Weed removal composition and weed removal method and application thereof

Abstract

The invention belongs to the technical field of agriculture, and particularly relates to a weed removal composition and a weed removal method and application thereof. The weeding composition comprises the following effective components: penoxsulam and bicyclopyrone, wherein the penoxsulam and the bicyclopyrone are used as active ingredients; the penoxsulam and the bicyclopyrone are combined for use, so that the weeding composition has good synergy in a weed control spectrum, can efficiently kill different groups of weeds, and expands the control spectrum. The composition disclosed by the invention is particularly remarkable in prevention effect on the resistant beckmannia syzigachne, and the result of the embodiment shows that the prevention effect on the resistant beckmannia syzigachne can reach 90% or above when the composition is applied to a field. Meanwhile, the efficient chemical removal time is selected, the safe chemical removal window period is prolonged, the pesticide application safety coefficient is increased, the high and stable yield of the wheat after rice is achieved, and the planting income is increased.

Description

Technical Field

[0001] This invention belongs to the field of agricultural technology, specifically relating to a weed-control composition, its weed-control method, and its application. Background Technology

[0002] In the Huaibei region, the area sown with wheat after rice harvest is nearly 20 million mu (approximately 1.3 million hectares), accounting for nearly 90% of the region's total wheat planting area. High and stable yields of wheat after rice harvest are crucial to local food security. Weeds not only restrict the improvement of wheat yield and quality but also increase the cost of control, leading to a decline in wheat planting profits. *Clerodendrum trichotomum*, an annual or biennial grass belonging to the genus *Clerodendrum*, thrives near water and in damp areas. Since the beginning of this century, *Clerodendrum trichotomum* has become the dominant species in wheat fields after rice harvest in the Huaibei region. In wheat fields, *Clerodendrum trichotomum* can generally cause a 10% to 30% reduction in wheat yield, with severely affected fields experiencing yield reductions of over 50%. Control of *Clerodendrum trichotomum* is mainly achieved through chemical control. However, due to years of continuous use of a single type of herbicide, the resistance of *Clerodendrum trichotomum* in rice-wheat fields has increased. Surveys indicate that the resistance multiples of *Clerodendrum trichotomum* populations in local rice-wheat fields to herbicides such as quizalofop-p-ethyl and mesosulfuron-methyl range from 4 to 200. As the difficulty of controlling purslane increases year by year, there is an urgent need for new compositions in production to control it and improve the control effect. Summary of the Invention

[0003] The purpose of this invention is to provide a weed control composition, a weed control method, and its application; the composition can effectively control different groups of weeds, especially showing significant control effect on resistant purslane, with a control effect of over 90% on resistant purslane.

[0004] The present invention provides a weed control composition, wherein the active ingredients of the composition include penoxsulam and cyclopyrfluthrin.

[0005] As a preferred embodiment, the weight ratio of penoxsulam to cyclopyrfluthrin is 1–3:2.5–10.

[0006] As a preferred embodiment, the dosage of the active ingredient in penoxsulam is 15–45 g ai / hm. 2 The effective ingredient dosage of the cyclopyridoxine is 37.5–150 g ai / hm. 2 .

[0007] As a preferred embodiment, the weeds include: grass weeds and / or broadleaf weeds; the grass weeds include one or more of the following: barnyard grass, American privet, and Japanese American privet; the broadleaf weeds include one or more of the following: cleavers, chickweed, cowherb, shepherd's purse, and shepherd's purse.

[0008] This invention provides the application of the above-mentioned weed-control composition in crop cultivation.

[0009] The present invention provides a method for chemical weed control in wheat fields, comprising the following steps: chemical weed control using the above-mentioned composition during the 10th to 60th day of the wheat's overwintering period.

[0010] As a preferred embodiment, the weed control is performed on wheat with three or more leaves.

[0011] The present invention also provides a method for increasing wheat yield, comprising the following steps: sowing wheat seeds in rice stubble wheat fields, ensuring smooth irrigation and drainage, using the above-mentioned chemical weed control method to control weeds, and harvesting the wheat after it matures.

[0012] As a preferred embodiment, the wheat variety includes: semi-winter wheat varieties; the semi-winter wheat varieties include one or more of Huaimai 33, Huaimai 55, Jiangmai 186 and Xinong 979.

[0013] As a preferred embodiment, the soil relative moisture content is 70%–80% at the time of sowing, the land level difference is ≤5cm, the sowing depth is 2–3cm, and the seed exposure rate is <5%.

[0014] Beneficial Effects: This invention provides a weed control composition, the active ingredients of which include penoxsulam and cyclopyrflufenoxam. The combination of penoxsulam and cyclopyrflufenoxam in this invention exhibits good synergy across the weed control spectrum, effectively killing different groups of weeds and broadening the control range. The composition of this invention is particularly effective against resistant barnyardgrass. Results from the examples show that applying this composition to the field achieves a control efficacy of over 90% against resistant barnyardgrass.

[0015] This invention provides the application of the above-mentioned weed-control composition in crop cultivation. Using the composition of this invention for weed control results in very little weed emergence in the field after a single application, and has no impact on crop growth, making it safe and effective.

[0016] This invention provides a method for chemical weed control in wheat fields, comprising the following steps: applying the above-mentioned composition for weed control during the 10th to 60th day of wheat's overwintering period. This invention selects a highly efficient weed control time, which not only extends the safe control window but also improves the safety factor of the herbicide application. Using the chemical control method described in this invention, wheat did not exhibit stunting or yellowing, indicating that controlling weeds during the 10th to 60th day of wheat's overwintering period is highly safe for wheat. Compared to autumn and spring chemical control, which is prone to low-temperature phytotoxicity, this method extends the safe control period and is easier for farmers to implement.

[0017] This invention also provides a method for increasing wheat yield, comprising the following steps: sowing wheat seeds in a rice-stubble wheat field, ensuring smooth irrigation and drainage, using the aforementioned chemical weed control method, and harvesting the wheat after maturity. The method of this invention comprehensively and effectively controls common grasses and broadleaf weeds in rice-stubble wheat fields, without affecting wheat growth. The operation is simple and highly safe. This invention selects the optimal time for chemical weed control, not only extending the safe window period for chemical control but also improving the safety factor of pesticide application, achieving high and stable yields of rice-stubble wheat and increasing planting profits. Results from the embodiments show that the method of this invention significantly increases the number of wheat spikes, grains, and thousand-grain weight, resulting in a final wheat yield increase of 3.35%–7.30%. Detailed Implementation

[0018] The present invention provides a weed control composition, wherein the active ingredients of the composition include penoxsulam and cyclopyrfluthrin.

[0019] Unless otherwise specified, the present invention does not have special requirements for the raw materials used in the preparation, and commercially available products well known to those skilled in the art can be used.

[0020] The weight ratio of penoxsulam and cyclopyrflufenican described in this invention can be any value within the range of 1–3:2.5–10, for example, 1:2.5, 1:5, 1:7.5, 1:10, 2:2.5, 2:5, 2:7.5, 2:10, 3:2.5, 3:5, 3:7.5, or 3:10. Penoxsulam, as described in this invention, is a systemic sulfonylurea herbicide and an inhibitor of acetolactate synthase (ALS). It is absorbed through stems, leaves, young buds, and roots, and translocated through the xylem and phloem to the meristem, inhibiting plant growth, causing chlorosis of the growing point, resulting in reddening and necrosis of the terminal bud 7–14 days after treatment, and plant death within 2–4 weeks. Cyclopyrflufenican inhibits HPPD activity, blocking the conversion of p-hydroxyphenylpyruvic acid to hydantoin, thereby preventing the normal synthesis of tocopherol and plastoquinone, affecting the synthesis of carotenoids in the target plant, leading to whitening of the leaves. This invention combines the two ingredients to achieve a synergistic effect. Through scientific formulation of the active ingredients, it can effectively control weeds, especially resistant purslane.

[0021] The effective ingredient dosage of penoxsulam described in this invention can be 15–45 g ai / hm. 2 Any value within the range, such as 15, 20, 25, 30, 35, 40, or 45 g ai / hm 2 The effective component of cyclopyridoxine described in this invention can be used at a dosage of 37.5–150 g ai / hm. 2 Any value within the range, such as 37.5, 60, 75, 90, 105, 120, 135, or 150 g ai / hm. 2The method of applying the composition of the present invention includes spraying. The spraying tools of the present invention include boom sprayers and / or agricultural drones.

[0022] The weeds described in this invention may include: grassy weeds and / or broadleaf weeds; the grassy weeds may include one or more of the following: barnyard grass, American privet, and Japanese American privet; the broadleaf weeds may include one or more of the following: cleavers, chickweed, common chickweed, shepherd's purse, and shepherd's purse. The weeds described in this invention are common and difficult-to-control weeds in wheat fields. The active ingredients in the composition of this invention have good synergistic effects, effectively controlling weeds and expanding the weed control spectrum.

[0023] This invention provides the application of the above-mentioned weed-control composition in crop cultivation. Using the composition of this invention for weed control results in very little weed emergence in the field after a single application, and has no impact on crop growth, making it safe and effective.

[0024] The present invention provides a method for chemical weed control in wheat fields, comprising the following steps: chemical weed control using the above-mentioned composition during the 10th to 60th day of the wheat's overwintering period.

[0025] This invention allows for chemical weed control using the above-described composition at any time within the 10-60 day range of wheat entering its overwintering period, such as 10, 20, 22, 30, 35, 40, 43, 50, 54, or 60 days. Taking the Huaibei region as an example, the overwintering period described in this invention begins in mid-to-late December, for example, December 15th, 17th, 20th, 22nd, 25th, or 28th. A single spray within 10-60 days of entering the overwintering period is sufficient to kill weeds, requiring less pesticide than spring chemical weeding, while achieving higher efficacy and significantly extending the safe window for chemical weed control. This invention targets wheat with at least three leaves. Wheat with at least three leaves exhibits stronger resistance to herbicide damage, a result obtained through years of comparative trials.

[0026] The present invention also provides a method for increasing wheat yield, comprising the following steps: sowing wheat seeds in rice stubble wheat fields, ensuring smooth irrigation and drainage, using the above-mentioned chemical weed control method to control weeds, and harvesting the wheat after it matures.

[0027] This invention allows for the selection of high-yielding, high-quality, and highly resistant wheat seeds. The wheat varieties described in this invention may include: semi-winter wheat varieties; these semi-winter wheat varieties may include one or more of Huaimai 33, Huaimai 55, Jiangmai 186, and Xinong 979. The seeds described in this invention may include: seeds that have passed quarantine inspection and are free from weeds, especially *Hemiberlesia lataniae* seeds.

[0028] This invention may include rice stubble return to the field and land preparation before sowing. Rice stubble return to the field includes the following steps: when the rice is mature and harvested, the rice straw is chopped and evenly spread back into the field. At harvest, the stubble height can be any value within the range of 7-11 cm, for example, 7, 7.8, 8.3, 8.7, 9.4, 10.2, or 11 cm. The length of the chopped straw can be any value within the range of 3-5 cm, for example, 3, 3.5, 4, 4.5, 4.8, 4.9, or 5 cm. Land preparation includes the following steps: after deep plowing to remove stubble, rotary tillage is performed to bury straw, achieving a level surface. The soil depth during plowing is any value within the range of 20-25 cm, for example, 20, 20.5, 21, 21.5, 22, 22.3, 22.5, 23.2, 23.5, 24, 24.5, or 25 cm. The soil depth for rotary tillage and weeding described in this invention is any value within the range of 11-14 cm, for example, 11, 11.4, 12, 12.5, 12.8, 13, 13.7, or 14 cm. Land leveling as described in this invention can be based on the absence of visible or hidden clods on the soil surface. Following this standard for field leveling, the absence of large clods on the soil surface facilitates even spraying of the aforementioned weed-control composition, improving weed control effectiveness and also facilitating mechanized operations.

[0029] The sowing method described in this invention can be carried out at an appropriate time according to the maturity and harvest progress of the previous rice crop, generally from mid-to-late October to mid-November. During sowing, the relative soil moisture content can be any value within the range of 70% to 80%, for example, 70%, 72%, 74%, 76%, 78%, or 80%; the elevation difference of the land can be any value within ≤5cm, and there should be no large clods; high-quality land preparation facilitates increased soil coverage of the weed control composition during spraying. If the land is uneven, large clods will block the pesticide, allowing weeds to easily "hide" under the clods and grow normally, thus failing to achieve the expected weed control effect. This invention allows for the selection of appropriate tillage and sowing methods based on soil moisture (the amount of water content in the crop's topsoil), with mechanical row seeders being the preferred method. During sowing as described in this invention, the sowing depth can be any value within the range of 2-3 cm, for example, 2, 2.3, 2.5, 2.7, or 3 cm; the exposed seed rate can be any value within the range of <5%, for example, 1%, 2%, 3%, or 4%; strictly controlling the proportion of exposed seeds can prevent exposed seeds from germinating and rooting on the soil surface, thus avoiding the risk of herbicide damage. The sowing process also includes covering with soil; the thickness of the soil is any value within the range of 0.5-1 cm, including 0.5, 0.7, 0.9, or 1 cm; the soil includes: fine soil from the original field. This invention improves the quality of tillage and sowing, which is conducive to timely emergence after sowing, reduces the area of ​​rotten soil and seeds, and improves the quality of chemical weed control. The sowing method described in this invention preferably uses high-quality sowing, which refers to sowing according to the requirements of "appropriate timing, appropriate quantity, appropriate soil moisture, appropriate machine, and appropriate depth," achieving the comprehensive goal of "appropriate sowing depth, consistent depth, uniform emergence, and reasonable seedling quantity."

[0030] The present invention ensures smooth irrigation and drainage by utilizing a supporting ditch system; the supporting ditch system may include: three interconnected inner and outer ditches in the field; the inner three ditches include: vertical ditches, horizontal ditches, and waist ditches; the outer three ditches include: water-blocking ditches, agricultural drainage ditches, and drainage sewer ditches. Ensuring smooth irrigation and drainage can prevent drought in the field or waterlogging damage to wheat seedlings. At the same time, if there is a water layer on the ground, it can easily cause herbicide damage. Smooth irrigation and drainage can also avoid herbicide damage caused by the formation of a water layer on the field surface.

[0031] This invention allows for chemical weed control using the aforementioned method during the 10th to 60th day of wheat's overwintering period. Field cultivation practices can further influence the effectiveness of weed control in wheat fields. The wheat is harvested after maturity. This method is primarily applicable to rice-wheat stubble fields in the Huaihe River Basin region; other planting systems and ecological environments with similar conditions can be implemented with reference to this method.

[0032] To further illustrate the present invention, the following detailed description, in conjunction with embodiments, provides a weed-control composition, a weed-control method, and its application, but these descriptions should not be construed as limiting the scope of protection of the present invention.

[0033] Example 1: Screening test of formulation ratio of penoxsulam·cyclopyrflufenoxam composition

[0034] An experiment was conducted in a large rice stubble wheat field in Jiufang Village, Liulaozhuang Town, Huaiyin District.

[0035] 1.1 Tested Resistant Blanched Weed: Before this experiment, on May 24, 2021, researchers collected resistant Blanched Weed samples from a paddy field in Xiqiao Community, Shanyang Street, Huaian District. Specifically, for seven consecutive years, mesosulfuron-methyl was applied to the stems and leaves of this sample field. Conventional doses were ineffective against Blanched Weed. In the autumn of 2020 (November 17), when Blanched Weed was at the 1-2 leaf stage, 25 mL / mu of mesosulfuron-methyl diluted with 30 L / mu of water was applied manually as a single spray. Seeds of mature Blanched Weed that had not died were collected from the wheat field. A total of 1800 weed seeds were collected on May 24, 2021, which constituted the resistant Blanched Weed sample.

[0036] 1.2 Binary Composition Formulation and Ratio Screening Test: Reagent Dosage Settings

[0037] (1) The dosage settings for each single dose are as follows:

[0038] Penflusulfonamide (denoted as A): 0 (denoted as A0), 15g ai / hm 2 (recorded as A15), 30g ai / hm 2 (recorded as A30), 45g ai / hm 2 (Recorded as A45), purchased from Jiangsu Futian Agricultural Chemicals Co., Ltd.;

[0039] Cyclopyralid (denoted as B): 0 (denoted as B0), 37.5 g ai / hm 2 (Recorded as B37.5), 75ga.i. / hm 2 (recorded as B75), 150g ai / hm 2 (Referred to as B150). Cyclopyralid is a novel p-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor herbicide independently developed by Qingdao Qingyuan Compound Co., Ltd., and is a new pesticide variety exclusively registered by Jiangsu Qingyuan Nongguan Weed Control Co., Ltd.

[0040] (2) The formulation ratio and dosage settings of the binary composition are shown in Table 1. For example, A15B0 corresponds to 15g ai / hm of penoxsulam. 2 The mixture of cyclopyridaben 0, A30B37.5 corresponds to penoxsulam 30g ai / hm. 2 And cyclopyridaben 37.5g ai / hm 2 A mixture.

[0041] Table 1. Formulation, proportions, and dosage combinations of binary compositions.

[0042] A0B0 (Control Group) A15B0 A30B0 A45B0 A0B37.5 A15B37.5 A30B37.5 A45B37.5 A0B75 A15B75 A30B75 A45B75 A0B150 A15B150 A30B150 A45B150

[0043] 1.3 Experimental Design

[0044] The previous rice crop was Q Liangyou 1606, transplanted by machine. The rice matured and was harvested on October 20, 2022, with a stubble height of 10.2cm and chopped straw length of approximately 4.9cm. The soil depth reached 22.5cm, and the rotary tillage with straw burying reached 12.8cm, with no visible or hidden clods on the soil surface. Wheat was sown on October 22, the variety being Huaimai 33, using mechanical row sowing. The soil relative moisture content was approximately 74%, and the sowing depth was approximately 2cm. A supporting drainage system was used to ensure smooth irrigation and drainage. This system included three inner ditches (vertical, horizontal, and waist ditches) and three outer ditches (water-blocking ditch, farm drainage ditch, and outfall ditch). Each plot was 2.3m wide, with an area size of 3.5m long × 2.3m wide, and the plots were randomly arranged, totaling 68 plots. Twenty-five collected resistant barnyardgrass seeds were sown in each plot, and covered with approximately 0.7 cm of fine soil from the original field, with a seed exposure rate of 3%. Each sown barnyardgrass seed location was marked with a toothpick (marking the locations facilitates tracking and calculating the control efficacy after spraying the herbicide mixture). When the wheat reached the 4-leaf, 1-heart stage (approximately January 12th, about 22 days after the wheat entered its overwintering period), the resistant barnyardgrass was sprayed at the 2-3 leaf stage using a Shandong Weishi WS-4Y electric sprayer, diluted with 450 kg / hm² of water. 2 The standard application rate was (i.e., the pesticide was diluted with 450 kg of water per hectare before spraying). Sixteen treatments were set up in the experiment (dosage combinations are shown in Table 1), with a control group receiving water. Each treatment was repeated four times in parallel. Forty-five days after application, the tested resistant *Bombyx mori* plants were collected individually, and the aboveground fresh weight of the resistant *Bombyx mori* plants in each plot was measured.

[0045] Calculate the fresh weight inhibition rate (E) and theoretical fresh weight inhibition rate (E0) of weeds among different treatments of single-agent and binary compound herbicides. Use the Gowing method to compare E and E0 values ​​to evaluate the synergistic effect of binary compound herbicides.

[0046] Measured fresh weight inhibition rate (E) = (Fresh weight of control group – Fresh weight of treatment group) ÷ Fresh weight of control group × 100%

[0047] Theoretical fresh weight inhibition rate (E0) = X + Y(100-X) / 100, where E0 is the theoretical fresh weight inhibition rate after the combination of penoxsulam and cyclopyrflufenican, X is the measured fresh weight inhibition rate of penoxsulam alone, and Y is the measured fresh weight inhibition rate of cyclopyrflufenican alone.

[0048] When E–E0 > 10%, it indicates that the two herbicides have a synergistic effect; when E–E0 < -10%, it indicates that the two herbicides have an antagonistic effect; when the value of E–E0 is between -10% and 10%, it is an additive effect.

[0049] 1.4 Test Results

[0050] The theoretical fresh weight inhibition rate (E0) of penoxsulam and cyclopyrfluthrin single-agent treatments was equal to the measured fresh weight inhibition rate (E), indicating no synergistic effect. The synergistic effects of different combinations on *Bletilla striata* are shown in Table 2.

[0051] Table 2. Inhibition rate of fresh weight of resistant *Begonia veitchii* by different formulation ratios (prevention efficacy, %)

[0052]

[0053] By comparing the measured and theoretical inhibition rates of two herbicides under different combinations, the combined effect of the mixed weed-control compositions on resistant *Triticum aestivum* was investigated (Table 2). The results showed that penoxsulam at 15–45 g ai / hm²... 2 With cyclopyridaben at 37.5–150 g ai / hm 2 Different dosage combinations all showed that the measured inhibition rate exceeded the theoretical inhibition rate by more than 10%, demonstrating a synergistic effect. Therefore, the optimal ratio of penoxsulam to cyclopyrfluthrin is (1–3):(2.5–10) by weight.

[0054] The dosage of penoxsulam is 30–45 g ai / hm. 2 The (E–E0) is 15 g ai / hm higher than that of penflusulfonamide. 2 Low dose (E–E0); when penoxsulam dosage is 30 g ai / hm 2 At that time, the dosage of cyclopyridaben was 75–150 g ai / hm. 2 The (E–E0) was higher than that of cyclopyridoxine at a dose of 37.5 g ai / hm. 2 Low dose (E–E0); when penoxsulam dosage is 45 g ai / hm 2 At that time, the dosage of cyclopyridaben was 75–150 g ai / hm. 2 The (E–E0) was higher than that of cyclopyridoxine at a dose of 37.5 g ai / hm. 2 Low dose (E–E0). Therefore, the optimal ratio range of penoxsulam to cyclopyrflufen is: penoxsulam to cyclopyrflufen by weight (1–3):(2.5–5).

[0055] The dosage of penoxsulam is 30–45 g ai / hm. 2 At that time, the concentration of cyclopyridaben was 150 g ai / hm. 2 The combined effect value (E–E0) of the combined formulation was significantly higher than that of cyclopyridazine at 750 g ai / hm. 2 Therefore, the optimal ratio range for penoxsulam and cyclopyrflufen is: penoxsulam to cyclopyrflufen by weight of 1:(3.3-5).

[0056] In addition, the safety of each treatment on wheat seedlings in the field was visually assessed at 30, 45, and 60 days after application of the herbicide mixture. The results showed that all tested herbicide treatments were safe for wheat growth, with no chlorosis, stunting, or other phytotoxic effects observed.

[0057] Example 2: Screening test on the time of effective control of winter chemical weeds in wheat fields by penoxsulam·cyclopyrflufenoxam combination.

[0058] To determine the optimal time for chemical weed control using a combination of penoxsulam and cyclopyrfluthrin in winter, a study was conducted in a rice-wheat stubble field in Dingji Town, Huaiyin District. This field is typically infested with common grasses and broadleaf weeds, primarily resistant barnyard grass, barnyard grass, wild oats, Japanese wild oats, cleavers, chickweed, shepherd's purse, and shepherd's purse. The preceding rice crop was Nanjing 5718, transplanted by machine. The rice matured and was harvested on October 24, 2022, with a stubble height of 8.7 cm and chopped straw length of 4.8 cm at harvest. The soil was tilled to a depth of 23.2 cm, and the depth of straw burial during rotary tillage reached 12.8 cm, with no visible or hidden clods on the soil surface. Wheat, variety Huaimai 33, was sown on October 26th using mechanical row sowing. The relative soil moisture content was approximately 70%, and the sowing depth was approximately 2.3 cm. A supporting drainage system was used to ensure smooth irrigation and drainage. The supporting drainage system consisted of three inner ditches (vertical, horizontal, and waist ditches) and three outer ditches (water-blocking ditch, farm drainage ditch, and drainage sewer). After sowing, a layer of fine original soil of about 1 cm was applied, resulting in a seed exposure rate of 2%.

[0059] Each plot is 4m wide and has an area of ​​6.2m long x 4m wide. The plots are arranged randomly, for a total of 64 plots.

[0060] The experimental design was as follows: three groups of different dosage mixtures were set up, and five treatments were set up according to different application times in the field, for a total of 15 treatments; a control group sprayed with water was also included; each treatment was repeated in four parallel experiments. Shandong Weishi WS-4Y electric sprayers were used for spraying, with the pesticide diluted in water at a rate of 450 kg / hm². 2 Standard application method. 45 days after application, collect and weigh all weeds in each treatment plot.

[0061] The three different dosage mixtures were: penoxsulam 15g ai / hm 2 and cyclopyridaben 60 g a.i. / hm 2 The mixture is denoted as (15+60); penoxsulam 30g ai / hm 2 and cyclopyridaben 90ga.i. / hm 2 The mixture is denoted as (30+90); penoxsulam 45g ai / hm 2 and cyclopyridaben 150 g a.i. / hm 2 The mixture is denoted as (45+150). The five time periods are as follows: after entering the overwintering period, that is, starting from December 20, 2022, when the wheat leaf age is about 3.2, the pesticide is applied once on December 30, 2022 (10 days), January 9, 2023 (20 days), January 19, 2023 (30 days), January 29, 2023 (40 days), and February 8, 2023 (50 days). The above three groups of different dosage mixtures are used for each application.

[0062] The specific experimental design and results are shown in Table 3. For example, the experiment corresponding to the application time of 10 days and the group (15+60) involved applying penoxsulam once on December 30, 2022 (10 days), using 15g ai / hm. 2 and cyclopyridaben 60g ai / hm 2 The mixture; the experiment corresponding to the application time of 10 days and the group (30+90) was carried out on December 30, 2022 (10 days) with a single application of penoxsulam at a rate of 30g ai / hm. 2 and cyclopyridaben 90g ai / hm 2 The mixture; the experiment corresponding to the application time of 10 days and the group (45+150) was carried out on December 30, 2022 (10 days) with a single application of penoxsulam at a rate of 45 g ai / hm. 2 and cyclopyridaben 150 g a.i. / hm 2 The mixture was prepared, and the inhibition rate results obtained from different doses of the mixture over 10 days of application were averaged to obtain the average result on the 10th day of application, in order to compare the overall efficacy of application at different time periods. Similarly, on January 9, 2023 (20 days), January 19 (30 days), January 29 (40 days), or February 8 (50 days), three groups of different doses of the mixture of penoxsulam and cyclopyrfluthrin were applied; at the same time, water was sprayed as a control at the corresponding time period of the mixture application, which was recorded as CK.

[0063] Table 3. Total herbicide application rate and fresh weight inhibition rate (efficacy, %) at different stages of wheat overwintering after rice stubble.

[0064]

[0065]

[0066] Analysis of Table 3 shows that when wheat is at the 3-leaf stage after rice stubble, and the herbicide is applied during the 10-50 day period before overwintering, different dosage combinations of the penoxsulam and cyclopyrfluthrin combination of this invention achieve a fresh weight control efficacy of over 80% for *Triticum aestivum* in wheat fields. The total fresh weight control efficacy exceeds 80% except for the treatment applied 10 days after overwintering. Wheat growth was observed normally after application at irregular intervals. Further comparison of the fresh weight control efficacy and total fresh weight control efficacy for *Triticum aestivum* after application at different times reveals that the control efficacy for wheat after rice stubble with 3 or more leaves is significantly higher 20-40 days after overwintering than the treatments applied at 10 and 50 days. Therefore, the optimal time range for winter chemical control of weeds in rice stubble wheat fields using the penoxsulam / cyclopyrfluthrin combination is 20-40 days after wheat reaches the 3-leaf stage and enters overwintering. Application during this window period yields the best weed control efficacy.

[0067] Example 3: Experiment on the effects of different chemical weed control methods on total weed control efficacy and wheat planting yield

[0068] In 2023, the study was conducted in rice stubble wheat fields belonging to two households, one in Liu Laozhuang Town, Huaiyin District, and the other in Chahe Town, Hongze District. Both rice stubble wheat fields were infested with common grasses and broadleaf weeds year-round. Resistant barnyard grass was the dominant weed in the field, while other weeds included barnyard grass, wild oats, Japanese wild oats, cleavers, chickweed, shepherd's purse, and shepherd's purse.

[0069] The rice crop in the rice-wheat stubble fields of Liu Laozhuang Town was Nanjing 9308, transplanted by machine. The rice matured and was harvested on October 24, 2023, with a stubble height of 10.2 cm and chopped straw length of 4.8 cm. The soil depth reached 21 cm, and the rotary tillage and straw burial depth reached 12.5 cm, with no visible or hidden clods on the soil surface. Wheat was sown on October 27th, the variety being Huaimai 55, using mechanical row sowing. The relative soil moisture content was approximately 78%, and the sowing depth was approximately 2.7 cm. A supporting drainage system was used to ensure smooth irrigation and drainage. This system included three inner ditches (vertical, horizontal, and waist ditches) and three outer ditches (water separation ditch, farm drainage ditch, and drainage canal). After sowing, a layer of fine original soil about 1 cm thick was applied, resulting in a seed exposure rate of 2%.

[0070] The rice variety in the rice-wheat stubble fields of Chahe Town is Nanjing 9108, transplanted by machine. The rice matured and was harvested on October 30th, with a stubble height of 9.4cm and chopped straw length of 4.5cm. The soil depth reached 22.3cm, and the rotary tillage and straw burial depth reached 13.7cm, with no visible or hidden clods on the soil surface. Wheat was sown on November 3rd, the variety being Xinong 979, using mechanical row sowing. The relative soil moisture content was approximately 76%, and the sowing depth was approximately 2.7cm. A supporting drainage system was used to ensure smooth irrigation and drainage. The supporting drainage system consisted of three inner ditches (vertical, horizontal, and waist ditches) and three outer ditches (water separation ditch, agricultural drainage ditch, and drainage weir). After sowing, a layer of fine original soil of about 1cm was used as a cover, with an exposed seed rate of 2%.

[0071] The weed control experiment was designed as follows, with four treatments, each using a different weed control composition at different time points, denoted as T1, T2, T3, and T4. T1 was a soil-applied pre-emergence treatment, applied after wheat sowing at a rate of 112.5 g a.i. / hm² for pyrifluquinazon. 2 and isoproturon 1125g ai / hm 2 The mixture was used for foliar spraying, with the sealing time for rice stubble wheat fields in Liulaozhuang Town being October 28th, and the sealing time for rice stubble wheat fields in Chahe Town being November 5th. T2 was an autumn foliar spray, applied at the 2-leaf-1-heart stage of wheat, using 9g mesosulfuron-methyl ai / hm². 2 and isoproturon 1125g ai / hm 2 The mixture was used for foliar weeding in Liulaozhuang Town on November 15th and in Chahe Town on November 22nd. T3 was a winter foliar treatment, applied after the start of winter, after the wheat reached the 3-leaf stage, using 45g penoxsulam at ai / hm. 2 and cyclopyridaben 150g ai / hm 2 The mixture was applied in Liulaozhuang Town on January 8th and in Chahe Town on January 5th. T4 is a spring foliar treatment, applied after the beginning of spring during the wheat tillering stage, using 15g mesosulfuron-methyl at ai / hm². 2 and isoproturon 1500g ai / hm 2 The mixture was applied in Liu Laozhuang Town on February 23 and in Chahe Town on February 19. See Table 4 for specific treatments.

[0072] Each processed cell has an area of ​​3335m². 2 Additionally, a small area (10m²) is set up. 2 The control group (CK) sprayed with water on the application date was randomly arranged without replication. Large-area plots were sprayed using agricultural drones, while the control group was sprayed using a Shandong Weishi WS-4Y electric sprayer, diluted with 450 kg / hm² of water. 2Standard application of pesticides. Thirty days after application, all weeds in each treatment plot were collected and weighed. The control efficacy of different chemical weed control methods is shown in Table 5. Wheat field performance was observed periodically. At the milk stage, 100 individual ears were continuously sampled, and the number of grains per ear was counted. Maturity was defined as 1 meter from the point where the number of tillers was measured. 2 After manual harvesting, the grains were threshed and naturally air-dried. The moisture content and weight of the grains were measured and converted to the yield at 13% moisture content. Samples were taken from the threshed grains, and three groups of 1000 grains each were counted to determine their weight and moisture content, which were then converted to the thousand-grain weight at 13% moisture content. The overall yield was compared, and the results are shown in Tables 6 and 7.

[0073] Table 4 Experimental Design of Different Chemical Weed Control Methods in Rice-Wheat Stubble Fields and Minimum Temperature 7 Days After Application

[0074]

[0075] Table 5. Weed fresh weight inhibition rate (control efficacy, %) of different chemical control methods in rice stubble wheat.

[0076]

[0077]

[0078] Table 6. Yield and constituent factors of wheat stubble after rice harvest with different weeding methods.

[0079]

[0080] Table 7 Comparison of the comprehensive benefits of different chemical weeding methods in rice stubble wheat fields.

[0081]

[0082] Note: Economic benefits are calculated using the following formula: Total cost (yuan / hm²) 2 = Herbicide cost + Other costs; Output value (yuan / hm²) 2 = Actual grain yield × Wheat price per unit area; Net profit (yuan / hm²) 2 = Output value - Herbicide cost - Other costs. The wheat price is calculated at 2.36 yuan / kg. Other costs include land rent, machinery, seeds, fertilizer, labor, etc. The land rent for large-scale farmers in Liu Laozhuang, Huaiyin District is lower than that for large-scale farmers in Chahe Town, Hongze District.

[0083] A comprehensive analysis of Tables 5-7 shows that among the four chemical weed control methods, T3, which uses a combination of penoxsulam and cyclopyrfluthrin and is applied in winter, achieved the highest weed suppression rate (control efficacy), with both *Trichoderma repens* and total fresh weight suppression rates (control efficacy) exceeding 90%. T3's weed control efficacy was significantly higher than other methods, contributing to higher wheat yields. Wheat spike number, grain number, and thousand-grain weight were also higher with T3, resulting in a final yield increase of 3.35%–7.30% compared to other methods (T1, T2, T4). Its net profit was 467.08–1125.64 yuan / hm² higher than other methods. 2 .

[0084] Therefore, the weed control composition of the present invention is highly efficient and safe. At the same time, selecting the time for efficient weed control not only extends the safe weed control window period, but also improves the safety factor of pesticide application, thereby achieving high and stable yields of wheat after rice and increasing planting income.

[0085] Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, and not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A weed-control composition, characterized in that, The active ingredients of the composition include penoxsulam and cyclopyrfluthrin.

2. The composition according to claim 1, characterized in that, The weight ratio of penoxsulam to cyclopyrfluthrin is 1–3:2.5–10.

3. The composition according to claim 2, characterized in that, The effective ingredient dosage of penoxsulam is 15–45 g ai / hm. 2 The effective ingredient dosage of the cyclopyridoxine is 37.5–150 g ai / hm. 2 .

4. The composition according to claim 1, characterized in that, The weeds include: grass weeds and / or broadleaf weeds; the grass weeds include one or more of the following: barnyard grass, wild oat, and Japanese wild oat; the broadleaf weeds include one or more of the following: cleavers, chickweed, cowherb, shepherd's purse, and shepherd's purse.

5. The use of the weed-control composition according to any one of claims 1 to 4 in crop cultivation.

6. A method for chemical weed control in wheat fields, characterized in that, Includes the following steps: Weed control is carried out using the composition according to any one of claims 1 to 4 during the 10th to 60th day of the wheat's overwintering period.

7. The method for chemical removal according to claim 6, characterized in that, The weed control is applied to wheat with 3 or more leaves.

8. A method for increasing wheat yield, characterized in that, Includes the following steps: Wheat seeds are sown in rice stubble fields, ensuring smooth irrigation and drainage. Weeds are controlled using the chemical weeding method described in claim 6 or 7. The wheat is then harvested after it matures.

9. The method according to claim 8, characterized in that, The wheat varieties include: semi-winter wheat varieties; the semi-winter wheat varieties include one or more of Huaimai 33, Huaimai 55, Jiangmai 186 and Xinong 979.

10. The method according to claim 8, characterized in that, When sowing, the relative soil moisture content should be 70%–80%, the elevation difference of the land should be ≤5cm, the sowing depth should be 2–3cm, and the exposed seed rate should be <5%.

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