WO2009064830A1

WO2009064830A1 - Selective weed control using karbutilate herbicidal compositions, and herbicidal composition comprising karbutilate and ametryn

Info

Publication number: WO2009064830A1
Application number: PCT/US2008/083310
Authority: WO
Inventors: Dario Isauro Jeronimo; Jose Ovidio Bessa; Ronaldo Pereira; Kim G. Watson; James E. Lappin; James T. Bahr; Sandra L. Shinn
Original assignee: Sds Biotech K.K.
Priority date: 2007-11-16
Filing date: 2008-11-13
Publication date: 2009-05-22

Abstract

The present invention provides a method of using a herbicidal composition comprising 3-[[(dimethylamino)carbonyl]amino]phenyl (1,1-dimethylethyl)carbamate, which when applied pre-emergent and at low rates, exhibits excellent initial and residual weed control while maintaining crop safety in sugar cane. The present invention further provides an herbicidal composition comprising 3-[[(dimethylamino)carbonyl]amino]phenyl (1,1-dimethylethyl)carbamate and N-ethyl-N'-(1-methylethyl)-6-(methylthio)-1,3,5-triazine-2,4-diamine,in which the ratio of the former compound to the latter compound is usually from of 1:0.1 to 1:10, and an herbicidal method of use thereof.

Description

SELECTIVE WEED CONTROL USING KARBUTILATE HERBICID AL

COMPOSITIONS, AND HERBICID AL COMPOSITION COMPRISING

KARBUTILATE AND AMETRYN

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S. C. 119(e) of U.S. Provisional Application No. 60/988,504 filed on November 16, 2007. The entire disclosure of the prior application, Application No. 60/988,504, is hereby incorporated by reference.

FIELD OF THE INVENTION

This invention relates to a method of using herbicidal compositions containing 3- [[(dimethylamino)carbonyl]amino]phenyl (l,l-dimethylethyl)carbamate for selective control of weeds in crops. This invention also relates to herbicidal compositions containing 3-[[(dimethylamino)carbonyl]amino]phenyl (l,l-dimethylethyl)carbamate and a second herbicidal compound.

BACKGROUND OF THE INVENTION

U. S. Patent 3,434,822 discloses 3-[[(dimethylamino)carbonyl]amino]phenyl (1,1- dimethylethyl)carbamate . Karbutilate, the common name for 3-[[(dimethylamino)carbonyl]amino]phenyl

(l,l-dimethylethyl)carbamate, when used at soil-sterilant rates, is a non-selective pre- and post-emergence herbicide for use in non-crop applications, such as along railway lines, roadsides, drainage ditch banks, utility and pipeline rights-of-way and industrial plant sites. The use of karbutilate for weed control in crops such as sugarcane has been discouraged since karbutilate is known to be phytotoxic to sugarcane. Revue Agricole et Suciere de L'lle Maurice, (1982) Vol. 61, No. 3, pages 155-166, discloses that karbutilate provided good weed control but was too phytotoxic to sugarcane.

SUMMARY OF THE INVENTION In accordance with the first embodiment of the present invention, it has been found that an herbicidal composition comprising 3- [[(dimethylamino)carbonyl]amino]phenyl (l,l-dimethylethyl)carbamate has unexpected herbicidal properties in certain crops.

In accordance with the second embodiment of the present invention, it has been found that an herbicidal composition comprising a first herbicide and a second herbicide in which the first herbicide is 3-[[(dimethylamino)carbonyl]arnino]phenyl (1,1- dimethylethyl)carbamate and the second herbicide is N-ethyl-iV'-(l-methylethyl)-6- (methylthio)-l,3,5-triazine-2,4-diamine, wherein the first herbicide and the second herbicide are present in an herbicidally effective amount, has unexpected advantageous properties over the individual components.

DETAILED DESCRIPTION OF THE INVENTION In accordance with the first embodiment of the present invention, it has been unexpectedly found that an herbicidal composition comprising karbutilate, when applied pre-emergent and at low rates, exhibits excellent initial and residual weed control while maintaining crop safety. In particular, it has been found that crops such as sugarcane are tolerant of low rates of karbutilate.

In the method of the first embodiment of the present invention, other herbicides can be employed in conjunction with karbutilate provided they do not adversely affect the selective herbicidal properties of this invention. For example, it can sometimes be useful to include additional herbicides to extend the range of activity in order to control a wider spectrum of weeds when using lower than normal use rates of one or both herbicides. Additional herbicides which are useful as a second herbicide in the first embodiment of the present invention include: ametryn, the common name for iV-ethyl-iV'-(l- methylethyl)-6-(methylthio)-l,3,5-triazine-2,4-diamine; clomazone, the common name for 2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolinone; sulfentrazone, the common name for Λ^r-[2,4-dichloro-5-[4-(difluoromethyl)-4,5-dihydro-3-methyl-5-oxo- lif-l,2,4-triazol-l-yl]phenyl]methanesulfonamide; hexazinone, the common name for 3- cyclohexyl-6-(dimethylamine)- 1 -methyl- 1 ,3 ,5-triazine-2,4-(l H,3H)-dione and atrazine, the common name for 6-chloro-N-ethyl-N'-(l-methylethyl)-l,3,5-triazine-2,4-diamine. For pre-emergence control of weeds in crops such as sugarcane, the preferred use rate of karbutilate active ingredient (AI) is from 100 grams AI per hectare to 1000 grams AI per hectare. More preferred is a use rate of 200 grams AI per hectare to 800 grams AI per hectare. When combining karbutilate with a second herbicide, e.g. ametryn, the preferred use rate is from 200 grams to 800 grams of karbutilate with 1250 grams of ametryn. Another embodiment of the present invention is a method for controlling broadleaf weeds, grass weeds and sedges in crops such as coffee, tea, agave, oil palm and hard or soft wood forestry plantations which comprises applying a herbicidally effective amount of a composition comprising karbutilate to a locus where weeds are present or are expected to be present.

In accordance with the second embodiment of the present invention, it has been unexpectedly found that an herbicidal composition comprising a first herbicide and a second herbicide in which the first herbicide is 3- [[(dimethylamino)carbonyl]amino]phenyl (l,l-dimethylethyl)carbamate and the second herbicide is N-ethyl-iV'-(l-methylethyl)-6-(methylthio)-l,3,5-triazine-2,4-diamine, has unexpected advantageous properties in weed control over the individual components. For example, the mixture controls a broader variety of weeds at lower rates than either component alone. In addition, the composition provides quicker weed control than either component alone. The present composition can also be useful in overcoming reduced sensitivity by a weed to either of the individual components.

The ratio of 3-[[(dimethylamino)carbonyl]amino]phenyl (1,1- dimethylethyl)carbamate to N-ethyl-iV'-(l-methylethyl)-6-(methylthio)-l,3,5-triazine-2,4- diamine varies over a wide range but is usually in the range of 1 :0.1 to 1 : 10, preferably 1:1 to 1 :5. Other herbicides can be employed in conjunction with the first and second herbicides described above providing they do not adversely affect the interaction between the components of this invention. For example it can sometimes be useful to include additional herbicides to extend the range of activity in order to control a wider spectrum of weeds. Further there is provided a method of use of an herbicidal composition comprising 3-[[(dimethylamino)carbonyl]amino]phenyl (l,l-dimethylethyl)carbamate and N-ethyl- iV'-(l-methylethyl)-6-(methylthio)-l,3,5-triazine-2,4-diamine for controlling weeds.

Another embodiment of the present invention is a method for controlling broadleaf weeds, grass weeds and sedges in crops such as sugarcane, coffee, tea, agave, oil palm and hard or soft wood forestry plantations which comprises applying an herbicidally effective amount of a composition comprising 3-

[[(dimethylamino)carbonyl]amino]phenyl (l,l-dimethylethyl)carbamate and iV-ethyl-iV'- (l-methylethyl)-6-(methylthio)-l,3,5-triazine-2,4-diamine, either together or sequentially, to a locus where weeds are present or are expected to be present.

The terms "weed" and "weeds" refer to any unwanted vegetation in agricultural crops and orchards, as well as, but not limited to, around buildings, along fences, roadways and rail lines. The herbicidal compositions of the present invention which contains at least karbutilate, or karbutilate and ametryn, and optionally the other herbicidal compounds may be employed in many forms and are often most conveniently prepared in aqueous form immediately prior to use. One method of preparing such a composition is referred to as "tank mixing" in which the ingredients in their commercially available form are mixed together by the user in a quantity of water.

In addition to tank mixing immediately prior to use, the herbicidal compositions containing the herbicidal compound or compounds may be formulated into a more concentrated composition which is diluted with water or other diluent before use. Such compositions may comprise a surface active agent in addition to the active ingredients and examples of such compositions are set forth below.

An herbicidal composition of the present invention may be formulated as a granule of relatively large particle size (for example, 8/16 or 4/8 US Mesh), as water- soluble or water-dispersible granules, as powdery dusts, as wettable powders, as emulsifiable concentrates, as suspension concentrates, as aqueous emulsions, as solutions, or as any of the other known types of agriculturally-useful formulations, depending on the desired mode of application to the areas in which suppression of vegetation is desired. These formulations may contain as little as 0.1%, 0.2% or 0.5% to as much as 95% or more by weight of karbutilate or the total of karbutilate and additional herbicides (exemplarily ametryn).

The herbicidal composition can be in the form of a dispersible solution which comprises the herbicidal compound or compounds dissolved in a water-miscible solvent with the addition of a dispersing agent. Alternatively it can comprise the herbicidal compound or compounds in the form of a finely ground powder in association with a dispersing agent and intimately mixed with water to give a paste or cream which can if desired be added to an emulsion of oil in water to give a dispersion of the herbicidal compound or compounds in an aqueous oil emulsion.

Alternatively, the herbicidal composition can be in the form of water-soluble or water-dispersible granules that disperse readily in water or other dispersant. Water- soluble or water-dispersible granules (WG) normally are prepared to contain about 5-80% of the active ingredients, depending on the absorbency of the carrier, and usually also contain a wetting, dispersing or emulsifying agent to facilitate dispersion and may contain a preservative. Typical carriers for water-soluble or water-dispersible granules include Fuller's earth, natural clays, silicas, and other highly absorbent, readily wet inorganic diluents. For example, a useful water-soluble or water-dispersible granule formulation contains 26.71 parts of the herbicidal compound or compounds, 30.90 parts of ammonium sulfate, 30.89 parts of continental clay, 10.00 parts of sodium lignosulfonate as a dispersant, 1.00 part of sodium dioctylsuccinate as a wetting agent and 0.50 part of citric acid as a preservative. The mixture is milled, diluted with water to form a paste and the paste is extruded and dried to produce granules.

Other alternatives that may be employed are dusts which are free flowing admixtures of the herbicidal compound or compounds with finely divided solids such as talc, natural clays, kieselguhr, flours such as walnut shell and cottonseed flours, and other organic and inorganic solids which act as dispersants and carriers for the herbicides. These finely divided solids have an average particle size of less than about 50 microns. A typical dust formulation useful herein is one containing 1.0 part or less of the herbicidal compounds and 99.0 parts of talc. Also useful formulations for the herbicidal compositions of the present invention are wettable powders in the form of finely divided particles that disperse readily in water or other dispersant. The wettable powder is ultimately applied to the locus where weed control is needed either as a dry dust or as an emulsion in water or other liquid. Typical carriers for wettable powders include Fuller's earth, kaolin clays, silicas, and other highly absorbent, readily wet inorganic diluents. Wettable powders are prepared to contain about 5-80% of the herbicidal compound or compounds depending on the absorbency of the carrier, and usually also contain a small amount of a wetting, dispersing or emulsifying agent to facilitate dispersion. For example, a useful wettable powder formulation contains 80.0 parts of the herbicidal compound or compounds, 17.9 parts of Palmetto clay, and 1.0 part of sodium lignosulfonate and 0.3 part of sulfonated aliphatic polyester as wetting agents. Additional wetting agents and/or oils will frequently be added to a tank mix to facilitate dispersion on the foliage of the plant.

Other useful formulations for the herbicidal compositions of the present invention are emulsifϊable concentrates (ECs) which are homogeneous liquid compositions dispersible in water or other dispersant, and may consist entirely of the herbicidal compound or compounds, and a liquid or solid emulsifying agent, or may also contain a liquid carrier, such as xylene, heavy aromatic naphthas, isophorone, or other non-volatile organic solvents. For herbicidal application these concentrates are dispersed in water or other liquid carriers and applied as a spray to the area to be treated. The percentage by weight of the herbicidal compounds may vary according to the manner in which the composition is to be applied, but in general comprises 0.5 to 95% of the herbicidal compounds by weight of the total composition.

Suspension concentrate formulations (SCs) may also be employed. These are similar to ECs, except that the herbicidal compound or compounds is suspended in a liquid carrier, generally water. Suspension concentrates, like ECs, may include small amounts of surfactants, emulsifiers, stabilizers, thickeners, antifoam agents and/or preservatives and will typically contain the herbicidal compound or compounds in the range of 0.5 to 95%, frequently from 10 to 50%, by weight of the total composition. For herbicidal application, suspension concentrates may be diluted in water or other liquid vehicle, and are normally applied as a spray to the area to be treated. Other useful formulations include suspensions of the herbicidal compound or compounds in a relatively non- volatile solvent such as water, corn oil, kerosene, propylene glycol, or other suitable solvents.

Still other useful formulations for these herbicidal compositions include simple solutions of the herbicidal compound or compounds in a solvent in which the active ingredients are completely soluble at the desired concentration, such as acetone, alkylated naphthalenes, xylene, or other organic solvents. Granular formulations, wherein the herbicide, or herbicides, is carried on relative coarse particles, are of particular utility for aerial distribution or for penetration of cover crop canopy. Pressurized sprays, typically aerosols wherein the herbicidal compound or compounds is dispersed in finely divided form as a result of vaporization of a low-boiling dispersant solvent carrier may also be used.

Another useful formulation for the herbicidal compositions of the present invention is micro encapsulation. This method of formulation is a process in which either one or, if more than one herbicide is present, both of the herbicidal compounds may be encapsulated in a shell of polyurea, polyamide or amide-urea copolymer as disclosed in EP 0792100 Bl and U. S. Patent 5,583,090.

In some circumstances it may be desirable to combine two types of formulations if more than one herbicide is present, e.g. one of the herbicidal compounds is used as an emulsifϊable concentrate and the second herbicidal compound is dispersed as a powder in this concentrate.

The concentrate of karbutilate (when used as the sole active components) in a composition for direct application to the crop by conventional ground methods is preferably within the range of 0.001 to 10 % by weight of the composition, especially 0.005 to 5 % by weight, but more concentrated compositions containing up to 40 % may be desirable.

Typical wetting, dispersing or emulsifying agents that may be used in the herbicidal compositions of the present invention include, but are not limited to, the alkyl and alkylaryl sulfonates and sulfates and their sodium salts; alkylaryl polyether alcohols; sulfated higher alcohols; polyethylene oxides; sulfonated animal and vegetable oils; sulfonated petroleum oils; fatty acid esters of polyhydric alcohols and the ethylene oxide addition products of such esters; and the addition product of long-chain mercaptans and ethylene oxide. Many other types of useful surface-active agents are available in commerce. Surface-active agents, when used, normally comprise 1 to 15% by weight of the herbicidal composition. In use on the field, the granular formulations, emulsifiable concentrates, flowable concentrates, aqueous emulsions, solutions, etc., may be diluted with water to give a concentration of the active ingredient in the range of 0.01% or 0.2% to 1.5% or 2.0%.

The invention is illustrated in the following Examples which describe experiments in which selective herbicidal activity and a beneficial effect was observed. The desired concentration of the active ingredients was achieved by diluting, with water, the commercially available herbicide formulation of 3-

[[(dimethylamino)carbonyl]amino]phenyl (l,l-dimethylethyl)carbamate (common name, karbutilate) and N-ethyl-N'-(l-methylethyl)-6-(methylthio)-l,3,5-triazine-2,4-diamine (common name, ametryn), each of which contained conventional surfactants, emulsifiers, stabilizers, thickeners, antifoam and/or preservatives.

EXAMPLE 1

Pre-emergent Herbicidal Evaluation of Karbutilate and Mixtures of Karbutilate and Ametryn For Control of Weeds in Sugarcane

The compositions of the present invention were tested for herbicidal efficacy in the following manner:

Test compositions of karbutilate were prepared in a spray tank that provided the appropriate grams per hectare application rate.

Test compositions of mixtures of karbutilate and ametryn were prepared in a tank mix that provided appropriate rates of application of combinations of karbutilate and ametryn.

The application of the test rate was performed with manual back-pack sprayers calibrated to spray 475 liters per hectare. The test applications were made prior to planting of the sugarcane (variety CP722086) and prior to the emergence of any weeds. The experimental design used randomized plots with one post-emergent treatment and four replications per test trial. An untreated check plot was included for each trial to compare to the treated plots for percent control purposes. The size of each experimental plot was 4.2 meters by 8.0 meters.

The appearance of the population of the weeds were assessed and averaged at 15 days and 30 days after application (DAA) of each test rate, the results are in Table 1-1 below. The appearance of the population of the weeds were assessed and averaged at 45 days after application (DAA) of each test rate, the results are in Table 1-2 below. The test weeds include: pricklepoppy (Argemone mexicanά), burcucumber (Sicyos spp.), Mexican clover (Richardia spp.), groundcherry (Physalis spp.), purslane (Portulaca oleracea) and nightshade (Solarium spp.). Phototoxicity to the sugarcane crop (Species ??) was also assessed at 15 and 30 DAA.

TABLE 1-1 Pre-emergence Herbicidal Activity of Karbutilate (Cmpd 1) and Ametryn (Cmpd 2) in Sugarcane

* A=pricklepoppy; B=burcucumber; C=Mexican clover; D=groundcherry; E=purslane; F=nightshade.

TABLE 1-2 Pre-emergence Herbicidal Activity of Karbutilate (Ctnpd 1) and Ametryn (Cmpd 2) in Sugarcane

* A=pricklepoppy; B=burcucumber; C=Mexican clover; D=groundcherry; E=purslane.

EXAMPLE 2 Post-emergent Herbicidal Evaluation of Karbutilate, Ametryn and Mixtures Thereof

The application of the test rate was performed with manual back-pack sprayers calibrated to spray 400 liters per hectare.

The experimental design used randomized plots with one post-emergent treatment and four replications per test trial. An untreated check plot was included for each trial to compare to the treated plots for percent control purposes. The size of each experimental plot was 3.9 meters by 7.0 meters. The appearance of the population of the weeds were assessed and averaged at 5 days and 7 days after application (DAA) of each test rate, the results are in Table 2-1 ( 5 DAA) and Table 2-2 (7 DAA) below. The test weeds include: junglerice (Echinochloa colonum), Signalgrass (Brachiariafasciculata), lobed croton (Croton lobatus), yellow nutsedge (Cyperus esculentus), large crabgrass (Digitaria sanguinalis) and tamarindillo (Phyllanthus sp.).

TABLE 2-1

Post-emergence Herbicidal Activity of Karbutilate (Cmpd 1), Ametryn (Cmpd 2) and Mixtures

Thereof

* A -junglerice. B - - signalgrass, C - large crabgrass, D - tamarindillo

TABLE 2-2

Thereof

* A -junglerice. B - - signalgrass, E - lobed croton, F - yellow nutsedge

Those of ordinary skill in the art will appreciate that variations of the invention may be used and that it is intended that the invention may be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications encompassed within the spirit and scope of the invention as defined by the following claims.

Claims

What is claimed is:

1 A method of controlling weeds in sugarcane by applying an herbicidal composition comprising 3-[[(dimethylamino)carbonyl]amino]phenyl (1,1- dimethylethyl)carbamate to a locus where weeds are present or are expected to be present.

2 The method according to claim 1 wherein the herbicidal composition further comprises N-ethyl-N'-(l-methylethyl)-6-(methylthio)-l,3,5-triazine-2,4-diamine.

3 The method according to claim 1 in which 3-

[[(dimethylamino)carbonyl]amino]phenyl (l,l-dimethylethyl)carbamate is applied at a use rate of from 100 grams per hectare to lOOOgrams per hectare.

4 The method according to claim 3 in which 3-

[[(dimethylamino)carbonyl]amino]phenyl (l,l-dimethylethyl)carbamate is applied at a use rate of from 200 grams per hectare to 800 grams per hectare.

5 The method according to claim 2 in which 3- [ [(dimethylamino)carbonyl] amino]phenyl (1,1 -dimethylethyl)carbamate is applied at a use rate of from 200 grams per hectare to 800grams per hectare and iV-ethyl -./V-(I- methylethyl)-6-(methylthio)-l,3,5-triazine-2,4-diamine is applied at a use rate of 1250 grams per hectare.

6 An herbicidal composition comprising 3-

[[(dimethylamino)carbonyl]amino]phenyl (l,l-dimethylethyl)carbamate and iV-ethyl-iV'- (l-methylethyl)-6-(methylthio)-l,3,5-triazine-2,4-diamine.

7 The composition according to claim 6 wherein the ratio of 3- [[(dimethylamino)carbonyl]amino]phenyl (l,l-dimethylethyl)carbamate to iV-ethyl-iV-(l- methylethyl)-6-(methylthio)-l,3,5-triazine-2,4-diamine is from 1:0.1 to 1:10. 8 The composition according to claim 7, wherein the ratio of 3- [[(dimethylamino)carbonyl]arnino]phenyl (l,l-dimethylethyl)carbamate to Λ/^'-ethyl-Λ^r'-(l- methylethyl)-6-(methylthio)-l,3,5-triazine-2,4-diamine is from 1:1 to 1:5.

9 A method for controlling weeds comprising applying a composition of any one of claims 6 to 8 to a locus where weeds are present or are expected to be present.