treatment indicates 0% spore germination after 24 hours of incubation.

[0293] In Figure 13, it is observed that free MZ (without MCS) applied at a concentration of 25 pg / mL exhibits antifungal activity not exceeding 6%. Consistent with the results of the assay in Example 14, preincubation of Mancozeb with the particles for 24 hours achieves fungicidal activity ranging from 80% to 93% for particles tested with different TPP concentrations.

[0294] This assay confirms that the preincubation time before applying Mancozeb and MCS formulations is critical. Specifically, for Mancozeb, the TPP concentration did not significantly influence fungicidal activity. A synergistic effect of the formulations with particles increases the fungicidal effect between 14X and 16X compared to free Mancozeb. That is, the enhancing effect of the composite microspheres of the invention ranges from 1233% to 1450% compared to Mancozeb alone if the invention's formulation is mixed approximately 24 hours prior. Conversely, if the invention's formulation is mixed only two hours before application, the enhancement ranges from 230% to 300%. A particularly significant antifungal enhancing effect is observed with particles of different TPP concentrations, particularly in assays 5 and 7, where after two hours of contact between MZ and the invention's composite microspheres, enhancement reaches approximately 300%, achieving nearly 20% fungicidal power compared to 6% for MZ alone. Example 17: Use Case MZ + MCS 0.8 Field Trial for the Control of Foliar Diseases (Alternaria and Phytophthora infestans) in Potato Crops

[0295] The objective is to evaluate the yield response and health performance of a potato crop using carrier technology as a biological fungicide for the control of foliar diseases (Alternaria and Phytophthora infestans).

[0296] The synergistic effect between MZ and MCS 0.8-G (without gum arabic) on the growth of phytopathogenic fungi in potato crops and the harvest yield was assessed.

[0297] A randomized complete block design with four replicates was used. Each plot consisted of four furrows, 5 meters in length, separated by 85 cm. "Pre-foundation category" Innovator variety seed potatoes were planted, with 5 cuts per linear meter. Four treatments were evaluated, as indicated in Table 13. The treatments were sprayed using a constant-pressure backpack sprayer with a CO2source.

[0298] Table 13. Treatments to evaluate the yield response and health performance of a potato crop treated with MZ and MCS 0.8.

[0299] Data on agronomic (vigor) and health aspects were collected during the crop cycle. Severity, incidence, and product control efficacy for the evaluated diseases were estimated.

[0300] Once the growth period ended, the yield was weighed, and commercial yield was calculated by subtracting the yield of tubers smaller than 50 mm, rotted tubers, and those with defects from the total yield. The crop developed without health problems, with good plant development. There was no water deficit during the crop cycle, and the plants remained vigorous, followingtheirgrowth cycle. No climatic, health, or nutritional events affected normal development, and full surface coverage was achieved in the trial.

[0301] Crop yield was quantified, distinguishing between total yield (gross production) and commercial yield (production meeting commercial standards and therefore suitable for marketing).

[0302] Table 14. Total and Commercial Yield of Potato Crops Obtained for Each Treatment Tested By using 60% less MZ than the labeled dose or full dose (i.e., 50 g instead of 125 g of MZ per 20 liters of formulation) and mixing it with 5% by weight of the invention's composite microspheres without dispersant (no gum), potato production increased by 20%. This is another common way of measuring fungicide efficacy: the difference in yield since fungi drastically reduce crop productivity.

[0303] Example 18: Use of Cripton for Controlling Yellow Spot and Yellow Rust in Wheat: Cripton™ + MCS 0.8-0.1 Field trials were conducted to control yellow spot (Drechslera tritici-repentis) and yellow rust (Puccinia striiformis) in wheat crops in Miramar, Buenos Aires Province, Argentina. The final yield of treated plots was measured.

[0304] Cripton™ is a commercial fungicide from Bayer, composed of Prothioconazole (17.5%) and Trifloxystrobin (15%). In all cases, it was applied with the commercial adjuvant Optimizer™ at a rate of 300 cc / ha.

[0305] Table 15. Field Trials

[0306] Foliar application was carried out at the flag leaf stage (Zadoks 39). At harvest, the yield was determined in kg / ha, corrected for moisture (14%).

[0307] Using a lower dose of Cripton (500 cc / ha) in combination with the invention's composite microsphere (MCS 0.8-0.1) achieved yields similar to those obtained with the higher dose of Cripton alone, allowing a 29% reduction in fungicide dose.

[0308] Example 19: Herbicidal Activity Assay of Dicamba Combined with Particles in Tomato Plants (Solanum lycopersicum)

[0309] Tomato seeds were sterilized with 20% bleach (v / v) and evenly sown in polypropylene trays containing 22 grams of GrowMix Multipro substrate (2.5 g of seeds per tray). Seeds were germinated and grown for 14 days under controlled light, temperature, and humidity conditions as previously described. After this period, each treatment was applied by foliar spraying using the solutions described in Table 17. A PVC sprayer (EPA brand) was used for application. The application volume for each solution was 0.8 ml per tray. Table 17. Treatments to Evaluate the Herbicidal Activity of Dicamba Combined with MCS on Tomato Plants

[0310] To prepare the application solutions, the required amount of MCS solution (as per the treatment) was mixed with the specified dose of Dicamba. Once each mixture was prepared, it was placed on an orbital shaker (Vicking, model: M23) for 2 hours. After 8 days from the start of treatments (8 DAA), plants were harvested and dried in an oven (San Jor, model SE60A) at 40°C for 6 days before weighing with an analytical balance (Sartorius, model BCE224I-1S) to quantify the aerial dry biomass. Foliar biomass per plant was estimated.

[0311] In Figure 14, it is shown that plants treated with 2 L ha-1Dicamba exhibited a 39% reduction in dry foliar biomass compared to the H2O control. Plants treated with 0.8 L ha"1Dicamba alone showed a 12% biomass reduction relative to the same control (H2O). These percentages correspond to agrochemical efficacy, in this case herbicidal activity.

[0312] For plants treated with the invention formulation of 5% MCS 0.8 + 0.8 L ha"1Dicamba, foliar biomass was reduced by 30.8% compared to the same control (H2O), whereas Dicamba alone at the same concentration reduced biomass by only 12%. The combination of 5% MCS 0.8 with 0.8 L ha"1Dicamba, forming the formulation of the present invention, demonstrated a 19% increase in herbicide efficacy compared to the same Dicamba dose without MCS (Figure 15).

[0313] These results indicate that the microspheres enhanced Dicamba's herbicidal effect in 157%:

[0314] Potentiation=(30.8-12) / 12)xl00=157% The surprising effect of adding the composite microspheres to the agrochemical Dicamba significantly enhanced its herbicidal activity.

[0315] Example 20: Field Herbicidal Activity Assay of Dicamba Combined with Composite Microspheres on Soybean Weeds

[0316] Field trials were conducted to evaluate the enhancing effect of composite microspheres combined with the herbicidal agrochemical Dicamba. In all trials, Dicamba was formulated at two concentrations, always combined with composite microspheres MCS 0.8-0.1 dried by the spray method. Trials targeted soybean weeds, and measurements were taken at different days post-treatment.

[0317] General Protocol:

[0318] The trials were conducted during the summer (2023 / 2024) in Argentina. Herbicidal activity of Dicamba on soybean weeds was evaluated. The design consisted of microplots measuring 3 meters wide by 8 meters long, with three randomized replications. Different solutions were applied to the fallow soil using a CO2-pressurized backpack sprayer. Table 18 describes the evaluated treatments. Treatments were randomly assigned to represent each experimental group equally (n = 3). The weed control percentage was measured 7 and 13 days after application (DDA). Weed control percentage for a treatment was estimated relative to untreated weeds. Measurements were conducted periodically following EWRS (European Weed Research Society) standards. Monthly and accumulated precipitation during the growing season was recorded.

[0319] Table 18. Treatments to Evaluate Dicamba Combined with Composite Microspheres

[0320] MCS 0.8-0.1 and Weed Control % at 7 and 13 Days After Application (DDA)

[0321] Results and Observations:

[0322] The trials targeted soybean weeds. The increase in weed control percentage was used as an indicator of enhanced herbicidal activity.

[0323] The enhancing effect of microspheres at 5% or 10% w / w concentration is evident. Treatments with added composite microspheres showed increased efficacy at 13 DDA. At 13 DDA, weed control percentages were 69% and 72% with the addition of 5% and 10% composite microspheres, respectively, compared to 60% for the same treatment without microspheres.

[0324] This represents an increase of 12% in weed control percentage. Based on these results, the microspheres enhanced Dicamba's herbicidal effect by 20%.

[0325] Example 21: Insecticidal Activity Assay of Engeo S (14.1% Thiamethoxam + 10.6% Lambda-Cyhalothrin) Combined with MCS

[0326] Field trials were conducted to evaluate the enhancing effect of composite microspheres combined with the insecticide Engeo. The trials were carried out in San Francisco, Cordoba, targeting stink bug complexes (Nezara viridula, etc.) in soybean crops. The evaluated treatments are described in Table 19 below:

[0327] Table 19. Treatments to Evaluate the Efficacy of Engeo Combined with Composite Microspheres MCS 0.8-0.1

[0328] In this trial, the efficacy of the treatments (number of stink bugs after treatment relative to the number of stink bugs before application) was measured 3 days after application (3 DAA). Table 19 shows the results, where the addition of composite microspheres increased the efficacy of the insecticide, achieving maximum control values 3 days after application. This represents a 28% enhancement.

[0329] Example 22: Insecticidal Activity Assay of Coragen (20% Chlorantraniliprole) Combined with MCS Field trials were conducted to evaluate the enhancing effect of composite microspheres combined with the insecticide Coragen. The trials were carried out in San Francisco, Cordoba, targeting armyworms (Rachiplusia nu) in soybean crops. Treatments included full doses of Coragen (50 cc / ha) alone or with the addition of 5% and 10% MCS, as well as a reduced dose with 10% MCS. The treatments and efficacy results (number of armyworms present after application relative to the number present before application) were measured at 3 and 7 days post-application (DAA), as shown in Table 20.

[0330] Table 20. Treatments to Evaluate the Efficacy of Coragen Combined with Composite Microspheres MCS 0.8-0.1

[0331]

[0332] Results and Observations:

[0333] • The addition of 5% w / w MCS improved the performance of the full dose of Coragen at 3 DAA by 5.1%, while 10% w / w MCS improved it by 5.8%. At 7 DAA, all treatments achieved 100% control of armyworms.

[0334] • Treatment 4, which used 10% w / w microspheres and a 64% reduced dose of insecticide compared to the full dose, showed similar results to Treatment 1.

[0335] These findings demonstrate the significant dose-reduction capability provided by the composite microspheres, enabling effective pest control with substantially lower amounts of insecticide.

[0336] Example 23: Biofungicide Activity Assay Combined with MCS

[0337] Field trials were conducted to evaluate the enhancing effect of composite microspheres combined with a commercial biofungicide (BF). The percentage of control was assessed based on the hyphal length of Botrytis cinerea. Table 21 shows the treatments tested.

[0338] Table 21. Treatments to Evaluate the Efficacy of Commercial Biofungicide (BF)

[0339] Combined with Composite Microspheres MCS 0.8-0.1

[0340] A lower percentage of hyphal growth indicates greater efficacy of the agrochemical formulation of the invention. As observed in Table 21, the addition of BF at different doses reduced hyphal growth compared to the control, with a clear dose-dependent effect. • The hyphal inhibition was 29% (100-71) for Treatment 2 with 100 ml L~1BF.

[0341] • When a formulation of the invention (Treatment 4) containing 100 ml L~1BF and 10 pg ml-1MCS was prepared, the inhibition percentage (efficacy) increased to 63% (100-37).

[0342] These results indicate that the composite microspheres of the invention enhanced the fungicidal effect of BF by 117%, calculated as:

[0343] Enhancement=(63-29)29xl00=117%

[0344] Example 24: Activity Assay of a Biofertilizer: Bioelicitor Combined with MCS

[0345] Field trials were conducted to evaluate the enhancing effect of composite microspheres combined with the bioelicitor Howler. The yield during the R1 phase of soybean crops was assessed. Table 22 shows the treatments tested.

[0346] Table 22. Treatments to Evaluate the Efficacy of Bioelicitor Howler Combined with

[0347] Composite Microspheres MCS 0.8-0.1

[0348] The incorporation of microspheres into Howler resulted in yield increases of 10% and 14% with the addition of 5% and 10% of particles, respectively. This indicates that the agrochemical active ingredient was enhanced by up to 15%.

[0349] References

[0350] 1. Oerke E-C. Crop losses to pests. The Journal of Agricultural Science. 2006;144(l):31-43. doi:l 0.1017 / S0021859605005708 .

[0351] 2. Fisher, M., Henk, D., Briggs, C. et al. Emerging fungal threats to animal, plant and ecosystem health. Nature 484, 186-194 (2012). https: / / doi.org / 10.1038 / naturel0947

[0352] 3. Agrios, G.N. Introduction to Plant Pathology, 5th ed.; Elsevier Academic Press Publication: New York, NY, USA, 2005; p. 922.

[0353] 4. Vinutha, J.S.; Bhagat, D.; Bakthavatsalam, N. Nanotechnology in the management of polyphagous pest Helicoverpa armigera. J. Acad. Ind. Res. 2013, 1, 606-608.

[0354] 5. Dhekney, S.A.; Li, Z.T.; Van Aman, M.; Dutt, M.; Tattersail, J.; Kelley, K.T.; Gray, D.J. Genetic transformation of embryogenic cultures and recovery of transgenic plants in Vitis vinifera, Vitis rotundifolia and Vitis hybrids. In Proceedings of the International Symposium on Biotechnology of Temperate Fruit Crops and Tropical Species, Daytona Beach, FL, USA, 10-14 October 2005; Volume 738, pp. 743-748.

[0355] 6. Fernandez-Perez, M.; Gonzdlez-Pradas, E.; Villafranca-Sdnchez, M.; Flores-Cespedes, F. Mobility of isoproturon from an alginate- bentonite controlled release formulation in layered soil. Chemosphere 2000, 41, 1495-1501.

[0356] 7. Razzaghi-Abyaneh M, Chang P-K, Shams-Ghahfarokhi M and Rai M (2014) Global health issues of aflatoxins in food and agriculture: challenges and opportunities. Front. Microbiol. 5:420. doi: 10.3389 / fmicb.2014.00420

[0357] 8. BEDMAR, F, EYHERABIDE, G. H., SATORRE, E.H. 2002. Bases para el manejo de malezas. Bases para el manejo del malz, el girasol y la soja. 273-311. CREA.

[0358] 9. Green-Tracewicz E, Page ER, Swanton CJ. Light Quality and the Critical Period for Weed Control in Soybean. Weed Science. 2012;60(l):86-91. doi:10.1614 / WS-D-ll-00072.1

[0359] 10. Islam MM, Megharaj M, Asaduzzaman M and Sudharsanam A (2024) Editorial: Agrochemicals in agricultural and non-agricultural settings: fate, distribution, and potential human and environmental health hazards. Front. Sustain. Food Syst. 8:1461954. doi: 10.3389 / fsufs.2024.1461954

[0360] 11. Duhan JS, Kumar R, Kumar N, Kaur P, Nehra K, Duhan S. Nanotechnology: The new perspective in precision agriculture. Biotechnol Rep (Amst). 2017 May 24;15:ll-23. doi: 10.1016 / j.btre.2017.03.002. PMID: 28603692; PMCID: PMC5454086. 12. Auffan, M., Rose, J., Bottero, JY. et al. Towards a definition of inorganic nanoparticles from an environmental, health and safety perspective. Nature Nanotech 4, 634-641 (2009). https: / / doi. org / 10.1038 / nnano.2009.242

[0361] 13. Kumar, S.; Bhanjana, G.; Sharma, A.; Sidhu, M.C.; Dilbaghi, N. Synthesis, characterization and on-field evaluation of pesticideloaded sodium alginate nanoparticles. Carbohydr. Polym. 2014, 101, 1061-1067.

[0362] 14. Faizan, M.; Rajput, V.D.; Al-Khuraif, A. A.; Arshad, M.; Minkina, T; Sushkova, S.; Yu, F. Effect of Foliar Fertigation of Chitosan Nanoparticles on Cadmium Accumulation and Toxicity in Solanum lycopersicum. Biology 2021, 10, 666.

[0363] 15. Campos, E.V.R.; De Oliveira, J.L.; Da Silva, C.M.G.; Pascoli,M.; Pasquoto, T.; Lima, R.; Abhilash, P.C.; Fraceto, L.F.U. Polymeric and solid lipid nanoparticles for sustained release of carbendazim and tebuconazole in agricultural applications. Sci. Rep. 2015, 5, 13809.

[0364] 16. Salgueiro, A.M.; Daniel-da-Silva, A.L.; Fateixa, S.; Trindade, T. -Carrageenan hydrogel nanocomposites with release behaviour mediated by morphological distinct Au nanofillers. Carbohydr. Polym. 2013, 91, 100-109.

[0365] 17. Albuquerque, P.; Coelho, L.C.; Teixeira, J. A.; Carneiro-da-Cunha, M.G. Approaches in biotechnological applications of natural polymers. AIMS Mol. Sci. 2016, 3, 386-425.

[0366] 18. Sharma, A.; Sood, K.; Kaur, J.; Khatri, M. Agrochemical-loaded biocompatible chitosan nanoparticles for insect pest management. Biocatal. Agric. Biotechnol. 2019, 18, 101079.

[0367] 19. Slade, G.G.; Dourado, S.M., Jr.; Oliveira, R.J.D.; Moreto, J.A. Developing a mathematical model for the controlled release over time of sulfentrazone herbicide from a biodegradable polymer. Mater. Res. 2019, 22.

[0368] 20. Rashidipour, M.; Maleki, A.; Kordi, S.; Birjandi, M.; Pajouhi, N.; Mohammad!, E.; Rasoulian, R.; Davari, B. Pectin / chitosan / tripolyphosphate nanoparticles: Efficient carriers for reducing soil sorption, cytotoxicity, and mutagenicity of paraquat and enhancing its herbicide activity. J. Agric. Food Chem. 2019, 67, 5736-5745.

[0369] 21. Elabasy, A.; Shoaib, A.; Waqas, M.; Shi, Z.; Jiang, M. Cellulose nanocrystals loaded with thiamethoxam: Fabrication, characterization, and evaluation of insecticidal activity against Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae). Nanomaterials 2020, 10, 788.

[0370] 22. Roberts, G. A. F. Chitin Chemistry; Macmillan Press: London, 1992.; 64. 23. Bautista-Ba~nos, S.; Hernandez-Lauzardo, A. N.; Velazquez-del Valle, M. G.; Hernandez- Lopez, M.; Ait Barka, E.; Bosquez- Molina, E.; Wilson, C. L. Chitosan as a potential natural compound to control pre and postharvest diseases of horticultural commodities. Crop Prot. 2006, 25, 108-118. DOI: 10.1016 / j.cropro. 2005.03.010.

[0371] 24. Sahariah, P.; Masson, M. Antimicrobial chitosan and chitosan derivatives: a review of the structure-activity relationship. Biomacromolecules 2017, 18, 3846-3868. DOI: 10.1021 / acs.biomac. 7b01058.

[0372] 25. Francesconi, S.; Steiner, B.; Buerstmayr, H.; Lemmens, M.; Sulyok, M.; Balestra, G.M. Chitosan Hydrochloride Decreases Fusarium graminearum Growth and Virulence and Boosts Growth, Development and Systemic Acquired Resistance in Two Durum Wheat Genotypes.

[0373] 26. Rychter P. Chitosan / glyphosate formulation as a potential, environmental friendly herbicide with prolonged activity. J Environ Sci Health B. 2019;54(8):681-692. doi: 10.1080 / 03601234.2019.1632644. Epub 2019 Aug 12. PMID: 31403392.

[0374] 27. Das, R. K., Sarma, S. J., Brar, S. K., & Verma, M. (2014). Nanoformulation of insecticides- Novel products. J Biofertil Biopestici, 5(1), el20.

[0375] 28. Grenha A. Chitosan nanoparticles: a survey of preparation methods. J Drug Target. 2012 May;20(4):291-300. doi: 10.3109 / 1061186X.2011.654121. Epub 2012 Feb 2. PMID: 22296336.

[0376] 29. Tokumitsu H, Ichikawa H, Fukumori Y, Block LH. (1999a). Preparation of gadopentetic acid-loaded chitosan microparticles for gadolinium neutron-capture therapy of cancer by a novel emulsion-droplet coalescence technique. Chem Pharm Bull, 47, 838-842.

[0377] 30. El-Shabouri MH. (2002). Positively charged nanoparticles for improving the oral bioavailability of cyclosporin-A. Int J Pharm, 249, 101-108.

[0378] 31. Mitra S, GaurU, Ghosh PC, MaitraAN. (2001). Tumour targeted delivery of encapsulated dextran-doxorubicin conjugate using chitosan nanoparticles as carrier. J Control Release, 74, 317-323.

[0379] 32. Calvo P, Remunan-Lopez C, Vila-Jato JL, Alonso MJ. (1997). Novel hydrophilic chitosanpolyethylene oxide nanoparticles as protein carriers. J Appl Polym Sci, 63, 125-132.

[0380] 33. Sarmento B, Martins S, Ribeiro A, Veiga F, Neufeld R, Ferreira D. (2006). Development and comparison of different nanoparticulate polyelectrolyte complexes as insulin carriers. Int J Peptide Res Ther, 12, 131-138. 34. Tian XX, Groves MJ. (1999). Formulation and biological activity of antineoplastic proteoglycans derived from Mycobacterium vaccae in chitosan nanoparticles. J Pharm Pharmacol, 51, 151-157.

[0381] 35. Chan HK, Kwok PC. (2011). Production methods for nanodrug particles using the bottom- up approach. Adv Drug Deliv Rev, 63, 406-416.

[0382] 36. Wang J, Byrne JD, Napier ME, DeSimone JM. (2011). More effective nanomedicines through particle design. Small, 7, 1919-1931.

[0383] 37. Fan W, Yan W, Xu Z, Ni H. (2012). Formation mechanism of monodisperse, low molecular weight chitosan nanoparticles by ionic gelation technique. Colloids Surf B Biointerfaces, 90, 21- 27. Fan W, Yan W, Xu Z, Ni H.

[0384] 38. Bhumkar DR, Pokharkar VB. Studies on effect of pH on cross-linking of chitosan with sodium tripolyphosphate: a technical note. AAPS PharmSciTech. 2006 Jun 2;7(2):E50. doi: 10.1208 / pt070250. PM ID: 16796367; PMCID: PMC2750277.

[0385] 39. Janes KA, Calvo P, Alonso MJ. (2001). Polysaccharide colloidal particles as delivery systems for macromolecules. Adv Drug Deliv Rev, 47, 83-97.

[0386] 40. Terbojevich M, Muzzarelli RAA. (2009). Chitosan. In: Phillips GO, Williams P, eds. Handbook of Hydrocolloids. Cambridge: Woodhead Publishing Ltd., 367-378.

[0387] 41. Bhattarai N, Gunn J, Zhang M. (2010). Chitosan-based hydrogels for controlled, localized drug delivery. Adv Drug Deliv Rev, 62, 83-99.

[0388] 42. Bodmeier R, Chen HG, Paeratakul O. (1989). A novel approach to the oral delivery of micro- or nanoparticles. Pharm Res, 6, 413-417.

[0389] 43. Carvalho EL, Grenha A, Remuhdn-Ldpez C, Alonso MJ, Seijo B. (2009). Mucosal delivery of liposome-chitosan nanoparticle complexes. Meth Enzymol, 465, 289-312.

[0390] 44. Kumar, R.; Nain, V.; Duhan, J.S. An Ecological Approach to Control Pathogens of Lycopersicon esculentum L. by Slow Release of Mancozeb from Biopolymeric Conjugated

[0391] 45. Silva Mdos S, Cocenza DS, Grillo R, de Melo NF, Tonello PS, de Oliveira LC, Cassimiro DL, Rosa AH, Fraceto LF. Paraquat-loaded alginate / chitosan nanoparticles: preparation, characterization and soil sorption studies. J Hazard Mater. 2011 Jun 15;190(l-3):366-74. doi: 10.1016 / j.jhazmat.2011.03.057. Epub 2011 Mar 23. PMID: 21493003. 46. Grillo R, Pereira AE, Nishisaka CS, de Lima R, Oehlke K, Greiner R, Fraceto LF. Chitosan / tripolyphosphate nanoparticles loaded with paraquat herbicide: an environmentally safer alternative for weed control. J Hazard Mater. 2014 Aug 15;278:163-71. doi: 10.1016 / j.jhazmat.2014.05.079. Epub 2014 Jun 11. PMID: 24968252. 47. Costa, Marcia & Rabelo, Kissila & Ferreira, Ivana & Cruz, Mauricio. (2021). Sodium alginate / chitosan / glyphosate superabsorbent bio-foam as a release system for herbicide. Journal of Applied Polymer Science. 139. 51776. 10.1002 / app.51776.

[0392] 48. Butstraen C, Salatin F. Preparation of microcapsules by complex coacervation of gum Arabic and chitosan. Carbohydr Polym. 2014 Jan;99:608-16. doi: 10.1016 / j.carbpol.2013.09.006. Epub 2013 Sep 8. PMID: 24274550.

Claims

Claims1. A composite microsphere enhancing the efficacy of an agrochemical active ingredient, comprising chitosan with an average molecular weight in the range from 190,000 to 310,000 g / mol, and a crosslinking agent, in the absence of an agrochemical active ingredient.

2. The composite microsphere of claim 1, wherein the microsphere has an adjustable surface electrical charge (zeta potential) in an aqueous medium based on the concentration of the crosslinking agent, and wherein the chitosamcrosslinking agent mass ratio is 1:X, where X varies in a range from 0.08 and 1.5.

3. The composite microsphere of claim 1, wherein the crosslinking agent is selected from the group consisting of sodium tripolyphosphate (TPP), sodium hexametaphosphate, and their derivatives.

4. The composite microsphere of claim 1, wherein the crosslinking agent is sodium tripolyphosphate (TPP).

5. The composite microsphere of claim 1, further comprising a dispersant that improves the redispersion of the microsphere when combined with an aqueous solution of the agrochemical active ingredient, wherein the dispersant is selected from the group consisting of gum arabic, xanthan gum, guar gum, carrageenan, pectin, alginates, dextrins, cyclodextrins, maltodextrins, tragacanth gum, mesquite gum, and mixtures thereof.

6. The composite microsphere of claim 5, wherein the chitosan:dispersant mass ratio is Y:l, where Y is in a range from 5 to 20.

7. The composite microsphere of claim 5, wherein the dispersant is gum arabic.

8. An agrochemical formulation comprising an agrochemical active ingredient and composite microspheres of claim 1 that enhance agrochemical efficacy on crops, wherein the composite microspheres are included at a concentration ranging from 2% to 200% w / w relative to the agrochemical active ingredient.

9. An agrochemical formulation comprising an agrochemical active ingredient and composite microspheres of claim 1 that enhance agrochemical efficacy on crops, wherein the composite microspheres are included at a concentration ranging from 2% to 20% w / w relative to the agrochemical active ingredient.

10. An agrochemical formulation comprising an agrochemical active ingredient and composite microspheres of claim 1 that enhance agrochemical efficacy on crops, wherein the composite microspheres are included at a concentration ranging from 5% to 10% w / w relative to the agrochemical active ingredient.

11. The agrochemical formulation of claim 8, wherein the agrochemical active ingredient is selected from the group consisting of fertilizers, plant growth regulators, biostimulants, pesticides, pest control agents, herbicides, fungicides, nematicides, insecticides, rodenticides, agricultural biocompounds, crop protection agents, phytohormones, and mixtures thereof.

12. The agrochemical formulation of claim 8, comprising an agrochemical active ingredient selected from the group consisting of pre-emergent herbicides, contact herbicides, systemic herbicides, residual herbicides, biological herbicides, glyphosate, glufosinate ammonium, imazapyr, imazapic, imazamox, imazaquin, atrazine, simazine, diuron, pendimethalin, trifluralin, fluorochloridone, fluazifop-p-butyl, quizalofop-p-ethyl, dicamba, paraquat, clethodim, haloxyfop, fomesafen, lactofen, 2,4-dichlorophenoxyacetic acid (2,4- D), thiencarbazone-methyl, pyraclostrobin, diflufenican, sulfentrazone, S- metolachlor, flumioxazin, pyroxasulfone, MCPA, saflufenacil, bromoxynil, chlorantraniliprole, abamectin, thiamethoxam, cypermethrin, bifenthrin, imidacloprid, lambda-cyhalothrin, deltamethrin, dimethoate, flubendiamide, difenoconazole, trifloxystrobin, cyproconazole, metalaxyl, prothioconazole, carbendazim, isopyrazam, chlorothalonil, epoxiconazole, fluoxastrobin, mancozeb, propiconazole, prothioconazole, sedaxane, tebuconazole, thiram, azoxystrobin, their derivatives, and their mixtures.

13. The agrochemical formulation of claim 8, comprising an agrochemical active ingredient selected from the group consisting of insecticides, biologicalinsecticides, imidacloprid, thiamethoxam, acetamiprid, clothianidin, dinotefuran, lambda-cyhalothrin, cypermethrin, deltamethrin, permethrin, bifenthrin, chlorpyrifos, dimethoate, malathion, methyl parathion, diazinon, carbaryl, methomyl, aldicarb, propoxur, chlorantraniliprole, cyantraniliprole, diflubenzuron, novaluron, lufenuron, buprofezin, pyriproxyfen, abamectin, spinosad, spinetoram, Beauveria bassiana, flubendiamide, azadirachtin, mineral oils, insecticidal soaps, their derivatives, and their combinations.

14. The agrochemical formulation of claim 8, comprising an agrochemical active ingredient selected from the group consisting of fungicides, systemic fungicides, biological fungicides, prothioconazole, trifloxystrobin, cyproconazole, carbendazim, difenoconazole, isopyrazam, chlorothalonil, epoxiconazole, fluoxastrobin, mancozeb, zineb, thiram, tebuconazole, propiconazole, azoxystrobin, pyraclostrobin, thiabendazole, metalaxyl, boscalid, captan, folpet, dithiocarbamates, triazoles, strobilurins, benzimidazoles, anilides, organochlorines, phthalimides, sedaxane, biofungicides, their derivatives, and their combinations.

15. The agrochemical formulation of claim 8, comprising an agrochemical active ingredient selected from the group consisting of controlled-release fertilizers, foliar fertilizers, low-biuret urea, potassium nitrate, monoammonium phosphate, monopotassium phosphate, ammonium nitrate, ammonium sulfate, zinc sulfate, zinc chelates (EDTA, DTPA, HEDTA), iron sulfate, iron chelates (EDDHA, DTPA, EDTA), copper sulfate, copper chelates (EDTA), manganese sulfate, manganese chelates (EDTA), boron sulfate, sodium borate, boric acid, sodium molybdate, ammonium molybdate, calcium nitrate, magnesium nitrate, magnesium sulfate, potassium silicate, potassium carbonate, potassium bicarbonate, seaweed extracts, amino acid-based fertilizers, protein hydrolysates, humic acid, fulvic acid, plant-based biostimulants, soluble NPK blends with micronutrients, concentrated nitrogen solutions, concentrated phosphorus solutions, concentrated potassium solutions, chelated micronutrient solutions, complexed calcium solutions, plant polysaccharides, silicon in the form of silicic acid, plant extract-based products, liquid fertilizerswith phytohormones, organic liquid fertilizers, alginate-based compounds, binary fertilizers including diammonium phosphate (DAP), monoammonium phosphate (MAP), triple superphosphate (TSP), simple superphosphate (SSP), potassium chloride, potassium sulfate, rock phosphate, NPK fertilizers (nitrogen, phosphorus, potassium blends), controlled-release fertilizers, foliar fertilizers, animal manure, compost, guano, biofertilizers, iron chelates, zinc chelates, sodium nitrate, wood ash, and their mixtures.

16. The agrochemical formulation of claim 8, wherein said agrochemical active ingredient is mancozeb.

17. The agrochemical formulation of claim 8, wherein said agrochemical active ingredient is dicamba.

18. The agrochemical formulation of claim 8, wherein said agrochemical active ingredient is glyphosate.

19. The agrochemical formulation of claim 8, wherein said agrochemical active ingredient is glufosinate.

20. The agrochemical formulation of claim 8, wherein said agrochemical active ingredient is an insecticide.

21. The agrochemical formulation of claim 8, wherein said agrochemical active ingredient is 2,4-D.

22. The agrochemical formulation of claim 8, wherein said agrochemical active ingredient is prothioconazole.

23. The agrochemical formulation of claim 8, wherein said agrochemical active ingredient is trifloxystrobin.

24. The agrochemical formulation of claim 8, wherein said agrochemical active ingredient is thiamethoxam.

25. The agrochemical formulation of claim 8, wherein said agrochemical active ingredient is lambda-cyhalothrin.

26. The agrochemical formulation of claim 8, wherein said agrochemical active ingredient is chlorantraniliprole.

27. The agrochemical formulation of claim 8, wherein said agrochemical active ingredient is a biofungicide.

28. The agrochemical formulation of claim 8, wherein said agrochemical active ingredient is a biofertilizer.

29. The agrochemical formulation of claim 8, wherein said agrochemical active ingredient is a foliar fertilizer.

30. The agrochemical formulation of claim 8, wherein said microsphere comprises chitosan with an average molecular weight ranging from 190,000 to 310,000 g / mol, a dispersant, and a crosslinking agent, wherein the chitosan:crosslinking agent mass ratio is 1:X, where X ranges from 0.08 to 1.2, and defines the zeta potential in an aqueous solution of said microspheres.

31. The agrochemical formulation of claim 8, wherein said microspheres comprise chitosan, gum arable, and tripolyphosphate, in the absence of agrochemical active ingredients.

32. The agrochemical formulation of claim 8, wherein said microsphere has a zeta potential in an aqueous solution ranging from +30 mV to -30 mV, adjustable by the concentration of the crosslinking agent.

33. The agrochemical formulation of claim 8, wherein it further comprises a coadjuvant selected from the group consisting of an adhesive, a surfactant, a stabilizer, an anti-foaming agent, a pH buffer, a sequestrant, and their derivatives and combinations.

34. The agrochemical formulation of claim 8, wherein said agrochemical active ingredient is present at a concentration equal to or less than the field application recommendation.

35. The agrochemical formulation of claim 8, wherein the agrochemical active ingredient and the microspheres are mixed in the field prior to application.

36. The agrochemical formulation of claim 8, wherein the agrochemical active ingredient and the microspheres are mixed at least 2 hours before application.

37. The agrochemical formulation of claim 8, wherein it comprises an aqueous composition of the agrochemical active ingredient and microspheres, packaged in containers after being mixed at the production facility for sale and distribution.

38. The agrochemical formulation of claim 8, wherein it comprises an aqueous composition of the agrochemical active ingredient and, separately, the microspheres in powder form for mixing prior to use.

39. A method for obtaining the agrochemical formulation of claim 8, comprising the steps of: a) preparing an aqueous solution of the agrochemical active ingredient at the desired concentration, b) adding the dry microspheres at a concentration of up to 100% relative to the agrochemical active ingredient, c) mixing prior to application.

40. The method of claim 39, further comprising adding a co-adjuvant.

41. A method for preventing and controlling plant diseases caused by fungi, bacteria, insects, and weeds, comprising applying the agrochemical formulation of claim 8 to a crop.

42. The method of claim 41, wherein said crop is selected from the group consisting of cereals, oilseeds, forest crops, fruit trees, ornamental plants, vegetables, wheat, barley, rye, triticale, oats, corn, sunflower, rice, soybean, peas, broad beans, beans, peanuts, rapeseed, kale, cotton, potato, sugar beet, sugarcane, chard (Beta vulgaris), chili peppers (Capsicum spp.), garlic and onions (Allium spp.), celery (Apium graveolens), eggplant (Solanum melongena), pumpkin (Cucurbita moschata), chayote (Sechium edule), cabbage (Brassica oleracea), spinach (Spinacia oleracea), green beans (Phaseolus vulgaris), lettuce (Lactuca sativa), corn (Zea mays), peanuts (Arachis hypogaea), tomatoes (Solanumlycopersicum), cucumber (Cucumis sativus), okra (Hibiscus esculentus), radish (Raphanus sativus), beet (Beta vulgaris), carrot (Daucus carota), avocado (Persea americana), sugar apple (Annona squamosa), star apple (Chrysophyllum cainito), canistel (Pouteria campechiana), cherry (Malpighia punicifolia), custard apple (Annona reticulata), hog plum (Spondias dulcis), coconut (Cocos nucifera), papaya (Carica papaya), soursop (Annona muricata), guava (Psidium guajava), pomegranate (Punica granatum), lime (Citrus aurantifolia), lemon (Citrus limonum), mamey sapote (Calocarpum mammosum), mammee apple (Mammea americana), Spanish lime (Melicoccus bijugatus), mandarin orange (Citrus reticulata), mango (Mangifera indica), passionfruit (Passiflora laurifolia), watermelon (Citrullus lanatus), bitter orange (Citrus aurantium), sweet orange (Citrus sinensis), pineapple (Ananas comosus), banana (Musa paradisiaca), plantain (Musa balbisiana), tamarind (Tamarindus indica), grapefruit (Citrus paradisi), pummelo (Citrus grandis), grape (Vitis vinifera), beans (Phaseolus vulgaris), rice (Oryza sativa), coffee (Coffea arabica), sugarcane (Saccharum officinarum), cotton (Gossypium hirsutum), gherkin (Melothria guadalupensis), sweet potato (Ipomoea batatas), potato (Solanum tuberosum), criolla potato (Solanum phureja), goldenberry (Physalis peruviana), cassava (Manihot esculenta), soybean (Glycine max), strawberries (Fragaria spp.), mulberries (Morus spp.), blackberries (Rubus spp.), palms of the Aracaceae family, oil palm (Elaeis guineensis), apple tree, cacao (Theobroma cacao), tamarillo (Solanum betaceum), lu Io (Solanum quitoense).

43. The method of claim 41, wherein the agrochemical action is enhanced by at least 15% compared to the action of the agrochemical agent in the absence of the composite microspheres.

44. The method of claim 41, wherein said infections are caused by fungi selected from the group consisting of Magnaporthe oryzae, Botrytis cinerea, Puccinia spp., Fusarium spp., Fusarium graminearum, Fusarium oxysporum, Blumeria gram in is, Mycosphaerella spp., Mycosphaerella fijiensis, Mycosphaerella graminicola, Colletotrichum spp., Ustilago maydis, Melampsora lini, Phakopsora pachyrhizi, Stemphylium lycopersici, and Rhizoctonia solani.

45. An agrochemical formulation enhancing the effectiveness of an agrochemical active ingredient by at least 15%, comprising said agrochemical active ingredient and composite microspheres, wherein said composite microspheres comprise chitosan with an average molecular weight in the range from 190,000 to 310,000 g / mol and a crosslinking agent; wherein the mass ratio of chitosan to crosslinking agent is 1:X, where X ranges from 0.5 to 1.5; and wherein the concentration of said composite microspheres is between 2% and 200% w / w relative to said fungicide in aqueous phase.

46. The agrochemical formulation of claim 45 or claim 8, wherein said composite microspheres further comprise a dispersant, said dispersant being selected from the group consisting of gum arabic, xanthan gum, guar gum, carrageenan, pectin, alginates, dextrins, cyclodextrins, maltodextrins, tragacanth gum, mesquite gum, and mixtures thereof.

47. The agrochemical formulation of claim 45 or claim 8, wherein said dispersant is gum arabic.

48. The agrochemical formulation of claim 45 or claim 8, wherein the mass ratio of chitosan to dispersant is Y:l, where Y ranges from 5 to 20.

49. The agrochemical formulation of claim 45 or claim 8, wherein said composite microspheres comprise a surface charge or zeta potential adjustable by the concentration of the crosslinking agent, with X ranging from 0.08 to 0.8, and wherein said crosslinking agent is TPP.

50. The agrochemical formulation of claim 45 or claim 8, wherein said agrochemical active ingredient is in an aqueous solution stored in a container, and said composite microsphere is a powder configured to be added to said container.

51. A process for obtaining the composite microsphere of claim 1, comprising the steps of: mixing acetic acid, chitosan, and water, followed by stirring; adding said dispersant and stirring; adding the crosslinking agent solution dropwise; allowing the mixture to rest; and drying the obtained microspheres.

52. The process of claim 51, comprising the steps of: a. dissolving chitosan in 1% v / v acetic acid under constant stirring at 20°C until no clumps are observed;b. adding the dispersant and stirring until completely dissolved, achieving a mass ratio of chitosan to dispersant of Y:l, where Y ranges from 5 to 20; c. adding a crosslinking agent solution dropwise to the mixture, achieving a chitosan-to-crosslinking agent mass ratio of 1:X, where X ranges from 0.08 to 1.2, in the absence of an agrochemical active ingredient; d. adjusting the pH to approximately 6.5; and e. drying the composite microspheres.

53. The process of claim 52, wherein step e) involves lyophilization using a 220 V lyophilizer at -45°C and 10 Pa pressure, followed by grinding with a mortar and sieving through a 100-mesh filter.

54. The process of claim 52, wherein step e) involves spray drying at an inlet temperature of 200°C.

55. A process for obtaining the agrochemical formulation of claim 45 or claim 8, comprising the steps of: a) preparing an aqueous fungicide solution; b) adding dry composite microspheres to the aqueous fungicide solution; c) allowing the mixture to remain in contact for at least 2 hours; d) stirring and applying to the crop.

56. The composite microsphere of claim 1, wherein it is a co-formulator that enhances agrochemical formulations.

Images