Enhancing tolerance of rice to group 15 herbicides with fluxofenim

Abstract

Disclosed herein is the use of fluxofenim (l-(4-chlorophenyl)-2,2,2-trifluoroethanone O- (l,3-dioxolan-2-ylmethyl)oxime) as a rice safener.

Description

[0001] ENHANCING TOLERANCE OF RICE TO

[0002] GROUP 15 HERBICIDES WITH FLUXOFENIM

[0003] CROSS-REFERENCE TO RELATED APPLICATIONS

[0004] This patent application claims the benefit of priority of United States Provisional Patent Application No. 63 / 568,953, filed March 22, 2024, which is incorporated herein by reference in its entirety.

[0005] BACKGROUND OF THE INVENTION

[0006] Rice is an ancient agricultural crop that remains one of the principal food crops of the world. There are two cultivated species of rice: Oryza saliva L., the Asian rice, and O. glaberrima Steud., the African rice. 0. sativa L. constitutes virtually all the world's cultivated rice and is the species grown in the United States. Given the importance of cereal grains as food crops, methods for improved cultivation of such grains are needed.

[0007] BRIEF SUMMARY OF THE INVENTION

[0008] Disclosed herein is a method for growing a cereal crop, such as rice. The method comprises applying an effective amount of fluxofenim to rice seed prior to planting and applying an effective amount of a Group 15 herbicide to the planting area The herbicide may be a chloroacetamide, such as S-metolachlor. The methods may also include applying a herbicide at a greater than recommended amount. The disclosed methods may provide commercially acceptable weed control. The disclosed methods may provide weed control and the same or lower amount of injury or mortality rate as compared to a control plant. The disclosed methods may also provide weed control and improved rice density, rice stand counts, or rice biomass as compared to a control plant.

[0009] BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Non-limiting embodiments of the present invention will be described by way of example with reference to the accompanying figures, which are schematic and are not intended to be drawn to scale. In the figures, each identical or nearly identical component illustrated is typically represented by a single numeral. For purposes of clarity, not every component is labeled in every figure, nor is every component of each embodiment of the invention shown where illustration is not necessary to allow those of ordinary skill in the art to understand the invention.

[0011] Figure 1 illustrates the ‘Diamond’ rice plants 7 days after emergence following Warrant and Dual Magnum applied at planting (preemergence) or after rice germination but before crop emergence (delayed preemergence) as influenced by seed treatments. The non-treated control had an average of 15 3 plants emerge

[0012] Figure 2 illustrates the injury to ‘Diamond’ rice 7 days after emergence from Warrant and Dual Magnum applied at planting (preemergence) or after rice germination but before crop emergence (delayed preemergence) as influenced by seed treatments.

[0013] Figure 3 illustrates the injury to ‘Diamond’ rice 14 days after emergence from Warrant and Dual Magnum applied at planting (preemergence) or after rice germination but before crop emergence (delayed preemergence) as influenced by seed treatments.

[0014] Figure 4 illustrates the injury to ‘Ozark’ rice 7 days after emergence in the field trial from Warrant and Dual Magnum applied at planting (preemergence) or after rice germination but before crop emergence (delayed preemergence) as influenced by seed treatments.

[0015] Figure 5 illustrates the injury to ‘Ozark’ rice 14 days after emergence in the field trial from Warrant and Dual Magnum applied at planting (preemergence) or after rice germination but before crop emergence (delayed preemergence) as influenced by seed treatments.

[0016] DETAILED DESCRIPTION OF THE INVENTION

[0017] Disclosed herein is the use of fluxofenim (l-(4-chlorophenyl)-2,2,2-trifluoroethanone O- (l,3-dioxolan-2-ylmethyl)oxime) as a safener for herbicides applied to rice. In the Examples, the inventors demonstrate that applying fluxofenim to rice seeds enhanced crop tolerance and reduced rice plant injury caused by herbicides. Specifically, in conjunction with the application of herbicides, rice grown from fluxofenim-treated seeds was shown to exhibit improved rice establishment, such as decreased mortality rates, decreased injury, increased rice stand counts, or any combination thereof as compared to control plants grown from seeds that were not treated with fluxofenim. These effects may result in improved weed control and allow for greater amounts of herbicides to be used with the same or reduced injury when compared against herbicide application without fluxofenim safening.

[0018] Methods of safening rice to provide enhanced tolerance to herbicides: One aspect of the present disclosure provides a method of growing rice applying an effective amount of fluxofenim to rice seed prior to planting and applying an effective amount of a Group 15 herbicide to the planting area.

[0019] The term “herbicide” refers to substances used to control weeds. In some embodiments, the rice is treated with one or more herbicides. Suitable herbicides include preplant, preemergence, and postemergence herbicides. Where an herbicide is referenced generically herein by name unless otherwise restricted, that herbicide includes all commercially available forms known in the art, such as salts, esters, free acids, and free bases, as well as stereoisomers thereof. Herbicides are commonly used as emulsifiable concentrates (EC) or soluble concentrates. However, in the present invention, the herbicide may also be utilized in a microencapsulated (ME) formulation in which herbicide molecules are protected from degradation processes by a porous, polymer shell. See, for example, US Patent No. 9,877478, which is incorporated herein by reference in its entirety. When exposed to soil moisture (e.g., by an activating rainfall), the polymer shell dissolves and allows a slow release of herbicide. The delayed release of herbicide allows time for rice to imbibe soil water during germination and grow uninhibited for a period following application. In some embodiments, the herbicide is applied as a microencapsulated formulation. In some embodiments, the herbicide is applied as an emulsifiable concentrate or a soluble concentrate.

[0020] In some embodiments, the rice is treated with one or more herbicides. In some embodiments, herbicides that are used in combination with the fluxofenim seed treatment include, without limitations, Group 15 herbicides. In some embodiments, herbicides that are used in combination with the fluxofenim seed treatment include herbicides from the chloroacetamide chemical family, such as acetochlor and metolachlor. In some embodiments, the herbicide is acetochlor or S-metolachlor.

[0021] In microencapsulated formulations, the release rate of the core material can be controlled through the selection of several parameters, including the shell wall composition, the weight ratio of the herbicide to shell wall material, the core material components, the mean microcapsule particle size, process conditions such as mixing shear and time, and combinations thereof. In some formulations, a diluent, such as a solvent, may be added to change the solubility characteristics of the core material to increase or decrease the release rate of the active ingredient from the microcapsule. The diluent may be selected from essentially any known in the art if it is compatible with the core material and shell. In some formulations, the core material may comprise a blend of a first and second population of a particulate microencapsulated herbicide to provide a multi-modal (e.g., bimodal) release rate. Additional ingredients may be added to the core material to improve its properties. Exemplary ingredients include, without limitation, thickeners, stabilizers, antipacking agents, drift control agents, biocides or preservatives, antifreeze agents, and antifoam agents.

[0022] Group 15 herbicides are very-long-chain fatty acid (VLCFA)-inhibitors. Accordingly, the terms "Group 15 herbicide", "VLCA-inhibitor", and "VLCFA-inhibiting herbicide" may be used interchangeably throughout the present application. These soil-applied herbicides are primarily absorbed through seedling shoots and roots where they inhibit cell development and cell division. Only five weed species worldwide are resistant to VLCFA-inhibiting herbicides, which suggests there is a lower risk for resistance to this class of herbicides relative to other rice herbicides. VLCFA-inhibiting herbicides include the chloroacetamide chemical family (e.g., acetochlor, alachlor, metolachlor, dimethenamid, pethoxamid, pretilachlor, butachlor) and the isoxazoline chemical family e.g., pyroxasulfone).

[0023] The Group 15 herbicides may be applied either prior to or after the rice is planted. In some embodiments, the herbicide is applied after planting, and the application may be either preemergence or postemergence. “Preemergence” refers to anytime during the interval from the planting of a crop plant up to, but not including, emergence of the crop plant (i.e., before cracking or spiking). Preemergence treatment includes both the treatment of the crop area before sowing i.e., preplant incorporation), and the treatment of the sown crop areas in which the plants have not yet emerged. Postemergence treatments include early postemergence (EPOST) application, as well as application at the spiking, one- to two-leaf, or three- to four-leaf stage. Notably, the activity of herbicides such as acetochlor is highly dependent upon rainfall, and greater potential for rice injury exists at earlier application timings. Thus, in some other embodiments, the chloroacetamide herbicide is applied delayed preemergence. "Delayed preemergence" generally refers to the time after rice germination but before emergence of the seedlings. In some embodiments, the herbicide application is preemergence. In some other embodiments, the herbicide application is delayed preemergence.

[0024] The effective amount of herbicide to be applied to an agricultural field is dependent upon the identity of the herbicide, the release rate of the herbicide, the crop to be treated, and environmental conditions, especially soil type and moisture. Generally, application rates of herbicides, such as, for example, a Group 15 herbicide, are on the order of about 0.1 , 0.25, 0.5, 0.75, 1, 2, 3, 4 or 5 kilograms of herbicide per hectare, or ranges thereof, such as from 0.1 to 5 kilograms per hectare, from 0.1 to 4 kilograms per hectare, from 0.1 to 3 kilograms per hectare, from 0. 1 to 2 kilograms per hectare, from 0. 1 to 1 kilograms per hectare, from 0.25 to 5 kilograms per hectare, from 0.25 to 4 kilograms per hectare, from 0 25 to 3 kilograms per hectare, from 0.25 to 2 kilograms per hectare, from 0.25 to 1 kilograms per hectare, from 0.5 to 5 kilograms per hectare, from 0.5 to 4 kilograms per hectare, from 0.5 to 3 kilograms per hectare, from 0.5 to 2 kilograms per hectare, from 0.5 to 1 kilograms per hectare, from 0.75 to 5 kilograms per hectare, from 0.75 to 4 kilograms per hectare, from 0.75 to 3 kilograms per hectare, from 0.75 to 2 kilograms per hectare, from 0.75 to 1 kilograms per hectare, from 1 to 5 kilograms per hectare, from 1 to 4 kilograms per hectare, from 1 to 3 kilograms per hectare, or from 1 to 2 kilograms per hectare.

[0025] In some embodiments, the effective amount of the herbicide is an amount of the herbicide that results in commercially acceptable rate of weed control. In some embodiments, the effective amount of herbicide is an amount of herbicide, that in combination with the use of the safener, results in weed control and the same or lower amount of injury, mortality rate, bleaching, or any combination thereof as compared to a control plant. In some embodiments, the effective amount of herbicide is an amount of herbicide, that in combination with the use of the safener, results in weed control and improved early season vigor as compared to a control plant. For example, the effective amount of herbicide may be an amount of herbicide, that in combination with the use of the safener, results in weed control and improved rice density, rice stand counts, rice biomass, or any combination thereof as compared to a control plant.

[0026] The methods may be applied in combination with additional herbicides. Applying several herbicides with distinct mechanisms of action may be useful, for example, for treating fields with herbicide-resistant weeds such as barnyardgrass. Exemplary co-herbicides include, without limitation, ACCase inhibitors (e.g, aryloxyphenoxypropionics), enolpyruvyl shikimate-3- phosphate synthaste (EPSPS) inhibitors (e.g, glyphosate), glutamine synthetase inhibitors (e.g, glufosinate), synthetic auxins (e.g., aromatic acid, phenoxy and pyridine herbicides), photosystem II (PS II) inhibitors (e.g., ureas and triazines), AES or AHAS inhibitors (e.g., sulfonylureas, triazolopyrimidines and imidazolinones), photosystem I (PS I) inhibitors (e.g., paraquat), protoporphyrinogen oxidase (PPO) inhibitors (e.g., diphenyl ethers, phenyl pyrazoles, aryl triazones and oxadiazoles), mitosis inhibitors e.g., anilide, amide, certain organophosphorus and carbanilate herbicides), cellulose inhibitors (e.g, nitrile and oxazole herbicides), oxidative phosphorylation uncouplers, dihydropteroate synthase inhibitors, fatty acid and lipid biosynthesis inhibitors (e.g., thiocarbamate and certain organophosphorus herbicides), auxin transport inhibitors (e.g., amide and urea herbicides) and carotenoid biosynthesis inhibitors (e.g., isoxazolidinone, benzoylcyclohexanedione and benzoylpyrazole herbicides), salts and esters thereof, and mixtures thereof.

[0027] As used herein, the word "safener" is used to refer to compounds that antagonize the harmful effects of an herbicide on cultivated plants. Safeners were formerly referred to as "antidotes", and these terms may be used interchangeably. Preferably, these compounds protect cultivated plants without noticeably influencing the herbicide's action on the weeds that it is meant to control. The methods of the present invention may utilize any safener that protects rice plants against injury from a Group 15 herbicide. In some embodiments, the safener is fluxofenim (l-(4- chlorophenyl)-2,2,2-trifluoroethanone O-(l,3-dioxolan-2-ylmethyl)oxime), including all available forms such as salts, esters, free acids and free bases, as well as stereoisomers thereof,

[0028] Safeners are most effective when applied prior to or simultaneously with the herbicides whose injury they prevent. Depending on their properties, safeners can be used for pretreating the seeds of the cultivated plants (dressing seeds or seedlings), can be incorporated in the soil (e.g., in the furrow) before or after sowing seeds, or else applied alone or together with the herbicide (e.g., as a tank mixture) before or after emergence of the plants. Thus, treatment of the plant or seeds with the safener can be carried out independently of the time of application of the herbicide, or alternatively, the treatment can be carried out simultaneously. In preferred embodiments, the safener is applied to the seeds prior to planting (i.e., by coating the seeds with the safener).

[0029] The safener may be used in an unmodified form or as a composition with conventional adjuvants and carriers. Safeners may be formulated in any known manner, for example, as emulsifiable concentrates, directly sprayable or dilutable solutions, dilute emulsions, wettable powders, soluble powders, dusts, granulates, and also encapsulations in e.g. polymer substances. The compositions can also contain further ingredients such as stabilizers, antifoams, viscosity regulators, binders, adhesives, as well as fertilizers or other active compounds, in order to attain special effects. The safener formulations are prepared in known manner, e.g. by mixing and / or grinding the active ingredients with extenders, e.g. solvents, solid carriers and, where appropriate, surfaceactive compounds (surfactants). Suitable safener solvents include without limitation: aromatic hydrocarbons, preferably the fractions containing 8 to 12 carbon atoms, e.g. xylene mixtures or substituted naphthalenes, phthalates such as dibutyl phthalate or dioctyl phthalate, aliphatic hydrocarbons such as cyclohexane, or paraffins, alcohols and glycols and their ethers and esters, such as ethanol, ethylene glycol, ethylene glycol monomethyl or monoethyl ether; ketones such as cyclohexanone, strongly polar solvents such as N-methyl-2-pyrrolidone, dimethyl sulfoxide or dimethyl formamide; as well as epoxidised vegetable oils such as epoxidised coconut oil or soybean oil; or water. Suitable solid carriers used e.g. for dusts and dispersible powders are normally natural mineral fillers such as calcite, talcum, kaolin, montmorillonite or attapulgite. Highly dispersed silicic acid or highly dispersed absorbent polymers can also be added to improve the physical properties. Suitable granulated adsorptive carriers are porous types, for example pumice, broken brick, sepiolite or bentonite; and suitable nonsorbent carriers are materials such as calcite or sand. In addition, a great number of pregranulated materials of inorganic or organic nature can be used, e.g. especially dolomite or pulverized plant residues. Depending on the nature of the safener to be formulated, suitable surface-active compounds are nonionic, cationic and / or anionic surfactants having good emulsifying, dispersing, and wetting properties. The surfactants customarily employed in such formulations are described e.g. in the following publications: "McCutcheon's Detergents and Emulsifiers Annual", MC Publishing Corp., Ringwood, N.J., 1979; Sisely and Wood, "Encyclopedia of Surface Active Agents", Chemical Publishing Co. Inc., New York, 1964.

[0030] Cereal seeds may be planted using several techniques. For example, in the United States, rice production is broadly categorized as either dry-seeded or water-seeded. In dry-seeded methods, rice is sown into a prepared seedbed with a grain drill or by broadcasting the seed and incorporating it with a disk or harrow. Moisture for seed germination is then provided by irrigation or rainfall. Thus, in some embodiments, fluxofenim is applied to the rice seeds as a dusting or concentrated formulation, and the seeds are planted by a dry-seeded method. In contrast, in water- seeded methods, rice seed is soaked for 12 to 36 hours to initiate germination, and the seed is broadcast by airplane into a flooded field. The seedlings emerge through a shallow flood, or the water may be drained from the field for a short period of time to enhance seedling establishment. Thus, in some embodiments, fluxofenim is applied to the rice seeds by including it in a soaking solution used to initiate germination, and the seeds are planted by a water-seeded method.

[0031] The rate of application in which the safener is applied in relation to the herbicide depend on the mode of application. When the safener is applied as a field treatment, either alone or as a tank mixture with the herbicide, the ratio of safener to herbicide is usually from 1 : 100 to 10: 1, but more typically from 1 :5 to 8: 1. However, when safeners are applied as a seed dressing, much smaller amounts per hectare of crop area are required than when they are applied later. For seed dressing, 0.1 to 10 g of safener is usually required per kg of seeds. In some embodiments, the seed dressing comprises from 0.1 to 3, 0.1 to 4, or 0.1 to 5 g per kg seed. In some embodiments, the seed dressing comprises at least 0.1 g, 0.5 g, 1.0 g, 1.5 g, 2.0 g, or 2.5 g per kg seed of the safener.

[0032] The term “effective amount of fluxofenim” refers to an amount of fluxofenim that provides the desired effect (e.g., rice safening effect such as decreased mortality rates, decreased injury, decreased bleaching, increased density, increased rice stand counts, and increased rice biomass), either following single or multiple applications. An effective amount can be determined by one skilled in the art using known techniques and by observing results obtained under analogous circumstances. In determining the effective amount of fluxofenim to be applied to a seed, a number of factors can be considered, such as: the species or variety of the seed, the growing location, the time of planting, soil conditions, abiotic stresses, and the like. In some embodiments, an effective amount of fluxofenim may be an amount that, when used with an effective amount of an agrochemical, allows for or improves the efficacy of the agrochemical as compared to the same amount of the agrochemical alone. In embodiments where the agrochemical is an herbicide, an effective amount of fluxofenim improves the control of weeds as compared to the same amount of the agrochemical alone administered under the same conditions. In some embodiments, an effective amount of fluxofenim may allow the herbicide to be applied to the rice plant or seed at an amount that is greater than recommended. In some embodiments, the rice seeds are treated with fluxofenim at a rate of about 2.5 g ai / kg-seed.

[0033] Seed treatment with the safener can improve early season vigor or canopy formation. The term “early season vigor” refers to the ability of a plant to grow and thrive during the early season. The term “early season” refers to a period of less than 60 days after emergence (i.e., less than 60 days after a growing plant has emerged from the soil). In some contexts, early season refers to a period of less than 30, 35, 40, 45, 50, or 55 days after emergence. Suitably, early season may refer to a period from about 1-60, 10-55, 20-50, or 30-45 days after emergence.

[0034] The term “canopy formation” refers to the formation of the aboveground portion of a plant and is measured as a percentage of the ground area covered by the plant. Early season vigor or canopy formation can be assessed based on various parameters including, without limitation, plant injury, the number of alive plants, leaf area, plant density, plant height, dry matter accumulation, and various growth parameters.

[0035] In some embodiments, at 7-28 days after emergence, rice plants grown from fluxofenim- treated seeds have exhibited improved rice establishment as compared to control plants. Indicators of improved rice establishment include, without limitations, decreased mortality rates, decreased injury, decreased bleaching, increased density, increased canopy formation, improved early season vigor, increased rice stand counts, and increased rice biomass. In some embodiments, the methods of the present invention decrease mortality rates, decrease injury, increase rice stand counts, or any combination thereof of the rice plant relative to a control plant. In some embodiments, the methods decreased mortality rates, decreased injury, increased rice stand counts, or any combination thereof of the rice plant by a statistically significant amount relative to the control plant.

[0036] As used herein, a “control plant” is a comparable plant (e.g., of the same species, variety, and age) that was grown under substantially similar conditions but was grown from a seed that was not treated with fluxofenim. Plants that are grown in “substantially similar conditions” are grown in similar locations and soil conditions, are planted with similar timing, are subjected to similar abiotic stresses, and the like.

[0037] When grown under substantially similar conditions, plants of the same variety are expected to exhibit statistically insignificant differences in the absence of a difference in treatment. The term “statistically significant” refers to an experimentally verifiable result that is not likely to occur randomly but is instead likely to be attributable to specific cause (e.g., the fluxofenim seed treatment). In some embodiments, a statistically significant result is one based on Fisher’s protected Least Significant Different (LSD) test at a = 0. 1.

[0038] In some embodiments, the methods result in a statistically significant decrease in injury of the rice plant. In some embodiments, the methods result in a statistically significant decrease in plant injury 7-28 days after emergence. In some embodiments, plant injury decreased by at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, or more than 95% 7-28 days after emergence as compared to a control plant.

[0039] The term “bleaching” refers to interference with pigment production and protection of chlorophyll, causing whitening of the plant. Some herbicides may cause chlorophyll to be destroyed. The absence of these pigments allows excessive light energy to destroy chlorophyll, which causes visible leaf bleaching. Plants are unable to photosynthesize due to a lack of pigments, and they may die after their energy reserves run out. Leaves turn white and may look bleached, and this symptom may be most severe near the leaf veins while interveinal areas may remain green. Purpling of leaf edges may also occur. Leaves that grow after application or exposure may look crinkled.

[0040] The term “biomass” refers to the mass of a portion of plant material (i.e., both live and dead). Biomass may be calculated as dry weight or fresh weight. “Fresh weight” is determined by simply harvesting plant material and weighing it, whereas “dry weight” is determined by harvesting plant material, drying it in an oven, and then weighing it. For example, the plant material may be dried in an oven at 140-160°F (60-70°C) for 24-48 hours.

[0041] As used herein, the terms “aboveground biomass” and “shoot biomass” refer to the biomass of the aboveground portion of a plant.

[0042] The methods of the present invention may be used to grow a variety of cereal plants. Suitable cereal plants include, without limitation, maize, rice, wheat, barley, sorghum, millet, oat, rye, and triticale. However, in preferred embodiments, the cereal plant is a rice plant and / or the cereal seed is a rice seed. Cultivated rice is typically from the species Oryzct sativa. The methods may be used with long-grain, medium-grain, and short-grain rice cultivars. Specific cultivars that may be used with the methods provided herein include, but are not limited to, the rice cultivars ‘Diamond’, ‘Jewel’, ‘DG363L’, CLL 15’, ‘CLL 16’, ‘CLL 17’, ‘PVL02’, ‘PVL03’, ‘RTV7231MA’, ‘CLJ 01’, ‘Jupiter’, ‘Titan’, ‘Lynx’, ‘RT753XP’, ‘RT7321FP’, and ‘RT7521FP’.

[0043] By enhancing rice tolerance to herbicides and reducing plant injury, the methods of the present invention may improve weed control. A “weed” is a plant that is considered a nuisance to or a competitor of a commercially important crop plant. As used herein, the term “weed control” refers to any observable reduction in weed growth or vigor. Weed control can include (1) killing, (2) inhibiting growth, reproduction or proliferation, or (3) removing, destroying, or otherwise diminishing weeds. Weed control can be assessed visually. For example, weed control can be assessed by comparing the number or size of weeds surrounding treated plants to that of weeds surrounding untreated plants. Weed control may be defined, for instance, in terms of the number of weed plants or weight of the weeds that grow around treated plants as a percentage of the number or weight of the weeds that grow around untreated plants. A “commercially acceptable rate of weed control” varies with the weed species, degree of infestation, environmental conditions, and the associated crop plant. Commercially effective weed control may be defined as the destruction (or inhibition) of at least about 40%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, or even at least 85%, or even at least 90%. Although it is generally preferable from a commercial viewpoint that 70%- 80% or more of the weeds be destroyed, commercially acceptable weed control can occur at much lower destruction or inhibition levels, particularly with some very noxious, herbicide-resistant plants.

[0044] Examples of weeds that may be controlled using the methods of the present invention include, but are not limited to, barnyardgrass (Echinochloa crus-galli) and other weed species within the Echinochloa genus, crabgrasses within the genus Digitaria, Palmer amaranth (AmarciHthus palmeri) and other weed species within the Amaranthus genus, common purslane {Portulaca oleracea) and other weed species in the Portulaca genus, Chenopodium album and other Chenopodium spp., Setaria lutescens and other Setaria spp., Solanum nigrum and other Solanum spp., Lolium multiflorum and other Loliuni spp., Brachiaria platyphylla and other Brachiaria spp., Conyza canadensis and other Conyza spp., mA Eleusine indica.

[0045] Methods of comparing rice plants’ tolerance to herbicides:

[0046] In another aspect, the present invention provides methods for comparing the herbicide tolerance of rice grown from a seed that was treated with an effective amount of fluxofenim to that of a control plant. The methods comprise (a) growing the cereal plant and the control plant under substantially similar conditions; (b) measuring an indicator of tolerance to herbicides in both the cereal plant and the control plant; and (c) comparing the measurements obtained in (b).

[0047] Suitable indicators of tolerance to herbicides include, without limitation, mortality rates, plant injury, number of alive plants, bleaching, plant density, rice stand counts, rice biomass, plant height, dry matter accumulation, and various growth parameters. In some embodiments, the inventors demonstrate that rice plants grown from fluxofenim-treated seeds have decreased mortality rates, decreased injury, increased rice stand counts, or any combination thereof as compared to control plants. Thus, in some embodiments, the indicator of tolerance to herbicides is mortality rates, rice injury, rice stand counts, or any combination thereof.

[0048] Additional treatments:

[0049] In some embodiments, the cereal seed may be additionally treated with one or more agrochemicals, such as an insecticide, fungicide, or plant growth regulator. Application of the fluxofenim seed treatment may occur before, at the same time, or after the application of another agrochemical.

[0050] In some embodiments, all seeds, including seed that was not treated with fluxofenim, were treated with a base treatment comprising a standard rice insecticide and fungicide. Thus, in some embodiments, the rice seed is further treated with an insecticide and / or fungicide, or the methods further comprise treating seed of the cereal plant with an insecticide and / or fungicide. An “insecticide” is a chemical used to control insects by killing them or preventing them from engaging in undesirable or destructive behaviors. Examples of suitable insecticides for use with the present invention include, without limitation, Nipslt®, CruiserMaxx®, Dermacor®, and Fortenza®. A “fungicide” is a chemical used to kill or prevent the growth of fungi and their spores. Examples of suitable fungicides for use with the present invention include, without limitation, metalaxyl, fludioxonil, carboxin, and thiram.

[0051] Grow regulators can be used to promote vigorous root growth and early emergence. Thus, in some embodiments, the cereal seed is further treated with a growth regulator, or the methods further comprise treating seed of the cereal plant with a growth regulator. A “growth regulator” is a chemical used to modify plant growth. Growth regulators can be used, for example, to increase branching, increase shoot growth, or alter fruit maturity. Growth regulators include both synthetic and naturally occurring substances. Examples of growth regulators include auxin and gibberellin.

[0052] The present invention may also provide an agricultural method that improves the efficacy of an herbicide, by reducing plant injury, increasing early season vigor, and increasing canopy formation. The methods may achieve a commercially acceptable rate of weed control.

[0053] Herbicide may be applied to the cereal plant or seed at an amount that is less than recommended. The recommended amount of herbicide may be the amount of herbicide recommended for application to the cereal plant according to the herbicide’s label. The reduction in applied about of herbicide may be at least 10%, 20%, 30%, 40%, or 50% or between 10 - 90%, 20 - 90%, 30 - 90% 40 - 90% or 50 - 90% to achieve a commercially acceptable rate of weed control.

[0054] In some instances, the herbicide may be applied to the cereal plant or seed at an amount that is greater than recommended. This is accomplished by increasing the plants tolerance to the herbicide The recommended amount of herbicide may be the amount of herbicide recommended for application to the cereal plant according to the herbicide's label. The increase in the applied amount of herbicide may be the amount of herbicide that, in combination with the use of the safener, results in the same or lower amount of injury or bleaching as the control plant. The herbicide may be applied to the cereal plant or seed at 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, more than 100%, more than 200%, more than 300%, or more than 400% more than the recommended amount to achieve a commercially acceptable rate of weed control. The herbicide may be applied to the cereal plant or seed at between 10 - 200%, 20 - 190%, 30 - 180%, 40 - 170%, 50 - 160%, 60 - 150%, 70 - 140%, 80 - 130%, or 90 - 120% more than recommended amount to achieve a commercial acceptable rate of weed control.

[0055] Miscellaneous

[0056] Unless otherwise specified or indicated by context, the terms “a”, “an”, and “the” mean “one or more.” For example, “a molecule” should be interpreted to mean “one or more molecules.”

[0057] As used herein, “about”, “approximately,” “substantially,” and “significantly” will be understood by persons of ordinary skill in the art and will vary to some extent on the context in which they are used. If there are uses of the term that are not clear to persons of ordinary skill in the art given the context in which it is used, “about” and “approximately” will mean plus or minus <10% of the particular term and “substantially” and “significantly” will mean plus or minus >10% of the particular term.

[0058] As used herein, the terms “include” and “including” have the same meaning as the terms “comprise” and “comprising.” The terms “comprise” and “comprising” should be interpreted as being “open” transitional terms that permit the inclusion of additional components further to those components recited in the claims. The terms “consist” and “consisting of’ should be interpreted as being “closed” transitional terms that do not permit the inclusion additional components other than the components recited in the claims. The term “consisting essentially of’ should be interpreted to be partially closed and allowing the inclusion only of additional components that do not fundamentally alter the nature of the claimed subject matter. All methods described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g., “such as”) provided herein, is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0059] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference to the same extent as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

[0060] Preferred aspects of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred aspects may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect a person having ordinary skill in the art to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context.

[0061] EXAMPLES

[0062] Fluxofenim rice seed treatment was evaluated in a greenhouse experiment and compared to fenclorim for safening the crop to a microencapsulated formulation of acetochlor (Warrant®) and an emulsifiable concentration formation of S-metolachlor when the herbicides were applied at planting (preemergence) or after rice germination but before emergence (delayed preemergence). As demonstrated here, fluxofenim coated on rice seed results in enhanced crop establishment and improved tolerance when followed by an application of a chloroacetamide herbicide compared to an application of the herbicide in the absence of the seed treatment. Currently, there are no chloroacetamide herbicides registered in rice for applications made before crop emergence. Example 1

[0063] Methods

[0064] In a greenhouse experiment, rows of ‘Diamond’ rice were seeded at a 0.5-inch depth into silt loam soil in trays. Two rows were seeded with 1) rice not treated with a potential safener, 2) seeds treated with fenclorim at 2.5 g ai / kg-seed, and 3) seeds treated with fluxofenim at 2.5 g / kg- seed. All rice seeds were also treated with insecticide and fungicide. The Warrant® formulation of acetochlor was applied at 2.5 pt / A (1.05 kg Al / ha) and Dual Magnum® formulation of S- metolachlor was applied at 0.75 pt / A (0.8 kg Al / ha). at either preemergence (immediately after planting) or delay preemergence (after rice germination but before emergence). There were four replications for each treatment. Herbicides were applied in a spray chamber using standard procedures. Immediately after each herbicide application, sufficient overhead irrigation was supplied to activate the herbicides. Subsequently, plots were overhead irrigated at least twice daily to increase the likelihood of rice injury from herbicides.

[0065] Injury ratings were visually taken 7 and 14 days after treatment (DAT) along with determination of rice plants emerged per plot at 7 days after emergence of the nontreated control. Data were subjected to analysis of variance (ANOVA), and means were separated using Fisher’s protected least significant difference (LSD) with an alpha (a) value of 0.1.

[0066] Results

[0067] Fluxofenim protected rice against injury or stand loss caused by preemergence or delayed preemergence application of Warrant® and Dual Magnum® (Figures 1-3). Rice establishment in the presence of herbicide was improved using the fluxofenim seed treatment for Warrant® applied preemergence and Dual Magnum® applied preemergence or delayed preemergence (Figure 1). The fluxofenim seed treatment did not eliminate injury to rice from either herbicide, but injury never exceeded 20% at 7 or 14 days after emergence when the herbicides were applied delayed preemergence (Figures 2 and 3).

[0068] Example 2

[0069] Methods

[0070] In a field experiment, Ozark rice was drill seeded at 72 seed m-row using standard drill- seeded rice practices. Rows were spaced 19 cm apart, with 9 rows of rice / plot. Within each plot, 3 rows of rice contained no herbicide safener, the next three were treated with fenclorim, and the last three were treated with fluxofenim. Both seed treatments were applied at 2.5 g / kg of seed. Each whole plot was treated with the herbicides Warrant and Dual Magnum at 3 pt / A and 0.75 pt / A, respectively. Both herbicides were applied at planting before the rice seed had germinated (preemergence) or the herbicides were applied delayed-preemergence, which occurred after the rice seeds had germinated but before emergence. All data were analyzed using ANOVA with letter separation based on Fisher’s protected least significant difference.

[0071] Results

[0072] A reduction in crop injury was observed when rice seeds had the fluxofenim seed treatment for Warrant applied preemergence and delayed preemergence (Figure 4). For both application timings, rice injury was reduced by 39 to 27 percentage points. This trend carried forward 14 days after emergence for Warrant, and with delayed-preemergence-applied Dual Magnum, rice injury was reduced by the fluxofenim seed treatment (Figure 5).

Claims

CLAIMSI / We claim:

1. A method of growing rice comprising applying an effective amount of fluxofenim to rice seed prior to planting and applying an effective amount of a Group 15 herbicide to the planting area.

2. The method of claim 1, wherein the herbicide is a chloroacetamide.

3. The method of claim 1, wherein the herbicide is acetochlor or S-metolachlor.

4. The method of any one of claim 1-3, wherein the herbicide is applied as a microencapsulated formulation.

5. The method of any one of claim 1-3, wherein the herbicide is applied as an emulsifiable concentrate or a soluble concentrate.

6. The method of any one of claims 1-5, wherein the herbicide is applied after the rice seed is planted.

7. The method of claim 6, wherein the herbicide is applied preemergence.

8. The method of claim 5, wherein the herbicide is applied delayed preemergence.

9. The method of any one of claims 1-8, wherein the method comprises applying a herbicide at a greater than recommended amount.

10. The method of any one of claim 1-9, wherein the effective amount of the herbicide is between 0.1 - 5 kilograms active ingredient per hectare.

11. The method of any one of claim 1-10, wherein the effective amount of the herbicide is between 0.75 - 2 kilograms active ingredient per hectare.

12. The method of any one of claims 1-11, wherein the effective amount of the herbicide is an amount of the herbicide that results in commercially acceptable weed control.

13. The method of any one of claims 1-12, wherein the effective amount of herbicide is an amount of herbicide, that in combination with the use of the safener, results in weed control and the same or lower amount of injury or mortality rate as compared to a control plant.

14. The method of any one of claims 1-13, wherein the effective amount of herbicide is an amount of herbicide, that in combination with the use of the safener, results in weed control and improved rice density, rice stand counts, or rice biomass as compared to a control plant.

15. The method of any one of claim 1-14, wherein the effective amount of fluxofenim is between 0.1 - 10 grams of safener per kilogram of seed.

16. The method of any one of claim 1-15, wherein the effective amount of fluxofenim is between 0.1 - 3 grams of safener per kilogram of seed.

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