HERBICIDAL COMPOSITION CONTAINING AMITROLE AND

METHOD FOR CONTROLLING WEEDS

This application claims priority from US Provisional Application No. 60/815865 of 23 June 2006 the contents of which are herein incorporated by reference.

Field

This invention relates to a herbicidal composition containing the herbicide 3- amino-1 ,2,4-triazole (Amitrole) and to a method of controlling weeds using the composition.

Background

Amitrole was introduced as a herbicide in the 1950's and this is described in US Patent No. 2,670,282. Amitrole is used in control of annual and perennial broad leaf weeds and grasses and is generally an effective broad spectrum herbicide. Amitrole is typically used in combination with ammonium thiocyanate synergist.

A number of wetting agents have been used in combination with amitrole. Examples of such wetting agents include sodium laurel sulfate, sodium cetyl sulfate, sodium sulfate and alkyl naphthalene, polyoxy alkylene derivatives of sorbitan monoolyate, polyalkalene ether alcohols and polyethylene glycols.

The discussion of documents, acts, materials, devices, articles and the like is included in this specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters formed part of the prior art base or were common general knowledge in the field relevant to the present invention as it existed before the priority date of each claim of this application.

Summary

We have now found that a significant improvement in activity of amitrole herbicide compositions particularly compositions containing a coformulated herbicide is provided by using an amount of phospholipid, particularly soyal

phospholipid which is at least 1 part by weight of phospholipid for every 10 parts by weight of amitrole. More preferably the amount of phospholipid, particularly soyal phospholipid, provides a ratio of Phospholipid : Amitrole in the range of from 1 :10 to 10:1 . More preferably the ratio of Phospholipid : Amitrole is in the range of from 1 :10 to 2:1 . We have found the ratio of Phospholipid : Amitrole in the range of 1 :10 to 2:1 to be particularly useful in practice.

In one embodiment of the invention the amitrole composition is in the form of a concentrate comprising at least 50 grams, preferably at least 50 grams, preferably at least 100 grams and more preferably at least 20Og and more preferably at least 200 grams of amitrole per kilogram of total composition and an amount of phospholipid (preferably soyal phospholipid) to provide a ratio of

Phospholipid : Amitrole in the range of from 1 :10 to 2:1 , preferably 1 :10 to 1 :1 and most preferably from 1 :10 to 1 :2.

In a further embodiment the invention provides a method of post-emergent & pre-emergent control of weeds by applying the composition as described above to target weeds or soil. Preferably the method of control will include applying the herbicide to target weeds as a foliar/topical spray and/or to the ground surface. The rate at which the herbicide is applied will generally be in the range of from 0.175 to 15 kilograms of amitrole per hectare.

Throughout the description and the claims of this specification the word "comprise" and variations of the word, such as "comprising" and "comprises" is not intended to exclude other additives, components, integers or steps.

Detail Description

The invention provides an amitrole herbicide composition comprising a phospholipid adjuvant, particularly soyal phospholipid, in an amount of at least 1 part by weight of phospholipid for every 10 parts by weight of amitrole. More preferably the amount of phospholipid, particularly soyal phospholipid, provides a ratio of Phospholipid : Amitrole in the range of from 1 :10 to 10:1 . More preferably the ratio of Phospholipid : Amitrole is in the range of from 1 :10

to 2:1. We have found the ratio of Phospholipid: Amitrole in the range of 1 :10 to 2:1 to be particularly useful in practice.

The amitrole may be present alone or more preferably is combined with at least one other herbicide.

The preferred other herbicides for use in combination with amitrole in this embodiment are thiocyanate salts, triazinone herbicides, organophosphorus herbicides, phenoxyacetic herbicides and quaternary ammonium herbicides, Proto-porphyrinogen oxidase (PPO) inhibitors, benzoic acids and pyridine- carboxylic herbicides.

Typically the composition will contain a thiocyanate particularly selected from alkali metal and ammonium salts which are particularly suitable for use in compositions of the invention.

In one embodiment, which is particularly prefrred the concentrate contains amitrole, the thiocyanate salt and at least one additional herbicide selected from the group consisting of:

(a) 4-amino-6-(1 ,1 -dimethylethyl)-3-(alkylthio)-1 ,2,4-triazin-5(4H)-ones represented by the formula:

Ji - N (D

[CHa)SC

wherein R represents a linear or branched alkyl radical comprising from 1 to 4 carbon atoms. The preferred herbicide of this type is metribuzin;

(b) organophosphorus herbicides include amiprofos-methyl, anilofos, bensulide, bilanafos, butamifos, 2,4-DEP, DMPA, EBEP, fosamine, glufosinate, glyphosate and piperophos and preferably glyphosate and its salts such as the alkali metal (e.g. potassium), ammonium, alkyl ammonium (e.g

isopropyl ammonium). Glyphosate and its salts and glufosinate are particularly preferred;

(c) phenoxyacetic herbicides includes 4-CPA, 2,4-D, 3,4-DA, MCPA, MCPA- thioethyl and 2,4, 5-T. MCPA & 2,4-D are the most preferred from this group. The group of herbicides known as Proto-porphrinogen oxidase (PPO) inhibitors include but are not limited to Triazolinones e.g. Carfentrazone-ethyl: N-Phenyl-phthalamides e.g. flumioxazin, cinidon-ethyl; Phenyprazoles eg. Pyraflufen-ehtyl; Pyrimidindiones e.g. butafenacil and Diphenyl-ethers e.g oxyfluorfen. Examples of pyridine herbicides which may be used in combination with amitrole include fluroxpyr, clopyralid, triclopyr and picloram. Examples of benzoic acids include dicamba; and

(d) quaternary ammonium herbicides includes cyperquat, diethamquat, difenzoquat, diquat, morfamquat and paraquat. Paraquat is the most preferred from this group. It will be understood by those skilled in the art that the herbicides nominated in each of these groups may exist in the form of the parent compound or a herbicidally effective derivative of the compound such as an acid or ester. Fer example many of the organophosphorus compounds are used in the form or an effective salt and many of the phenoxy acids are used in the form of an ester or salt. It will be understood that reference to such compounds includes reference to the herbicidally effective derivatives.

The compositions of the invention most preferably include amitrole in an intimate mixture with at least one other herbicide selected from the group comprising alkaline, alkaline-earth metal and ammonium thiocyanates, glyphosate, MCPA sodium salt, 2,4-D, sulfosate, glufosinate, paraquat and metribuzin, dicamba, and pyridine-carboxylic acids and PPO Inhibitors. More preferably the composition will contain amitrole, ammonium thiocyanate and at least one of glyphosate, MCPA sodium salt, 2,4-D, sulfosate, glufosinate, paraquat and metribuzin, dicamba, and pyridine-carboxylic acids and PPO Inhibitors.

Speaking generally, the weight ratio of amitrole to one or more other herbicides is typically in the range of from 10000:1 to 1 :200 and more preferably from 5000:1 to 1 :100 based on active ingredient per hectare.

The optimum ranges will differ depending on the class of herbicide used in combination with amitrole.

For example, when the herbicide is a PPO inhibitor the weight ratio of amitrole to PPO is preferably in the range of from 4500:1 to 1 :10.

When the herbicide is phenoxy acid the weight ratio of amitrole to phenoxy acid is preferably in the range of from 20:1 to 1 :10.

When the herbicide is a pyridine-carboxylic acid the weight ratio of amitrole to pyridine is preferably in the range of from 500:1 to 1 :10.

When the herbicide is a benzoic acid the weight ratio of amitrole to benzoic acid is preferably in the range of from 250:1 to 1 :15.

When the herbicide is a glutamine synthetase inhibitor the weight ratio of amitrole to glutamine acid is preferably in the range of from 100:1 to 1 :20.

When the herbicidal composition includes a mixture of amitrole and thiocyanate the weight ratio amitrole/thiocyanate (expressed in ammonium thiocyanate) is preferably in the range of from 95/5 to 40/60 and more preferably from 54/46 to 70/30.

When the composition contains one or more aminotriazones such as metribuzin the composition preferably has a ratio in the range of 4:1 to 1 :4, i.e. from 25 to 400% of total triazinone with respect to the amitrole. The triazinone herbicide may be used in a weight ratio from 100/1 to 7/1 , preferably from 40/1 to 25/1 .

In a particularly preferred embodiment of the invention the composition contains amitrole and glyphosate preferably in the form of its salts such as the alkali metal (e.g. potassium), ammonium, alkyl ammonium (e.g isopropyl ammonium) salts. We have found that combinations of amitrole and glyphosate in certain proportions provide an unexpected increase in activity making the combination extremely effective as a fast knock down herbicide. Accordingly we provide in one embodiment a composition comprising amitrole and glyphosate containing a weight ratio of amitrole to glyphosate (based on glyphosate acid) of from 3:1 to 1 :3.

The preferred ratio of amitrole to glyphosate for improved knockdown on certain weeds exist in the range of from 2:1 through to 1 :2 with a ratio of from 2:1 to 1 :1 active ingredient ratio being more preferred.

We have found antagonism generally occurs when the ratio of amitrole to glyphosate departs from this.

In a preferred embodiment of the invention the composition comprises

(a) Amitrole (b) At least one further herbicide preferably selected from the group consisting of alkaline, alkaline-earth metal and ammonium thiocyanates, glyphosate, phenoxy acids (particularly MCPA) sodium salt and 2,4-D, sulfosate, glufosinate, paraquat and metribuzin; PPO inhibitors (preferably selected from carfentrazone, butafenacil, flumioxazin, cinidon ethyl and oxyfluorofen) pyridines (preferably selected from fluroxpyr, clopyralid, triclopyr and picloram) and benzoic acid (preferably dicamba)

(c) Phospholipids adjuvant.

Examples of herbicidal compositions according to the present invention (in which amounts are expressed on a weight basis) are as follows; (i) aqueous suspension concentrates which comprise from 5 to 70%

(preferably 10 to 70%) by weight of herbicides and from 2 to 15% phospholipid;

(ii) wettablθ powders which comprise from 5 to 95% (preferable 10 to 95%) of herbicides from 2 to 20% e.g. 5 to 15% phospholipid and from 8 to

88% of solid diluent or carrier;

(iii) water dispersible granules which comprise from 5 to 95%, (preferably 10 to 95% e.g. 25 to 95%) of herbicides from 1 to 15%, e.g. 2 to 10%, of phospholipid and from 0 to 95 % e.g. 1 to 95% of solid diluent, e.g. clay, granulated with the addition of water to form a paste and then dried; (iv) water soluble or water dispersible powders which comprise from 5 to

90% (preferably 10 to 90%) of herbicides from 2 to 30% of phospholipid and from 0 to 88% of solid diluent;

(v) liquid water soluble concentrates which comprise from 5 to 50%,

(preferably 10 to 50% e.g. 10 to 30%) of herbicides 5 to 25% of phospholipid and from 10 to 90%, e.g. 45 to 85%, of water miscible solvent, or a mixture or water-miscible solvent and/or water and preferably substantially water;

(vi) liquid emulsifiable suspension concentrates which comprise from 5 to

70% (preferably 10 to 70%) of herbicides from 5 to 15% of phospholipid and from 0.1 to 5% of thickener and from 10 to 84% of organic solvent, e.g. mineral oil; and (vii) emulsifiable concentrates which comprise 5 to 95%, and preferably from

10 to 60% of herbicides, from 0.5 to 20% phospholipid, from 0.01 to 10%, and preferably from 39 to 98.99%, of organic solvent.

Compositions (i) to (iv) are particularly preferred.

The invention uses a phospholipid adjuvant, particularly soyal phospholipid, in an amount of at least 1 part by weight of phospholipid for every 10 parts by weight of amitrole. More preferably the amount of phospholipid, particularly soyal phospholipid, provides a ratio of Phospholipid : Amitrole in the range of from 1 :10 to 10:1 . More preferably the ratio of Phospholipid: Amitrole is in the range of from 1 :10 to 2:1. We have found the ratio of Phospholipid: Amitrole in the range of 1 :10 to 2:1 to be particularly useful in practice.

Phospholipids are a class of lipids consisting of four key components, fatty acids, a negatively-charged phosphate group, an alcohol and a backbone. Most phospholipids have an additional chemical group bound to the phosphate. The polar nature of the head is typically hydrophilic whilst the non- polar tail is hydrophobic thus creating an amphipathic character that allows lipsomes or small lipid vesicles that can be used to transport materials into living organisms. Examples of phospholipids include but are not limited to phosphatidylcholine, or lecithin, phosphatidylglycerol, phosphatidylinositol, phosphatidylserine, and phosphatidylethanolamine. Of particular relevance to this invention are soyal lecithin phospholipids and more particularly those that are used in conjunction with propionic acid.

The phospholipid used in the composition of the invention is preferably a soyal phospholipid although other sources of phospholipid may be used. The phospholipids used in the compositions of the invention may be poly alkylene glycol derivitized phospholipids particularly PEG derivatized phospholipids.

The composition of the invention will preferably further contain a carboxylic acid particularly propionic acid which is preferably present in a ratio of carboxylic acid to amitrole of at least 1 part by weight propionic acid to 10 parts by weight amitrole, more preferably with a weight ratio of carboxylic acid to amitrole in the range of from 1 :10 to 10:1 , still more preferably 1 :10 to 2: 1 and most preferably 10:1 to 1 :1 . The phospholipids may be used in the form of an aqueous mixture (e.g. solution or dispersion), a solid or semisolid (optionally containing an absorbent material) and/or in a mixture with other admixtures and/or pesticidal agents.

Compositions of the invention in the form of a water dispersible particulate material may contain high concentrations (20 to 70% by weight) of herbicidal compounds including amitrole (and optional other herbicides).

The composition of the invention may be formulated as a water dispersible powder or granule containing a particulate carrier. Examples of solid carriers may be selected from the group consisting of synthetic and natural minerals

such as kaolin clay, attapulgite clay, bentonite, terra alba, pyrophyllite, talc, diatomacθous earth, calcite, walnut shell powder, urea, soybean powder, sodium benzoate, vermiculite, lime, siliceous sand, gypsum, ammonium sulfate and urea ammonium sulfate, synthetic hydrated silica and organic materials including cellulosic materials such as ground plant materials.

The preferred carrier material is an aluminosilicate or silica particularly a silica such as precipitated or high surface area silicas.

As used herein, the term "high surface area silica" refers to a silica having a surface area of from about 80 to about 600 g/m ² .

The preferred high surface area silica for use in the compositions and process of this invention is a silica sold under the trade name Hi-Sil ^® , which has a surface area of 120 g/m ² and is sold by PPG Company. Other high surface area silicas can also be used.

In one embodiment the compositions are prepared utilizing naturally occurring swelling hydrous aluminum silicate clays which remain free-flowing and do not agglomerate, lump-up or fuse when stored.

Alternatively the composition may be prepared using sufficient quantities of specially treated silica derivatives to absorb all the materials as stated above.

Naturally-occurring swelling clays suitable for use in said compositions may be described as hydrous, sodium and magnesium aluminum silicates having a montmorillonite unit cell structure. The montmorillonite unit cell has two silicon- oxygen sheets with an aluminium hydroxyl sheet sandwiched between them. Montmorillonite is described as a "Si-Al-Si" structure.

Commercially available, naturally occurring swelling clays include VOLCLA Y ^® , Wyoming Bentonites, VEEGUM ^® , or other naturally occurring swelling clays which contain the same montmorillonite unit structure and properties.

Thus, from about 20 to 70% by weight (preferably 30-60%) of herbicide component including amitrole may be mixed with 30 to 70% by weight of a particulate carrier, 2-20% by weight of phospholipid, until a homogeneous mixture is obtained.

If a wettable powder is desired, this material is then blended with a hydrophobic silica powder and packaged. A particulate composition may also be prepared using a mill fitted with a 1/16 to 1 /4 inch screen followed by air milling at 100-105 psi to a particle size 5 to 10 microns

The mixture alternatively is formed into granules by extrusion, pan granulation or using a suitable screen or rolling process for braking down extrusions. The amitrole herbicide or mixture with other herbicides can be uniformly mixed with or dissolved in suitable adjuvants such as solid carrier such as talc, bentonite, clay, kaolin, diatomaceous earth, silica gel, vermiculite, lime, siliceous sand, ammonium sulfate or urea; liquid carriers such as alcohols, dioxane, acetone, in the presence of the phospholipids and any other adjuvants.

Wettable powder:

Active ingredient: 5 to 95 wt. % (preferably 10 to 95%wt)

Phospholipids Surfactant: 1 to 20 wt. %

Solid carrier: 1 to 85 wt. %

The active ingredient is admixed with the solid carrier and the surfactant and the mixture is pulverized.

These may be uniformly mixed and pulverized to prepare a wettable powder. The composition is applied for weed control after diluting with water.

Composition 3 (Granule):

Amitrole 10 to 60 Wt. parts

Bentonite 10 to 30 Wt. parts

Talc 20 to 60 Wt. parts

The composition of the present invention can be prepared as a wettable powder or water dispersible granular composition by utilizing existing equipment in the art. For example, powder components such as the carrier and surface active agent are charged into a ribbon type mixer or a screw type mixer, and a mixture formed by dissolving a part or all of the active pesticidal ingredient in the organic solvent is added and mixed with the carrier and the like at a temperature of from about 20° to about 100 ⁰ C, more preferably from 30° to 8O ⁰ C. To uniformly mix the components, the mixture is next disintegrated by passing it through a pulverizer such as a hammer mill, a pin mill or a jet-o-mizer. The pulverization product is typically uniformly mixed again with the ribbon type or screw type mixer to obtain the intended water- dispersible pesticide. If a high-speed rotary vane mixer such as a juice mixer type blender or a Henschel mixer is used, the mixing/pulverizing/mixing process as mentioned above can be accomplished in one apparatus merely by adjusting the stirring speed.

A granular herbicidal composition may be prepared by directing through orifices of a grid or of an extrusion device. The amitrole may be milled to a suitable particle size (optionally mixed and/or co-milled with at least one other herbicide), mixed with an amount of water sufficient to ensure its cohesion under a moderate pressure and brought together with the phospholipid. The extrusion operation may provide granules of cylindrical shape which can be dried.

In one embodiment the invention provides a method of post emergent and/or pre-emergent weed control comprising applying an amitrole composition to target weeds or to soil in which control is required.

The preferred rate for application of amitrole compositions (independently of physical form of the composition) is in the range of from 62gai/ha to 6250 gai/ha and more preferably from 175 gai/ha to 5000 g/ha.

In one embodiment the composition of the invention includes at least one further herbicide which may (a) be included in the concentrate (b) be included at the time of mixing to form a dilute composition for application or (c) during the process of application.

When the additional herbicide is carfentrazone-ethyl it is generally applied at a rate of from 1.2 gai carfentrazone-ethyl/ha to 960 gai carfentrazone-ethyl/ha and more preferably from 2.4 g ai/ha to 240 g ai/ha.

When the additional herbicide is oxyfluorofen it is preferably applied at a rate of 1.2 gai oxyfluorofen/ha to 2400 gai oxyfluorfen/ha and more preferably from 6 gai/ha to 1200 g ai/ha.

When the additional herbicide is fluroxpyr it is preferably from 5 gai fluroxpyr/ha to 2000 gai fluroxpyr/ha and more preferably from 10 g ai/ha to 1000 g ai/ha.

When the additional herbicide is glufosinate it is preferably applied at a rate of from 20 gai glufosinate/ha to 4000 gai glufosinate/ha and preferably from 200 g/ha to 1600 g/ha.

When the additional herbicide is Dicamba it is preferably applied at a rate of from 20 gai Dicamba/ha to 4000 gai Dicamba/ha and more preferably from 200 gai/ha to 1200 gai/ha.

When the additional herbicide is 2,4-D it is preferably applied at a rate of from 25 gai 2,4-D/ha to 5000 gai 2,4-D/ha and more preferably from 50 gai/ha to 2500 gai/ha.

The present invention is described with reference to the following examples. It is to be understood that the examples are illustrative of and not limiting to the invention described herein.

EXAMPLES

Examples 1 and 2

These examples demonstrate compositions of the invention in the form of aqueous mixtures of amitrole ammonium thiocyanate and phospholipid adjuvant.

Herbicidal concentrates of Examples 1 and 2 were prepared using the components in the amounts by weight shown below.

Example 1

This formulation contains 103.5g of Soyal phospholipid (surfactant) - this equates to 35.0g/L of Soyal Phospholipids and 35.0g/L of Propionic Acid. The ratio of Soyal Phospholipids: Amitrole = (35: 250) = (1 : 7.1 ). The ratio of Propionic acid: Amitrole = (35: 250) = (1 : 7.1 ).

Example 2

This formulation contains 103.5g of COMPANION - this equates to 34.5g/L of Soyal Phospholipids and 35.5g/L of Propionic Acid.

The ratio of Soyal Phospholipids: Amitrole = (34.5: 250) = (1 : 7.2).

The ratio of Propionic acid: Amitrole = (35.5: 250) = (1 : 7.0).

Example 3 This example relates to granular water dispersible compositions in accordance with the invention.

A granular composition in accordance with the invention may be prepared using the following general procedure.

The following are introduced into an impeller disc mill/mixer:

50 g of technical amitrole

47 g of technical ammonium thiocyanate and

7.04g of a soyal phospholipid surfactant e.g. as marketed by SST Australia under the name of Companion.

After homogenization of the powder is obtained, the mixture is placed in a crystallizing dish with a diameter of 150 mm and moistening is carried out by fine sprays of water alternating with rehomogenizations using a spatula; the total amount of water added is 6%.

When the mixture becomes sticky, it can be subjected to extrusion through a grid pierced with cylindrical holes with a diameter of 1 .2 mm.

The cylindrical granules collected are dried in a closed chamber with a controlled humidity which is less than 20% relative humidity at 22 ⁰ C.

The fraction which passes through a sieve with a mesh opening of 2.5 mm and which is retained on a sieve with a mesh opening of 0.8 mm is selected.

The cylindrical granules thus obtained have a satisfactory hardness and dissolve in approximately two minutes.

Examples 4 and 5

These examples relate to compositions of the invention containing combinations of amitrole and the triazinone herbicide metribuzin.

Herbicidal compositions of Examples 4 and 5 (in accordance with the invention) may be prepared by combining the following components in the proportions by weight indicated.

amitrole (g/l) soyal phospholipid metribuzin (g/l) adjuvant (g/l)

Example 4 120 4.5 49.7g/L

Example 5 120 3 49.7g/L

These compositions are prepared starting: on the one hand, from an aqueous solution of technical amitrole identified under CA 1558 and comprising 240 g/l of active substance,

on the other hand, from a wettable powder comprising 35% of metribuzin marketed under the trademark SENCORAL® 35.

For example, in order to obtain one liter of composition 1 , 12.86 g of SENCORAL® 35 are added to half a liter of CA 1558 as well as an amount of water sufficient and soyal phospholipid to provide 1 liter of composition.

The source of the soyal phospholipids includes but is not limited to that marketed by the Applicant Company under the tradename of Spraymate Ll- 700 Surfactant or that marketed by SST Australia under the name of Companion.

Example 6

This example related to a composition in the form of water dispersible granules containing amitrole, a thiocyanate salt and glyphosate salt.

38.65 g of glyphosate in its acid form, with a purity of 97%, 18.625 g of sodium bicarbonate and 4.685 g of water are intimately mixed in a beaker. The mixture is left to react, with periodic rehomogenization, until a constant weight is obtained, which can require several days, depending on the more or less fine particle size of the constituents of the mixture.

The above powder is then intimately mixed with 15 g of sodium lauryl sulphate, 154.8 g of amitrole with a purity of 96%, 145.25 g of sodium thiocyanate with a purity of 92.5%, 61 .3g of "Companion", 44.67g of ammonium sulphate of agricultural quality and 70.45 g of sodium carbonate.

The moist powder, which then has the desired consistency, is subjected to extrusion through a grid pierced with holes with a diameter of 0.8 mm.

The cylindrical granules obtained are dried in an oven as a thin stationary bed with a thickness of a few millimeters for a period of 2 hours at a temperature of 6O ⁰ C. They are graded on a sieve between 2 and 0.6 mm.

The cylindrical granules thus obtained have a satisfactory hardness and dissolve in approximately two minutes.

Example 7

This example relates to compositions of the invention in the form of a wettable powder.

The compounds (I) can be uniformly mixed with or dissolved in suitable adjuvants such as solid carrier such as talc, bentonite, clay, kaolin, diatomaceous earth, silica gel, vermiculite, lime, siliceous sand, ammonium sulfate or urea; liquid carriers such as alcohols, phospholipids surfactant and other adjuvants.

Wettable powder:

Active ingredient: 5 to 95 wt. % Surfactant: 1 to 20 wt. % Solid carrier: 5 to 85 wt. %

The active ingredient is admixed with the solid carrier and the surfactant and the mixture is pulverized.

Example 8

A suitable amitrole composition may be prepared from the following components:

The components are weighed and the amounts of amitrole and sodium bicarbonate adjusted taking into account the active content of technical amitrole the powders are mixed to provide a mixture free of agglomerates.

The phospholipid liquids are mixed with process water (from 5 to 7% depend on the equipment) and sprayed onto the powder mixture. Low speed mixing is continued for about 5 minutes to reach correct consistency after adding the liquids.

Extrusion may be conducted using 1 mm aperture screen. A suitable temperature is 6O ⁰ C and it takes 20 minutes on fluidised bed to dry to a water content of less than about 0.8%. Final screening is done between 0.6 to 2 mm (fine particles and agglomerates are processed to be recycled after checking their characteristics).

Example 9

This example examines the preparation of a concentrate product containing a mixture of amitrol, ammonium thiocyanate and glufosinate.

Formulation & Product Details

Formulation details of product formulated (Example 9 composition)

Formulation Procedure

STEP 1 : Add the amount of Ammonium Thiocyanate allocated for the batch size to a 2L glass beaker and commence stirring.

STEP 2: While stirring add to the 2L beaker the amount of Amitrole Technical allocated for the batch size and continue stirring until all the Amitrole Technical has completely dissolved to form a homogenous mixture. NOTE: The reaction is endothermic, therefore the mixture requires heating assisting to dissolve the Amitrole Technical. The mixture was heated on a hot plate (Temperature of the mixture did not exceed 45°C).

STEP 3: Cool the temperature of the mixture to 20 ⁰ C and while continuing to stir, add to the mixture 277.5 of the commercial glufosinate product of Table.

STEP 4: While continuing to stir, add the remainder of the materials allocated for the batch size. Once all the materials have been added, continue stirring until a homogenous mixture has been obtained.

STEP 5: Transfer the contents of the 2L beaker to a 1 L volumetric flask and make up to the mark with water.

Results

Physical and chemical properties

Dilution stability (CIPAC MT41 ) - 5ml_/95ml_ dilution in CIPAC STD A & STD C waters.

Example 10 to 12

This Example examines the efficacy of compositions of the invention against several weeds which are persistent and have proved difficult to control.

Treatments were applied to annual weeds in 2.4 x 10 metre plots in a zero- tillage fallow with a light cover of wheat stubble on August 17, 2006 using a 2 m hand held boom equipped with 4 Hardi 2080-10 flat fan nozzles calibrated to deliver either 75 L/ha at a ground speed of 5.4 kph and a pressure at the nozzle of 240 kPa. Weather details at application are summarised in table below. Details of weeds treated are summarised in table below.

Soil moisture was fair to good at the time of treatment on the box-belah clay loam soil, following rain late July that produced the germination of fleabane and other weeds. The weed spectrum was dominated by seedling stages of flax-leaf fleabane (Conyza bonariensis), milk thistle (Sonchus oleracea), and urochloa (Urochloa panicoides). Fleabane was concentrated in patches beneath old plants that had set seed late in 2005 and early 2006 and these together with light crop residues provided partial cover for fleabane seedlings in particular.

Weeds details at treatment

Assessment of brownout of weeds individually was undertaken 8 and 34 days after treatment using a 0-100 scale where 0 = no effect and 100 = complete desiccation. Control of assessments were undertaken 34 and 50 DAT using a subjective 0-100 scale where 0 = no control and 100 = complete control. Data was entered into ARM7 and subjective to an analysis of variance. Untreated plots were not included in the analysis.

The trial of Example 10 shows enhanced efficacy of the combination of the Composition of Example 2 when combined with glufosinate and a significant enhancement in the control of Urachloa.

The trial of Example 1 1 shows enhanced efficacy and speed of kill of Urochloa for compositions of the invention containing glufosinate.

The trial of Example 12 compares the efficacy of the Composition of the invention of Example 2 with a comparison composition with equivalent Amitrole rate and shows enhanced efficacy and enhanced efficacy with lower Amitrole rates.

Finally, it is understood that various other modifications and/or alterations may be made without departing from the spirit of the present invention as outlined herein.