WO1999056546A1 - Methods and compositions for controlling unwanted vegetation - Google Patents

Abstract

Methods and compositions for controlling the growth of unwanted vegetation are provided. The compositions comprise a benzyl ester of an aromatic acid or aliphatic acid or a salicylate. Preferred compounds include benzyle benzoate, benzyl salicylate and benzyl acetate. The composition can include at least one fatty-acid ester to increase its effectiveness in controlling unwanted vegetation. The subject method controls the unwanted vegetation by providing a plant part of the unwanted vegetation with the benzyl ester composition. The subject method reduces the environmental and health hazards in plant control by minimizing the toxicity of the subject composition.

Description

METHODS AND COMPOSITIONS FOR CONTROLLING UNWANTED VEGETATION

BACKGROUND Field of the invention This invention relates to methods and compositions for controlling growth of unwanted vegetation using a benzyl ester of an aromatic acid or acetic acid or a salicylate derivative to either eliminate the undesired vegetation or to deter its growth. This invention is exemplified by the eradication of annual weeds with the benzyl ester composition.

Background of the invention Unwanted vegetation costs farmers billions of dollars annually in crop losses and in the expense of keeping unwanted vegetation under control. The losses caused by unwanted vegetation, such as weeds, in agricultural production environments include decreases in crop yield, reduced crop quality, loss of top soil, increased irrigation costs, increased harvesting costs, reduction of agricultural land, decreased land value, injury to livestock, and crop damage from insects and diseases harbored by the weeds. Traditional methods of removing unwanted vegetation include hoeing, hand pulling, and burning. Hoeing and hand pulling are labor intensive and are not effective or efficient in controlling unwanted vegetation in large areas. Burning of unwanted vegetation causes air pollution and presents a health hazard. Some plants, for example, poison oak, generally cannot safely be removed by burning because this introduces the components responsible for allergic reactions in humans into the air, damaging the lungs of those who are reactive. In the past 45 years, herbicides, or chemical weedkillers, have largely replaced mechanical methods of agricultural and industrial weed control, especially in intensive and highly mechanized agriculture. Herbicides provide a more effective and economical means of weed control than cultivation, hoeing, and hand pulling (except in the home garden). Without the use of herbicides in agriculture, it would have been impossible to mechanize fully the production of cotton, sugar beets, grains, potatoes, and corn. However, many of the herbicides in current use are toxic and/or have undesirable side effects.

The first chemicals utilized in weed control were inorganic compounds, for example, brine and mixtures of salt and ash. Later, copper sulfate was used to kill selectively weeds in grain fields. Copper sulfate also is used to control algae, but is toxic to trout at recommended treatment rates and is moderately toxic to most other fish species. The toxicity of copper to fish increases with decreased total alkalinity of water. Acrolein, which is used for control of submersed weeds in flowing water, is highly toxic to fish and many other forms of aquatic life. Additionally, inorganic herbicides, which remove all vegetation from an area, are not a wise choice for use around the home unless they are used with great care. A variety of organic herbicides, both selective and non-selective, are used and have provided an effective method of controlling unwanted vegetation. These include the commonly used organic selective herbicides bentazon, arsenicals (disodium methanearsonate, monosodium acid methanearsonate), phenoxy herbicides (2,4-D amine), diphenyl ethers (fluazifop-P-butyl), dinitroanilines (benefin, oryzalin, pendimethalin and trifluralin), substituted ureas (siduron), thiocarbamates, and aliphatic acids (dalapon). The commonly used organic non-selective herbicides are glyphosphate (N-(phosponomethyl) glycine (sold under the name ROUNDUP^®, Monsanto) or its isopropylamine salt, triazines, phthalic acids (Dacthal^®), benzonitriles (dichlorobenil and bromoxynil), bipyridyliums (diquat and paraquat). The above organic herbicides are not of natural origin and have low LD₅₀s. However, the public has become concerned about the amount of residual chemicals which might be found in food, ground water, and the environment. For example, the currently most widely-used herbicide, ROUNDUP^®, is reported as the third most common source of pesticide-related illness among farm workers. This isopropylamine salt of glyphosate is toxic to fish and is not approved in the United States for use on aquatic vegetation. Another disadvantage of ROUNDUP^® is that its active portion in deliverable (water-soluble) compounds, the glyphosate segment, is chemically unstable even in weakly basic environments. Thus, glyphosate is hydrolyzed in weak base, which may account for its failure to control vegetation in some instances. Mineral dust, which accumulates on vegetation, is generally alkaline, and hydrolysis, which can occur in that environment, deactivates glyphosate as an herbicide. Another widely-used herbicide, paraquat, is known as a poison. Intensive EPA restrictions have been placed on some of the inorganics because of their persistence in soil. Stringent new restrictions on the use of herbicides and the elimination of some effective herbicides from the market place could limit economical and effective options for the costly control of weeds. Additionally, the visually-apparent, phytotoxic effects of some systemic herbicides appear very slowly on the target weeds, so users often seek methods by which the apparent speed of action of the herbicide is increased. There is a great need for novel methods and compositions of controlling unwanted vegetation which reduce the environmentally-harmful amount of chemical herbicide necessary to obtain acceptable levels of weed control. The new method ideally uses a composition which is a chemical substance of natural origin that can be synthesized, or has lower toxic side effects than other herbicides currently in use.

Relevant Literature Frances, et al. (J. Med. Entomol. (1996) 33(2):232-235) disclose a composition of white cotton fabric impregnated with benzyl benzoate.

Frances, et al. (J. Med. Entomol. (1994) 31(4):628-630) disclose a composition of an ethanol solution containing 5 % benzyl benzoate.

Objects of the Invention One object of this invention is to provide a new family of herbicides based on easily obtainable compounds which are benzyl esters of an aromatic acid or acetic acid or a salicylate derivative. Another object of this invention is to provide a new family of herbicides using naturally- occurring compounds.

Yet another object of this invention is to provide a new family of herbicides having low toxicity to animals when used at a herbicidally effective level.

Other objects may be apparent to one of skill in the art upon reading the following specification.

SUMMARY OF INVENTION The present invention is directed to methods for controlling weeds, such as by inhibiting weed growth, by applying to a plant part of the weed, such as foliage, an herbicidally effective amount of a composition comprising an agriculturally-acceptable carrier in combination with a benzyl ester of an aromatic acid or acetic acid or a salicylate derivative. The invention also provides a composition comprising an herbicidally active compound of the invention, and optionally a surfactant. The invention is further directed to an article of manufacture that comprises a container in association with instructions for controlling weeds and holding a composition comprising an agriculturally-acceptable carrier and an herbicidally active compound of the invention. The composition finds use in clearing areas of vegetation, in killing weeds both before and after planting crops, and in control of aquatic weeds. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Herbicides are generally classified as selective or non-selective. When selective, a herbicide is used to kill weeds without harming a crop; when non-selective, it is used to kill all vegetation. Selective and non-selective materials can be applied as a function of their mode of action to the weed foliage or to the soil containing weed seeds and seedlings. Selectivity is the capacity of a herbicide, when properly applied, to be active only against certain species of plants. Selectivity can be achieved, however, also by spray placement, a method of spraying only the target weeds and not the crop plants. The compounds of the invention have herbicidal activity against one or more weed species. However, it is understood that certain compounds may be more effective on some weeds than others, and may even be ineffective against some weeds. It follows that one compound of the invention may be more selective than others. However, that does not in any way detract from their value as herbicides since the invention contemplates using some of these compounds as broad, general acting non-selective herbicides, while others have utility as specific or selective herbicides. The Examples set forth below illustrate methods by which the broad-acting or selectivity of herbicidal activity may be readily ascertained.

A weed can be defined as a plant without virtue. Accordingly, as used herein the term "weed" is intended to include all such plants whose growth, reproduction or proliferation is undesired or unwanted. These include both annual and perennial plants, for example, broadleaf plants, grasses, sages, aquatic plants, trees, and parasitic flowering plants, such as dodder, mistletoe, and witchweed. Numerous examples of weeds are set forth in the discussion and Examples.

The present invention provides very efficacious herbicides with rapid time course control of weeds. The compounds are particularly effective for controlling broad leaf plants and for grasses. In its preferred aspect, certain of the herbicides are designated as biorational. A biorational herbicide is a chemical substance of natural origin that can be synthesized. The preferred herbicides of the present invention have a lethal effect on specific targets, possessing a unique mode of action. Unlike the bulk of currently available herbicides on the agricultural market, the preferred agents have ingredients that have been proven to be substantially non-toxic to man and domestic animals and which have minimal adverse effects on wildlife and the environment. The efficacy of the subject composition is monitored by determining its adverse effect upon treated weeds. This includes phytotoxicity or damage to the weeds, inhibition of weed growth, inhibition of weed reproduction or proliferation, or complete destruction/death of the weed, all of which are encompassed by the term "controlling". As used herein, the terms "herbicidal activity" and "herbicidally active" are intended to mean that the compound has an adverse affect on one or more weed species, i.e., is effective to control weeds. The term "herbicidally effective amount" is an amount of the compound, or a composition containing the compound, that has an adverse affect on at least 25% of the weeds treated, more preferably at least 50% of the weeds treated, and most preferably at least 70% or greater. The actual value of an herbicidally effective amount for a given compound is preferably determined in field bioassays on a plant-by-plant basis. The routine screening procedures employed to evaluate herbicidal activity and efficacy usually includes a complement of monocotyledonous and dicotyledonous test species. The viable action seen and discerned at the whole-plant level when herbicides are applied under field conditions yields a time course of herbicide action. Visible injury can be observed of the time course which includes rapid visible signs of phytotoxicity such as desiccation and epinasty. It is expected that about 0.5 to 6 pounds of the compound of the invention will be needed to treat an acre of weeds. It is expected that compounds of the invention having a higher level of herbicidal activity can be used in smaller amounts and concentrations, while those having a lower level of activity may require larger amounts or concentrations in order to achieve the same herbicidal effect. It is preferred that the compounds of the invention have minimal or no adverse effect on desired vegetation such as ornamental and agricultural plants, wildlife and humans that may come into contact with such compound or with weeds that have been treated with a composition containing such compound.

The compounds useful in this invention are represented by Formula (I) and (II):

wherein R¹ is alkylcarbonyl, preferably C,.₅alkylcarbonyl; R² is H, OH, halogen, alkyl, preferably C^alkyl or -COOH; and R³ is alkyl, preferably C,.₆alkyl, aryl or arylalkyl, preferably arylC,.₆alkyl such as benzyl; with the proviso that only one of R² and R³ is alkyl.

As used herein, "alkyl" means a branched or unbranched saturated monovalent hydrocarbon radical containing 1 to 12 carbon atoms, such as methyl, ethyl, propyl, isopropyl, tert-butyl, butyl, n-hexyl, dodecyl, and the like, unless otherwise indicated. Preferably the alkyl group is a lower alkyl (branched or unbranched saturated monovalent hydrocarbon radical) having 1 to 6 carbon atoms (C,.₆), such as methyl, ethyl, tert-butyl, and the like.

"Alkoxy" means the group alkyl-O- wherein alkyl is as herein defined. Preferably the alkoxy group has 1 to 4 carbon atoms (C_M).

"Arylalkyl" refers to a monovalent unsaturated aromatic carbocyclic radical having a single ring (e.g., phenyl) attached through an alkyl group, which preferably has 1 to 6 carbon atoms (C,.₆), i.e., arylC^alkyl. More preferably the arylalkyl group is an aromatic ring attached through a -CH₂-group (e.g., benzyl). "Alkylcarbonyl" refers to an alkyl group attached through a carbonyl, -C(O)- group, and includes by way of example, methyl carbonyl and ethyl carbonyl. Preferably the alkylcarbonyl group is a C,_.5alkylcarbonyl carbonyl group.

Compounds of particular interest include those listed in Tables I and II below, where the "R" groups correspond to the "R" groups defined for Formulas (I) and (II). It is to be understood that the compounds shown are merely representative and not exhaustive. Others will be apparent to those of skill in the art, given this disclosure.

Table I - Formula (I) Compounds

Name R² R³ methyl salicylate -OH Me ethyl salicylate -OH Et benzyl salicylate -OH Bz benzyl benzoate H Bz phenethyl salicylate -OH -Et-Ph phenyl salicylate -OH Ph benzyl phthalate -COOH Bz

Table II - Formula (II) Compounds

Name benzyl acetate

The following abbreviations are used in Tables I and II: "Et" is ethyl, "Me" is methyl, "Bu" is butyl, "Ph" is phenyl and "Bz" is benzyl.

Compounds useful in the composition of this invention are available from commercial sources known in the art, such as Aldrich Chemical Co., Sigma Chemical Co., or are readily synthesized by techniques as are well known in the art. For example, benzyl benzoate, benzyl salicylate and benzyl acetate can be obtained from B.F. Goodrich/Kalama Chemical Inc. (Kalama, WA) and Pentagon Chemical (Los Angeles, CA).

Benzyl benzoate, (CAS Registration number 120-51-4), is widely used in the perfume and pharmaceutical industries. Its high molecular weight and nearly odorless nature make it a widely used perfume fixative. Benzyl benzoate has application in confectioneries and chewing gums and is produced commercially to meet the specifications described in the United States Pharmacopoeia (USP) and the Food Chemicals Codes (FCC). Benzyl benzoate is found as a natural chemical in the volatile oil of the Myroxylon pereirae (Royle) Klotzch of the Family Leguminosae or Fabaceae. Benzyl benzoate also is found in the balsams of Tolu and Peru and in the oils of tuberose, ylang-ylang, and hyacinth. Benzyl benzoate can be synthesized via the Cannizarro reaction from benzyl chloride and sodium benzoate. Benzyl salicylate, (CAS Registration number 118-58-1), is a natural product of Dianthus Caryophyllus L.. Benzyl salicylate can be prepared by sodium salicylate and benzyl chloride (J. Am. Chem. Soc. (1921) 43:1672), and is readily available from commercial sources such as B.F. Goodrich/Kalama

Chemical. Benzyl acetate occurs in a number of plants, particularly jasmine. Benzyl acetate can be prepared from benzyl chloride, acetic acid or sodium acetate and triethylamine (J. Ore. Chem. (1961) 26:5180). Benzyl phthalate can be prepared from disodium phthalate and benzyl chloride (U.S. Patent No. 3,012,065). The LD₅₀s on rats of benzyl benzoate, benzyl salicylate and benzyl acetate are 1,830; 2,227; and 2,490 mg/Kg, respectively, (Merck Index); higher than those of many currently used pesticides.

Referring to Formula (I), the preferred R² substituent is H, OH or -COOH, more preferably H or -OH. The preferred R³ substituent is C,.₆alkyl such as methyl and ethyl, phenyl or arylC_1-6alkyl such as benzyl and phenethyl. More preferably R³ is C,.₆alkyl such as methyl and ethyl.

Particularly preferred compounds of Formula (I) include methyl salicylate, ethyl salicylate, benzyl salicylate, benzyl benzoate, phenethyl salicylate, phenyl salicylate and benzyl phthalate. Even more preferred compounds of Formula (I) include methyl salicylate, ethyl salicylate, benzyl salicylate, benzyl benzoate and phenethyl salicylate. Most preferred compounds of Formula (I) include methyl salicylate and ethyl salicylate.

Referring now to Formula (II), the preferred the preferred R¹ substituent is C^alkylcarbonyl, most preferably methylcarbonyl. Preferred compounds of Formula (II) include benzyl acetate.

The subject compositions offer several advantages over currently used herbicides. First, the compounds are either of natural origin or have high LD₅₀s for mammals, thus, are less toxic to man and domestic animals, and have minimally adverse effects on wildlife and the environment. By using the subject compositions, the environmental and health hazards involved in plant control are minimized by reducing the toxicity of the chemical compounds. A second advantage of the subject composition is that, in comparison with, for example, ROUNDUP^®, it is relatively chemically stable and is active during the treatment period. The subject benzyl ester composition does not deactivate significantly during the usual treatment period of one to seven days. Another advantage is that the compounds used have not previously been used to control unwanted vegetation, and therefore the vegetation has not acquired resistance to them. As current herbicides are used repeatedly, one can expect that resistant populations appear suddenly, either by selection of resistant individuals in a population or by a single gene mutation. Generally, the more specific the site and mode of herbicidal action, the greater the likelihood for a vegetation to develop a tolerance to that chemical. The compounds used appear to have a non- specific phytotoxic effect and therefore are less likely to promote resistance. The new composition can be added to the current arsenal of integrated pest management (IPM) herbicides. Another advantage of the subject method is that it presents fast action in controlling unwanted vegetation. The subject method has an observable effect in control of the growth of unwanted vegetation within one day to a week, faster than ROUNDUP^® which usually takes one to three weeks. The composition may be solid (i.e., in a powdered form) or liquid depending on the carrier and the needs of the agriculturist using the composition. If the composition is solid, suitable carriers include various known, agriculturally-useful powders that are generally used for this purpose. If the composition is liquid, it may be aqueous or non-aqueous and may be a solution, suspension, or emulsion, depending on the needs of the agriculturist applying the herbicidal composition.

Generally, a composition of this invention will be prepared as a concentrate for industrial application and further dilution or as a fully diluted ready-to-apply composition. Preferably, the composition is applied as a liquid, whether aqueous or non-aqueous, but preferably the former. The concentrate, if solid, will be formulated to be mixed to form an appropriate non-aqueous or aqueous composition. Thus, the composition will generally contain the active compound along with a surfactant carrier to effect miscibility or suspendability of the composition in a liquid.

In general, the percentage by weight of the active compound, i.e., the active ingredient will be about 0.1% to 50wt%. Higher concentrations are usually preferred for purposes of manufacture, shipment, and storage. For example, as a concentrate for use by professional agronomists the percentage will be at least about 10wt%, preferably about 25 to 50% by weight. Prior to use, the high concentration composition is diluted in a solvent to an appropriate concentration for the intended use of the composition. When fully diluted for consumer use as a "ready for use" product, the composition will be typically be about 0.5% to 10wt%, more preferably 1 to 5wt%.

An antioxidant may also be included at a level sufficient to increase the product shelf life, inhibit decomposition of the active compound in the herbicidal composition, or improve the stability of the controlling effect when the composition is applied to weeds. Suitable antioxidants include, but are not limited to, ascorbyl palmitate, anoxomer, benzoic acid, benzlkonium chloride, benzethonium chloride, benzyl alcohol, butylated hydroxyanisole, butylated hydroxytoluene, chlorobutanol, dehydroacetic acid, ethylenediamine, ferulic acid, potassium benzoate, potassium metabisulfite, potassium sorbate, n-propyl gallate BP, propylparaben, sassafras oil, sodium benzoate, sodium bisulfite, sodium metabisulfite, sorbic acid, vitamin E, eugenol, and α-tocopherol and the like. The antioxidant can be present in an amount of about 0.01-10wt%, but generally no more than about lwt% will be needed. A preferred amount can be determined by shelf-life stability trial according to an EPA standard protocol. A minimal amount of antioxidant which maintains the shelf stability is selected to save the cost of manufacturing.

The subject composition can be an aqueous composition using water solvent or an organic composition using an organic solvent, such as ether, ketone, kerosene, or alcohol. A water solvent is preferred because it mimics nature (biorational), is environmentally safe, and also costs little. The compositions of this invention, particularly liquids and soluble powders, preferably contain, as a conditioning agent, one or more surface-active agents in amounts sufficient to render a given composition readily dispersible in water or in an organic solvent. The incorporation of a surfactant into the compositions greatly enhances their efficiency. The water, organic solvent, or surfactant (alone or in combination with a solvent) functions as the agriculturally-acceptable carrier.

By the term "surfactant" it is understood that wetting agents, dispersing agents, suspending agents, and emulsifying agents are included therein. Anionic, cationic and non-ionic agents can be used, although non-ionic agents are preferred. The non-ionic surface-active agents include allinol, nonoxynol, octoxynol, oxycastrol, oxysorbic (for example, polyoxyethylated sorbitol fatty-acid esters (TWEEN^®)); thalestol, and polyethylene glycol octylphenol ether (TRITON^®). The anionic type of agents include fatty-acid salts, higher alcohol sulfuric esters and alkylallylsulfonates; the cationic type of agents include aliphatic amino salts, quaternary ammonium salts and alkylpyridinium salts, individually or in combination. Particularly suitable surfactants include, by way of illustration and not limitation, TWEEN^®20 (polyoxyethylene sorbitan monolaurate), TWEEN^®40, TWEEN^®80, along with TRITON^®SP150, TRITON^®SP180 and TRITON^®SP190; the most preferred being TWEEN^®80 and TRITON^®SP190. Of these, the nonionic surfactants are preferred. Usually, the amount of surfactant used is the minimum amount required to get the compound into solution/emulsion, and will generally be 0.5 to 10% by weight, more typically 0.5 to 1%.

The common and chemical names of other generally available adjuvants include, but are not limited to, the following list, in which the first name is the common name used in the industry, the second name is the general chemical name, the third name is the class of the compound, the fourth name is the type of surfactant, and the trade name is last. Albenate: Alkyl(C₁₈C₂₄)benzene sulfonic acid and its salts; Alkylaryl sulfonate; Anionic surfactant; Nacconol 88SA, Calsoft F-90, DDBSA, Santomerse No. 3.

10 Alfos: α-Alkyl(C₁₀-C_I6)-ω-hydroxypoly(oxyethylene) mixture of dihydrogen phosphates esters; polyoxyethylene alkyl phosphate ester; Anionic; Emcol PS-131.

Allinate: α-Lauryl-ω-hydroxypoly(oxyethylene) sulfate; lauryl polyoxyethylene sulfate salts; Anionic; Sipon ES. Allinol: α-Alkyl(C,,-C₁₅)-ω-hydroxypoly(oxy ethylene); C_nC₁₅ linear primary alcohol ethoxylate; Nonionic; Neodol 25-3, Alfonic 1014-40 and other alfonic materials.

Diocusate: Sodium dioctyl-sulfosuccinate; Dioctyl sodium sulfosuccinate; Anionic; TRITON GR-5, Aerosol OT.

Dooxynol : α-(p-Dodecyl-phenyl)-ω -hy droxypoly (oxy ethylene) ; dodecylphenol condensation with ethylene oxide; Nonionic; Igepal RC-630, Tergitol 12-P-9, Sterox D Series.

Ligsolate: Lignosulfonate, NH₄, Ca, Mg, K, Na, and Zn salts; Salts of lignosulfonic acids; Anionic; Marasperse N-22, Polyfon O.

Nofenate: α-(p-Nonylphenyl)-ω-hydroxypoly(oxyethelene) sulfate, NH₄, Ca, Mg, K, Na, Zn salts, Nonyl group is a propylene trimer isomer; Salts of sulfate ester of nonylphynoxypoly(ethyleneoxy) ethanol; Anionic; Alipal CO Series

Nonfoster: α-(p-Nonylphenyl)-ω-hydroxypoly(oxyethylene); mixture of dihydrogen phosphate and nonophosphate esters; Polyoxyethylene nonylphenol phosphate esters; Anionic; Gafac RM 510.

Nonoxynol: α-(p-Nonylphenyl)-ω-hydroxypoly(oxyethylene); polyoxyalkylene nonylphenol; Nonionic; Sterox N Series, Makon 6, Igepal CO Series TRITON N Series, T-DET N.

Octoxynol: α-[p-l,l,3,3-Tetramethyl butyl phenyl]-ω-hydroxypoly(oxyethylene); polyoxyethylene octyl phenol; Nonionic; Igepal CA-630, TRITON X-100.

Oxycastol: Castor oil polyoxyethylated; Ethoxylated castor oil; Nonionic; Emulphor EL- 719, Emulphor EL-620, Trylox CO-40, T-DET C-40

Oxysorbic: Polyoxyethylated sorbitol fatty acid esters (nonosterate, monoleate etc); Polyoxyethylated sorbitol fatty acid esters; Nonionic; Atlox 1045, Drewmulse POE-STS, TWEEN Series G-1045.

Tall oil: Tall oil, fatty acids not less than 58%, rosin acids not greater than 44%, unsapolifiables not greater than 8%; Tall oil; Anionic; Ariz. S.A. Agent 305.

11 Thalestol: Poly gly eery 1 phthalate ester of coconut oil fatty acid; Modified phthalic glycerol alkyl resin; Nonionic; TRITON B-1956.

The subject composition may be prepared by simply mixing together the requisite amount of at least one compound of the invention and at least one agriculturally acceptable carrier, i.e., surfactant, alone or with a solvent. Other additives, such as saponins and antioxidants, may be included prior to mixing.

Water-dispersible powder, capsule, or pellet compositions can be made containing one or more compounds of the invention, an inert solid extender, and one or more wetting and dispersing agents. The inert solid extenders are usually of mineral origin, such as natural clays, diatomaceous earth and synthetic minerals derived from silica and the like. Examples of such extenders include kaolinites, attapulgite clay and synthetic magnesium silicate. The water- dispersible powders can also include fatty-acid esters and antioxidants.

The subject methods apply the compositions to unwanted vegetation, i.e., weeds, during preplanting, preemergence, and postemergence, with regard to the stage of weed development or planting crops. Preplanting applications for control of unwanted vegetation are made prior to planting crops in an area containing the unwanted vegetation, usually within a few days or weeks of planting crops. Preemergence applications are completed prior to emergence of the weeds after planting of crops. Postemergence applications are made after the weed emerges from the soil. The subject methods apply the composition by broadcast applications, which cover the entire area including the crop; by spot treatments, which are confined to small areas of weeds; by directed sprays, which are applied to selected weeds or are applied to the soil to avoid contact with the crop.

The subject method provides for application of the composition to a plant part of the weeds. For example, the composition, in a liquid or dust form, can be applied directly to plant parts of the unwanted vegetation, such as foliage/leaves, trunk, stem or roots. The contacting method is most effective against annuals, those weeds that germinate from seeds and grow to maturity each year. Complete coverage of plant parts with contact materials is preferred.

The composition can also be provided to a plant part by translocation, i.e., the composition can migrate from one cell to another such as between a cell on the plant's surface to a cell beneath the surface, or between adjacent cells.

12 One embodiment of the subject method is to apply the subject composition to above- ground portions of plants. The application of liquid and particulate solid compositions to above- ground portions of plants can be carried out by conventional methods, e.g., power dusters, boom and hand sprayers and spray dusters. The compositions can also be applied from airplanes as a dust or a spray because of their effectiveness at low dosages. The subject method controls unwanted vegetation by application to the foliage of an effective amount of the subject composition. While very minor dosage rates of the novel compositions deter weed growth, adequate control usually involves the application of a sufficient amount to either eliminate undesired vegetation or significantly deter its growth. Dosage rates required to accomplish these effects, of course, vary depending on plant type (due to variations in specific plant resistance), plant size, and maturity. More mature plants are generally more resistant to herbicides and require higher dosage rates for a comparable level of control. Useful dosage rates can best be expressed in relation to active ingredient dosage rates and generally correspond to at least about 1 gallon active ingredient per acre, preferably at least about 10 gallons per acre, and more preferably at least about 50 gallons per acre. Dosage rates of about 10-100 gallons per acre are generally adequate to control most weeds and brush prevalent in field crop areas. The composition is usually applied once or twice to the unwanted vegetation. However, more frequent applications can be carried out to control more resilient vegetation. The phytotoxic effect of the treatment is observed usually between 1-7 days. Phytotoxicity measurements can be recorded using a ten-point scale, with zero indicating no visible phytotoxic effects and ten indicating death and total brown-down. Scale 0-10 indicates 0 (no death), 10, 20, 30, 40, 50, 60, 70, 80, 90, 100% (total death), respectively.

Another embodiment of the subject method is to apply the composition to the rhizosphere in an area containing unwanted vegetation, particularly non-woody vegetation. The subject method can employ the compositions of this invention, along with sequential treatments with other phytotoxicants, fertilizers, and the like for maximum effect. For example, the field could be sprayed with a composition of this invention either before or after being treated with fertilizers, other phytotoxicants, and the like. The compositions of this invention can also be admixed with other materials, e.g., fertilizers, other phytotoxicants, etc., and can be applied in a single application.

13 As noted above, the subject method can be used to control weeds selectively or non- selectively. When selective, the method kills weeds without harming the desired crop, when non-selective, the method kills all vegetation. Selectivity can also be achieved mechanically by spray placement, a method of spraying only the target vegetation and not the crop plants. For example, a limited selectivity in crops such as cotton, soybeans, sugarcane, and like crops can be obtained by directing the spraying of a composition of this invention at a selected concentration on vegetation around the base of such plants with minimal spray contact with the leafy portions of such crop plants. The directed spraying can be done with or without a protective device to prevent contact of the spray with the leaves of such crop plants. These methods are best illustrated by the preferred embodiments set forth below. One aspect of this invention is a method of controlling weeds, for example by inhibiting weed growth, which involves applying a composition of this invention to a weed at a herbicidally- effective level. Application methods include ground, aerial, chemigation, surface, soil incorporation, preplant, preemergent, postemergent, and the like, depending on the conditions of the weather, the type of plant, the time of year, and other factors known to those of skill in the art. Preferably, the composition is applied above ground to the surfaces of a growing plant such as the leaves, stem, blossoms and exposed roots. One application is generally enough, but more than one application may be made to obtain the desired results.

An exemplary method for controlling weeds comprises applying (such as by spraying) to a plant part of the weed, an herbicidally effective amount of a composition comprising an agriculturally-acceptable carrier in combination with a compound of Formula (I). This can be accomplished by contacting a plant part of said weed with the composition, where this part is preferably foliage or a root. In addition, another aspect of the invention involves translocation from a first plant part to a second plant part, which is typically from one plant cell to another plant cell. The methods described herein are useful for killing weeds, or clearing an area of unwanted vegetation, where unwanted vegetation may include weeds or other plants, crops or flowers, etc., whose removal is desired.

There are numerous ways to minimize potential damage to the desired vegetation such as agricultural crops. For example, the methods described herein can be conducted prior to planting crops in an area containing weeds, or the application method can be performed selectively to the weeds in a given area as compared to agricultural or ornamental vegetation in the same area.

14 The active ingredients of the herbicides of the present invention preferably are biorational chemicals that qualify for the US EPA Biorational Program.

The subject method effectively controls dry-land vegetation, including varieties of grasses, broad leafs, and succulents ranging from crabgrass, to varieties of forest trees, including broad leafs and conifers. For example, common annual weeds include barley, barnyard grass, black nightshade, broadleaf signal grass, burcumber, chickweed, cocklebur, common ragweed, crabgrass, field pennycress, rough fleabane, foxtail, giant ragweed, goose grass, groundcherry, hemp sesbarria, henbit, jungle rice, kochia, lambs quarters, mare's tail/horseweed, morning-glory spp., mustard, fall and Texas panicum, palma amaranth, Pennsylvania smartweed, pigweed spp., prickly sida (teaweed), red rice, rye, seedling Johnson grass, shattercone, shepherd's purse, sicklepod, sprangletop, sunflower, velvet leaf, volunteer corn, common and tall waterhemp, wheat, wild proso millet, witchgrass, wolly cupgrass; and common perennial weeds including Canada thistle, common milkweed, field bindweed, hemp dogbane, nutsedge spp., quackgrass, red vine, rhizone Johnson grass, tall fescue, trumpet creeper, swamp smartweed and wisteria mukly. Star Thistle, Poison Oak, and Ivy are also weeds suited for treatment by the invention. Other annual and perennial weeds not listed here or described in the Examples, but known to those of ordinary skill in the art, would be suitable as targets by the composition of the present invention.

The subject method is also used to control aquatic vegetation. Excessive growth by aquatic vegetation diminishes the habitat for fish, although it initially increases shelter for smaller or younger fish. The flow of water through a system may be impeded, disrupting water delivery for human consumption or for irrigation. Other aquatic activities, such as boating and swimming, or transportation, may be curtailed. The subject method is used to control aquatic weeds, such as immersed aquatic weeds (cattails, bulrushes and arrowheads), submersed aquatic weeds (pondweeds, coontails and watermifoils), floating aquatic weeds (duckweeds, water hyacinth, waterlettuce, waterferns and waterlilies), and algae (waternet, pithophora and chara).

The application of herbicidal compositions to aquatic plants is usually carried out by spraying the compositions on the aquatic plants in the area where control of the aquatic plants is desired. Granules or larger-size pellets of clay and other materials impregnated with the subject compositions, can be applied to treat the water surface, the total water volume, the bottom 1 to 3- foot layer of water, or the bottom soil surface. Slow-release granules or pellets designed to

15 release the subject composition in small amounts over an extended period in the water can also be used in treating aquatic weeds and aquatic pests.

The subject method is useful for control of weeds between cropping seasons, for the renovation of stale seed beds, and the like. The subject method is useful in minimum-tillage methods of crop culture. For example, in those instances where it is desirable to plant a sodded or otherwise vegetated acreage with an agricultural crop without plowing or otherwise mechanically preparing a seed bed, the crop seed can be drill planted in combination with a prior or subsequent application of a composition of this invention to kill undesired growing vegetation provided that the composition is applied before the emergence of the crop plant.

The subject method is also useful in sod (turf, alfalfa, pasture, etc.) renovation or conversion procedures. For example, in situations where a sod or parts thereof has become overgrown with undesirable plant species, the plants in said area can be sprayed with the subject composition to control all growing plants, and from about 2 to 24 hours later depending upon weather conditions etc., the desired species can be seeded into the dying vegetation. In an alternate method of sod renovation, the area can be seeded and immediately sprayed with a composition of this invention. In either method, the seeds fall among the vegetation and as the sprayed plants wither and die, they act as a mulch and moisture-retaining layer in which the seeds can germinate. Seeds which are in the soil can germinate and grow without any apparent effects from the spraying of the unwanted plants prior to the time that the seed actually germinates.

The subject method can be used in agricultural and industrial sites. The industrial sites include roadsides, ditch banks, irrigation canals, fence lines, recreational areas, railroad embankments, and power lines. The subject methods remove undesirable plants that might cause damage, present fire hazards, or impede work crews. They also reduce costs of labor for mowing.

Use of herbicides is regulated in the United States by the Environmental Protection Agency (EPA) under authority of the Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). Tolerance for residues of pesticides in agricultural commodities are established by the (EPA) and enforced by the Food and Drug Administration (FDA) under authority of the Federal Food, Drug and Cosmetic Act (FD&C Act).

16 This regulatory environment leads to another aspect of this invention, which is an article of manufacture. In this aspect a herbicidally active compound represented by Formula (I) or (II), as defined above, is combined with an agriculturally-acceptable carrier in a container that will be suitable for storing the composition for its shelf life. Associated with the container is printed labeling providing instructions for using the composition for herbicidal purposes in accordance with the treatment method set forth herein. The container may have associated with it a delivery device that allows the composition to be applied to the weeds to be treated. For liquid compositions this is generally a hand-operated, motorized or pressurized pressure-driven sprayer. The container may be made of any suitable material such as a polymer, glass, metal, or the like. Usually, the labeling is associated with the container by being adhered to the container, or accompanying the container in a package sold to the user. Such label may indicate that the composition is approved for use as an herbicide. The instructions will spell out the type of plant for which the herbicidal composition is to be used, the application method, the rate of application, dilution requirements, use precautions, and the like. The following examples are offered by way of illustration and not by way of limitation.

EXAMPLES Abbreviations AC Active Compound

BB Benzyl Benzoate BS Benzyl Salicylate

T20 TWEEN^®20

T-SP150 TRITON^®SP150 (Union Carbide, Santa Ana, CA) T-SP190 TRITON^®SP190 (Union Carbide, Santa Ana, CA)

Example 1 Treating Weeds with Benzyl Esters

Treatment Formulation

Test formulations include six different kinds of chemical compositions in water solvent, a positive control (glufosinate ammonium, AgrEvo's Finale™ or equivalent, obtained from

Orchard Supply (Woodland, CA)) and a negative control (see Table III). Benzyl benzoate, benzyl salicylate and benzyl acetate, are obtained from Kalama Chemical Inc. (Kalama, WA) and

Pentagon Chemical (Los Angeles, CA) and respectively.

17 Experiment Protocol

A randomized complete block design of winter annual weeds is employed. Plots are laid out in a 1.5 x 3.0 meter grid, appropriately flagged, and contain early post-emergence young weeds (young seedlings or to those with 5th/6th leaf). Test formulations are applied topically, using 2-gallon, CO₂ charged back-pack sprayers with standard 3 -nozzle boom (BH Tanks, WeedTech or equivalent). Treatments are sprayed at

30 psi at a rate approximating 50 gallons/acre for the first application, and at a rate of around 100 gallons/acre to approximate spray until runoff for the second application. All spraying should take place in calm conditions to minimize spray drift. Observation Methods

Visual observations for phytotoxicity are at 1, 2, 24, and 48 hours, 7 and 14 days after the treatments have been applied. Phytotoxicity measurements are recorded using a ten-point scale, with zero indicating no visible phytotoxic effects and ten indicating death and total brown-down.

More than one trained observer ranks phytotoxicity, and all visual observations are accompanied by photographs. Regrowth evaluations are conducted 14 and 28 days after treatment.

Table Ill-Test Formulations Active Compound ACf%) T-SPlSO /o) Benzyl benzoate 1.0 0.1

3.0 0.3

5.0 0.5

Benzyl salicylate 1.0 0.1

3.0 0.3

5.0 0.5

Benzyl acetate 1.0 0.1

3.0 0.3

5.0 0.5 negative control 0 0.5 Formula blank

Positive control at label rate

The above example demonstrates methods of controlling winter annual weeds with aqueous compositions comprising different benzyl esters. The example also provides a method of determining phytotoxicity after treatment of the weeds.

18 Example 2 Summary Results

Table IV - Herbicidal Efficacy

Efficacy Efficacy on BLW Efficacy on GW

Phytoon Moss

Active compound toxicity 5% 1% 3% 5% 1% 3% 5% benzyl moderate H L M M H L M M salicylate⁽¹'²⁾ benzyl acetate* ^{l 2)} very mild — — — — — — — benzyl benzoate^{(1 2)} moderate H L L/M L/H L M M ethyl salicylate⁽¹'²⁾ very strong — — — — — — — methyl very strong — — — — — — — salicylate⁽¹'²⁾ phenethyl mild — — — — — — — salicylate phenyl salicylate very strong* — — — — — — —

⁽¹⁾ Naturally occurring compound ⁽²⁾ GRAS ("Generally Recognized As Safe") compound

* Does not take effect immediately

Phytotoxicity was rated qualitatively based upon field data from field trials using plots of mixed weed species, both broadleaf weeds ("BLW") and grass weeds ("GW"), and from laboratory experiments using tobacco plants, strawberry plants or turfgrass. Efficacy is a quantitative scoring of phytotoxicity based upon independent field trials using formulations with 1, 3 or 5 % by weight of the AC on a collection of BLW and GW types. Variables in three experimental parameters such as temperature, humidity, plant age and species, along with soil conditions has a pronounced effect on results. Scores of low ("L"), moderate ("M") and high ("H") were based on independent experiments where L = 1-3, M = 4-7 and H = 8-10. A rating of H corresponds to an acceptable level of herbicidal activity. Ratings reported with a slash (e.g., M/H) indicate varying levels of efficacy on the tested weeds, where susceptibility was a function of species, age and developmental stage. Blanks (" — ") in Table IV indicate that the Active Compound was not tested against the weed listed.

The types of BLW and GW tested included purslane speedwell, henbit, shepherd's purse, common chickweed, knotweed, wild stem filaree, fiddleneck, miner's lettuce, red maids, velvetleaf, lambs quarters, groundcherry, prostrate pigweed, hairy nightshade, black nightshade,

19 Poa, perennial ryegrass, tall fescue, annual bluegrass, wild barley, barnyard grass, jungle rice and crabgrass.

All compounds in Table IV exhibited herbicidal activity. In particular, BS was shown to be a slow-acting, moderately effective contact herbicide that was generally less effective on GW species such as Poa and wild barley, than on BLW species. BS was shown to be particularly effective on moss. These experimental results were validated during different seasons and in various geographical regions.

Phytotoxicity was also observed for all the compounds in Table IV. Ethyl salicylate exhibited a high level of phytotoxic activity, and methyl salicylate was almost as effective. Based on the experiments conducted, the types of symptoms observed on plants treated with the compounds listed above, were consistent with those of a contact herbicide.

Symptoms induced by some compounds, such as BS, generally did not become apparent until approximately one week after application. Time course of symptom development is dependent on variables such as plant species, age, size and developmental stage. In addition, grow-back is a function of the age and species of weed, as well as environmental conditions and the time elapsed since treatment. Grow-back was not observed to a significant degree over the time course tested.

In general, a positive correlation was observed between the amount of active compound applied and the efficacy, which further supports a contact herbicidal mode of action. This trend was observed both when the concentration of active compound was increased (such as 1% to 5%) and when the total volume of applied formulation was increased (such as from 100 gallons/acre to 200 gallons/acre). Depending upon the weed size, it was observed that as little as 60 gallons/acre was sufficient for runoff.

TWEEN® 20, TWEEN® 80 and TRITON® SP190 were found to particularly suitable for use as surfactants, generally at one-fifth the concentration of the active compound.

Example 3 Herbicidal Activity of Benzyl Salicylate

The objective of the experiment was to evaluate the general effectiveness of BS at varying concentrations and rates of application against a broad spectrum of annual weeds. BS was applied at three different concentrations (1 wt%, 3wt% and 5wt%) and two different rates (100 gallons/acre and 200 gallons/acre). Emulsions comprised of BS, 2% T20 and

20 water were applied with three replicates per treatment. Controls were evaluated including Scythe at 3% (label rate) and glufosinate at 0.5 pounds/acre (both positive controls), no treatment

(negative control) and T20 only (formula blank). The emulsions initially were prepared with

10% BS and 2% T20 and were diluted in the field at the time of spray. The formulations details are provided below:

Table V Active Active

Formulation compound (°/o) compound (z) T20 (g) Water CmH Controls:

TWEEN 20 0.0 0.0 10.0 490

Scythe 3.0 — — —

Glufosinate label rate — — —

Formulation:

BS 10.0 50.0 10.0 440

A randomized complete block design was employed as the plot design. Plots were laid on a 5'x5' grid, appropriately flagged and contained early, post-emergence young weeds, i.e., young seedlings or those with the S'Vό* leaf. Poa, common chickweed, fiddleneck, wild barley, wild stem filaree, red maids and miner's lettuce were reasonably well represented across the 5'x5' treatment plots. Other weeds including Henbit and Shepherd's purse were also present, but were not sufficiently well represented across the plots to enable meaningful comparisons. The weeds had 1-6 leaves, were between 1-2" high and were of a size consistent with the use of a postemergence, pre-plant herbicide.

The treatments were applied topically as sprays using a 2 gallon CO₂ charged back-pack sprayer with a standard 3-nozzle boom (BH Tanks, Weed tech of equivalent). Efforts were made to conduct all spraying under calm conditions to minimize spray drift. The treatments were sprayed at 30 psi at rates equivalent to 100 gallons/acre and 200 gallons/acre, i.e., 217.5 ml/plot and 435 ml/plot, respectively. There was only one treatment application per plot.

The field conditions were overcast with temperatures ranging from 9-15°C. Spaying commenced at 9 am and continued until noon. Heavy rain was observed 26 hours after spraying.

Visual evaluations of the degree of phytotoxicity were make at 48 hours after the treatments had been applied. Phytotoxic evaluations are, by definition, subjective. General

21 phytotoxicity measurements were recorded using the following ten-point scale, with a score of 9 being regarded as acceptable, i.e., sufficient for weed elimination: 0 = No visible phytotoxic effects 3 = Distinct phytotoxic, chlorotic or necrotic activity 6 = Fairly large portions of the leaves becoming chlorotic; some die-back

9 = 90% of foliage is necrotic 10 = Complete burn-down In all cases, younger, smaller weeds were more affected by the treatments than mature, larger weeds. The following observations were made with the controls tested. For no treatment, no meaningful phytotoxic effect was observed. Treatment with Scythe provided clear phytotoxicity at the label rate (3%). There was some weed re-growth 7 days after treatment, most notably in Poa and wild barley. There was no effect on filaree and red maids. Treatment with glufosinate provided results similar to those observed for Scythe, with the exception that glufosinate was more effective on every species. Glufosinate was least active on filaree and red maids. For treatment with T20 only, no meaningful phytotoxic effect was observed. The following observations were made with the BS formulations tested. The formulations took some time to achieve results. A good dose response was observed, with activity generally better at higher concentration (5wt%) and lower efficacy at concentrations at or below 3wt%. Better efficacy was observed at lower quantities, i.e., 5% at 100 gallons/acre was more effective than 5wt% at 200 gallons/acre. BS was found to be moderately effective against Poa and wild barley, filaree and red maids.

All publications and patent applications mentioned in this specification are indicative of the level of skill of those skilled in the art to which this invention pertains. All publications and patent applications are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.

The invention now having been fully described, it will be apparent to one of ordinary skill in the art that many changes and modifications can be made thereto without departing from the spirit or scope of the appended claims.

22

Claims

CLAIMS What is claimed:

1. A method for controlling weeds, which method comprises applying to a plant part of the weed an herbicidally effective amount of a composition comprising an agriculturally- acceptable carrier in combination with a compound of Formula (I) or (II):

OFT OR¹ i_^y (D yy an

wherein R¹ is alkylcarbonyl; R² is H, OH, halogen, alkyl or -COOH; and R³ is alkyl, aryl or arylalkyl, with the proviso that only one of R² and R³ is alkyl.

2. The method of Claim 1 wherein R¹ is C^alkylcarbonyl; R² is H, OH, halogen, C,_.6alkyl or -COOH; and R³ is C,.₆alkyl, aryl or arylC,.₆alkyl.

3. The method of Claim 2 wherein R¹ is methylcarbonyl; R² is H, OH or -COOH; and R³ is C,.₆alkyl, phenyl, benzyl or phenethyl.

4. The method of Claim 1 wherein R¹ is methylcarbonyl.

5. The method of Claim 1 wherein R² is H or -OH.

6. The method of Claim 1 wherein R³ is methyl, ethyl, benzyl or phenethyl.

7. The method of Claim 1 wherein said compound is selected from the group consisting of methyl salicylate, ethyl salicylate, benzyl salicylate, benzyl benzoate, phenethyl salicylate and benzyl acetate.

8. The method of Claim 7 wherein said compound is selected from the group consisting of methyl salicylate and ethyl salicylate.

9. The method of Claim 1 wherein the weed is a broadleaf weed or grass.

10. The method of Claim 1 wherein the agriculturally-acceptable carrier comprises a surfactant.

23

11. The method of Claim 10 wherein the surfactant is a polyoxyethylated sorbitol fatty acid ester.

12. The method of Claim 10 wherein the surfactant is a poly ethylenegly col ether.

13. The method of Claim 1 wherein said plant part is foliage.

14. The method of Claim 1 wherein said plant part is a root.

15. The method of Claim 1 wherein said applying to a plant part occurs prior to planting crops in an area containing said weeds.

16. The method of Claim 1 wherein said applying to a plant part is performed selectively to said weeds in an area as compared to agricultural or ornamental vegetation in said area.

17. The method of Claim 1 wherein said weeds are aquatic weeds.

18. The method of Claim 1 wherein the composition is applied to an area of weeds at a rate of about 0.5 pounds to about 6 pounds per square acre.

19. The method of Claim 1 wherein the composition is applied by spraying.

20. The method of Claim 1 wherein the compound is a naturally-occurring compound.

21. A composition for controlling a weed, which composition comprises an agriculturally- acceptable carrier in combination with an herbicidally active compound of Formula (I) or (II):

o ^y7< OR-⁵

7y © yy (in

wherein R¹ is alkylcarbonyl; R² is H, OH, halogen, alkyl or -COOH; and R³ is alkyl, aryl or arylalkyl, with the proviso that only one of R² and R³ is alkyl.

22. The composition of Claim 21 wherein R¹ is C,_.5alkylcarbonyl; R² is H, OH, halogen, C,.₆alkyl or -COOH; and R³ is C,.₆alkyl, aryl or arylC,.₆alkyl.

24

23. The composition of Claim 22 wherein R¹ is methylcarbonyl; R² is H, OH or -COOH; and R³ is C,_.6alkyl, phenyl, benzyl or phenethyl.

24. The composition of Claim 21 wherein R¹ is methylcarbonyl.

25. The composition of Claim 21 wherein R² is H or -OH.

26. The composition of Claim 21 wherein R³ is methyl, ethyl, benzyl or phenethyl.

27. The composition of Claim 21 wherein said compound is selected from the group consisting of methyl salicylate, ethyl salicylate, benzyl salicylate, benzyl benzoate, phenethyl salicylate and benzyl acetate.

28. The composition of Claim 27 wherein said compound is selected from the group consisting of methyl salicylate and ethyl salicylate.

29. The composition of Claim 21 wherein the compound is a naturally-occurring compound.

30. The composition of Claim 21 wherein said composition is a concentrated product and the compound of Formula (I) or (II) is present in the amount of 25 to 50% by weight.

31. The composition of Claim 21 wherein said composition is a ready for use product and the compound of Formula (I) or (II) is present in the amount of 1 to 5% by weight.

32. The composition of Claim 21 wherein the agriculturally-acceptable carrier comprises a surfactant.

33. The composition of Claim 32 wherein the surfactant is a polyoxyethylated sorbitol fatty acid ester.

34. The composition of Claim 32 wherein the surfactant is a polyethyleneglycol ether.

35. The composition of Claim 32 wherein said surfactant comprises 0.5 to 10% by weight of the composition.

36. An article of manufacture that comprises a container in association with instructions for controlling weeds and holding a composition comprising an agriculturally-acceptable carrier and an herbicidally active compound of Formula (I) or (II):

25 OR^J (D yy cm

wherein R¹ is alkylcarbonyl; R² is H, OH, halogen, alkyl or -COOH; and R³ is alkyl, aryl or arylalkyl, with the proviso that only one of R² and R³ is alkyl.

37. The article of manufacture of Claim 36 wherein R¹ is C_Lsalkylcarbonyl; R² is H, OH, halogen, C,.₆alkyl or -COOH; and R³ is C^alkyl, aryl or arylC,.₆alkyl.

38. The article of manufacture of Claim 37 wherein R¹ is methylcarbonyl; R² is H, OH or -COOH; and R³ is C^alkyl, phenyl, benzyl or phenethyl.

39. The article of manufacture of Claim 36 wherein R¹ is methylcarbonyl.

40. The article of manufacture of Claim 36 wherein R² is H or -OH.

41. The article of manufacture of Claim 36 wherein R³ is methyl, ethyl, benzyl or phenethyl.

42. The article of manufacture of Claim 36 wherein said compound is selected from the group consisting of methyl salicylate, ethyl salicylate, benzyl salicylate, benzyl benzoate, phenethyl salicylate and benzyl acetate.

43. The article of manufacture of Claim 42 wherein said compound is selected from the group consisting of methyl salicylate and ethyl salicylate.

44. The article of manufacture of Claim 36 wherein the agriculturally-acceptable carrier comprises a surfactant.

45. The article of manufacture of Claim 44 wherein the surfactant is a polyoxyethylated sorbitol fatty acid ester or a polyethyleneglycol ether.

26