Improving rice resistance to whitening herbicides through fenchlorim seed treatment.

Abstract

This specification discloses the use of fenchlorim (4,6-dichloro-2-phenylpyrimidine) as a phytotoxicity mitigation agent for rice.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the priority of U.S. Provisional Application No. 63 / 513,561, filed on July 13, 2023, the content of which is incorporated herein by reference in its entirety.

Background Art

[0002] Rice is a crop that has been cultivated since ancient times and is still one of the major food crops in the world. There are two cultivated species of rice: Asian rice (Oryza sativa L.) and African rice (O. glaberrima Steud.). O. sativa L. accounts for almost all of the rice cultivated in the world and is also a variety cultivated in the United States. Considering the importance of grains as food crops, there is a need for methods to improve the cultivation of such grains.

Summary of the Invention

[0003] This specification discloses a method for cultivating cereal crops such as rice. The method includes applying an effective amount of fenchlorim to rice seeds before sowing and applying an effective amount of a herbicide of Group 12, Group 13, or Group 27 to the sowing area. In some embodiments, the herbicide is a Group 13 herbicide such as chromazone. In some embodiments, the herbicide is a Group 27 herbicide such as mesotrione, tembotrione, or isoxaflutole. In some embodiments, the herbicide is a Group 12 herbicide such as fluridone. In some embodiments, the method includes applying more herbicide than the recommended amount.

Problems to be Solved by the Invention

[0004] Non-limiting embodiments of the present invention will be described illustratively with reference to the accompanying drawings, which are schematic diagrams and not drawn to scale. In the drawings, each identical or substantially identical component shown is usually represented by a single number. For clarity, not all components are labeled in each drawing, and not all components of each embodiment are shown where it is unnecessary for a person skilled in the art to understand the invention. [Brief explanation of the drawing]

[0005] [Figure 1] This graph shows the number of surviving 'Diamond' rice plants 28 days after emergence, depending on the amount of Chromazon applied and the use of fenchlorim seed treatment. For both application rates, the left bar graph shows the number of surviving plants grown from untreated fenchlorim seeds. The right bar graph shows the number of surviving plants grown from fenchlorim-treated seeds. Chromazon application of 337 g ai / ha is equivalent to 1x application in siltrom soil. In Fisher's LSD test at a=0.10, the same lettered mean values ​​are not different. [Figure 2] This graph shows the phytotoxicity rates of 'Diamond' rice at 21 days post-emergence, depending on the application rate of Chromazon and the use of fenchlorim seed treatment. The top curve shows the phytotoxicity rate (%) for rice without fenchlorim seed treatment. The bottom curve shows the phytotoxicity rate for rice treated with fenchlorim seed treatment. Chromazon application of 337 g ai / ha is a 1x application rate in siltrom soil. Both responses were described using the Weibull growth function. The predicted Chromazon application rate required to achieve a 50% phytotoxicity rate in rice is 1.08 times the rate without fenchlorim treatment and 2.29 times the rate with fenchlorim treatment. [Figure 3]This graph shows the whitening rate of 'Diamond' rice at 21 days post-emergence, depending on the application rate of Chromazon and the use of fenchlorim seed treatment. The uppermost curve shows the whitening rate (%) of rice without fenchlorim seed treatment. The lowermost curve shows the whitening rate (%) of rice with fenchlorim seed treatment. Chromazon application of 337 g ai / ha is a 1x application rate in siltrom soil. Both responses were described using the Weibull growth function. The predicted application rate of Chromazon required to give rice a 50% whitening rate is 1.06 times without fenchlorim treatment and 2.07 times with fenchlorim treatment. [Figure 4] The graph shows the number of green pixels representing the ground cover of 'Diamond' rice at 28 days post-emergence, depending on the amount of Chromazon applied and the use of fenchlorim seed treatment. For each application rate, the bar graph on the left shows the number of green pixels for rice without fenchlorim treatment. The bar graph on the right shows the number of green pixels for rice with fenchlorim treatment. Chromazon application of 337 g ai / ha is equivalent to 1x application in siltrom soil. In Fisher's LSD test at a=0.10, the same lettered mean values ​​are not different. [Figure 5] This graph shows the above-ground biomass of 'Diamond' rice at 28 days post-emergence, depending on the application rate of Chromazon and the use of fenchlorim seed treatment. For each application rate, the left bar graph shows the biomass of rice without fenchlorim treatment, while the right bar graph shows the biomass of rice treated with fenchlorim. A Chromazon application rate of 337 g ai / ha is equivalent to 1x application in siltrom soil. In Fisher's LSD test at a=0.10, the same lettered mean values ​​are not different. [Figure 6]This graph shows the visible whitening rate of 'Diamond' rice at 7 days post-emergence, according to the use of herbicides and fenchlorim seed treatment in groups 12, 13, and 27. For each herbicide application, the left bar graph shows the whitening rate (%) of rice without fenchlorim treatment. The right bar graph shows the whitening rate (%) of rice with fenchlorim treatment. Chromazon was applied at 337 g ai / ha, which is equivalent to a 1x application rate in siltromic soil. Statistical significance was determined using a t-test. [Figure 7] This graph shows the visible whitening rate (%) of 'Diamond' rice at 21 days post-emergence, according to the use of herbicides and fenchlorim seed treatment in groups 12, 13, and 27. For each herbicide application, the left bar graph shows the whitening rate (%) of rice without fenchlorim treatment. The right bar graph shows the whitening rate (%) of rice with fenchlorim treatment. Chromazon application of 337 g ai / ha is considered a 1x application rate in siltromic soil. Statistical significance was determined using a t-test. [Figure 8] This graph shows the visible phytotoxicity rate (%) and inverse prediction to 50% for 'Diamond' rice at 14 days post-emergence, depending on the use of pre-emergence treatment with mesotrione and fenchlorim seed treatment. The top curve shows the phytotoxicity rate (%) for rice without fenchlorim seed treatment. The bottom curve shows the phytotoxicity rate for rice with fenchlorim seed treatment. Rice treated with fenchlorim seed treatment showed a phytotoxicity rate equivalent to that of rice treated with 1.7 times the amount of mesotrione. On the other hand, rice without fenchlorim seed treatment showed a phytotoxicity rate equivalent to that of rice treated with 2.1 times the amount of mesotrione. A mesotrione application rate of 210 g ai / ha in siltromic soil is considered 1x. [Modes for carrying out the invention]

[0006] This specification discloses the use of fenchlorim (4,6-dichloro-2-phenylpyrimidine) as a phytotoxicity reducer for rice. A "phytotoxicity reducer for rice" is a substance that reduces the potential phytotoxicity to rice caused by pesticides such as herbicides, fungicides, and insecticides, or combinations thereof. In the examples, the inventors demonstrated that applying fenchlorim to rice seeds reduces phytotoxicity to plants caused by herbicides. Specifically, in conjunction with herbicide application, rice grown from fenchlorim-treated seeds showed reduced mortality, reduced visible phytotoxicity, reduced whitening, increased rice stem count, increased ground cover, and increased rice biomass compared to control plants grown from untreated seeds. These effects can improve weed control and allow for the use of more herbicides while maintaining or reducing phytotoxicity rates at a similar level compared to herbicide application without fenchlorim saphenine. Methods to make rice plants safer by increasing their resistance to herbicides:

[0007] In one embodiment, the present invention provides an agricultural method for safeguarding rice plants by treating rice seeds with an effective amount of fenchlorim to improve their resistance to herbicides. The method comprises applying an effective amount of fenchlorim to rice seeds before sowing and applying an effective amount of a herbicide from group 12, group 13, or group 27 to the sowing area.

[0008] The term "herbicide" refers to a substance used to control weeds. Herbicides can kill weeds or inhibit their growth or reproduction. Unless otherwise specified, the names of herbicides used herein mean all commercially available forms of herbicides, including salts, esters, free acids, free bases, and their stereoisomers.

[0009] In some embodiments, rice is treated with one or more herbicides. Suitable herbicides include pre-sowing, pre-emergence, and post-emergence herbicides. Applying multiple herbicides with different mechanisms of action may be useful in treating fields where herbicide-resistant weeds grow. Examples of additional herbicides that can be used in combination with Group 12, Group 13, or Group 27 herbicides include ACCase inhibitors (e.g., aryloxyphenoxypropion), enolpyruvirshikimate-3-phosphate synthase (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., urea and triazine), ALS or AHAS inhibitors (e.g., sulfonylurea, triazolopyrimidine, and imidazolinone), and photosystem I (PS I) Inhibitors (e.g., paraquat), protoporphyrinogen oxidase (PPO) inhibitors (e.g., diphenyl ether, phenyl ether, allyl triazone, and oxadiazole), mitosis inhibitors (e.g., anilide, amide, certain organophosphorus, and carbanylate herbicides), cellulose inhibitors (e.g., nitrile and oxazole herbicides), oxidative phosphorylation uncouplers, dihydropteroyl acid synthase inhibitors, fatty acid and lipid biosynthesis inhibitors (e.g., thiocarbamate and oxazole herbicides), auxin transport inhibitors (e.g., amide and urea herbicides), carotenoid biosynthesis inhibitors (e.g., isoxazolidinone, benzoylcyclohexanedione, and benzoylpyrazole herbicides), as well as their salts, esters, and mixtures, but not limited to these.

[0010] In some embodiments, rice is treated with one or more whitening herbicides. In some embodiments, herbicides used in combination with fenchlorim seed treatment include, but are not limited to, group 13 herbicides such as cromazon, group 12 herbicides such as flulidone, and group 27 herbicides such as mesotrione, tenbotrione, and isoxaflutol.

[0011] "Pre-emergence" refers to any time between sowing a crop and the emergence of the seedlings (i.e., before splitting or before heading). Therefore, herbicides may be applied before delayed emergence. "Delayed emergence" generally refers to application after the seeds have absorbed water and germinated, but before they emerge. It is the stage after the seeds have absorbed water and germinated, but before the young seedlings emerge. Pre-emergence treatment includes both treatment of the crop cultivation area before sowing (i.e., pre-sowing mixing) and treatment of the crop cultivation area after sowing but before the plants have emerged. In some cases, the delayed emergence period can be at least 4 days after sowing, for example, between 4 and 14 days after sowing. Post-emergence treatment includes early post-emergence treatment (EPOST), as well as treatment at the heading stage, the 1-2 leaf stage, or the 3-4 leaf stage.

[0012] Herbicides may be applied before or after sowing rice seeds. In some embodiments, herbicides are applied before sowing rice seeds. In some embodiments, herbicides are applied before emergence, before delayed emergence, or at heading. In some embodiments, herbicides are applied before emergence.

[0013] In the method of the present invention, any herbicide formulation suitable for agricultural use may be used. Suitable herbicide formulations include, but are not limited to, emulsions, aqueous solutions, and microencapsulated formulations.

[0014] An "emulsion" is an oily liquid formulation prepared by dissolving an oil-soluble active ingredient in one or more organic solvents (e.g., benzene, toluene, xylene). Emulsions may further contain surfactants or other additives. Before use, the emulsion is diluted with water to form an oil-in-water emulsion in which the active ingredient is contained in the organic phase.

[0015] A "water-soluble formulation" is a liquid preparation prepared by dissolving a water-soluble active ingredient in water. Water-soluble formulations may also contain surfactants or other additives.

[0016] A "microencapsulated formulation" is a formulation in which the active ingredient is enclosed within a porous shell (e.g., a polymer shell), which prevents the degradation of the active ingredient. For a detailed description of microencapsulated formulations, see U.S. Patent No. 9,877,478, which is incorporated herein by reference in its entirety. When exposed to soil moisture, the polymer coating dissolves, and the active ingredient is released slowly. The delayed release of the active ingredient gives crop plants time to absorb soil water and grow unimpeded before being affected by the herbicide. Furthermore, the sustained release allows the residual weed control effect of the herbicide to last longer compared to non-microencapsulated formulations. In microencapsulated formulations, the release rate of the core material can be controlled by selecting parameters including shell composition, core material composition, weight ratio of core material to shell material, microcapsule particle size, and processing conditions such as shear force and time during mixing. In some formulations, the release rate may be adjusted by changing the solubility properties of the core material by adding a diluent such as a solvent. Any diluent may be used, as long as it is compatible with the core and shell materials. The microencapsulated formulation may contain multiple particle populations, each having a different core material composition. For example, to achieve a bimodal release rate, the microencapsulated formulation may contain particles having two different core material compositions, each containing the same active ingredient mixed with two different solvents. Additional components, including but not limited to thickeners, stabilizers, anticaking agents, drift control agents, bactericides, preservatives, antifreezes, and defoamers, may be added to improve the properties of the core material.

[0017] The "effective dose of herbicide" refers to the amount that produces the desired effect (e.g., commercially acceptable weed control) through either a single or multiple application. The effective dose of herbicide can be determined by those skilled in the art using known techniques. The effective dose of a particular herbicide depends on several factors, including the formulation of the herbicide, the target crop, and environmental conditions (e.g., cultivation site, sowing time, soil type, moisture, abiotic stress). For example, the amount of herbicide applied may be approximately 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.2, 0.5, 1, 2, 3, 4, or 5 kilograms per hectare, or within a range such as 0.01-5 kilograms, 0.01-4 kilograms, 0.01-3 kilograms, 0.01-2 kilograms, 0.01-1 kilogram, 0.01-0.5 kilograms, 0.01-0.4 kilograms, 0.01-0.3 kilograms, or 0.01-0.2 kilograms per hectare. The amount of ram may be 0.01-0.1 kilograms, 0.02-5 kilograms, 0.02-4 kilograms, 0.02-3 kilograms, 0.02-2 kilograms, 0.02-1 kilogram, 0.02-0.5 kilograms, 0.02-0.4 kilograms, 0.02-0.3 kilograms, 0.02-0.2 kilograms, 0.02-0.1 kilograms, 0.03-5 kilograms, 0.03-4 kilograms, 0.03-3 kilograms, 0.03-2 kilograms, 0.03-1 kilogram, 0.03-0.5 kilograms, 0.03-0.4 kilograms, 0.03-0.3 kilograms, 0.03-0.2 kilograms, or 0.03-0.1 kilograms. In some embodiments, the effective amount of herbicide may be 0.1-5 kilograms of the active ingredient per hectare. In some embodiments, the method enhances the efficacy of herbicides (e.g., herbicides of Group 12, Group 13, or Group 27) by reducing phytotoxicity to plants, suppressing whitening, increasing early growth vigor, and / or promoting canopy formation (since canopy formation is directly related to weed control). These methods can achieve commercially acceptable weed control rates.Commercially acceptable weed control rates vary depending on the weed species, the extent of infestation, environmental conditions, and the crops involved. Generally, commercially effective weed control refers to the destruction or suppression of at least approximately 60%, 65%, 70%, 75%, 80%, 85%, or 90% of weed plants. From a commercial standpoint, it is generally desirable to eradicate or suppress at least 70-80% of weeds, but commercially acceptable weed control is possible even at much lower levels of destruction or suppression, especially in the case of highly harmful herbicide-resistant weeds.

[0018] In some embodiments, herbicides may be applied to cereal plants or seeds at a lower rate than recommended. The recommended rate of herbicide may be the recommended application rate for cereal crops based on the herbicide label. The reduction in herbicide application rate to achieve a commercially acceptable weed control rate may be at least 10%, 20%, 30%, 40%, 50%, or in the range of 10–90%, 20–90%, 30–90%, 40–90%, 50–90%.

[0019] In some embodiments, the herbicide may be applied to cereal plants or seeds at an amount greater than the recommended amount. This can be achieved by enhancing the tolerance of the plants to the herbicide. The recommended amount of the herbicide can be the recommended application rate to cereal crops based on the label of the herbicide. The increase in the application rate of the herbicide can refer to the amount of the herbicide that results in herbicide damage or albino at the same level as or lower than that of the control plants when used in combination with a herbicide damage reducing agent. As shown in the examples, the predicted application rate of chromazone required to give a 50% herbicide damage rate to rice is 1.08 times that in the case of non-treatment with fenchlorim and 2.29 times that in the case of treatment with fenchlorim. Similarly, the predicted application rate of chromazone required to give a 50% albino rate to rice is 1.06 times that in the case of non-treatment with fenchlorim and 2.07 times that in the case of treatment with fenchlorim. In another example, rice treated with fenchlorim seed treatment showed the same herbicide damage rate as when treated with mesotrione at 1.7 times the amount. On the other hand, rice not treated with fenchlorim seed treatment showed the same herbicide damage rate as when treated with mesotrione at 2.1 times the amount. To achieve a commercially acceptable weed control rate, the herbicide can be increased by 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, 200%, 300%, 400%, 500%, or more than 500%, or in the range of 10 - 300%, 10 - 200%, 20 - 190%, 30 - 180%, 40 - 170%, 50 - 160%, 60 - 150%, 70 - 140%, 80 - 130%, or 90 - 120% compared to the recommended amount and applied to cereal plants or seeds.

[0020] In some embodiments, the effective amount of the herbicide is the amount of the herbicide that results in herbicide damage or albino at the same level as or lower than that of the control plants when used in combination with a herbicide damage reducing agent. In some embodiments, the effective amount of the herbicide is the amount of the herbicide that results in improved above-ground biomass or ground cover rate compared to the control plants when used in combination with a herbicide damage reducing agent. In some embodiments, the effective amount of the herbicide is the amount of the herbicide that results in improved early growth vigor or canopy formation compared to the control plants.

[0021] The term "phytotoxicity reducing agent" refers to a compound that antagonizes the harmful effects of herbicides on cultivated crops. Phytotoxicity reducing agents were once referred to as "detoxifying agents", and these terms can be used interchangeably. Preferably, these compounds protect cultivated plants without significantly affecting the action of the herbicide on the target weeds. In the method of the present invention, a phytotoxicity reducing agent that protects rice from phytotoxicity caused by one or more herbicides such as Group 12, Group 13, or Group 27 herbicides is utilized. The phytotoxicity reducing agent is fenclorim (4,6-dichloro-2-phenylpyrimidine), including all available forms including salts, esters, free acids, free bases, as well as its stereoisomers.

[0022] The phytotoxicity reducing agent can be applied prior to or simultaneously with the herbicide against which phytotoxicity is to be prevented. Depending on the characteristics, the phytotoxicity reducing agent can be used for pre-treatment of seeds of cultivated plants (seed treatment or seedling treatment), incorporated into the soil (e.g., between furrows) before or after sowing, or applied alone or mixed (e.g., tank mixing) with the herbicide before or after the emergence of the plant. Therefore, the treatment of the phytotoxicity reducing agent on the plant or seed can be carried out independently of or simultaneously with the application time of the herbicide. In some embodiments, the phytotoxicity reducing agent is applied to the seeds before sowing (e.g., by coating the seeds with the phytotoxicity reducing agent).

[0023] The phytotoxicity reducing agent may be used in its original form or formulated with conventional adjuvants and carriers. The phytotoxicity reducing agent can be formulated by any known method such as, for example, emulsions, directly sprayable or dilutable solutions, dilute emulsions, wettable powders, soluble powders, powders, granules, and encapsulation (e.g., by polymeric substances). These compositions may contain additional components such as stabilizers, defoamers, viscosity modifiers, binders, adhesives, and fertilizers or other active compounds to obtain special effects.

[0024] Formulations for pharmacotoxicity reducers are prepared by known methods, for example, by mixing and / or grinding the active ingredient with an expander (e.g., a solvent, a solid carrier, and optionally a surfactant). Suitable solvents for pharmacotoxicity reducers include, but are not limited to, aromatic hydrocarbons, preferably fractions containing 8 to 12 carbon atoms, e.g., xylene mixtures or substituted naphthalenes; phthalates (e.g., dibutyl phthalate or dioctyl phthalate); aliphatic hydrocarbons such as cyclohexane; paraffins, alcohols and glycols and their ethers and esters (e.g., ethanol, ethylene glycol, ethylene glycol monomethyl ether or monoethyl ether); ketones such as cyclohexanone; strongly polar solvents such as N-methyl-2-pyrrolidone, dimethyl sulfoxide, or dimethylformamide; and epoxidized vegetable oils such as epoxidized coconut oil or epoxidized soybean oil; or water. For example, suitable solid carriers for dust and dispersible powders are usually natural mineral fillers such as calcite, talc, kaolin, montmorillonite, and attapulgite. To improve physical properties, highly dispersible silicic acid or highly dispersible absorbent polymers may be added. Suitable granular adsorbent carriers are porous types, such as pumice, crushed brick, sepiolite, or bentonite. Suitable non-adsorbent carriers are materials such as calcite or sand. In addition, a number of inorganic or organic pre-granulating materials (e.g., dolomite or crushed plant residues in particular) are available. Depending on the properties of the phytotoxicity reducing agent being formulated, suitable surfactants are nonionic, cationic, and / or anionic surfactants with good emulsifying, dispersing, and wetting properties. Surfactants commonly used in such formulations are described, for example, in the following literature: "Mc Cutcheon's Detergents and Emulsifiers Annual," MC Publishing Corp., Ringwood, NJ, 1979; Sisely and Wood, "Encyclopedia of Surface Active Agents," Chemical Publishing Co. Inc., New York, 1964.

[0025] The term "effective dose of fenchlorim" refers to the amount of fenchlorim that, after one or more applications, produces the desired effect (i.e., a rice safety effect such as reduced mortality, reduced visible phytotoxicity, reduced whitening, increased rice stem count, increased ground cover, increased rice biomass, or any combination thereof). The effective dose can be determined by those skilled in the art using known techniques and by observing results obtained under similar conditions. When determining the effective dose of fenchlorim to apply to seeds, factors such as seed type or variety, cultivation site, sowing time, soil conditions, and abiotic stress may be considered. In some embodiments, 0.1–10.0 g, 0.1–9.0 g, 0.5–8.0 g, 1.0–7.0 g, 1.0–6.0 g, 1.0–5.0 g, 1.0–4.0 g, 1.5–3.5 g, or 2.0–3.0 g of fenchlorim may be applied per kg of seed. In some embodiments, rice seeds are treated with fenchlorim at a dosage of 2.5 g ai / 1 kg of seed.

[0026] In some embodiments, the methods disclosed herein may result in reduced phytotoxicity, suppression of whitening, improved early growth vigor, and / or improved canopy formation. The term “early growth vigor” refers to the ability of a plant to grow and thrive in its early growth stage. The term “early growth” refers to the period of less than 60 days after emergence (i.e., less than 60 days from the time the growing plant emerges from the soil). In some contexts, early growth refers to the period of less than 30, 35, 40, 45, 50, or 55 days after emergence. More precisely, early growth may refer to the period of approximately 1–60 days, 10–55 days, 20–50 days, or 30–45 days after emergence.

[0027] The term "crown formation" refers to the formation of the above-ground portion of a plant and is measured as the percentage of the ground area covered by the plant. Early growth vigor or crown formation can be evaluated based on a variety of parameters, including but not limited to plant phytotoxicity, number of surviving individuals, leaf area, planting density, plant height, dry matter accumulation, and various growth parameters.

[0028] In several embodiments, the inventors have demonstrated that rice grown from fenchlorim-treated seeds exhibits, at 7–28 days post-emergence, reduced mortality, reduced visible phytotoxicity, reduced whitening, increased number of stems, increased ground cover, increased rice biomass, or any combination thereof, compared to control plants. Therefore, in several embodiments, the method of the present invention has shown effects such as reduced mortality, reduced visible phytotoxicity, reduced whitening, increased number of stems, increased ground cover, increased rice biomass, or any combination thereof, compared to control plants. In several embodiments, the method has shown statistically significant effects such as reduced mortality, reduced visible phytotoxicity, reduced whitening, increased number of stems, increased ground cover, increased rice biomass, or any combination thereof, compared to control plants in the early growth stage.

[0029] In this specification, “control plants” means comparable plants (e.g., plants of the same species, variety, and age) grown from seeds that were not treated with fenchlorim, but were cultivated under substantially similar conditions. Plants grown under “substantially similar conditions” include plants grown in similar locations and soil conditions, sown at similar times, and exposed to similar abiotic stresses.

[0030] When grown under substantially similar conditions, plants of the same variety are expected to show no statistically significant differences unless there are differences in treatment. The term "statistically significant" refers to an experimentally verifiable result that is unlikely to occur by chance and is more likely to be attributable to a specific cause (e.g., fenchlorim seed treatment). In some embodiments, a statistically significant result is one in which the p-value is less than 0.05. In some embodiments, a statistically significant result is one in which the p-value is less than 0.02, 0.01, 0.005, 0.002, or 0.001.

[0031] In some embodiments, the method results in a statistically significant increase in the number of surviving rice plants. In some embodiments, compared to control plants that have not been treated with fenchlorim seeds, the number of surviving rice plants increases by at least 5%, 10%, 15%, 20%, 30%, 40%, 50%, or more than 50% after 7, 14, 21, 28, or 28 days or more.

[0032] In this specification, the term "leaf area" refers to the total surface area of ​​all living leaves on the above-ground part of a plant, expressed per unit area of ​​ground. In some embodiments, the method results in a statistically significant increase in leaf area during the early growth stage. In some embodiments, the method results in a statistically significant increase in leaf area within 45 or 30 days after germination. In some embodiments, compared to control plants not treated with fenchlorim seeds, the leaf area increases by at least 5%, 10%, 15%, 20%, or more than 20% after 7, 14, 21, 28, or more than 28 days.

[0033] In this specification, the term "ground cover" refers to the area of ​​the above-ground part of a plant that is covered by leaves as viewed from above. Ground cover can be determined, for example, based on the number of pixels of green leaves in an aerial image. In some embodiments, the method results in a statistically significant increase in ground cover in the early stages of growth. In some embodiments, the method results in a statistically significant increase in ground cover within 7 to 28 days after emergence. In some embodiments, the method results in a statistically significant increase in ground cover in siltromic soil. In some embodiments, compared to control plants that have not been treated with fenchlorim seeds, ground cover increases by at least 4%, 5%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or more than 90% after 7, 14, 21, 28 days, or more than 28 days.

[0034] In this specification, the term “biomass” is used to refer to a portion of the mass of plant material (i.e., both living and dead material). Biomass can be calculated as dry weight or fresh weight. “Fresh weight” is measured by simply weighing the harvested plant material, while “dry weight” is measured by weighing the harvested plant material after drying it in a dryer. For example, the plant material may be dried in a dryer at 140–160°F (60–70°C) for 24–48 hours.

[0035] In this specification, the terms “aerial biomass” and “foliar biomass” refer to the biomass of the above-ground parts of a plant. Aerial biomass can be measured, for example, based on the number of pixels of green leaves in an aerial image. In some embodiments, the method results in a statistically significant increase in aerial biomass in the early growth stage. In some embodiments, the method results in a statistically significant increase in aerial biomass within 7 to 28 days after emergence. In some embodiments, compared to control plants that have not been treated with fenchlorim seeds, aerial biomass increases by at least 5%, 10%, 20%, 30%, 40%, 50%, 60%, or more than 60% after 7, 14, 21, 28 days, or more than 28 days.

[0036] In this specification, the terms “underground biomass” and “root biomass” refer to the biomass of the underground parts of a plant.

[0037] In this specification, the term "total biomass" refers to the sum of the above-ground and below-ground biomass of a plant. In some embodiments, the method results in a statistically significant increase in total biomass during the early growth period. In some embodiments, the method results in a statistically significant increase in total biomass within 7 to 28 days after emergence. In some embodiments, compared to control plants that have not been treated with fenchlorim seeds, total biomass increases by at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, or more than 50% after 7, 14, 21, 28, or 28 days or more.

[0038] In this specification, “stem count” refers to the number of plants in a particular area. In some embodiments, the method results in a statistically significant increase in stem count during the early growth stage. In some embodiments, the method results in a statistically significant increase in stem count within 7 to 28 days after emergence. In some embodiments, compared to control plants not treated with fenchlorim seeds, the stem count increases by at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, or more than 50% after 7, 14, 21, 28, or 28 days or more.

[0039] In this specification, "whitening" refers to the whitening of plants. In some embodiments, the method statistically significantly reduces the rate of whitening in rice during the early growth stage. In some embodiments, the method results in a statistically significant reduction in the rate of whitening within 7 to 28 days after emergence. In some embodiments, compared to control plants that were not treated with fenchlorim seeds, the rate of whitening was reduced by at least 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 50%, or more than 50% after 7, 14, 21, 28, or 28 days or more.

[0040] The methods of the present invention can be used for cultivating various cereal plants. Suitable cereal plants include, but are not limited to, maize, rice, wheat, barley, sorghum, millet, oats, rye, and tritikale. However, in preferred embodiments, the cereal plant is a rice plant and / or the cereal seed is a rice seed. Cultivated rice is usually of the genus Oryza sativa. These methods can be used for long-grain, medium-grain, and short-grain rice varieties. Specific varieties usable in the methods described 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."

[0041] Seed treatment agents may be in the form of powder, slurry, or liquid. The primary purpose of seed treatment is to coat the seeds with an effective amount of the seed treatment agent. Typical methods of applying seed treatment agents to seeds include, but are not limited to, sprinkling the agent on the seeds, spraying concentrated agents onto the seeds, and immersing the seeds in a solution containing the agent.

[0042] Grain seeds can be sown in several ways. For example, in the United States, rice cultivation is broadly classified into dry-field sowing and paddy-field sowing. In dry-field sowing, rice is sown in a prepared seedbed using a grain seeder, or the seeds are broadcast and mixed into the soil with a disc or harrow. Moisture for seed germination is then supplied by irrigation or rainfall. Therefore, in some embodiments, fenchlorim is applied to rice seeds as a powder or concentrated formulation, and the seeds are sown by dry-field sowing. On the other hand, in paddy-field sowing, rice seeds are soaked in water for 12 to 36 hours to promote germination and then scattered in the paddy field by plane. Seedlings germinate from a shallow submerged state, or the water in the field may be drained for a short time to promote seedling establishment. Therefore, in embodiments, fenchlorim is applied to rice seeds by adding it to the soaking solution used to initiate germination, and the seeds are sown by paddy-field sowing.

[0043] Weed control can be improved by the method of the present invention by reducing phytotoxicity to plants, enhancing early growth vitality, and promoting canopy formation. This is because canopy formation is directly related to preventing weed growth. "Weeds" refers to plants that are harmful to or considered competitors to commercially important crops. In this specification, "weed control" means a reduction in weed growth or vigor that is visually observable. Weed control includes (1) killing weeds, (2) inhibiting weed growth, reproduction, and proliferation, and (3) removing, destroying, or otherwise reducing weeds. Weed control can be evaluated visually. For example, the effectiveness of weed control can be evaluated by comparing the number or size of weeds around treated plants with the number or size of weeds around untreated plants. The effectiveness of weed control may be defined, for example, as the ratio of the number or weight of weeds growing around treated plants to the number or weight of weeds growing around untreated plants.

[0044] Examples of weeds that can be controlled using the method of the present invention include, but are not limited to, the grass species Echinochloa crus-galli and other weed species within the genus Echinochloa, Digitaria species within the genus Digitaria, Amaranthus palmeri and other weed species within the genus Amaranthus, Portulaca oleracea and other weed species within the genus Portulaca, Chenopodium album and other species of the genus Chenopodium, Setaria lutescens and other species of the genus Setaria, Solanum nigrum and other species of the genus Solanum, Lolium multiflorum and other species of the genus Lolium, Brachiaria platyphylla and other species of the genus Brachiaria, Conyza canadensis and other species of the genus Conyza, and Eleusine indica. In certain preferred embodiments, the weed species is Oryza sativa L. var. sylvatica (wild rice) or Oryza sativa L. (red rice). How to compare herbicide resistance in rice plants:

[0045] In some embodiments, the method includes comparing the herbicide resistance of rice grown from seeds treated with an effective amount of fenchlorim to that of a control plant. These methods include (a) growing the cereal plant and the control plant under substantially similar conditions, (b) measuring an index of herbicide resistance in both the cereal plant and the control plant, and (c) comparing the measurements obtained in (b).

[0046] Appropriate indicators of herbicide resistance include, but are not limited to, plant phytotoxicity, number of surviving plants, whitening, leaf area, vegetation density, plant height, dry matter accumulation, and various growth parameters. In some embodiments, the inventors have demonstrated that rice grown from fenchlorim-treated seeds exhibits reduced mortality, reduced visible phytotoxicity, reduced whitening, increased stem number, increased ground cover, increased rice biomass, or any combination thereof, compared to control plants. Thus, in some embodiments, indicators of herbicide resistance are mortality, visible phytotoxicity, whitening effect, rice stem number, ground cover, rice biomass, or any combination thereof. Additional processing:

[0047] In some embodiments, cereal seeds may be further treated with one or more pesticides, such as insecticides, herbicides, fungicides, or plant growth regulators. The application of the fenchlorim seed treatment may be carried out before, simultaneously with, or after the application of other pesticides. In some embodiments, the method further includes applying an effective amount of fungicide or an effective amount of insecticide to the sowing area.

[0048] The effective dose of fenchlorim, when used in combination with the effective dose of a pesticide, is the amount that enables or enhances the efficacy of the pesticide compared to the same amount of the pesticide alone. In embodiments where the pesticide is a herbicide, the effective dose of fenchlorim improves the weed control effect compared to administering the same amount of the pesticide alone under the same conditions.

[0049] In some embodiments, improved efficacy means a reduction in the effective amount of pesticide needed to achieve the desired effect in combination with the metabolic inhibitor, compared to the same amount of pesticide alone. The reduction rate may be at least 10%, 20%, 30%, 40%, or 50%, or may be in the range of 10-90%, 20-90%, 30-90%, 40-90%, or 50-90%.

[0050] In the examples, all seeds, including those not treated with fenchlorim, were subjected to a basic treatment containing standard rice insecticides and fungicides. Therefore, in some embodiments, rice seeds are further treated with insecticides and / or fungicides, or the method includes further treating cereal plant seeds with insecticides and / or fungicides. "Insecticide" is a chemical substance used to control insects by killing them or preventing them from performing undesirable or destructive behaviors. Examples of insecticides usable in the present invention include, but are not limited to, NipsIt®, CruiserMaxx®, Dermacor®, and Fortenza®. "Fungicide" is a chemical substance used to kill or prevent the growth of fungi and their spores. Examples of fungicides usable in the present invention include, but are not limited to, metalaxyl, fludioxonil, carboxyne, and thyram.

[0051] Growth regulators can be used to promote vigorous root growth and early sprouting. Therefore, in some embodiments, cereal seeds are further treated with growth regulators, or the method involves further treating the seeds of a cereal plant with a growth regulator. “Growth regulator” refers to a chemical substance used to regulate plant growth. Growth regulators can be used, for example, to increase branching, promote stem growth, or alter fruit maturation. Growth regulators include both synthetic and naturally derived substances. Examples of growth regulators include auxins and gibberellins. others

[0052] Unless otherwise specified or made clear from the context, the terms "a," "an," and "the" mean "one or more." For example, "a molecule" should be interpreted as meaning "one or more molecules."

[0053] In this specification, the terms “about,” “approximately,” “substantially,” and “significantly” are understood to a person skilled in the art, and their meanings vary to some extent depending on the context in which they are used. Where a person skilled in the art cannot clearly understand the meaning of a term in the context in which it is used, “about” and “approximately” mean within ±10% of the term, and “substantially” and “significantly” mean more than ±10% of the term.

[0054] In this specification, the terms “include” and “including” are synonymous with the terms “comprise” and “comprising.” The terms “comprise” and “comprising” should be interpreted as “open” conjunctions that allow for the inclusion of additional components in addition to those described in the claims. The terms “consist” and “consisting of” should be interpreted as “restrictive” conjunctions that do not allow for the inclusion of additional elements other than those described in the claims. The term “consisting essentially of” should be interpreted as partially restrictive, allowing for the inclusion of additional elements that do not fundamentally alter the essence of the subject matter of the claim.

[0055] All methods described herein may be performed in any suitable order, unless otherwise specified herein or unless clearly contradicted by the context. Any examples or exemplary language provided herein (e.g., "etc.") are intended solely to illustrate the invention more clearly and, unless otherwise noted, do not limit the scope of the invention. Nothing in this specification should be construed as indicating that any unclaimed element is essential for the practice of the invention.

[0056] All references cited herein (including publications, patent applications, and patents) are incorporated by reference in the same way as they are presented herein, with each reference explicitly and specifically indicated as being incorporated by reference.

[0057] Preferred embodiments of the present invention, including the best embodiments known to the inventors, are described herein. Those skilled in the art will readily understand variations of these preferred embodiments upon reading the above description. The inventors anticipate that those skilled in the art will make various modifications to a reasonable extent and intend to carry out the invention in ways other than those specifically described herein. Accordingly, the present invention includes, to the extent permitted by applicable law, all modifications and equivalents of the subject matter described in the appended claims. Furthermore, unless otherwise specifically stated herein or clearly contradicted by the context, any combination of any possible variations of the above elements is included in the present invention. Examples

[0058] Current research at the University of Arkansas is exploring new methods of weed management in rice cultivation. Chloroacetamide herbicides are not registered for rice production in the United States. However, studies conducted by our research group have demonstrated the efficacy and safety of fenchlorim seed treatment in combination with these herbicides. Recently, crop damage from the group 13 herbicide (diterpene synthesis inhibitor) chromazon, applied to the soil after sowing fenchlorim-treated rice seeds, was less than that without the addition of a phytotoxicity reducer. To evaluate the degree of rice tolerance development to chromazon after fenchlorim seed treatment, a greenhouse experiment was conducted in Fayetteville, Arkansas, in the fall of 2022. In this experiment, fenchlorim-treated rice was compared to untreated rice in siltrom soil, with Chromazon applied at seven different doses (0x, 0.5x, 1x, 1.5x, 2x, 3x, and 4x the recommended field application rate of 336 g ai / ha). As the Chromazon application rate increased, the rate of phytotoxicity in rice in the form of whitening increased, but this was more pronounced in untreated rice. At 4x the Chromazon application rate, all emerging rice plants were wiped out. In contrast, fenchlorim-treated rice had a mortality rate of only 40% compared to the untreated group, even at the same application rate as the Chromazon-treated group. Rice above-ground biomass and ground cover, based on green pixels determined by Turf Analyzer software, showed a similar trend to the observed phytotoxicity in rice, suggesting that rice has greater tolerance to Chromazon than to fenchlorim. This study provides evidence that fenchlorim-treated rice may mitigate the whitening effect of chromazon treatment, and further evaluation through field trials under various soil and environmental conditions is needed. Furthermore, this seed treatment has been shown to confer additional resistance to rice treated with other whitening herbicides belonging to multiple sites of action and herbicide lines. method

[0059] In the greenhouse experiment, four rows of 'Diamond' rice were sown at a depth of 0.5 inches in siltrom soil in trays approximately 6 inches wide, 12 inches long, and 4 inches deep. Two rows contained rice that had not been treated with fenchlorim but had been treated with insecticides and fungicides. The other two rows contained seeds treated with fenchlorim at 2.5 g ai / kg of seed, in addition to insecticides and fungicides. Eleven seeds were sown in each 6-inch row, which corresponds to 22 seeds per foot of row, the recommended sowing rate for 'Diamond' rice. Chromazon (Command 3ME) was applied immediately after sowing (before emergence) at doses of 0 (untreated), 168 (0.5x), 253 (0.75x), 337 (1x), 505 (1.5x), 673 (2x), 1010 (3x), and 1350 (4x) g ai / ha. Overhead watering was then performed, and overhead watering was carried out on the trays daily throughout the experimental period. The phytotoxicity rate and whitening rate of rice in each plot were evaluated at 7, 14, 21, and 28 days after emergence. Furthermore, the number of emerged rice plants was counted at 7 days after emergence, and the number of surviving rice plants was counted again at 28 days after emergence (28DAE). At 28DAE, photographs were taken from directly above each plot, and the number of green pixels in each plot was measured using a Turf Analyzer. For the above-ground biomass of rice, harvesting took place at 28 DAE, and after drying in a dryer at 66°C for 3 days, the weight was measured.

[0060] Since "Diamond" rice is a long-grain, self-pollinated variety and is sown in small quantities, the effect of this technology is likely to be greater in hybrid rice than observed in this study. Even a slight reduction in the number of tillers in hybrid rice can have a serious impact on rice grain yield, especially if environmental conditions in the early stages of growth are not ideal. result

[0061] Results for Group 13: The number of rice plants standing in 7DAE was similar across all treatments (data not shown). However, in 28DAE, a clear effect of chromazon application rate on the number of surviving rice plants in each plot was observed. In the case without fenchlorim seed treatment, the number of surviving rice plants decreased when the chromazon application rate exceeded 1x. On the other hand, in rice treated with fenchlorim, no decrease in the number of plants was observed at any chromazon application rate except for the highest application rate (4x) (Figure 1). Based on visible phytotoxicity and whitening of rice, fenchlorim increased rice tolerance to chromazon by approximately twofold (Figures 2 and 3). Furthermore, when chromazon was treated at 1x, 1.5x, and 2x doses, the fenchlorim-treated plots had a higher rice ground cover rate (measured as the number of green pixels) in 28DAE compared to the untreated plots (Figure 4). Similarly, in 28DAE, fenchlorim seed treatment increased rice biomass compared to the untreated group when chromazon was applied at 1x, 1.5x, 2x, and 3x doses (Figure 5). These results clearly demonstrate that fenchlorim seed treatment provides some protection to rice from phytotoxicity caused by chromazon pre-emergence treatment.

[0062] Results for Groups 12 and 27: In a similar manner to the previously described method for responding to chromazon dose, fenchlorim reduced the whitening rate of rice in addition to chromazon, along with two herbicides in Group 27 (mesotrione and tenbotrione) and one herbicide in Group 12 (fluridone) (Figure 6). In 21DAE, the safety-enhancing effect of tenbotrione was attenuated, but fenchlorim, along with other herbicides, safeguarded isoxaflutol (Group 27) (Figure 7). In additional dose-response tests using Diamond rice treated with mesotrione (with and without fenchlorim) before emergence, herbicide tolerance improved across a wide range of treatment concentrations (Figure 8). [Prior art documents] [Non-patent literature]

[0063] [Non-Patent Document 1] Mc Cutcheon's Detergents and Emulsifiers Annual, MC Publishing Corp., Ringwood, NJ, 1979. [Non-Patent Document 2] Sisely and Wood, "Encyclopedia of Surface Active Agents," Chemical Publishing Co. Inc., New York, 1964.

Claims

1. A method for cultivating rice, comprising: applying an effective amount of fenchlorim to rice seeds before sowing; and applying an effective amount of a herbicide from group 12, group 13, or group 27 to the sowing area.

2. The method according to claim 1, wherein the herbicide is a group 13 herbicide.

3. The method according to claim 2, wherein the herbicide is Chromazon.

4. The method according to claim 1, wherein the herbicide is a group 27 herbicide.

5. The herbicide is mesotrione, tenbotrione, or isoxaflutol. The method according to claim 4.

6. The method according to claim 1, wherein the herbicide is a group 12 herbicide.

7. The method according to claim 6, wherein the herbicide is flulidone.

8. The method according to any one of claims 1 to 7, wherein the method includes applying a herbicide in a larger amount than recommended.

9. The method according to claim 8, wherein the effective amount of herbicide is the amount of herbicide that, when used in combination with a phytotoxicity reducing agent, causes phytotoxicity or whitening equivalent to or less than that of a control plant.

10. The method according to claim 8, wherein the effective amount of herbicide is the amount of herbicide that, when used in combination with a phytotoxicity reducer, improves above-ground biomass or ground cover compared to a control plant.

11. The method according to claim 8, wherein the effective amount of herbicide is the amount of herbicide that, when used in combination with a phytotoxicity reducer, improves the early growth vitality or canopy formation compared to a control plant.

12. The method according to any one of claims 1 to 11, wherein the effective amount of the herbicide is 0.1 to 5 kilograms of active ingredient per hectare.

13. The method according to any one of claims 1 to 12, wherein the effective amount of fenchlorim is 0.1 to 10 grams per kilogram of seeds as a phytotoxicity reducing agent.

14. The method according to claim 13, wherein the effective amount of fenchlorim is 1 to 5 grams per kilogram of seeds as a phytotoxicity reducer.

15. The method according to any one of claims 1 to 14, wherein the herbicide is applied after sowing rice seeds.

16. The method according to claim 15, wherein the herbicide is applied before germination, before delayed germination, or at the time of heading.

17. The method according to claim 16, wherein the herbicide is applied before germination.

18. The method according to any one of claims 1 to 17, wherein the herbicide is applied as an emulsion or a water-soluble agent.

19. The method according to any one of claims 1 to 17, wherein the herbicide is applied as a microencapsulated formulation.

20. The method according to any one of claims 1 to 19, further comprising applying an effective amount of a fungicide or an effective amount of an insecticide to the sowing area.

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