Description:FIELD OF THE INVENTION
[0001] The present disclosure relates to the field of agriculture and plant nutrition. More specifically, it pertains to a foliar fertilizer composition comprising potassium and boron, particularly in the form of Dipotassium octaborate tetrahydrate (DPOBT), for enhancing the growth, yield, and stress tolerance of crops including but not limited to cotton, marigold, paddy, and banana.

BACKGROUND OF THE INVENTION
[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.
[0003] Agricultural productivity is closely tied to the balanced availability of essential nutrients such as potassium (K) and boron (B), both of which play critical roles in plant physiology. Potassium is involved in water regulation, enzyme activation, and photosynthesis, while boron is indispensable for cell wall integrity, pollen tube development, and fruit/seed formation. Despite this, a significant portion of cultivated soils worldwide remains deficient in these nutrients due to either intensive cropping or limited bioavailability from conventional fertilization practices.
[0004] Traditional soil-applied fertilizers often exhibit low nutrient use efficiency due to leaching, fixation in soil particles, volatilization, and poor plant uptake. Moreover, boron-containing fertilizers such as disodium octaborate tetrahydrate, though widely used, introduce sodium into the soil, which gradually contributes to salinization, adversely affecting soil permeability, microbial balance, and long-term fertility.
[0005] Multiple prior art disclosures have attempted to address these deficiencies but have limitations that restrict their applicability or effectiveness. For instance, a patent document EP1310456B1 discloses a process for producing potassium octaborate tetrahydrate via high-temperature reactions (95°C) using concentrated potassium hydroxide and boric acid. The drying is performed using spray-drying at 435°C, followed by grinding. Although this process provides an agricultural-grade boron-potassium fertilizer, it is energy-intensive, capital-heavy, and relies on bulk processing infrastructure, making it unsuitable for decentralized or small-scale manufacturing. Moreover, the high-temperature drying may introduce phase instability or degrade the micronutrient content. There is also no mention of mother liquor recycling, resulting in potential waste generation and environmental burden.
[0006] Another patent document CN111187117A describes a foliar fertilizer composition specifically formulated for promoting cotton growth, comprising urea, potassium dihydrogen phosphate, and zinc sulfate heptahydrate. While effective for phosphorus and zinc supplementation, the formulation lacks any boron component, thereby missing out on reproductive enhancements and structural strengthening offered by boron. Additionally, the fertilizer is limited in scope to cotton, and the disclosure does not contemplate improvements across diverse crop categories like fruit-bearing plants or cereals. Moreover, the method lacks a sodium-free boron-potassium synergy, essential for sustainable micronutrient delivery.
[0007] Further, EP3841880A1 discloses a sprayable suspension fertilizer based on potassium pentaborate with a viscosity modifier and boric acid. Though this formulation attempts to stabilize boron in suspension form, it uses sodium-free but structurally different borate species that may differ in plant bioavailability and efficiency. The focus here is on suspension stability and not on crystal formation, recrystallization efficiency, or drying process optimization. The absence of a structured production process that ensures high yield, process control, or zero-waste generation is another shortcoming.
[0008] In light of the above, it is evident that prior art fails to fully resolve several critical agronomic and manufacturing challenges such as high production costs and energy consumption due to inefficient drying techniques; absence of closed-loop or environmentally sustainable processing; limited or no application of boron-potassium synergy in a chemically stable, sodium-free form; inadequate data on crop-wise efficacy across cereals, vegetables, fruits, and ornamental plants as well as lack of flexibility in application method, dosage optimization, and shelf-life stability.
[0009] Furthermore, no prior art discloses a process that enables low-temperature crystallization, supersaturated solution handling, wet-solid drying, and internal recycling of process streams while simultaneously ensuring high purity and bioavailability of potassium and boron nutrients. The pressing need of the hour is thus a technically sound, field-validated, scalable, and eco-sustainable solution for boron and potassium delivery that works efficiently across multiple crops through foliar application.

OBJECTIVE OF THE INVENTION
[0010] Primary objective of the present disclosure is to provide a method of preparation and application of dipotassium octaborate tetrahydrate (DPOBT) as a foliar spray to improve the growth, yield, and quality of various crops.
[0011] Another objective of the present invention is to establish a low-energy and environmentally sustainable method for the production of dipotassium octaborate tetrahydrate (DPOBT).
[0012] Another objective of the present invention is to provide a boron and potassium-based fertilizer composition that is free from sodium and suitable for foliar application.
[0013] Another objective of the present invention is to enhance nutrient uptake efficiency and bioavailability in crops through foliar delivery.
[0014] Another objective of the present invention is to support crop development, yield, and stress resilience by supplying boron and potassium in a chemically stable and bioavailable form.
[0015] Another objective of the present invention is to provide a closed-loop, low-waste process that enables recycling of mother liquor and reduces environmental impact.
[0016] Another objective of the present invention is to develop a formulation that is adaptable to multiple crops such as cotton, paddy, marigold, and banana.
[0017] Another objective of the present invention is to offer an economical and scalable solution that enhances key agronomic parameters such as plant height, biomass, flowering duration, boll retention, grain weight, and fruit size.
SUMMARY OF THE INVENTION
[0018] The present invention generally relates to a method for preparing dipotassium octaborate tetrahydrate (DPOBT), a water-soluble and stable compound combining boron and potassium. The process involves dissolving a boron-containing compound such as boric acid or borax in water, adding a potassium source such as potassium carbonate, allowing recrystallization, filtering, drying, and pulverizing to yield fine DPOBT powder. The DPOBT is subsequently used in preparing a foliar spray formulations for crops, with concentration ranges from 0.1% to 0.3% w/v. The foliar application has shown to improve crop yield, reproductive success, stress tolerance, and nutrient efficiency.
[0019] In an embodiment, the present invention relates to a method for preparing dipotassium octaborate tetrahydrate (DPOBT), the method comprising:
dissolving a boron-containing compound in water to form a slurry;
gradually adding a potassium-containing compound to the slurry;
stirring the mixture for the duration ranging from 1 to 2 hours in room temperature to promote reaction;
allowing the mixture to cool and stand undisturbed to recrystallize and form DPOBT crystals;
seperating DPOBT crystals by filtration;
drying the crystals at a temperature between 85°C to 95°C; and
pulverizing the dried crystals to obtain DPOBT.
[0020] In another embodiment, the present disclosure provides a foliar fertilizer composition, comprising 0.1% to 0.3% by weight of dipotassium octaborate tetrahydrate (DPOBT);
wherein the DPOBT is a crystallized compound formed by reacting a boron-containing compound selected from boric acid, boric oxide, or borax with a potassium-containing compound selected from potassium carbonate, potassium hydroxide, or potassium bicarbonate; and
99.7% to 99.9% by weight of an agronomically acceptable aqueous carrier;
wherein the composition is adapted for foliar application to crops during their vegetative and/or reproductive growth stages.
[0021] In another embodiment, the present disclosure provides kit for enhancing crop growth and yield, comprising:
a pre-measured quantity of dipotassium octaborate tetrahydrate (DPOBT) in powder form,
an instruction leaflet comprising recommended foliar spray concentrations of DPOBT; and
optionally, a dispensing or mixing container adapted for preparing the foliar spray.
[0022] Unlike conventional boron fertilizers, the composition is sodium-free, highly bioavailable, and does not degrade soil quality. The process is energy-efficient and enables internal recycling of process liquids. The invention is applicable to a wide range of crops and addresses the need for sustainable, effective, and environmentally benign nutrient formulations in agriculture.
[0023] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments.

BRIEF DESCRIPTION OF FIGURES
The accompanying drawings are included to provide a clear understanding of the present invention and a detailed description, and they constitute a part of this complete specification.
[0024] FIG. 1 illustrates a method of synthesizing DPOBT.

DETAILED DESCRIPTION OF THE INVENTION
[0025] The following is a full description of the disclosure's embodiments. The embodiments are described in such a way that the disclosure is clearly communicated. The level of detail provided, on the other hand, is not meant to limit the expected variations of embodiments; rather, it is designed to include all modifications, equivalents, and alternatives that come within the spirit and scope of the current disclosure as defined by the attached claims. Unless the context indicates otherwise, the term "comprise" and variants such as "comprises" and "comprising" throughout the specification are to be read in an open, inclusive meaning, that is, as "including, but not limited to."
[0026] When "one embodiment" or "an embodiment" is used in this specification, it signifies that a particular feature, structure, or characteristic described in conjunction with the embodiment is present in at least one embodiment. As a result, the expressions "in one embodiment" and "in an embodiment" that appear throughout this specification do not necessarily refer to the same embodiment. Furthermore, in one or more embodiments, the specific features, structures, or qualities may be combined in any way that is appropriate.
[0027] Unless the content clearly demands otherwise, the singular terms "a," "an," and "the" include plural referents in this specification and the appended claims. Unless the content explicitly mandates differently, the term "or" is normally used in its broad definition, which includes "and/or."
[0028] All processes described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention.
[0029] The headings and abstract of the invention provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.
[0030] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.
[0031] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description that follows, and the embodiments described herein, is provided by way of illustration of an example, or examples, of particular embodiments of the principles and aspects of the present disclosure. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the disclosure.
[0032] It should also be appreciated that the present invention can be implemented in numerous ways, including as a system, a method or a device. In this specification, these implementations, or any other form that the invention may take, may be referred to as processes.
[0033] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing.
Definitions:
[0034] For the purpose of the present invention, foliar fertilizer may refer to a liquid fertilizer applied directly to the leaves of plants for nutrient absorption.
[0035] For the purpose of the present invention, Micronutrient may refer to essential elements required by plants in small quantities, such as boron.
[0036] For the purpose of the present invention, Macronutrient may refer to nutrients required in large amounts, such as potassium.
[0037] For the purpose of the present invention, Boric Acid may refer to a weak acid used as a boron source in fertilizers.
[0038] For the purpose of the present invention, Borax may refer to a sodium borate compound, used as an alternative boron source.
[0039] For the purpose of the present invention, Boric Oxide may refer to an oxide of boron used in fertilizer formulations.
[0040] For the purpose of the present invention, Potassium Carbonate may refer to an alkali potassium salt used as a potassium source.
[0041] For the purpose of the present invention, Potassium Hydroxide may refer to a strong base used to introduce potassium into fertilizer formulations.
[0042] For the purpose of the present invention, Potassium Bicarbonate may refer to less alkaline potassium source for fertilizer production.
[0043] For the purpose of the present invention, Recrystallization may refer to process by which crystals are formed from a solution to purify compounds.
[0044] For the purpose of the present invention, Mother Liquor may refer to the residual solution remaining after crystallization.
[0045] For the purpose of the present invention, Dry Matter Production may refer to total biomass excluding water content, a measure of plant growth.
[0046] For the purpose of the present invention, Boll Retention may refer to the capacity of cotton plants to retain fruiting structures.
[0047] For the purpose of the present invention, Panicle Formation may refer to the development of a compound flower cluster, particularly in paddy.
[0048] For the purpose of the present invention, Hand Weight may refer toa measure of the weight of a banana bunch.
[0049] For the purpose of the present invention, Abiotic Stress may refer to stress caused by non-living factors such as drought or salinity.
[0050] For the purpose of the present invention, Harvest Index may refer to the ratio of economic yield (e.g., grains) to total plant biomass.
[0051] For the purpose of the present invention, super-saturated solution may refer to a solution that contains more dissolved solute than normal at a given temperature.
[0052] For the purpose of the present invention, Closed-Loop Process may refer to a production system where materials are recycled and reused within the process.
[0053] For the purpose of the present invention, Agronomic Efficiency may refer to the effectiveness of an input in increasing crop yield or performance.
[0054] In a general embodiment, the present invention discloses a novel and industrially applicable method for synthesizing dipotassium octaborate tetrahydrate (DPOBT), a chemically stable and sodium-free compound that delivers both boron and potassium—two essential nutrients required for optimal plant development. The invention addresses multiple longstanding challenges in the agricultural and fertilizer industries, including low nutrient use efficiency, soil salinization from sodium-based fertilizers, energy-intensive manufacturing processes, and poor bioavailability of micronutrients.
[0055] In another embodiment, through the strategic selection of boron and potassium sources, optimization of dissolution and crystallization kinetics, and implementation of a solid wet-feed drying process, the invention achieves high yields (up to 98%) and enables a closed-loop, zero-liquid-discharge system. These features reduce both the energy footprint and environmental impact of DPOBT production, making the process scalable, cost-effective, and suitable for both centralized and decentralized fertilizer manufacturing units.
[0056] In another embodiment, the resultant DPOBT product, when applied as a foliar spray at 0.1%–0.3% concentrations, demonstrates significant agronomic benefits across multiple crop categories including cotton, marigold, paddy, and banana. Field trials have confirmed improvements in parameters such as plant height, dry matter accumulation, reproductive organ development (boll, panicle, flower, and fruit), grain weight, and overall yield. Additionally, the composition enhances stress tolerance, making it highly suitable for cultivation under suboptimal environmental conditions.
[0057] In another embodiment, the invention is flexible and adaptable, as demonstrated by its various embodiments, including formulation kits for small-scale users and controlled-release variants for precision nutrient delivery. This adaptability ensures that the invention caters to a wide spectrum of end users, from smallholder farmers to large-scale agricultural enterprises.
[0058] In an embodiment, the present invention relates to a method for preparing dipotassium octaborate tetrahydrate (DPOBT), the method comprising:
dissolving a boron-containing compound in water to form a slurry;
gradually adding a potassium-containing compound to the slurry;
stirring the mixture for the duration ranging from 1 to 2 hours in room temperature to promote reaction;
allowing the mixture to cool and stand undisturbed to recrystallize and form DPOBT crystals;
seperating DPOBT crystals by filtration;
drying the crystals at a temperature between 85°C to 95°C; and
pulverizing the dried crystals to obtain DPOBT.
[0059] In another embodiment, the boron-containing compound is selected from boric acid, borax, boric oxide, or combinations thereof.
[0060] In another embodiment, the boron-containing compound is used in an amount ranging from 100 g to 145 g per 75 mL of water.
[0061] In another embodiment, the potassium-containing compound is selected from potassium carbonate, potassium hydroxide, potassium bicarbonate or a combination thereof.
[0062] In another embodiment, the potassium-containing compound is used in an amount ranging from 20 g to 45 g per 75 mL of water.
[0063] In another embodiment, the mixture is stirred for 30 minutes to 2 hours and left undisturbed for 8 to 24 hours to allow recrystallization.
[0064] In another embodiment, the mother liquor is recycled after filtration to reduce process waste.
[0065] In another embodiment, the drying is performed on the solid wet feed of DPOBT to reduce energy consumption compared to evaporative drying.
[0066] In another embodiment, the DPOBT is in the form granular form obtained by spray granulation.
[0067] In another embodiment, the DPOBT is stable at the temperature ranging from-5oC to 60oC for the time duration ranging from three years under normal conditions
[0068] In another embodiment, the present disclosure provides a foliar fertilizer composition for enhancing plant growth and yield, comprising 0.1% to 0.3% by weight of dipotassium octaborate tetrahydrate (DPOBT);
wherein the DPOBTis a crystallized compound formed by reacting a boron-containing compound selected from boric acid, boric oxide, or borax with a potassium-containing compound selected from potassium carbonate, potassium hydroxide, or potassium bicarbonate; and
99.7% to 99.9% by weight of an agronomically acceptable aqueous carrier;
wherein the composition is adapted for foliar application to crops during their vegetative and/or reproductive growth stages.
[0069] In another embodiment, the DPOBT has a purity of at least 95% and is in the form of a fine powder with moisture content below 5%.
[0070] In another embodiment, the foliar fertilizer is applied at a spray volume of 500 to 1000 liters per hectare.
[0071] In another embodiment, the aqueous carrier is water having a pH between 6.0 and 7.5.
[0072] In another embodiment, the present disclosure provides a method for applying the DPOBT on selected crops, the method comprising:
preparing dipotassium octaborate tetrahydrate (DPOBT) as disclosed herein; and
applying a foliar spray comprising 0.1% to 0.3% by weight of the prepared DPOBT in water to the foliage of the crop during at least one of its vegetative or reproductive growth stages.
[0073] In another embodiment, the crop is selected from, but not limited to, cotton, marigold, paddy, and banana.
[0074] In another embodiment, the DPOBT is applied at a concentration of between 0.1% and 0.3% by weight in water as a foliar spray.
[0075] In another embodiment, the present disclosure provides kit for enhancing crop growth and yield, comprising:
a pre-measured quantity of dipotassium octaborate tetrahydrate (DPOBT) in powder form,
an instruction leaflet comprising recommended foliar spray concentrations of DPOBT; and
optionally, a dispensing or mixing container adapted for preparing the foliar spray.
[0076] In another embodiment, the DPOBT forms a stable supersaturated solution, reducing water and energy consumption during the process.
[0077] In another embodiment, the isolated mother liquor is recycled within the system to minimize waste liquid discharge.
[0078] In another embodiment, direct evaporation drying is replaced with drying of the solid wet feed of DPOBT to reduce energy consumption.
[0079] In another embodiment, the DPOBT is in granular form obtained by spray granulation.
[0080] In an exemplary embodiment, the DPOBTis can be in the form of fine powder.
[0081] In an additional embodiment, the DPOBT is prepared in the form of granules using a spray granulation process. The spray granulation technique allows for the formation of uniform granules provide improved flow ability and handling characteristics. In another embodiment, the process produces DPOBT with high purity, suitable for use in agricultural applications.
[0082] In another embodiment, the present disclosure provides a method for improving plant health, comprising applying DPOBT as prepared by the method disclosed herein, to provide an effective source of both boron and potassium for optimal plant nutrition and stress tolerance.
[0083] In another embodiment, the DPOBT is applied at a concentration of between 0.1% and 0.3% by weight in water as a foliar spray.
[0084] In another embodiment, the crop is cotton and the DPOBT is applied at a concentration of 0.3% during vegetative growth and early flowering stages.
[0085] In another embodiment, the foliar application of DPOBT improves the harvest index, seed quality, and boll retention in cotton plants.
[0086] In another embodiment, the crop is marigold and the DPOBT is applied at a concentration of 0.15% during vegetative and flowering stages.
[0087] In another embodiment, the crop is paddy and the DPOBT is applied at a concentration of 0.3% during vegetative and reproductive stages.
[0088] In another embodiment, the foliar application of DPOBT increases plant height, dry matter production, number of branches, and yield per hectare compared to untreated control plants.
[0089] In another embodiment, the DPOBT treatment leads to an increase in flower size, flowering duration, and early flower bud initiation in marigold plants.
[0090] In another embodiment, the DPOBT treatment improves grain weight and overall grain yield in paddy plants.
[0091] In another embodiment, the present invention provides a method for enhancing the growth and yield of banana plants, comprising the foliar application of a formulation containing DPOBT at 0.3% at regular intervals starting from the 7th month of planting.
[0092] In another embodiment, the application of DPOBT results in increased finger weight, finger length, finger girth, hand weight, and overall yield compared to untreated banana plants.
[0093] In another embodiment, the foliar application of DPOB Timproves the size and firmness of banana fruits, as evidenced by higher finger weight, length, and girth compared to untreated controls.
[0094] In another embodiment, the DPOBT treatment improves the bunch weight of banana plants, resulting in a hand weight of 1.26 kg compared to 0.82 kg in the control group.
[0095] In another embodiment, the application of DPOBT enhances the overall yield of banana plants, with treated plants exhibiting superior biometric parameters compared to untreated controls.
[0096] In another embodiment, the foliar application of DPOBT provides an efficient means for nutrient absorption and improves resistance to environmental stressors in banana plants.
[0097] In another embodiment, the resultant DPOBT is formulated as a 0.3% w/v foliar spray solution and applied to cotton plants at the vegetative and early flowering stages (e.g., 40 and 60 DAS). Field trials confirm that the foliar application improves plant height, boll number, dry matter accumulation, and overall lint yield compared to untreated controls.
[0098] In another embodiment, the same DPOBT formulation is applied to marigold crops during the vegetative and bud initiation stages. The treatment results in significant increases in plant height, number of branches, number of flowers per plant, flower size, and flowering duration, thereby improving both aesthetic quality and marketable yield in ornamental horticulture.
[0099] In yet another embodiment, the DPOBT foliar spray is used on paddy (Oryza sativa) at the tillering and panicle initiation stages. Application of the 0.3% solution increases panicle density, grain filling, and 1000-grain weight, leading to an overall grain yield improvement of up to 8–10% over control groups.
[00100] In a further embodiment, banana plants are treated with the DPOBT foliar spray beginning at the 7th month after planting and continued at monthly intervals. The application improves finger length, girth, individual finger weight, and hand weight, with enhanced fruit development observed at harvest.
[00101] Each of these embodiments validates the multifunctional benefits of DPOBT in different crops and under various agronomic conditions, demonstrating the versatility, efficiency, and crop-specific advantages of the invention. The described process and formulations are scalable, reproducible, and adaptable to diverse climatic and soil conditions, making them suitable for commercial agricultural deployment and precision nutrient management systems.
[00102] In a further embodiment, a formulation kit is provided for preparing and applying a foliar spray of dipotassium octaborate tetrahydrate (DPOBT). The kit comprises: a sealed, moisture-resistant pouch containing pre-measured 25 grams of DPOBT powder (sufficient to prepare 10 liters of 0.25% spray solution); a foldable plastic mixing container with volume markings; a measuring scoop; and an instruction leaflet specifying dilution ratios, recommended crops (cotton, marigold, paddy, banana), spray timings, and frequency of application.
[00103] The kit is designed for on-field, low-resource environments, enabling smallholder farmers to achieve uniform nutrient delivery without complex equipment. The portability and simplicity of the kit facilitate its deployment in decentralized or remote agricultural areas, while ensuring consistent foliar nutrition and improved crop outcomes.
[00104] In an exemplary embodiment, a controlled-release formulation is developed using dipotassium octaborate tetrahydrate (DPOBT) encapsulated in a biodegradable polymer matrix comprising polyvinyl alcohol (PVA) or alginate. The encapsulated DPOBT particles are dispersed in an aqueous suspension and applied as a foliar spray or drip irrigation additive.
[00105] This controlled-release system is designed to release boron and potassium ions over an extended period of 7 to 10 days, thereby reducing the frequency of spray applications and improving nutrient use efficiency. The encapsulation also enhances shelf life and stability of the formulation under variable storage conditions. In field evaluations, crops treated with the controlled-release DPOBT formulation demonstrated sustained nutrient uptake, improved chlorophyll content, and reduced stress symptoms during periods of water or heat stress.
[00106] In an additional embodiment, the controlled-release DPOBT formulation is combined with other micronutrients such as zinc (Zn), iron (Fe), or manganese (Mn) in chelated form to create a multi-micronutrient foliar complex. This integrated approach addresses multiple deficiencies in a single application, enhancing root development, flowering, and grain or fruit formation in nutrient-stressed soils.
[00107] Hence, by integrating innovations in chemistry, process engineering, and agronomy, this invention not only contributes a novel composition and method but also introduces an environmentally sustainable, technically superior, and economically viable solution for the global agriculture sector. As such, the present invention holds promise for significant commercial deployment and positive impact on food security and resource-efficient farming practices.
[00108] While the foregoing describes various embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions, or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

EXAMPLES
[00109] The present invention is further explained in the form of the following examples. However, it is to be understood that the following examples are merely illustrative and are not to be taken as limitations upon the scope of the invention.
[00110] The present invention involves the preparation and application of dipotassium octaborate tetrahydrate (DPOBT) as a foliar spray to improve the growth, yield, and quality of various crops, including cotton, marigold, and paddy. The following details outline the specific applications and results observed for each crop.

Example 1: Preparation of DPOBT using potassium carbonate-Scheme 1
[00111] The preparation of dipotassium octaborate tetrahydrate (DPOBT) involves a series of steps to yield a high-quality product suitable for agricultural use. The process begins with dissolving Boric Acid in water to create a slurry. Potassium sources are then gradually added to the slurry, and the mixture is left undisturbed overnight for recrystallization. As the mixture cools, dipotassium octaborate tetrahydrate (DPOBT) crystals begin to form. The following day, the solids are separated from the remaining liquid through filtration, resulting in the purified DPOBT crystals. This method ensures the production of a pure, stable, and high-quality final product, ideal for applications such as pest control and as a micronutrient fertilizer.
Example 2: Preparation of DPOBT using potassium carbonate-Scheme 2
[00112] The preparation of dipotassium octaborate tetrahydrate (DPOBT) involves a series of steps to yield a high-quality product suitable for agricultural use. The process begins with dissolving Boric Acid in water to create a slurry. Potassium sources are then gradually added to the slurry, and the mixture is left undisturbed overnight for recrystallization. As the mixture cools, dipotassium octaborate tetrahydrate (DPOBT) crystals begin to form. The following day, the solids are separated from the remaining liquid through filtration, resulting in the purified DPOBT crystals. This method ensures the production of a pure, stable, and high-quality final product, ideal for applications such as pest control and as a micronutrient fertilizer.
Example 3: Preparation of dipotassium octaborate tetrahydrate (DPOBT)
[00113] In a 500 mL beaker, 100 g of boric acid was dissolved in 75 mL of water, followed by gentle agitation at room temperature for one hour to achieve a homogeneous mixture. Gradually, 41 g of potassium hydroxide was introduced to the mixture, ensuring no foaming or splattering occurred. Continuous stirring was maintained for an additional hour to facilitate the reaction. The mixture was then allowed to cool to room temperature before being left undisturbed overnight, promoting the recrystallization of dipotassium octaborate tetrahydrate (DPOBT). The solid DPOBT crystals were separated from the solution by filtration, resulting in purified crystals. These crystals were subsequently transferred to a drying oven and heated at 90°C to eliminate moisture. After drying, the DPOBT was ground into a fine powder, making it easier to handle and store. The final product demonstrated a yield of 81%, with minimal impurities, rendering it suitable for agricultural applications.
Example 4
[00114] To prepare DPOBT, 100 g of boric acid was added to 75 mL of water in a 500 mLbeaker. The mixture was agitated gently at room temperature for one hour to ensure an even distribution of boric acid. Then, 20 g of potassium carbonate was slowly introduced to the solution, preventing foaming or splattering. Stirring continued for an additional hour to allow for thorough mixing. The mixture was then allowed to stand undisturbed overnight, allowing the formation of DPOBT crystals as the solution cooled. Following this, the solid crystals were separated by filtration, leaving behind a purified product. The filtered DPOBT crystals were dried in an oven at 90°C to remove any residual moisture. Once dry, the DPOBT was pulverized into a fine powder for easier handling and storage. The yield of the final product was 90%, with minimal impurities, suitable for agricultural uses.
Example 5
[00115] In a 500 mL beaker, 100 g of boric acid was combined with 75 mL of water. The mixture was agitated at room temperature for one hour to ensure uniform distribution. Afterward, 25 g of potassium carbonate was carefully added to the solution, and the slurry was continuously stirred for an additional hour at 90°C. Once the reaction was complete, the mixture was allowed to cool to room temperature and left undisturbed overnight for recrystallization. The solid DPOBT crystals were filtered out from the liquid phase. The filtered product was then placed in a drying oven, where it was heated to 90°C to remove any remaining moisture. The dried DPOBT was ground into a fine powder to facilitate storage and handling. This method resulted in a yield of 95%, with very few impurities, making the product ideal for agricultural applications.
Example 6
[00116] For the preparation of DPOBT, 125 g of boric acid was added to 75 mL of water in a 500 mL beaker. The mixture was stirred gently at room temperature for an hour to ensure uniform dissolution. Subsequently, 25 g of potassium carbonate was slowly introduced to the mixture to avoid foaming or splattering. The slurry was then stirred for an additional hour. After the reaction, the mixture was allowed to cool and left undisturbed overnight for the recrystallization of DPOBT. The solid DPOBT crystals were separated by filtration, yielding a purified product. These crystals were dried in an oven at 90°C to remove moisture. Once dried, the DPOBT was ground into a fine powder for easier handling and storage. The final yield of DPOBT was 98%, with minimal impurities, ensuring its quality for agricultural purposes.
Example 7
[00117] In this preparation, 145 g of boric acid was added to 75 mL of water in a 500 mL beaker. The solution was agitated at room temperature for one hour to ensure complete dissolution. Potassium carbonate, at a quantity of 25 g, was then slowly added to the mixture, with stirring to avoid splattering. The slurry was stirred continuously for one more hour. Afterward, the mixture was left to cool and stand overnight to allow for the recrystallization of dipotassium octaborate tetrahydrate (DPOBT) crystals. The solid DPOBT was separated through filtration, and the purified product was transferred to a drying oven where it was heated at 90°C to remove any moisture. The dried DPOBT was pulverized into a fine powder for easier handling and storage. The final yield was 98%, with negligible impurities, making it suitable for agricultural applications.
Example 8
[00118] A 500 mL beaker was used for the preparation, where 125 g of boric acid was dissolved in 75 mL of water. The mixture was stirred for one hour at room temperature to ensure a consistent solution. Gradually, 45 g of potassium bicarbonate was added, with care taken to prevent foaming or splattering. Stirring was continued for another hour to facilitate proper mixing. Afterward, the solution was left undisturbed overnight to allow for the formation of DPOBT crystals. These crystals were then separated from the solution by filtration, yielding a purified product. The crystals were dried in a 90°C oven to remove moisture and then ground into a fine powder. The final product showed a yield of 86%, suitable for agricultural applications.
Example 9
[00119] In this preparation, 100 g of borax was added to 75 mL of water in a 500 mL beaker. The mixture was gently stirred at room temperature for one hour to ensure even dissolution. Then, 25 g of potassium carbonate was gradually added to the solution to prevent foaming. Stirring continued for an additional hour. Once the reaction was complete, the mixture was left undisturbed overnight for the recrystallization of dipotassium octaborate tetrahydrate (DPOBT) crystals. After filtration, the solid DPOBT crystals were separated from the liquid. The crystals were then transferred to a drying oven at 90°C to remove moisture. Once dried, the DPOBT was pulverized into a fine powder for easy storage and handling. The final product displayed a yield of 36%, along with the formation of potassium tetraborate pentahydrate, which was suitable for agricultural uses.

Example 10
[00120] For the synthesis of DPOBT, 100 g of borax was added to 75 mL of water in a 500 mL beaker. The solution was gently agitated at room temperature for one hour to ensure uniform dissolution. Potassium hydroxide, at 41 g, was then slowly added to the solution to avoid foaming. Stirring continued for an additional hour to ensure thorough mixing. The solution was allowed to cool and left undisturbed overnight, promoting the recrystallization of DPOBT. The DPOBT crystals were separated by filtration and dried in an oven at 90°C to remove moisture. After drying, the DPOBT was ground into a fine powder, making it easier to store and handle. The yield of the final product was 36%, with the presence of potassium tetraborate pentahydrate, indicating that the product may require additional purification steps for agricultural applications.
Example 11
[00121] For this synthesis, 125 grams of borax were mixed into 75 mL of water inside a 500 mL beaker. The solution was gently stirred at ambient temperature for one hour to ensure thorough dissolution. Subsequently, 41 grams of potassium hydroxide were carefully incorporated into the solution to minimize foaming. The stirring continued for an additional hour to ensure a complete reaction. After the process, the solution was allowed to sit undisturbed overnight to promote recrystallization of dipotassium octaborate tetrahydrate (DPOBT). The resulting crystals were separated by filtration. The collected DPOBT crystals were dried at 90°C to eliminate moisture, after which they were ground into a fine powder for easier storage. The overall yield was 36%, with potassium tetraborate pentahydrate also being produced, suitable for agricultural applications.
Example 12
[00122] In a 500 mL beaker, 100 grams of boric oxide were dissolved in 75 mL of water. The mixture was stirred at room temperature for an hour to ensure full dissolution. Next, 30 grams of potassium carbonate were added slowly to the solution to prevent excessive foaming. The solution was stirred for an additional hour to ensure the reaction was complete. Afterward, the mixture was cooled and left to sit overnight for the recrystallization of dipotassium octaborate tetrahydrate (DPOBT). The formed crystals were separated by filtration. After drying at 90°C to remove residual moisture, the DPOBT crystals were powdered for storage. The yield was 34%, and potassium tetraborate pentahydrate was also obtained, suggesting the need for further processing before agricultural use.
Example 13
[00123] To begin the preparation, 100 grams of boric oxide were dissolved in 75 mL of water in a 500 mL beaker. The solution was stirred at room temperature for one hour to ensure uniform mixing. Gradually, 45 grams of potassium hydroxide were added to avoid foaming. After another hour of stirring, the solution was cooled and left undisturbed overnight to allow the recrystallization of dipotassium octaborate tetrahydrate (DPOBT). The solid DPOBT was isolated by filtration. After drying at 90°C to remove excess moisture, the DPOBT was pulverized into a fine powder for convenient handling and storage. The final yield was 34%, with potassium tetraborate pentahydrate present, indicating potential need for further purification for agricultural purposes.
Example 14
[00124] In a 500 mL beaker, 100 grams of boric oxide were dissolved into 75 mL of water. The solution was agitated at room temperature for one hour to ensure thorough dissolution. Then, 25 grams of potassium carbonate were gradually added to the solution, ensuring no foaming occurred. The mixture was stirred for another hour. Afterward, it was cooled and left undisturbed overnight to allow the recrystallization of dipotassium octaborate tetrahydrate (DPOBT). The resulting DPOBT crystals were separated via filtration, dried at 90°C, and ground into a fine powder for easy storage. The yield was 34%, accompanied by the formation of potassium tetraborate pentahydrate, suggesting that further purification could be needed for agricultural use.
Example 15
[00125] The process began by dissolving 100 grams of boric oxide into 75 mL of water in a 500 mL beaker. The mixture was stirred for one hour at room temperature to achieve complete dissolution. Following this, 45 grams of potassium carbonate were carefully added to the solution to avoid foaming. After one more hour of stirring, the mixture was cooled and left to stand overnight to facilitate the recrystallization of dipotassium octaborate tetrahydrate (DPOBT). The DPOBT crystals were then separated through filtration. After drying the crystals at 90°C to remove moisture, they were ground into a fine powder for easier handling. The yield achieved was 35%, with potassium tetraborate pentahydrate forming as a byproduct, suggesting additional purification may be necessary for agricultural applications.
Example 16
[00126] In this experiment, 125 grams of boric oxide were dissolved in 75 mL of water in a 500 mL beaker. The solution was stirred for one hour at room temperature to ensure complete dissolution. Following this, 45 grams of potassium carbonate were gradually added to avoid any foaming. The mixture continued to stir for another hour. Afterward, it was allowed to cool and remained undisturbed overnight to encourage the recrystallization of dipotassium octaborate tetrahydrate (DPOBT). The DPOBT crystals were isolated by filtration, then dried at 90°C to eliminate moisture. Once dried, the crystals were finely ground into powder for storage. The yield was 36%, and potassium tetraborate pentahydrate was also formed, suggesting further purification may be necessary for its use in agriculture.
Example 17: The foliar application of DPOBT on cotton
[00127] For cotton (Gossypium spp.), a foliar spray of 0.3% DPOBT was applied at crucial growth stages, particularly during the vegetative growth phase and the early flowering period. The results of the study revealed that cotton plants treated with DPOBT exhibited notable improvements in various growth parameters. Specifically, the treated plants showed enhanced height, reaching 115 cm at 120 days after sowing (DAS) and 125 cm at harvest, in comparison to untreated plants. In addition to increased height, dry matter production was significantly boosted, with treated plants showing a 20-25% increase in biomass. The values were 4100 kg ha⁻¹ at 120 DAS and 4925 kg ha⁻¹ at harvest, indicating a substantial improvement over the untreated controls. Moreover, the application of DPOBT led to a positive effect on branching patterns, with both monopodial and sympodial branches increasing. The number of monopodial branches rose to 2.1, while sympodial branches increased to 20.2 per plant. As a result, the treated plants produced an average of 25.6 bolls per plant, contributing to a marked increase in yield. Overall, the cotton yield from treated plants increased by 15%, reaching 2725 kg ha⁻¹, which was a significant improvement compared to the untreated control, further emphasizing the positive impact of the DPOBT foliar spray on cotton growth and productivity.
Example 18: The foliar application of DPOBT on Marigold
[00128] For marigold (Tagetes spp.), a 0.3% foliar spray of DPOBT was applied at key stages of growth, specifically during the vegetative and flowering phases. The results demonstrated that the application of DPOBT led to significant improvements in several growth and flowering parameters. Notably, treated marigold plants experienced a remarkable increase in plant height, reaching an impressive 75.26 centimeters. Additionally, vegetative growth was enhanced, as indicated by an increased number of primary branches, with treated plants producing an average of 55.36 branches, as well as an increase in the number of leaves, with an average of 198.12 leaves per plant. The positive effects of DPOBT were also evident in the flower yield. The treated plants produced 7.99 kg of flowers per plot, translating to 18.25 tons per hectare, showing a significant boost in productivity compared to untreated plants. Beyond yield, the size and overall quality of the flowers were enhanced as well. The flowers exhibited a larger diameter, reaching 5.05 cm, making them more visually striking. The application of DPOBT also resulted in earlier bud initiation, occurring at 32.1 days, and an extended flowering period lasting 88.5 days. This combination of earlier bloom initiation and a longer flowering duration not only prolonged the overall flowering period but also resulted in flowers of higher aesthetic value, contributing to more abundant and attractive blooms.
Example 19: The foliar application of DPOBT on paddy (Oryza sativa)
[00129] For paddy (Oryza sativa), a 0.3% foliar spray of dipotassium octaborate tetrahydrate (DPOBT) was applied during the early vegetative and reproductive growth stages. The results revealed significant improvements in plant growth and reproductive outcomes for the treated paddy plants. Specifically, the height of the treated paddy plants increased, reaching 104.2 cm at 120 days after sowing (DAS) and 115 cm at harvest. This growth boost was accompanied by an increased density of panicles per meter, with an average of 189.25 panicles, indicating improved plant productivity. The most notable impact of the DPOBT treatment was on grain yield, which showed a considerable increase, reaching 5.42 tons per hectare, compared to the control, which yielded 5.02 tons per hectare. Additionally, grain quality was enhanced, as demonstrated by a higher 1000-grain weight of 23.8 g, signifying improved seed quality. Another important indicator of the treatment’s success was the harvest index, which increased by 0.2% in the DPOBT-treated plants. This suggests a higher proportion of grain relative to the total plant biomass, further confirming the improved efficiency of resource allocation in these plants. These findings underscore that the foliar application of DPOBT significantly enhances plant growth, reproductive success, and overall yield in a variety of crops, including cotton, marigold, and paddy. This method not only aids in better nutrient uptake but also contributes to healthier plants with improved quality and productivity. The results highlight the potential of DPOBT to boost crop performance, offering a promising approach to increase agricultural output and the quality of harvested products.
Example 20: The foliar application of DPOBT on Banana Plant
[00130] For banana plant, the results demonstrated a significant improvement in all measured parameters for the banana plants treated with a 0.3% foliar spray of dipotassium octaborate tetrahydrate (DPOBT), as compared to the control. Notably, the finger weight, a critical indicator of fruit quality, was higher in the DPOBT-treated bananas, with an average of 72.28 g per finger, compared to 65.12 g in the control. This suggests that the foliar application of secondary nutrients, including the banana-specific formulation, effectively enhanced the growth and development of the fruit. Similarly, improvements were observed in finger length and girth, with finger length increasing from 11.35 cm in the control to 13.85 cm in the DPOBT treatment, and finger girth increasing from 30.25 mm to 35.65 mm. These changes are indicative of better fruit development, which could potentially lead to higher market value due to enhanced size and appearance. Additionally, hand weight was significantly higher in the DPOBT-treated plants, reaching 1.26 kg, compared to just 0.82 kg in the control. This increase in hand weight suggests that the application of secondary nutrients positively influenced both individual fruit size and overall bunch weight, pointing to improved yield potential. These findings support previous studies highlighting the beneficial role of secondary nutrients, such as boron, in fruit development. Boron is known to strengthen cell walls, improve fruit firmness, and enhance disease resistance, while also supporting better root development and overall plant health. The improved biometric parameters observed in the DPOBT-treated bananas further confirm the positive impact of this foliar treatment on fruit quality and plant productivity.
Example 21: Best Mode of carrying out the invention (Fig. 1)
[00131] The best mode of carrying out the present invention involves the preparation of dipotassium octaborate tetrahydrate (DPOBT) using boric acid as the boron source and potassium carbonate as the potassium source in an aqueous medium, followed by crystallization, drying, and application as a foliar spray. This method ensures high yield, chemical stability, and bioavailability of boron and potassium for foliar uptake.
[00132] To prepare the DPOBT, 125 grams of boric acid is dissolved in 75 mL of water at ambient temperature under constant agitation to form a homogenous slurry. To this solution, 25 grams of potassium carbonate is slowly added with continuous stirring to avoid foaming and promote complete dissolution. The reaction mixture is stirred for approximately 1 hour and then allowed to cool to room temperature. It is subsequently left undisturbed for 12 to 16 hours to allow recrystallization of DPOBT. The crystallized solid is then separated by filtration.
[00133] The filtered wet crystals are dried using a solid wet-feed drying technique at 90°C in a convection oven until a moisture-free product is obtained. The dried material is then ground into a fine powder. This method results in a final yield of approximately 98%, with the product demonstrating high purity and suitability for agricultural application.
[00134] The resulting DPOBT is formulated as an aqueous foliar spray solution at a concentration of 0.3% w/v, specific to the target crop. The composition is then applied at key vegetative or reproductive growth stages to improve nutrient uptake and crop performance.
Working Examples
Example 1: Preparation and Foliar Application of DPOBT in Cotton
Reagents and Conditions:
Boric acid: 125 g
Potassium carbonate: 25 g
Water: 75 mL
Drying temperature: 90°C
Stirring time: 1 hour
Crystallization time: 12–16 hours (overnight)
Preparation Steps:
[00135] In a 100 L capacity beaker, 125 g of boric acid is added to 75 mL of deionized water and stirred for 1 hour at room temperature.25 g of potassium carbonate is added gradually with continuous stirring. The reaction mixture is allowed to cool and stand overnight to recrystallize. The crystals are filtered and dried at 90°C in a tray dryer for 4–6 hours. The dried crystals are pulverized to a fine powder. The process yields approximately 98 kg of dry, pure DPOBT crystals per 100 kg of theoretical output. For application in Cotton, 0.3% w/v aqueous foliar spray is prepared using the DPOBT powder. The spray is applied to cotton plants at 40 and 60 days after sowing (DAS), corresponding to the vegetative and early flowering stages with the spray volume: 750 liters per hectare (Fig. 1).
[00136] Plant height at harvest increased from 115 cm (control) to 125 cm (treated).Dry matter production improved by 20–25%.Number of bolls per plant increased to 25.6.Overall yield improved by 15% compared to untreated controls.
[00137] This Best Mode and Working Example demonstrate the technical viability, agronomic effectiveness, and reproducibility of the invention, thereby satisfying the sufficiency and enablement criteria.
[00138] The foregoing examples are merely illustrative and are not to be taken as limitations upon the scope of the invention. Various changes and modifications to the disclosed embodiments will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the scope of the invention.

ADVANTAGES OF THE PRESENT INVENTION
[00139] The present invention offers a multitude of advantages, both in terms of agronomic performance and process innovation. First and foremost, the foliar application of dipotassium octaborate tetrahydrate (DPOBT) at optimized concentrations has demonstrated significant improvements in crop performance metrics such as plant height, dry matter production, boll retention, flower size, grain filling, and overall yield across diverse crops including cotton, marigold, paddy, and banana. The composition delivers a balanced supply of two critical nutrients—boron and potassium—in a chemically stable and plant-bioavailable form, thereby enhancing nutrient absorption, photosynthetic efficiency, and reproductive success.
[00140] From a manufacturing standpoint, the invention introduces a more economical, energy-efficient, and scalable synthesis method for DPOBT. Traditional methods involving disodium octaborate tetrahydrate not only introduce undesirable sodium into the soil, but also rely on energy-intensive convection drying techniques. In contrast, the present invention replaces convection-based drying of the reaction solution with a solid wet-feed drying approach, significantly lowering energy consumption and allowing for better process control. Moreover, the pre-mixing of boric acid with potassium carbonate before dissolution drastically reduces dissolution time, thus accelerating the reaction kinetics and shortening the overall reaction cycle, which contributes to increased throughput and reduced production costs.
[00141] A key innovation lies in the exploitation of stable supersaturated solutions, which minimizes the need for excess water, reduces solvent consumption, and enables efficient crystal separation through mechanical induction. This enhances the crystallization yield while simultaneously minimizing downstream drying requirements. Another major advantage is the implementation of a closed-loop process in which the mother liquor and intermediate reaction streams are entirely recycled, resulting in zero liquid discharge (ZLD) and minimal environmental impact. The reuse of internal materials also enhances raw material efficiency and reduces the ecological footprint of the process.
[00142] Together, these improvements provide a fertilizer composition that is sodium-free, non-toxic, crop-adaptable, and environmentally sustainable, making it highly suitable for widespread agricultural use. The technology is not only suited for large-scale commercial farming, but also scalable for localized production, offering cost-effectiveness, flexibility, and green credentials unmatched by prior-art solutions such as those disclosed in EP1310456B1 or CN111187117A, which either require high-temperature spray drying, rely on sodium-based compositions, or lack multi-crop applicability. Thus, the invention represents a significant advancement in the field of plant nutrition and sustainable agrochemical development.
, Claims:1. A method for preparing dipotassium octaborate tetrahydrate (DPOBT), the method comprising:
dissolving a boron-containing compound in water to form a slurry;
gradually adding a potassium-containing compound to the slurry;
stirring the mixture for the duration ranging from 1 to 2 hours in room temperature to promote reaction;
allowing the mixture to cool and stand undisturbed to recrystallize and form DPOBT crystals;
seperating DPOBT crystals by filtration;
drying the crystals at a temperature between 85°C to 95°C; and
pulverizing the dried crystals to obtain DPOBT.
2. The method as claimed in claim 1, wherein the boron-containing compound is selected from boric acid, borax, boric oxide, or combinations thereof.
3. The method as claimed in claim 1, wherein the boron-containing compound is used in an amount ranging from 100 g to 145 g per 75 mL of water.
4. The method as claimed in claim 1, wherein the potassium-containing compound is selected from potassium carbonate, potassium hydroxide, potassium bicarbonate or a combination thereof.
5. The method as claimed in claim 1, wherein the potassium-containing compound is used in an amount ranging from 20 g to 45 g per 75 mL of water.
6. The method as claimed in claim 1, wherein the mixture is stirred for 30 minutes to 2 hours and left undisturbed for 8 to 24 hours to allow recrystallization.
7. The method as claimed in claim 1, wherein the mother liquor is recycled after filtration to reduce process waste.
8. The method as claimed in claim 1, wherein drying is performed on the solid wet feed of DPOBT to reduce energy consumption compared to evaporative drying.
9. The method as claimed in claim 1, wherein the DPOBT is in the form granular form obtained by spray granulation.
10. The method as claimed in claim 1, wherein the DPOBT is stable at the temperature ranging from-5oC to 60oC for the time duration ranging from three years under normal conditions
11. A foliar fertilizer composition comprising 0.1% to 0.3% by weight of dipotassium octaborate tetrahydrate (DPOBT);
wherein the DPOBTis a crystallized compound formed by reacting a boron-containing compound selected from boric acid, boric oxide, or borax with a potassium-containing compound selected from potassium carbonate, potassium hydroxide, or potassium bicarbonate; and
99.7% to 99.9% by weight of an agronomically acceptable aqueous carrier;
wherein the composition is adapted for foliar application to crops during their vegetative and/or reproductive growth stages.
12. The composition as claimed in claim 1, wherein the DPOBT has a purity of at least 95% and is in the form of a fine powder with moisture content below 5%.
13. The composition as claimed in claim 1, wherein the foliar fertilizer is applied at a spray volume of 500 to 1000 liters per hectare.
14. The composition as claimed in claim 1, wherein the aqueous carrier is water having a pH between 6.0 and 7.5.
15. A method for applying the DPOBT on selected crops, the method comprising:
Preparing dipotassium octaborate tetrahydrate (DPOBT) as claimed in claim 1; and
applying a foliar spray comprising 0.1% to 0.3% by weight of the prepared DPOBT in water to the foliage of the crop during at least one of its vegetative or reproductive growth stages.
16. The method as claimed in claim 15, wherein the crop is selected from, but not limited to, cotton, marigold, paddy, and banana.
17. The method as claimed in claim 15, wherein the DPOBT is applied at a concentration of between 0.1% and 0.3% by weight in water as a foliar spray.
18. A kit for enhancing crop growth and yield, comprising:
a pre-measured quantity of dipotassium octaborate tetrahydrate (DPOBT) in powder form,
an instruction leaflet comprising recommended foliar spray concentrations of DPOBT; and
optionally, a dispensing or mixing container adapted for preparing the foliar spray.