AU5429101A - Defoliant - Google Patents

Description

P/00/011 28/5/91 Regulation 3.2(2)

AUSTRALIA

Patents Act 1990

ORIGINAL

COMPLETE SPECIFICATION STANDARD PATENT Application Number: Lodged: Invention Title: DEFOLIANT The following statement is a full description of this invention, including the best method of performing it known to us Aventis CropScience GmbH AGR 2000/M 216 Dr. PL/Lo Description Defoliant The invention relates to the field of defoliants, in particular thidiazuroncontaining mixtures, and their use in crops of cotton.

Thidiazuron [trade name Dropp has been known for some time as a defoliant, in particular for use in crops of cotton (see, for example, "The Pesticide Manual", 11th edition, British Crop Protection Council, Farnham 1997).

The use of thidiazuron in mixtures has also been described, see, for example, DE-A 26 46 712.

However, since the economical and ecological demands placed on modern defoliants are constantly being raised, for example with respect to effect, '20 application rate, residues, toxicity and favorable manufacturing, there exists the 00 permanent task of developing, for example by combining known active ingredients, novel defoliants which offer, at least in some areas, advantages compared with the known compounds.

Surprisingly, it has been found that mixtures of thidiazuron and/or diuron with glufosinate (for example in the formulation "BASTA" SL14") and/or glyphosate, including in commercially available formulations, have synergistic effects.

The present invention accordingly provides a mixture comprising the active ingredients thidiazuron and/or diuron, and glufosinate and/or glyphosate.

The mixtures according to the invention are suitable in particular for use as defoliants in crops of cotton, due, for example, to rapid action and/or increased activity or lower application rates. For the purpose of the invention, the term defoliant is synonymous with "desiccant" and also embraces the known growthregulating effect of thidiazuron and mixtures comprising thidiazuron.

The active ingredients used are known and commercially available, thidiazuron (for example Dropp") and glufosinate (for example BASTA") from Aventis Crop Science, France, and glyphosate, for example, as Roundup" from Monsanto, USA.

The active ingredients, with specifications about their preparation, mixing and handling, are described, for example in "The Pesticide Manual" (see above), and they are listed under the following entry numbers: Thidiazuron 703, Diuron 260, Glufosinate 382, Glyphosate 383.

The preferred component is thidiazuron. The preferred component is glufosinate.

The combination of the active ingredients can be used in a manner which is customary per se, for example by spray application of a spray liquor prepared from individual formulations of the active ingredients in a tank mix or of a spray 25 liquor prepared from a mixed formulation of the active ingredients by dilution with water. Methods which are suitable for the application are in particular those which are customary for the application of the individual active ingredients and oo. which allow a joint application.

In principle, the application can also be carried out by successive applications of the individual active ingredients, where the possible interval can be determined in simple routine preliminary trials. However, preference is given to joint application. If appropriate, the active ingredients can also be used in combination with other crop protection agents.

While having the same effect, the application rate of an individual active ingredient in the combination is considerably reduced compared with the application rate of the individual active ingredient in question when used on its own. The optimum choice of the ratio by weight and the application rates depends, for example, on the development stage, on environmental factors and climatic conditions or else on the type of the active crop-protective agents which are additionally employed, if appropriate, and can be determined quickly by the person skilled in the art in simple routine trials.

The application rate for component is generally in the range from 1 to 500 g of active ingredient For thidiazuron, it is preferably in the range from 5 to 500 g of a.i./ha, particularly preferably from 6 to 300 g of a.i./ha, very particularly preferably from 10 to 200 g of a.i./ha, in particular from 12.5 to 150 g of a.i./ha.

0 20 In the case of thidiazuron/glufosinate mixtures (typically in a ratio by weight of 20 from 1:1 to the application rate is generally in the range from 10 to 500 g of a.i./ha, preferably from 15 to 400 g of a.i./ha, particularly preferably from to 400 g of a.i./ha, very particularly preferably from 25 to 300 g of a.i./ha, in particular from 50 to 250 g of a.i./ha.

C

25 The application rates for the component can vary within wide limits, depending on the active ingredient, and they are generally between 0.1 and 4 000 g of a.i./ha.

Preferred application rates for the component are, for example: if glufosinate is used: from 5 to 400 g of a.i./ha, preferably from 10 to 300 g of a.i./ha, particularly preferably from 20 to 250 g of a.i./ha, in particular from 50 to 200 g of a.i./ha.

if glyphosate is used: from 5 to 4 000 g of a.i./ha, preferably from 5 to 2 500 g of a.i./ha, particularly preferably from 20 to 2 000 g of a.i./ha, in particular from 20 to 1 000 g of a.i./ha.

The ratios by weight of components can vary within wide limits, in general, they are between 1:50 and 1:0.1.

The approximate ratio of is preferably in the case of glufosinate: 1:0.1-100, particularly preferably 1:1-20, very particularly preferably 1:1-8; for glyphosate: 1:0.1-100, particularly preferably 1:0.5-50.

The invention also provides defoliants, i.e. compositions for effecting leaf 1 5 abscission, which defoliants comprise combinations of components and (B) and customary formulation auxiliaries.

S• The combinations according to the invention and their individual active ingredients can be formulated in various ways, depending on the prevailing 20 biological and/or chemico-physical parameters. Examples of possible suitable formulations are: wettable powders water-soluble powders watersoluble concentrates, emulsifiable concentrates emulsions such as oil-in-water and water-in-oil emulsions, sprayable solutions, suspension concentrates oil- or water-based dispersions, solutions which are miscible 25 with oils, capsule suspensions dusts granules (GR) in the form of microgranules, spray granules, coated granules and adsorption granules, waterdispersible granules water-soluble granules ULV (ultra-low-volume) formulations, microcapsules and WSBs (water-soluble bags).

The individual types of formulation are known in principle and are described, for example, in: Winnacker-KQchler, "Chemische Technologie" [Chemical Technology], Volume 7, C. Hanser Verlag Munich, 4th Ed. 1986, Wade van Valkenburg, "Pesticide Formulations", Marcel Dekker, 1973; K. Martens, "Spray Drying" Handbook, 3rd Ed. 1979, G. Goodwin Ltd. London.

The formulation auxiliaries required, such as inert materials, surfactants, solvents and other additives are also known and are described, for example, in: Watkins, "Handbook of Insecticide Dust Diluents and Carriers", 2nd Ed., Darland Books, Caldwell H.v. Olphen, "Introduction to Clay Colloid Chemistry"; 2nd Ed., J.

Wiley Sons, C. Marsden, "Solvents Guide", 2nd Ed., Interscience, N.Y.

1963; McCutcheon's "Detergents and Emulsifiers Annual", MC Publ. Corp., Ridgewood Sisley and Wood, "Encyclopedia of Surface Active Agents", Chem. Publ. Co. Inc., N.Y. 1964; Sch6nfeldt, "Grenzfldchenaktive Athylenoxidaddukte" [Surface-active ethylene oxide adducts], Wiss.

Verlagsgesell., Stuttgart 1976; Winnacker-Kuchler, "Chemische Technologie", Volume 7, C. Hanser Verlag Munich, 4th Ed. 1986.

Based on these formulations, it is also possible to prepare combinations with other crop protection agents, such as, for example, insecticides, acaricides, herbicides, fungicides, safeners, other growth regulators and/or fertilizers, for 20 example in the form of a ready mix or a tank mix.

Wettable powders are preparations which are uniformly dispersible in water and which, besides the active ingredient, also comprise ionic and/or nonionic surfactants (wetting agents, dispersants), for example polyethoxylated 25 alkylphenols, polyethoxylated fatty alcohols, polyethoxylated fatty amines, fatty alcohol polyglycol ether sulfates, alkanesulfonates, alkylbenzenesulfonates, sodium lignosulfonate, sodium 2,2'-dinaphthylmethane-6,6'-disulfonate, sodium dibutylnaphthalenesulfonate or else sodium oleoylmethyltaurinate, in addition to a diluent or inert substance. To prepare the wettable powders, the active ingredients are ground finely, for example in customary equipment such as hammer mills, blower mills and air-jet mills, and simultaneously or subsequently mixed with the formulation auxiliaries.

Emulsifiable concentrates are prepared by dissolving the active ingredients in an organic solvent, for example butanol, cyclohexanone, dimethylformamide, xylene, or else higher-boiling aromatics or hydrocarbons, or mixtures of the organic solvents with the addition of one or more ionic and/or nonionic surfactants (emulsifiers). Examples of emulsifiers which can be used are: calcium salts of alkylarylsulfonic acid such as calcium dodecylbenzenesulfonate, or nonionic emulsifiers such as fatty acid polyglycol esters, alkylaryl polyglycol ethers, fatty alcohol polyglycol ethers, propylene oxide/ethylene oxide condensates, alkyl polyethers, sorbitan esters, for example sorbitan fatty acid esters or polyoxyethylene sorbitan esters, for example polyoxyethylene sorbitan fatty acid esters.

Dusts are obtained by grinding the active ingredients with finely divided solid substances, for example talc, natural clays such as kaolin, bentonite and pyrophyllite, or diatomaceous earth. Suspension concentrates can be water- or oil-based. They can be prepared, for example, by wet grinding using commercially available bead mills with or without addition of surfactants as have already been mentioned above, for example in the case of the other types of 20 formulation.

Emulsions, for example oil-in-water emulsions can be prepared, for example, by means of stirrers, colloid mills and/or static mixers using aqueous organic solvents and, if appropriate, surfactants as have already been mentioned 25 above, for example in the case of the other types of formulation.

Granules can be prepared either by spraying the active ingredients onto adsorptive granulated inert material or by applying active ingredient concentrates to the surface of carriers such as sand, kaolinites or of granulated inert material by means of binders, for example polyvinyl alcohol, sodium polyacrylate or else mineral oils. The active ingredients can also be granulated in the manner which is conventional for the production of fertilizer granules, if desired in a mixture with fertilizers.

Water-dispersible granules are generally prepared by the customary methods such as spray-drying, fluidized-bed granulation, disk granulation, mixing with high-speed mixers and extrusion without solid inert material.

In general, the preparations according to the invention comprise 0.1 to 99% by weight, in particular 0.1 to 95% by weight, of active ingredients of the components and or The active ingredient concentration in wettable powders is, for example, approximately 10 to 90% by weight, the remainder to 100% by weight being composed of customary formulation components. In the case of emulsifiable concentrates, the active ingredient concentration may amount to approximately 1 to 90% by weight. Formulations in the form of dusts comprise, for example, 1 to 80% by weight of active ingredient, in most cases 5 to 60% by weight of I ~active ingredient. Sprayable solutions comprise, for example, 0.05 to 80, in 20 most cases 2 to 50, by weight of active ingredient. The active ingredient 20 content of water-dispersible granules depends partly on whether the active compound is in liquid or solid form and on which granulation auxiliaries, fillers and the like are being used. The active ingredient content of the water- OI dispersible granules amounts to, for example, between 1 and 95% by weight, in

S

most cases between 10 and 80% by weight.

2:"In addition, the abovementioned formulations of active ingredients comprise, if appropriate, adhesives, wetting agents, dispersants, emulsifiers, penetrants, preservatives, antifreeze agents, solvents, fillers, carriers, colorants, antifoams, evaporation inhibitors and pH and viscosity regulators, which are customary in each case.

8 Components which can also be used in combination with the active ingredients according to the invention in mixed formulations or in a tank mix are, for example, known active ingredients as are described, for example, in Weed Research 26, 441-445 (1986), or "The Pesticide Manual", 1 1lth edition, 1997, and the literature cited therein.

For use, the formulations, which are in commercially available form, are, if appropriate, diluted in the customary manner, for example using water in the case of wettable powders, emulsifiable concentrates, dispersions and waterdispersible granules, and then applied to the plants. This includes specific application variants customary in cotton cultivation, for example the application by plane. Preparations in the form of dusts, granules for soil application or for broadcasting and also sprayable solutions are conventionally not diluted any further with other inert substances prior to use.

The invention also provides the use of the compositions or mixtures according to the invention as defoliants, i.e. for effecting leaf abscission in plants, and as Gooo i growth regulators, preferably in suitable crops of useful plants, such as cotton, 2 sunflowers, avocados or potatoes. Particular preference is given to the use as 20 defoliant in crops of cotton.

The invention also provides a method for effecting leaf abscission in a plant, preferably a useful plant, particularly preferably a cotton plant, which comprises treating the plant with a mixture according to the invention or a composition 25 according to the invention.

lOO• 0ll The mixtures or compositions and the method can, of course, also be employed for treating genetically modified (transgenic) plants, preferably useful plants, particularly preferably cotton, where such plants contain, for example, one or more foreign genes in order to obtain resistance against insecticides and/or herbicides.

9 The disclosure in German patent application No. 100 33 832.1, from which this application claims priority, and in the abstract accompanying this application are incorporated herein by reference.

The invention is illustrated in more detail by the examples, without being limited thereby.

Examples 1. Assessment of the effect and evaluation of the synergism The effect on the plants is evaluated by leaf abscission according to a scale from 0 to 100%: 0% no noticeable effect when compared with the untreated plant; 100% all leaves have been dropped.

When assessing the synergism between the active ingredients employed here, 20 the highly different application rates of the individual active ingredients have to be taken into consideration. Thus, it is not expedient to compare the activities of the active ingredient combinations with those of the individual active ingredients *in each case at identical application rates. The amounts of active ingredients that can be saved according to the invention become evident from the superadditive 25 increase in activity when using the combined application rates or from the reduction of the application rates of the two individual active ingredients in the combination in comparison to the application rates of the active ingredients *r applied on their own, the activity remaining the same in each case.

In all instances, a distinction is made in the combinations between the calculated degree of action and the degree of action found. In most cases, the synergistic increase in activity is so high that the activity of the combination considerably surpasses the formal (calculated) total of the activities of the individual ingredients. Such a greatly increased activity was in no way to be expected based on the known activities of the individual active ingredients.

The expected theoretical degree of action of a combination can be approximately estimated by the formula of S. R. Colby (cf. "Calculation of synergistic and antagonistic responses of herbicide combinations", Weeds 15 (1967), pages 20-22).

For combinations of two compounds, this formula is: E=X+ Y- 100 where X activity by A at an application rate of x kg/ha; Y activity by B at an application rate of y kg/ha; E expected activity by A B at x y kg/ha If the actual activity exceeds the calculated expected activity, the activity of the i* 20 combination is more than additive, i.e. there is a synergistic effect.

*0 2. Action as defoliant 000 2.1. General procedure Cotton seeds of the cultivar Vulkano are sown at a depth of 1 cm and grown in 00.. a greenhouse (14 h of light, temperature during the day: 25 0 C, at night: 18 0

C)

0*00 until they had reached the 8 10 leaf stage.

2.2. Table 1 (Mixtures with glufosinate) 11 The active ingredients were applied in each case to 3 plants per treatment using an overhead laboratory sprayer with a Teejet 11002XR nozzle, in an amount of 300 I/ha. After the treatment, the cotton plants were returned to the greenhouse. At various points in time, the number of shed leaves was counted.

Active ingredient (combination) thidiazuron Dose g/ha 50 Activity in 4 0 15 days 86 S. S S. S 55

S.

S..

S.

S

S

*SSS

thidiazuron 25 0 0 62 76 81 thidiazuron 12.50 0 43 43 48 thidiazuron 6.25 0 0 24 29 33 glufosinate 200 0 0 10 24 33 glufosinate 100 0 5 33 33 33 glufosinate 20 0 0 10 10 glufosinate 5 0 0 0 0 0 glufosinate 200 0 71 95 100 100 thidiazuron glufosinate 100 0 29 71 86 86 thidiazuron glufosinate 5 0 5 71 71 71 thidiazuron glufosinate 200 0 52 90 95 thidiazuron 12.5 glufosinate 100 0 19 67 67 71 thidiazuron 12.5 glufosinate 20 0 24 62 62 76 thidiazuron 12.5 glufosinate 100 0 0 52 52 62 thidiazuron glufosinate 20 0 10 62 76 76 thidiazuron glufosinate 5 0 5 52 52 62 +thidiazuron The experiments clearly demonstrate a synergistic effect.

12 2.3 Table 2 (Mixtures with glyphosate) The active ingredients were applied in each case to 3 plants per treatment using an overhead laboratory sprayer with a Teejet 11002XR nozzle, in an amount of 300 I/ha. After the treatment, the cotton plants were returned to the greenhouse. At various points in time, the number of shed leaves were counted.

Active ingredient (combination) Dose g/ha Activity in 11 16 days e

C

C. C CC C Ce

*C

C

C

CCC.

CC

C.

thidiazuron 25 13 54 71 thidiazuron 12.5 13 46 67 thidiazuron 6.25 0 21 33 33 glyphosate 500 0 0 0 4 glyphosate 100 0 0 0 0 glyphosate 20 0 0 0 glyphosate 5 0 0 0 0 glyphosate 500 17 42 88 92 thidiazuron 12.5 glyphosate 100 29 54 83 96 thidiazuron 12.5 glyphosate 100 13 25 63 thidiazuron 6.25 glyphosate 20 4 33 63 thidiazuron 6.25 glyphosate 5 13 25 46 63 thidiazuron 6.25 The experiments clearly demonstrate a synergistic effect.

Claims (9)

1. A mixture, comprising the active ingredients: thidiazuron and/or diuron, and glufosinate and/or glyphosate.

2. The mixture as claimed in claim 1, where the ratio by weight of components 1/0.1-50.

3. The mixture as claimed in claim 1 and/or 2, where the component is glufosinate.

4. A defoliant, comprising the active ingredients: thidiazuron and/or diuron, and glufosinate and/or glyphosate, and also one or more formulation auxiliaries.

5. The use of a mixture as claimed in one or more of claims 1 to 3 or of a defoliant as claimed in claim 4 for effecting leaf abscission and/or growth 20 regulation of a plant. e

6. The use as claimed in claim 5, wherein the plant is a cotton plant.

7. The use as claimed in claim 6, wherein the cotton plants are transgenic 25 cotton plants.

8. A method for effecting leaf abscission and/or growth regulation of a plant, which comprises treating the plant with a mixture as claimed in one or more of claims 1 to 3 or a composition as claimed in claim 4.

9. The method as claimed in claim 8, wherein the plant is a cotton plant. The method as claimed in claim 9, wherein the cotton plant is a transgenic cotton plant. DATED this 10th day of July 2001. AVENTIS CIR)PSCIENCE GMIBH WATEIRvARK PATENT TRADEMARK ATTORNEYS 290 BURW(X)D ROAD HAWTHORN. VIC. 3122. 00 0 00000 a se*