A chlorimuron-ethyl and safener composition for controlling annual broadleaf weeds in soybean-corn strip interplanting fields and its use

Abstract

This invention discloses a composition of chlorpyrifos and a safener for controlling annual broadleaf weeds in soybean-corn strip intercropping fields, and its application. The composition of chlorpyrifos and a safener (pyrazosulfuron, bis(oxazolyl)sulfuron, and cyclopropanesulfonamide) in a specific ratio significantly alleviates phytotoxicity to corn in soybean-corn intercropping fields, while maintaining the control efficacy against annual broadleaf weeds (such as *Eclipta prostrata*, *Abutilon theophrasti*, and *Celosia argentea*). This invention solves a major problem in soybean-corn strip intercropping: limited use of herbicides, narrow weed control spectrum, and unsatisfactory weed control. It is beneficial for the promotion of soybean-corn strip intercropping technology. The composition of this invention is a feasible synergistic herbicide-safener combination for controlling annual broadleaf weeds in soybean-corn strip intercropping fields.

Description

Technical Field

[0001] This invention belongs to the field of plant protection technology, specifically involving the synergistic application of acetyllactone synthase inhibitor chlorpyrifos and a safener to control annual broadleaf weeds in soybean-corn strip intercropping fields. Background Technology

[0002] Soybeans, a legume rich in oil and protein, originated in China and are an extremely important oilseed, food, and feed crop. Currently, my country's soybean cultivation area is small and yields are low, resulting in a supply shortage and heavy reliance on imports. In contrast, my country has a large corn cultivation area, where supply and demand are in a tight balance.

[0003] The soybean-corn strip intercropping model aims to utilize existing corn-growing fields and promote the balanced development of the soybean industry through a scientifically sound strip intercropping layout, while ensuring stable corn yields, achieving a win-win goal of "no reduction in corn production and an extra season of soybeans." This technology began nationwide demonstration applications in 2022. However, severe weed infestations in the intercropping fields and the lack of effective supporting chemical control measures have affected the actual effectiveness and further promotion of the technology.

[0004] Soybean-corn intercropping fields exhibit a greater variety and quantity of weeds. A total of 16 weed species were identified in key demonstration areas of soybean-corn strip intercropping technology in my country, including 11 broadleaf weeds, 4 grasses, and 1 sedge. Broadleaf weeds were the dominant species, including difficult-to-control broadleaf weeds such as *Eclipta prostrata*, *Abutilon theophrasti*, and *Celosia argentea*, which caused significant damage. Currently, only a few herbicides, such as bentazon, are registered for use on both corn and soybeans to control broadleaf weeds. There is a real shortage of herbicides for controlling annual broadleaf weeds in intercropping fields, necessitating an expansion of the available herbicides to ensure safe and efficient control of broadleaf weeds and ultimately guarantee the widespread application of soybean-corn intercropping technology.

[0005] While chlorpyrifos is a highly effective herbicide for controlling broadleaf weeds in soybeans, studies have shown that its application in soybean fields has a serious adverse effect on the post-emergence plant height and yield of subsequent maize crops. Therefore, directly applying chlorpyrifos to soybean-maize strip intercropping fields poses a significant risk of herbicide damage to maize and fails to meet actual production needs.

[0006] To address the phytotoxicity problem of chlorpyrifos in corn, theoretically, adding a herbicide safener can protect the crop. However, safeners exhibit high selectivity, with different safeners showing significantly different effects on different herbicide-crop combinations. Currently, no existing technology discloses any herbicide safener that can effectively mitigate the phytotoxicity of chlorpyrifos in corn, nor does it disclose a herbicidal combination containing chlorpyrifos and a safener suitable for soybean-corn intercropping fields. Therefore, there is an urgent need to screen for a herbicidal solution that can be safely used in intercropping models and effectively control broadleaf weeds. Summary of the Invention

[0007] The purpose of this invention is to provide a combination of acetolactate synthase inhibitor chlorpyrifos and a safener for safe use in soybean-corn strip intercropping fields to control annual broadleaf weeds. Studies have shown that the synergistic use of different safeners—pyrazosulfuron, bis(oxazolyl)sulfuron, and cyclopropanesulfonamide—with the sulfonamide herbicide chlorpyrifos exhibits good safety for corn, while also demonstrating good indoor activity against representative annual broadleaf weeds such as *Eclipta prostrata*, *Abutilon theophrasti*, and *Celosia argentea* in intercropping fields, showing potential for controlling annual broadleaf weeds in soybean-corn strip intercropping fields.

[0008] The technical solution adopted in this invention is:

[0009] In a first aspect, the present invention protects a composition of chlorpyrifos and a safener for controlling annual broadleaf weeds in soybean-corn strip intercropping fields. The composition comprises chlorpyrifos, a branched-chain amino acid synthase inhibitor, and a safener as the main components, wherein the safener is selected from one or more of pyrazosulfuron, bis(oxazolyl) acid, and cyclopropanesulfonamide.

[0010] In the specific implementation plan, the dosage ratio of chlorpyrifos to pyrazosulfuron is 10~55:1, the dosage ratio of chlorpyrifos to cyclopropanesulfonamide is 25~55:1, and the dosage ratio of chlorpyrifos to bis(oxazolyl)sulfuron is 10~55:1.

[0011] In a more specific implementation plan, the dosage ratio of chlorpyrifos to pyrazosulfuron is 20-30:1, the dosage ratio of chlorpyrifos to cyclopropanesulfonamide is 20-30:1, and the dosage ratio of chlorpyrifos to bis(oxazolyl)sulfuron is 11-15:1.

[0012] In a more specific implementation plan, the dosage ratio of chlorpyrifos to pyrazosulfuron is 25:1, the dosage ratio of chlorpyrifos to cyclopropanesulfonamide is 25:1, and the dosage ratio of chlorpyrifos to bis(oxazolyl)sulfuron is 13:1.

[0013] In specific implementation plans, the combined application rate of chlorpyrifos and pyrazosulfuron is 32 g ai / ha: 0.63~2.5 g ai / ha; the combined application rate of chlorpyrifos and cyclopropanesulfonamide is 32 g ai / ha: 0.63~1.25 g ai. / ha; and the combined application rate of chlorpyrifos and bispyrazosulfuron is 32 g ai / ha: 0.63~2.5 g ai / ha.

[0014] In more specific implementation schemes, the combined application rate of chlorpyrifos and pyrazosulfuron is 32 g ai / ha: 0.63~1.25 g ai / ha, the combined application rate of chlorpyrifos and cyclopropanesulfonamide is 32 g ai / ha: 1.25 g ai. / ha, and the combined application rate of chlorpyrifos and bispyrazosulfuron is 32 g ai / ha: 2.5 g ai / ha.

[0015] The combination of chlorpyrifos-pyrazosulfuron-methyl at a ratio of 25:1 at a dosage of 22.12-32.64 g ai / ha, the combination of chlorpyrifos-chlorpyrifos-cyclopropanesulfonamide at a ratio of 25:1 at a dosage of 17.60-33.28 g ai / ha, and the combination of chlorpyrifos-chlorpyrifos-bis(oxazolyl)sulfuron-methyl at a ratio of 13:1 at a dosage of 18.89-34.46 g ai / ha can significantly alleviate the phytotoxicity of the herbicides on corn in soybean-corn intercropping fields, without affecting the control efficacy against annual broadleaf weeds (eelgrass, velvetleaf, and celosia). This invention solves a major problem in soybean-corn strip intercropping: the limited number of herbicides used, the narrow spectrum of weed control, and the unsatisfactory weed control effect. It is conducive to the promotion of soybean-corn strip intercropping technology. It is a feasible combination of safe herbicides for synergistic application to control annual broadleaf weeds (Eclipta prostrata, Abutilon theophrasti, Celosia argentea) in soybean-corn strip intercropping fields.

[0016] Secondly, the present invention protects a pharmaceutical preparation comprising any of the compositions described above.

[0017] Thirdly, the present invention protects the use of any of the compositions described above in controlling annual broadleaf weeds in soybean-corn strip intercropping fields.

[0018] Fourthly, this invention protects the application of the aforementioned pharmaceutical preparation in controlling annual broadleaf weeds in soybean-corn strip intercropping fields.

[0019] In a specific implementation plan, the composition is used as follows: when corn seedlings are at the 4-leaf stage and annual broadleaf weeds are at the 2-4-leaf stage, the foliar spray method is used for foliar treatment.

[0020] In the specific implementation plan, the weeds are angelica, velvetleaf, celosia, etc.

[0021] The beneficial effects of this invention are:

[0022] This invention combines chlorpyrifos, an acetyllactone synthase inhibitor that is unsafe for maize growth, with a safer agent, making it safe for maize growth. At the same time, it has a good indoor inhibitory effect on annual broadleaf weeds in soybean-maize strip intercropping fields, and has the potential to control annual broadleaf weeds in soybean-maize strip intercropping fields. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to the embodiments. Reagents or instruments used without a specified manufacturer are considered to be conventional products that can be purchased on the market.

[0024] Example 1

[0025] (I) Effects of combined use of chlorpyrifos and safeners on the safety of maize – Indoor test

[0026] The indoor experiments were conducted from June to October 2024 in the greenhouse of the Herbicide Toxicology and Resistance Laboratory at Nanjing Agricultural University.

[0027] The tested herbicide was 84% ​​chlorpyrifos-sulfuron-methyl water-dispersible granules (Corteva Agricultural Technology Co., Ltd.).

[0028] Test safeners: Pyrazosulfuron-methyl (Jiangsu Aikon Biomedical R&D Co., Ltd.), Bismuthoxazolic acid (Shanghai Bide Pharmaceutical Technology Co., Ltd.), Cyclopropanesulfonamide (Shanghai Aladdin Biochemical Technology Co., Ltd.)

[0029] Test crops: Yellow corn (Zhengdan 958), sweet waxy corn (Tiannuo 182), and fruit corn (Zhongnongtian 488).

[0030] Indoor experimental process

[0031] 1. Effects of combined use of chlorpyrifos and a safener on the safety of maize: test reagent and safener dosage settings.

[0032] Chlorpyrimethanil dosage: 32 g ai / ha

[0033] Safety agent dosage: 0, 0.32, 0.63, 1.25, 2.5, 5 g ai / ha

[0034] The treatment involves combining chlorpyrifos with a safener.

[0035] 2. Experimental Methods for the Effect of Combination Use of Chlorpyrifos and a Safener on the Safety of Maize

[0036] Nutrient soil was prepared using a 1:2 ratio of sand to nutrient substrate, with a pH of 6.3, an organic matter content of 1.1%, and no prior use of herbicides. This nutrient soil was filled into 10 cm × 10 cm × 8 cm white plastic pots with drainage holes at the bottom. Nine seeds were sown per small pot, covered with a layer of fine soil, and allowed to absorb water until saturated. The pots were then placed in a greenhouse for cultivation. Cultivation conditions included day / night temperatures of 30 ℃ / 25 ℃ and light / dark periods of 14 h / 10 h. Seedlings were thinned at the 3-leaf stage, with four uniformly growing plants per pot. Foliar spraying was performed at the 4-leaf stage using a 3WP-2000 mobile bioassay sprayer manufactured by the Nanjing Agricultural Mechanization Research Institute of the Ministry of Agriculture and Rural Affairs, with a spray volume of 30 mL. Each treatment was replicated four times, with a water control included. After the herbicide was absorbed, the pots were returned to the greenhouse for cultivation. After 21 days, the aboveground fresh weight was assessed, and the fresh weight inhibition rate was calculated. The herbicide's fresh weight inhibition rate against weeds was analyzed using DPS software, and the significance of the results was determined using Duncan's multiple range test (p=0.05).

[0037] Fresh weight inhibition rate % = (Control fresh weight - Treatment fresh weight) / Control fresh weight × 100

[0038] Table 1 shows that the addition of different safeners can alleviate the inhibitory effect of chlorpyrifos on the fresh weight of corn to varying degrees. With increasing safener dosage, the inhibitory effect on the fresh weight of corn generally shows a trend of first decreasing and then increasing. At a dosage of 32 g ai / ha, the fresh weight inhibition rates of chlorpyrifos on Zhengdan 958, Tiannuo 182, and Zhongnongtian 488 were 24.34%, 42.06%, and 20.57%, respectively. At a dosage of 32 ± 0.63 g ai / ha, the combination of chlorpyrifos-pyrazosulfuron-methyl significantly reduced the fresh weight inhibition rate of chlorpyrifos against Zhengdan 958, Tiannuo 182, and Zhongnongtian 488 by 3.57%, 1.13%, and 5.19%, respectively. At a dosage of 32 ± 1.25 g ai / ha, the combination of chlorpyrifos-cyprofenamide significantly reduced the fresh weight inhibition rate of chlorpyrifos against Zhengdan 958, Tiannuo 182, and Zhongnongtian 488 by -0.76%, -12.87%, and -1.49%, respectively. At a dosage of 32 ± 2.5 g ai / ha, the combination of chlorpyrifos-bis(oxazolyl)sulfuron-methyl significantly reduced the fresh weight inhibition rate of chlorpyrifos against Zhengdan 958, Tiannuo 182, and Zhongnongtian 488 by 2%, -2.49%, and 0.14%, respectively. In summary, the dosage ratios of chlorpyrifos-pyrazosulfuron-methyl at 50:1, chlorpyrifos-methylpropanesulfonamide at 25:1, and chlorpyrifos-methylpropanesulfonamide at 13:1 can all significantly improve the safety of chlorpyrifos for corn.

[0039]

[0040] *: Lowercase letters indicate significance at the 0.05 level using Duncan's new multiple range test with DPS software.

[0041] (II) Toxicity effect test of chlorpyrifos combined with safener against annual broadleaf weeds—indoor test

[0042] The indoor experiments were conducted from November to December 2024 in the greenhouse of the Herbicide Toxicology and Resistance Laboratory at Nanjing Agricultural University.

[0043] The tested herbicide was 84% ​​chlorpyrifos-sulfuron-methyl water-dispersible granules (Corteva Agricultural Technology Co., Ltd.).

[0044] Test safeners: Pyrazosulfuron-methyl (Jiangsu Aikon Biomedical R&D Co., Ltd.), Bismuthoxazolic acid (Shanghai Bide Pharmaceutical Technology Co., Ltd.), Cyclopropanesulfonamide (Shanghai Aladdin Biochemical Technology Co., Ltd.)

[0045] The tested weeds were: Eclipta prostrata (collected in September 2019 from opposite Sunshine Vineyard on Yinzhuang Street, Gulou District, Xuzhou City, Jiangsu Province), Abutilon theophrasti (collected in September 2022 from Cidian Farm, Wenshang County, Jining City, Shandong Province), and Celosia argentea (collected in September 2023 from Houling Street, Yongcheng City, Shangqiu City, Henan Province).

[0046] 1. Toxicity effect test of chlorpyrifos combined with a safener against annual broadleaf weeds and dosage settings of the pesticide and safener.

[0047] Chlorpyrimethanil dosage: 0, 0.41, 1.63, 6.5 g ai / ha

[0048] Safety agent dosages: pyrazosulfuron-methyl 0.13 g ai / ha, cyclopropanesulfonamide 0.26 g ai / ha, and bis(oxazolyl)acrylic acid 0.5 g ai / ha

[0049] Dosage combinations of chlorpyrifos with safeners: chlorpyrifos-pyrazosulfuron 0, 0.42, 1.66, 6.63 g ai. / ha; chlorpyrifos-cyclopropanesulfonamide 0, 0.42, 1.69, 6.76 g ai / ha; chlorpyrifos-bis(oxazolyl)ac 0, 0.44, 1.75, 7 g ai / ha.

[0050] 2. Test method for the toxicity effect of chlorpyrifos combined with a safener on annual broadleaf weeds.

[0051] Nutrient soil was prepared using a 1:2 ratio of sand to nutrient substrate, with a pH of 6.3, an organic matter content of 1.1%, and no prior use of herbicides. This nutrient soil was filled into 7 cm × 7 cm × 7 cm white plastic pots with drainage holes at the bottom. Seeds of *Eclipta prostrata*, *Abutilon theophrasti*, and *Celosia argentea*, with a germination rate exceeding 80%, were selected and sown evenly in the white pots, 30 seeds per pot. The plants were cultivated in a greenhouse under the following conditions: day / night temperature 30 ℃ / 25 ℃, light / dark duration 14 h / 10 h. When the weeds reached the 2-4 leaf stage, seedlings were thinned, retaining 10 plants of uniform growth. Foliar spraying was applied at the 2-4 leaf stage using a spray tower with a dosage of 30 mL. Each treatment was replicated four times, with a water control included. After the herbicide was absorbed, the plants were returned to the greenhouse for cultivation. After 21 days, the aboveground fresh weight of the weeds was assessed, and the fresh weight inhibition rate was calculated. The DPS software was used to analyze the fresh weight inhibition rate of herbicides on weeds and the significance of the Duncan multiple range test (p=0.05).

[0052] Fresh weight inhibition rate % = (Control fresh weight - Treatment fresh weight) / Control fresh weight × 100

[0053] Table 2 shows that adding different doses of safeners did not reduce the inhibitory effect of chlorpyrifos on annual broadleaf weeds. At the highest dose, the combination of chlorpyrifos with pyrazosulfuron, cyclopropanesulfonamide, and dibenzoxazolamide showed fresh weight inhibition rates of over 90% against *Eclipta prostrata*, specifically 91.02%, 92.59%, and 93.31%, respectively. The ED50 of *Eclipta prostrata* was also significantly reduced. 90 The values ​​were 4.48, 3.44, and 3.98 g ai / ha, respectively, all greater than the ED50 of chlorpyrifos alone against snake intestines. 90 The concentration was 2.58 g ai / ha, but its toxicity to *Eclipta prostrata* remained high. At the highest dose, the combination of chlorpyrifos with pyrazosulfuron, cyprofensulfuron, and bispyrazosulfuron showed an inhibition rate of over 90% on the fresh weight of *Abutilon theophrasti*, and also had a significant effect on the end-effector concentration (EDS) of *Abutilon theophrasti*. 90 The values ​​were 1.28, 1.43, and 1.06 ga.i. / ha, respectively, all lower than the ED50 of chlorpyrifos alone against velvetleaf. 90 The concentration of chlorpyrifos was 1.74 g ai / ha, indicating relatively high toxicity to velvetleaf. At the highest treatment dose, the combination of chlorpyrifos with pyrazosulfuron, cyprothylsulfonamide, and dibenzoxazolamide resulted in fresh weight inhibition rates of 71.20%, 75.91%, and 66.87% against celosia argentea, respectively. The effect-free ratio (EDR) against celosia argentea was [not specified]. 90 The values ​​were 22.12, 17.60, and 18.89 g ai / ha, respectively, all lower than the ED50 of chlorpyrifos alone against Celosia argentea. 90 The concentration of 35.46 g ai / ha has no significant impact on the toxicity of chlorpyrifos.

[0054] Based on the above results, it is recommended that combinations of 6.5 g ai / ha chlorpyrifos with 0.13 g ai / ha pyrazosulfuron, 6.5 g ai / ha chlorpyrifos with 0.26 g ai / ha cyclopropanesulfonamide, and 6.5 g ai / ha chlorpyrifos with 0.5 g ai / ha dibenzoxazolamide be applied to control annual broadleaf weeds in soybean-corn strip intercropping fields.

[0055]

[0056] *: Lowercase letters indicate significance at the 0.05 level using Duncan's new multiple range test with DPS software.

[0057] The scope of protection of this invention is not limited to the above embodiments. Variations and advantages that can be conceived by those skilled in the art without departing from the spirit and scope of the inventive concept are included in this invention and are protected by the appended claims.

Claims

1. A composition of chlorpyrifos and a safener for controlling annual broadleaf weeds in soybean-corn strip intercropping fields, characterized in that, The composition comprises chlorpyrifos and a safener as the main components, wherein the safener is selected from one or more of pyrazosulfuron, bis(oxazolyl)ac and cyclopropanesulfonamide.

2. The composition according to claim 1, characterized in that, The dosage ratio of chlorpyrifos to pyrazosulfuron is 10~55:1, the dosage ratio of chlorpyrifos to cyclopropanesulfonamide is 25~55:1, and the dosage ratio of chlorpyrifos to bis(oxazolyl)ac is 10~55:

1.

3. The composition according to claim 1, characterized in that, The dosage ratio of chlorpyrifos to pyrazosulfuron is 20~30:1, the dosage ratio of chlorpyrifos to cyclopropanesulfonamide is 20~30:1, and the dosage ratio of chlorpyrifos to bis(oxazolyl)sulfuron is 11~15:

1.

4. The composition according to claim 1, characterized in that, The combined application rate of chlorpyrifos and pyrazosulfuron is 32 g ai / ha: 0.63 ~ 2.5 g ai / ha; the combined application rate of chlorpyrifos and cyclopropanesulfonamide is 32 g ai / ha: 0.63 ~ 1.25 g ai / ha; and the combined application rate of chlorpyrifos and bispyrazosulfuron is 32 g ai / ha: 0.63 ~ 2.5 g ai / ha.

5. The composition according to claim 1, characterized in that, The combined application rate of chlorpyrifos and pyrazosulfuron is 32 g ai / ha: 0.63~1.25 g ai / ha; the combined application rate of chlorpyrifos and cyclopropanesulfonamide is 32 g ai / ha: 1.25 g ai / ha; and the combined application rate of chlorpyrifos and bispyribac-sodium is 32 g ai / ha: 2.5 g ai / ha.

6. A pharmaceutical preparation, characterized in that, The pharmaceutical preparation contains the composition according to any one of claims 1-5.

7. The use of the composition according to any one of claims 1-5 in controlling annual broadleaf weeds in soybean-corn strip intercropping fields.

8. The application of the pharmaceutical preparation according to claim 6 in controlling annual broadleaf weeds in soybean-corn strip intercropping fields.

9. The application according to claim 7 or 8, characterized in that, The method of application for the composition is as follows: when corn seedlings are at the 4-leaf stage and annual broadleaf weeds are at the 2-4-leaf stage, apply the foliar spray method for stem and leaf treatment.

10. The composition according to any one of claims 1-5, the pharmaceutical formulation according to claim 6, and the application according to any one of claims 7-9, characterized in that, The weeds mentioned are Eclipta prostrata, Abutilon theophrasti, or Celosia argentea.

Images