GB2435470A

GB2435470A - Agricultural fertiliser composition.

Info

Publication number: GB2435470A
Application number: GB0603468A
Authority: GB
Inventors: David Marks
Original assignee: Plant Impact PLC
Current assignee: Plant Impact PLC
Priority date: 2006-02-22
Filing date: 2006-02-22
Publication date: 2007-08-29
Anticipated expiration: 2026-02-22
Also published as: GB2435470B; GB0603468D0

Abstract

An agricultural fertiliser composition comprising (i) a water-soluble salt of a nutrient mineral, (ii) a plant oil, (iii) an emulsifier and (iv) a wax, wherein the water-soluble salt of a nutrient mineral is in suspension in the oil. Such compositions are useful in administering in particular secondary or micronutrients to plants.

Description

Agricultural composition The present invention relates to an

agricultural composition, in particular to a fertilizer composition, that optionally further has additional properties such as insect repellent properties.

Plants need a range of nutrients for healthy growth. These include macronutrients such as nitrogen, phosphorus, potassium, carbon and water, secondary nutrients such as calcium, magnesium, sodium, chloride and sulphur, as well as micronutrients which include copper, cobalt, iron, manganese, boron, molybdenum, zinc, silicon and nickel.

The introduction of particularly secondary and micronutrients into the plant can be difficult, even though they may be present in significant quantities in the soil. Their availability to the plant may be low.

One method, which has been used hitherto to enhance the availability of these nutrients to the plant is to apply them in conjunction with chemical chelating agents such as EDTA.

However, synthetic chemical chelates are damaging to the environment as they do not degrade in the soil and scavenge undesirable elements after completing their purpose.

The applicants have found an improved manner of administering nutrients and particularly secondary or micronutrients to plants.

The present invention provides an agricultural composition comprising (i) a water-soluble salt of a nutrient mineral, (ii) a plant oil, (iii) an emulsifier and (iv) a wax, wherein the water-soluble salt of a nutrient mineral is in suspension in the oil.

As used herein the term "wax" refers to a solid or semi-solid substance which comprises a high molecular weight hydrocarbon such a high molecular weight alkane, or an ester of a fatty acid, or a mixture of these.

The expression "high molecular weight" as used herein means that the molecular weight is generally in excess of 100, preferably in excess of 200. Wax molecules will generally comprise at least 8 carbon atoms and preferably from 10-100 carbon atoms, for example from 20-80 carbon atoms.

They may include waxes secreted by plant or animals, or mineral waxes such as paraffin wax. Alternatively they may comprise a synthetic wax such as cable wax.

A particularly preferred wax for use in the compositions comprise at least some ester of a fatty acid, and in particular beeswax. The composition of beeswax generally comprises one or more esters of straight-chain monohydric alcohols with straight chain acids which may be represented as compounds of formula (I) CH2+1OCOCH2+i ( I where x is from 20 to 40, and in particular is an even number between 24 and 36, and y is from 1-40 and suitably is an even number of from 14-38.

Examples of such esters include triacontanol hexadecanoate, hexaconasol hexacosanoate and myricyl ester of palmitic acid of formula C30H610C0C15H3-1 (I) The compounds of formula (I) may be mixed with, for example up to about 20%w/w hydrocarbons having from 15-51 carbon atoms, for example, from 21 to 33 carbon atoms, and usually odd-numbers of carbon atoms within this range.

The applicants have found, that wax acts as a thickening or suspending agent and can therefore support the water-soluble salt of a nutrient mineral in suspension, in a much more effective and efficient manner than many available thickening agents. This means that the formulation retains stability and is easy to use, as it does not require extensive shaking before use. By preventing the water soluble salt of a nutrient mineral from readily dropping out of suspension, there is less likelihood that the salts will be retained within the container, so that loss of salt and consequent inappropriate dosing is minimized.

The amount of wax included in the composition will vary depending upon the nature of the particular wax used, as well as the nature of the other components of the mixture, and these can be optimized using conventional procedures. Suitably the amount added is from 1 to 5%w/w, for example from 2-3%w/w.

Suitably the water-soluble salt of a nutrient mineral, is a water-soluble salt of a secondary nutrient such as calcium, magnesium, sodium, chloride and sulphur, or a micronutrient in particular, copper, cobalt, iron, manganese, boron, molybdenum, zinc, silicon and nickel. Most preferably, the water-soluble salt is a salt of a micronutrient, especially zinc, copper, cobalt, iron or manganese. Particular examples of minerals are zinc, calcium and boron.

Suitable water-soluble salts are nitrates, sulphates and chlorides, and preferably are nitrates and suiphates.

Suitably the water-soluble mineral salt is other than calcium chloride.

Particular examples of water-soluble mineral salts for inclusion in the compositions include zinc nitrate, iron sulphate, zinc sulphate, magnesium sulphate, manganese sulphate, iron nitrate or manganese nitrate.

The water-soluble mineral salt, which will be present as a solid powder, is suitably present in the composition in an amount of up to 20%v/v, preferably from 5 to 15% v/v and most preferably from 10-15% v/v.

Suitable plant oils for inclusion in the formulation of the invention include canola oil (oilseed rape oil), soybean oil, cottonseed, castor oil, linseed oil and palm oil.

The composition of the invention comprises an emulsifier, which may be any known agriculturally acceptable emulsifier. In particular, the emulsifier will comprise a surfactant, typically alkylaryl suiphonates, ethoxylated alcohols, polyalkoxylated butyl ethers, calcium alkyl benzene sulphonates, polyalkylene glycol ethers and butyl polyalkylene oxide block copolymers as are known in the art.

Nonyl phenol emulsifiers such as Triton N57TM are particular examples of emulsifiers, which may be used in the compositions of the invention, as are polyoxyethylene sorbitan esters such as polyoxyethylene sorbitan monolaurate (sold by Id under the trade name "Tween") . In some instances, natural organic emulsifiers may be preferred, particularly for organic farming applications. Coconut oils such as coconut diethanolamide is an example of such an compound. Palm oil products such as lauryl stearate may also be used.

The emulsifier is suitably present in an amount which is sufficient to ensure that the composition has the desired miscibility with water. For instance, the emulsifier may be present in amounts of from 1 to 20%w/w, suitably up to lO%w/w and in particular from 4-6%w/w.

Generally the plant oil will comprise the balance of the composition. However, the composition may comprise further components as described below, including water.

Typically, in use, the agricultural composition is shaken in the bottle and added to water where it forms an emulsion of vegetable oil / mineral element in the spray tank. It can them be applied to plants, in particular crop plants, in a conventional manner for example by spraying or drip irrigation methods.

Use of the composition of the invention improves the uptake of the mineral element by the plant in foliar sprays by improving its coverage. Emulsification in plant oil improves the spreading, wetting and sticking of the mineral across the foliage. This allows the mineral to cover a greater surface area of the vegetation giving better and more even uptake. Even uptake is essential in elements that are not very mobile within the plant such as calcium and boron.

The sticking action is beneficial in allowing the plant to absorb the mineral over a time period. Furthermore, it improves rainfastness without which the mineral can be removed from the leaf before it is absorbed fully.

Vegetable oil emulsification also minimizes the volatilization of the mineral into the atmosphere and so allows uptake to proceed over a longer period.

When applied through drip irrigation or fertigation systems, the compositions of the invention show improved spread of a mineral element through the soil, as a result of the plant oil emulsification. Specifically, the composition is not very mobile in the soil and so remains substantially in the vicinity in which it is applied, i.e. adjacent the root system.

However, the emulsion also protects the mineral from leaching by adhesion to the soil particles, which also means that it can be better absorbed by the plants root system. Specifically, emulsification can prevent the mineral from being "locked up" in soil, for example by being bound to organic matter, or by adverse soil conditions (pH etc.) and so becoming unavailable to the plant.

Vegetable oil emulsification also helps to delay drying of the soil, which can be a limiting factor in root uptake of mineral elements.

Compositions of the invention may also comprise other agriculturally acceptable components such as additional thickeners, suspension agents or wetting agents.

Examples of additional thickeners may comprise gums, for example xanthan gum or lignosulphonate complexes, as are known in the art.

Suitable suspension agents which may be included in the formulations include hydrophilic colloids (such as polysaccharides, polyvinylpyrrolidone or sodium carboxymethylcellulose) and swelling clays (such as bentonite or attapulgite) Wetting agents may be surfactants of the cationic, anionic, amphoteric or non-ionic type, as is known in the art.

In addition, the compositions of the invention may comprise additional nutritional products and/or growth stimulants used in crop nutrition, such as seaweed extract powders, humic and fulvic acid powders and amino acid powders.

In a particularly preferred embodiment, the compositions further comprise one or more essential oils, or active components thereof. Essential oils are a product of a plants secondary metabolism' a large and diverse group of reactions not essential to the core growth and development of the species. These compounds alter the gene expression and metabolism of plants when they are applied exogenously.

The composition suitably contains no more than 5%w/w of essential oil, more suitably no more than 3%w/w and preferably no more than l.5%w/w of essential oil. For instance, the composition may contain no more than 1%w/w essential oil.

As used herein, the expression "essential oil" refers to natural aromatic oils, obtainable from plants. Particular essential oils include tagetes oil, such as the oil obtainable Tagetes erecta and thyme oil, such as the oil obtainable from Thymus vulgaris, Wintergreen oil, Rosemary oil, garlic oil, oils from Chenopodium, Erythroxylum, Eugenia, Gaultheria, Myristica, Syzygium, Xanthophyllum, Cinnamonium, Gualtheria, Gossypium and mentha. However, essential oils for inclusion in the compositions of the invention are obtainable from in a wide range of plant families including those families listed in the following Table 1. The Table also includes examples of particular species found within each of these families

Table 1

Family Acanthaceae Adhatoda vasica (malabar nut) Anacardiaceae Anacardum occidentale (cashew nut) Annonaceae Annona reticulata (bullocks heart) Annona squamosa (custard apple) Monodora myristica (nutmeg) Apiacea (umbelliferae) Anethum graveolens (dill) carum carvi (caraway) Carum roxburghianum (Bishops weed) Pimpinella anisum (aniseed) Apocynaceae Nerium oleander (oleander) Araceae Acorus calamus (flagroot) Asteraceae Ageratum conzyaides (goatweed) Artemesia vulgaris (mugwort) Bulmea balsamifera (camphor) Chrysanthemum indicum (manzanhlla) Sausurea lappa Hellianthus annus (sunflower) Brassicaceae Raphanus sativus (radish) Ceasalpinaceae Erythrophleum suaveolens (ordeal tree) Cappardaceae Bosica senegalensis Cleome monophylla Cel lastraceae Celastrus angulatus (Chinese bittersweet) Chenopodiacea Chenopodium ambrosiodes (Sweet pigweed) Clusiaceae Calophyllum inophyligum (luarelwood) Convulvulaceae

Convulvulus arvensis (field bindweed)

Cucurbitaceae Momordica charantia (Balsam pear) Dipterocarpaceae Shorea robusta (sal tree) Ericaeae Gualtheria procumbens (wintergreen) Euphorbiaceae Jatropha curcus (Physic nut) Fabaceae Butea frondosa (flame of the forest) Gliricidia sepium (Madre de Cacao) Psoralea coylifolia Pongamia glabra (karanja) Trigonella foenum (fenugreek) Graminaceae Cymbopgon martini (gingergrass) Oryza sativa (rice) Laminaeae Bystropogon spp.

Coleus amboinicus (oregano) Hyptis spicigera (black sesame) Hyptis suaveolens Lavendula angustifolia (lavender) Mentha arvensis (cornmint) Mentha longifolia (Horsernint) Mentha piperita (peppermint) Mentha spicata (spearmint) Osimum basilicum (sweet basil) Osimum canum (American basil) Osirnum kilimandscharicum Osimum suave (wild basil) Origanum vulgarae (oregano) Pogostemon heyneanus Rosmarianus officianis (rosemary) Salvia officianalis (sage) Thymus vulgaris (garden thyme) Tetradenia riparia Lauraceae Cinnamomum arornaticum (cassia) Luaris nobilis (sweet bay) Liliaceae A lii urn Allium sativum (garlic) Meliaceae Azadirachta indica (neem) Melia azedarach (Persian lilac) Menisperaceae Cissampelos owariensis (Pareira brava) Myrsinaceae Embelia ribes Myrtaceae Eucalyptus spp.

Eucalyptus citriodara (lemon-scented gum) Eucalyptus globus (Blue gum tree) Eucalyptus terreticomis Psidium guajava (guava) Syzygium aromaticum (clove) Myristicaceae Myristica fragrans (mace) Piperaceae Piper cubeda (java long pepper) Piper guineense (Ashanti pepper) Piper nigrum (black pepper) Ranunculaceae Nigella sativa (black cumin) Rutaceae Aegle marmelos (Bengal quince) Citrus aurantifolia (lime) Citrus limon (lemon) Citrus paradisi (grapefruit) Citrus sinensis (sweet orange) Limonia acidissima (roem) Zanthoxylum alatum (prickly ash) Simarubaceae Quassia Africana Solanaceae Capsicum annum (bell pepper) Capsicum frutescens (Tabasco) Lycopersicon esculentum (tomato) Nicotiana tabacum (tobacco) Withania somnifera (winter cherry) Vebenaceae Clerodendron siphonanthus Lanatana camara (yellow sage) Lippia geminata (wild sage) Vitex negundo (begunnia) Zingiberaceae Afromomum melagueta (grains of pleasure) Alpinia galanga (greater galangal) Curcuma longa (tumeric) Zingiber officinale (ginger) The term "active components thereof" refers to the chemicals within the essential oil which give rise to the desired activity in plants. Such activities are explained in more detail below, but include metabolic stimulating effects, antimicrobial effects, insect or arachnid killing or repellent effects, antiviral and viral remediation effects.

The oils may be present alone or combinations of different oils may be included, provided the total essential oil content does not exceed the amounts specified above.

When essential oils are included in the compositions described above, they can stimulate the metabolism of the plant to which the composition is applied, thus increasing the uptake and utilization of the applied mineral either by root uptake or foliar absorption.

Some essential oils, or active components thereof, can actively stimulate root absorption, or leaf absorption.

In a particularly preferred embodiment, the essential oil or active component thereof, is selected as being one, which increases plant metabolic activity in a pathway that utilizes a specific mineral nutrient within the composition. As a result, the plant will absorb more of the nutrient to meet its requirements, and so synergy between the components can be obtained.

For example, wintergreen oil, or similar oils, stimulates the need for calcium and conversely calcium stimulates the need for the compounds present in wintergreen oil. Therefore the inclusion of wintergreen oil or similar, or an active component thereof within the composition of the invention which comprises a water soluble calcium salt as the mineral nutrient is advantageous.

The main component of wintergreen oil is methyl salicylate, and so this may be used instead of wintergreen oil itself, but other salicylate compounds such as salicyclic acid or esters thereof, in particular alkyl esters such as C110a1ky1 esters may be used. Salicylate compounds also reduce ethylene production or have antiviral effects. Ethylene production is increased following infection with many viruses, and application of compounds, which reduce this, can be used to remediate symptoms. Thus the inclusion of such compounds may further produce viral remediation effect.

Preferably, the salicylate compound used in the composition is in the form of an essential oil as these form a readily useable source of active ingredient, which is miscible with the composition.

Examples of essential oils which include salicylic acid or salicylates include wintergreen oil as explained above but also oils from Chenopodium, Erythroxylum, Eugenia, Gaultheria, Myristica, Syzygium, Xanthophyllum, Cinnamonium, Gualtheria, Gossypium and mentha.

A further example would be to incorporate into a composition described above comprising a water-soluble zinc or copper salt as the nutrient mineral, an essential oil which stimulate pathways related to auxin or carbohydrate production. This is because zinc or copper is required for auxin and carbohydrate metabolism, and therefore essential oils that would increase the requirement for these minerals would work synergistically to enhance uptake of the mineral nutrient.

O There is a large number of enzymes in which zinc is an integral component of the enzyme stucture (zinc enzymes) . In these enzymes, zinc has three functions: catalytic, cocatalytic or structural. Examples include carbonic anhydrase, carboxypeptidase, alcohol dehydrogenase, alkaline phospatase, phospholipase, and RNA polymerase.

Zinc pyrophosphatase (Zn.PPase), dehydrogenases, aldolases, isomerases and transphosphorylases are modulated by zinc also.

Any upgrade in activity of these pathways, for example as a result of the presence of an appropriate essential oil, would increase absorption of the water-soluble zinc salt which is being applied.

However, many other synergistic combinations can be envisaged.

For instance, copper is associated with IAA (auxin) oxidase, diamine oxidase, cytochrome oxidase, ascorbate oxidase, superoxide dismutase, phenol oxidases. Metabolism linked to copper includes lignin biosynthesis, carbohydrate metabolism, and nitrogen metabolism.

Nickel is linked to several enzymes including urease, whereas molybdenum is linked to nitrogenase, nitrate reductase, xanthene oxidase and xanthene dehydrogenase. Similarly, boron is involved in nucleic acid metabolism, auxin metabolism, and phenol metabolism, and iron is linked with heme protein metabolism, iron-sulphur protein metbolism, and strongly with ethylene metabolism. Specific enzymes linked with iron include ferrodoxin, and nitrate reductase, Manganese is utilised in a large number of enzymes, including malic enzyme, and isocitrate dehydrogenase. It is, as a result, involved in lipid, carbohydrate and protein metabolism.

Inorganic pyrophosphatases (PPases) can be linked with magnesium, manganese and zinc.

Co-administration of these nutrient minerals together with the essential oils which stimulate the pathways in which these enzymes are involved leads to further enhancement of nutrient uptake.

Other compounds or reagents may also produce these metabolic stimulating effects. For example, inclusion of cytokinin in the compositions of the invention will increase the requirement for calcium, and so it will advantageous in compositions in which water soluble calcium salts such as calcium nitrate or calcium sulphate is the nutrient mineral.

Such metabolic stimulant components may therefore be included in addition or as an alternative to the essential oils described above.

Essential oils supplied with nutrient can also direct the flow of the nutrient supplied, by stimulating local need through upregulation of activity requiring a nutrient in a specific tissues. For example, cell division increases flow of calcium to meristems. Therefore, administration of a composition as described above including an essential oil which stimulates cell division to, for example, the leaves of plants will have the effect of increasing the calcium content in the meristems.

This additional calcium is supplied by the composition in the form of a water soluble calcium salt such as calcium nitrate or calcium sulphate.

In addition, many essential oils have anti microbial or insect or arthropod and nematode repellant or killing activity, and in a preferred embodiment, these may be included in the composition of the invention.

A number of natural oils, such as tagetes oil and thyme oil have been demonstrated to have insect repellent properties on several insect species. However, their potential for use in mainstream agriculture is limited due to two factors: economics and taint. Generally speaking, these oils, when applied alone to crops, have to be applied in amounts of from 2 to 5 litres of oil per hectare to achieve reasonable pest control. The use of the oils requires too much material to be used for them to be cost effective. Furthermore, when used in these quantities, the crops can suffer significant post harvest taint.

Essential oils have been used for the treatment of stored grain, but again, the amounts applied to achieve effective insect repellence is high.

The applicants have found however, that when included in a composition of the invention, the amount of these oils needed to produce useful effects, can be significantly reduced.

In particular, the composition further comprises one or more essential oils selected from tagetes oil or a thymol containing essential oil, or a mixture thereof, or components thereof which have insect repellent or deterrent properties.

Thyme oil is a particularly suitable thymol containing essential oil, but others include Anabasis, carum, lavendula, Ocimum, and origanum oils.

In particular, the composition further comprises one or more essential oils selected from tagetes oil or thyme oil, or a mixture thereof.

However, it is also possible that one or more isolated components of these oils may be utilised, provided these have insect repellent or deterrent properties.

For instance, Thymus vulgaris essential oil comprises a mixture of thymol, caracrol, cymol, linalool, terpin-4-ol an monoterpenoids. Any of these components or mixtures thereof may be used in the composition.

Components of tagetes oil such as Tagetes erecta and Tagetes minuta essential oil include dihydrotagetone, thiophenes and ocimene, or which dihydrotagetone is the most important component.

Synergistic effects may be achieved if these insect repellant oils or active components therefore are using in compositions which comprise water-soluble salts of mineral nutrients which improving plant resistance to arthropod/nematode attack (such as root knot nematodes, and potato cyst nematodes.). In this way, the effects are achieved not only in the soil or on the leaves (depending upon how the composition is applied), but also following uptake by the plant.

Addition of essential oils which have antimicrobial effects (for example oils which have effects against fungi and bacteria, in particular species of phytophera, botrytis, pythium, rhizoctonia, powdery mildew, downy mildew) to the composition described above may also prevent microbial decomposition of the minerals. This may be particularly useful for instance, if supplied with nitrogen, for example in the form of water-soluble nutrient mineral nitrates. Microbes have a tendency to decompose nitrogen in the form of nitrates to ammonia, which is prone to leachng in the soil and volatilization. Prevention of microbial decomposition of this type will therefore lead to reduced leaching and volatilization and so improved nitrogen uptake by plant.

Again synergy in antimicrobial effects may be achieved by use of these antimicrobial essential oils or active components thereof in compositions which contain nutrient minerals known to have antimicrobial properties (eg. Zn, Mn, Cu) . Such a composition discourages plant pathogenic microorganisms both in soil or on foliage of the plant, depending upon where the composition is applied, and also within the plant upon uptake.

Inclusion of such essential oils or active components thereof in the composition also reduces microbial feeding on the composition during storage, and so will enhance shelf life.

Furthermore, the inherent anti-microbial properties in the trace elements, in particular, copper, manganese, and zinc can be obtained at lower rates by using a composition of the invention, as the vegetable oil emulsion has the effect of protecting the nutrient. This has big environmental benefits in that it allows nutrient control of disease (which in some cases, is better than using some synthetics) to be achieved efficiently, and with a reduced amount of nutrient. Excess nutrient material can be an environmental problem, in particular where these are heavy metals such as copper, as they may persist in the soil and entering water courses.

In summary, compositions of the invention are useful in enhancing not only the nutrient/plant interaction, but also the nutrient/environment interaction.

Compositions are suitably prepared by mixing the components together in a conventional manner. Suitably, the emulsifier together with any essential oil(s) or active components thereof which may be present, are added to the agriculturally acceptable carrier oil and mixed with stirring until the components are evenly diluted throughout the composition.

The wax component of the mixture may be added together with the emulsifier and other components as described above, or it may be added subsequently, with stirring until it dissolves. It is sometimes possible to heat the wax, and suitably the carrier oil or any pre-existing mixture, for example to temperatures in the range of from 25-70 C, for example from 55-65 C prior to addition in order facilitate mixing. However, addition of wax in a divided form such as a grated form followed by stirring at ambient temperature for a period sufficient to ensure that the wax dissolves is generally a preferred preparation procedure.

This mixture is then added to the water-soluble mineral nutrient in a container. The container may be then be shaken to form a suspension. This can be done at any time, but is preferably carried out shortly prior to use. The presence of the wax ensures that the resultant suspension is relatively stable in that the water-soluble mineral nutrient does not rapidly drop out of suspension. This assists in the process.

The compositions of the invention are suitably diluted in water before application. Thus the compositions described above are generally concentrates.

Thus in a further aspect, the invention provides a formulation for administration to plants or to the environment of the plants, the formulation comprising a composition as described above, and water.

The amount of water used will depend upon the particular mode of administration of the formulation, and to where it is being applied, for example to crops or to grain stores of the like.

This will generally be by means of a sprayer, such as an electrostatic or other conventional sprayer. However, in a further preferred embodiment, the formulations are applied in drip irrigation or fertigation systems, directly to the soil, so as to allow nutrient uptake through the roots.

In general, the final formulation will contain from 10-20% of the composition of the invention and the remainder is water.

In yet a further aspect, the invention provides a method for supplyingnutrients to plants, which method comprises applying to the plants or to the locus thereof, a composition as described above.

The product is suitable for use on most crops, but in particular can be used for the treatment of greenhouse crops, vegetables, and fruit crops.

The compositions have low phytotoxicity at the effective concentrations.

In a particular embodiment, the invention provides the use of a composition as described above as a fertilizer, for administration to crops at a rate of from 1 to 30 litres per hectare, and preferably from 1 to 10 litres per hectare.

The amount of composition applied in any particular situation will vary depending upon a number of factors such as the nature of the crop, the level of nutrient required etc. Typically, the amount of solution applied is sufficient to provide a solution concentration sprayed to runoff -rate of between 2m1/lt and 20m1/lt.

The compositions can be used either alone (and in this case, they may be suitable for organic growers) or in conjunction with other agrochemicals such as fungicides, insecticides or acaricides.

The invention will now be particularly described by way of

example.

Comparative Example A The following composition was prepared A base agrochemical formulation (Composition A) was prepared by mixing the following components Canola Oil 94%w/w Emulsifier (Tween) 4.9%w/w Thyme oil O.5%w/w Tagetes oil O.5%w/w Wintergreen oil O.l%w/w A composition was then prepared as follows: Composition A 88.7%w/w Zinc sulphate 8.4%w/w Magnesium sulphate 3.O%w/w The composition was manufactured by adding the zinc sulphate and magnesium sulphate in the form of powders to a lOOg jar.

Composition A was then added to the top of the powders and the jar was shaken.

The shaking of the content for the jar dispersed the powders throughout the oil. This formed a basic suspension.

The suspension broke down within 1 minute and 30 seconds. This left a product that was a brown oily liquid with slightly golden powders separated at the base of the jar. These powders were easily dispersed on gentle shaking.

There is clearly a need to reduce the sedimentation time of this composition.

Comparative Example B A similar formulation to that described in comparative example A was prepared.

However, in this case, 5%w/w of a 2% solution of a thickener, Klucel H was added. This solution was manufactured by forming a 2% solution of a Kiucel H in water at 24 C. Kiucel H was added was added slowly to the water with the Stuart mixer/heater at level 3 on the mixer setting (no heat was applied) . The speed was increased to 4 as the Klucel H was added. The speed eventually reached setting 8 due to the solution increasing in viscosity.

The 2% Klucel H solution was added to a Composition A above and shaken. As before, the zinc sulphate and magnesium sulphate powders were then added to this mixture to form a composition of the following components: Composition A 83.7%w/w Zinc sulphate 8.4%w/w Magnesium sulphate 3.O%w/w Klucel H 2% solution 5.O%w/w The product produced was slightly lighter in colour than that produced in comparative example A. The particle size of the powders seemed to increase in size. However, the sedimentation time of this product actually decreased to approximately 15 seconds.

Other methods of addition of the thickener produced similar results.

Example 1

The following composition was prepared: Composition A 86.l%w/w Zinc sulphate 8.3%w/w Magnesium sulphate 3.0%w/w Beeswax 2.6%w/w The composition was produced as follows: The Beeswax was chopped from the block of material and melted on a water bath. The Beeswax melted at approximately 65 C. The melted Beeswax was added to warm Composition A (approximately 60 C) As the Beeswax was poured into the Composition A some of the wax solidified and remained in the melting vessel. It is estimated that approximately 1.5 -2.0% w/w was transferred to the Composition A. The Composition A /Beeswax mixture was allowed to cool to approximately 25 C. The powders were than added to a jar and the mixture poured onto the powders.

The resultant mixture looked light brown in appearance with powders separated at the base of the container. Upon shaking the powders dispersed. The sedimentation time increased to 2 minutes 15.6 seconds.

Example 2

The following composition was prepared: Composition A 85.6%w/w Zinc sulphate 8.3%w/w Magnesium sulphate 3.0%w/w Beeswax 3.0%w/w The Beeswax was grated into fine strands. The Beeswax was weighed out and added to Composition A. Composition A was at room temperature (24 C) . The Stuart mixer/heater was set at level 3 on the speed dial (no heat was applied) . The first addition of Beeswax was made at 08.06 and the second addition at 08.15. The mixture was left stirring for 1 hour and 31 minutes.

After this time all the Beeswax was fully solubilised into the Composition A. The powders were added to the container and the Composition A /Beeswax mixture was added to the container. The container was then shaken to disperse the powders.

The resultant suspension was light brown in appearance. The powders seemed to stay permanently suspended.

Example 3

A stock solution (500g) of Composition A (see Comparative example 1 above) comprising Composition A (490g) and beeswax (lOg) was manufactured by mixing beeswax with heat (approx 45 -50 C) in Composition A for approximately one hour. The resultant mix was then allowed to cool to room temperature.

Once cooled the mixture was used to make up 50g sub lots with the materials listed below resulting in the amount of micronutrients listed in table 1 below.

Table 1: Amount of materials added per 50g sub lot and the resultant micronutrient content.

Amount Amount of Material %w/w added (g) /50g micronutrient Zinc Nitrate 5.660 11.320 3% Zinc Boric acid 4.285 8.570 1.5% Boron Copper Sulphate 5.000 10.000 3% Copper Copper Chloride 3.105 6.210 3% Copper Manganese 4.690 9.380 3% Manganese Sulphate Iron Sulphate 7.500 15.000 3% Iron Manganese 9.375 18.75 3% MgO Sulphate The resultant suspensions had their characteristics recorded.

They were then mixed with water, as they would be in the field, and the emulsion characteristics were recorded.

Observations: The following observations were recorded for the suspensions produced. The results are detailed in Table 2: Table 2: Suspension characterisation observations.

* Material, added Observations The product produced had a pale brown liquid with large crystals separated at the base. The crystals dispersed on Zinc Nitrate shaking but sediment quickly. Some smaller particles appear to stay in suspension.

Material added Observations The product produced had a pale brown liquid with small crystals at the base.

Boric acid The crystals dispersed on shaking and sediment within 30 seconds.

The product produced was a mucky brown liquid with light blue crystals at the base. The crystals dispersed on shaking Copper Sulphate and sediment within 10 seconds. Some smaller particles seem to stay in suspension.

The product produced was a mucky brown liquid with dark brown particles at the base. The particles dispersed on Copper Chloride shaking. The particles sediment within 1 minute but some smaller particles remained suspended.

The product produced was a pale brown liquid with golden powder at the base.

The powder dispersed on shaking. The Manganese Sulphate powder sediment within 1 minute 30 seconds. Smaller particles appeared to stay suspended.

The product produced was a dark brow liquid with a large amount of green particulate matter at the base. The Iron Sulphate particles dispersed on shaking. The particles sediment in approximately 30 seconds. Smaller particles seemed to stay within suspension.

Material added Observations The product produced had a pale brown liquid with white powder at the base.

The powder dispersed on shaking. The Magnesium Sulphate particles sediment in approximately 1.

minute. Some smaller particles seemed to stay in suspension.

The following observations were recorded for the emulsions produced. The results are detailed in Table 3 below: Table 3: Emulsion characterisation observations.

Material added Observations Formed an emulsion on initial mixing.

The emulsion separated into three layers over time (liquid, wax and oil) . There Zinc Nitrate was also a solid precipitate produced.

On gentle agitation this solid did not Formed an emulsion on initial mixing.

The emulsion separated into three layers Boric acid over time (liquid, wax and oil) . On gentle agitation this solid did Formed an emulsion on initial mixing.

The emulsion had a green colouration.

The emulsion separated into three layers Copper Sulphate over time (liquid, wax and oil) . On gentle agitation this solid did Material added Observations Formed an emulsion on initial mixing.

The emulsion had a green colouration.

The emulsion separated into three layers over time (liquid, wax and oil) . There Copper Chloride was also a solid precipitate produced (similar to Zinc Nitrate) . On gentle agitation this solid did not Formed an emulsion on initial mixing.

The emulsion had a green colouration.

The emulsion separated into three layers Manganese Sulphate over time (liquid, wax and oil) . On gentle agitation this solid did Formed an emulsion on initial mixing.

The emulsion had an orange colouration.

The emulsion had a green colouration.

Iron Sulphate The emulsion separated into three layers over time (liquid, wax and oil) . On gentle agitation this solid did Formed an emulsion on initial mixing.

The emulsion had a green colouration.

The emulsion separated into three layers Magnesium Sulphate over time (liquid, wax and oil) . On gentle agitation this solid did It can be concluded that boric acid, copper sulphate, manganese sulphate, iron sulphate and magnesium sulphate form acceptable

emulsions that could be used in the field.

Claims

Claims 1. An agricultural composition comprising (I) a water-soluble

salt of a nutrient mineral, (ii) a plant oil, (iii) an emulsifier and (iv) a wax, wherein the water-soluble salt of a nutrient mineral is in suspension in the oil.

2. P. composition according to claim 1 wherein the wax is beeswax.

3. A composition according to claim 1 or claim 2 wherein the water-soluble salt of a nutrient mineral is a water-soluble salt of a calcium, magnesium, sodium, chloride, sulphur, copper, cobalt, iron, manganese, boron, molybdenum, zinc, silicon or nickel.

4. A composition according to claim 3 wherein the water-soluble salt of a nutrient mineral is a water-soluble salt is a salt of copper, cobalt, iron, manganese, boron, molybdenum, zinc, silicon or nickel.

5. A composition according to any one of the preceding claims wherein the water-soluble salts are nitrates, suiphates or chlorides.

6. A composition according to claim 5 wherein the water-soluble salts are nitrates or sulphates.

7. A composition according to any one of the preceding claims wherein the water-soluble mineral salt is zinc nitrate, iron sulphate, zinc sulphate, magnesium sulphate, manganese sulphate, iron nitrate or manganese nitrate.

8. A composition according to any one of the preceding claims wherein the water-soluble mineral salt is in the form of a solid powder, and is present in the composition in an amount of up to 20%v/v.

9. A composition according to claim 8 wherein the water-soluble mineral salt is present in the composition in an amount of from 10-15% v/v.

10. A composition according to any one of the preceding claims wherein the plant oil is canola oil (oilseed rape oil), soybean oil, cottonseed, castor oil, linseed oil or palm oil.

11. A composition according to any one of the preceding claims wherein the emulsifier is present in an amount of from 1 to 20%w/w.

12. A composition according to claim 11 wherein the wax is present in an amount of from 1 to 5%w/w.

13. A composition according to any one of the preceding claims which further comprises a nutritional product and/or growth stimulant used in crop nutrition.

14. A composition according to claim 13 wherein the nutritional product and/or growth stimulant is seaweed extract powder, humic and fulvic acid powder and amino acid powder.

15. A composition according to any one of the preceding claims wherein the composition further comprises one or more essential oils, or active components thereof, or mixtures of these.

16. A composition according to claim 15 wherein composition contains no more than 5%w/w of essential oil or an active component thereof.

17. A composition according to claim 16 wherein the composition contains up to l%w/w essential oil or an active component thereof.

18. A composition according to claim 16 or claim 17 wherein the essential oil or active component thereof, increases plant metabolic activity in a pathway that utilizes a specific mineral nutrient, said specific mineral nutrient being component (i) within the composition.

19. A composition according to claim 18 wherein the essential oil or active component thereof is wintergreen oil or an oil from Chenopodium, Erythroxylum, Eugenia, Gaultheria, Myristica, Syzygium, Xanthophyllum, Cinnamonium, Gualtheria, Gossypium and mentha, or salicylic acid or an ester thereof, and the mineral nutrient is a water soluble calcium salt.

20. A composition according to claim 19 wherein the essential oil is wintergreen oil.

21. A composition according to claim 18 wherein the wherein the essential oil or active component thereof stimulates pathways related to auxin or carbohydrate production in plants, and wherein the water-soluble salt of a mineral nutrient is a water-soluble zinc or copper salt.

22. A composition according to any one of claims 15 to 17 wherein the essential oil or active component thereof has anti microbial or insect or arthropod and nematode repellant or killing activity.

23. A composition according to claim 22 wherein the essential oil or active component thereof is from tagetes oil or a thymol containing essential oil, or a mixture thereof, or components thereof which have insect repellent or deterrent properties.

24. A formulation for administration to plants or to the environment of the plants, the formulation comprising a composition according to any one of the preceding claims, and water.

25. A method for supplying nutrients to plants, which method comprises applying to the plants or to the locus thereof, a composition according to any one of claims 1 to 23 or a formulation according to claim 24.

26. The use of a composition according to any one of claims 1 to 23 as a fertilizer, for administration to crops.