Use of a herbicide containing fluazifop-butyl and a safener for controlling weeds in rice fields

Abstract

The application discloses application of a herbicide containing fluazifop-butyl and a safener in preventing and treating weeds in rice fields, wherein the herbicide takes fluazifop-butyl and the safener as effective components, and the mass ratio of the fluazifop-butyl and the safener is 1:0.25-1:100. The herbicide has not been used in the rice field, and thus there is no drug resistance to the main weeds, such as barnyard grass and leafflower, in the rice field. In addition, the herbicide has high activity, and the minimum 10 ghm ‑2 The fluazifop-butyl can prevent weeds, and it can be inferred that there is no cross-resistance between the fluazifop-butyl and other ACC herbicides commonly used in the rice field.

Description

Technical Field

[0001] This invention relates to the application of a herbicide in controlling weeds in paddy fields, and more particularly to the application of a herbicide containing clodinafop-propargyl and a safener in controlling weeds in paddy fields. Background Technology

[0002] Based on morphological differences, paddy field weeds can be divided into monocotyledonous and dicotyledonous weeds. Grasses and sedges are monocotyledonous weeds, while broadleaf weeds generally refer to dicotyledonous weeds. Among grasses, the main weeds are barnyard grass and Echinochloa crus-galli. Weed growth competes with rice for nutrients and growing space, leading to a decrease in yield and quality. Studies by Song Ying et al. have shown that a barnyard grass density of 3 plants / m² is optimal. 2 At densities of 21 plants / m², rice yields significantly decreased. Studies by Wu Shang et al. showed that when the density of *Arenaria lobata* in paddy fields was 21 plants / m², the yield decreased significantly. 2 At times, this can cause a reduction in the yield of early, mid, and late rice by 39.22%, 44.36%, and 37.8%, respectively.

[0003] Currently, chemical control is the most convenient and effective method for controlling weeds in rice paddies. Herbicides can be classified into pre-emergent herbicides and foliar herbicides based on the timing of application. They can also be classified according to the target weeds: grass herbicides, broadleaf herbicides, and herbicides that control both grass and broadleaf weeds. Furthermore, they can be classified according to their mechanism of action: acetyl-CoA carboxylase (ACCase) inhibitors (such as cyhalofop-butyl and oxadiazon), acetyllactic acid synthase (ALS) inhibitors (such as penflusulfonate and bispyribac-sodium), and p-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors (such as mesotrione and cyclosulfonamide), as well as hormone-based herbicides (such as quinclorac).

[0004] Currently, the soil-applied herbicides widely used in paddy fields mainly include single-agent and compound formulations of herbicides such as pretilachlor, butachlor, acetochlor, bensulfuron-methyl, oxadiazon, propyzoxystrobin, sedge, pyrimisulfuron, bensulfuron-methyl, pendimethalin, and quizalofop-p-ethyl. Commonly used foliar herbicides include single-agent and compound formulations of herbicides such as quinclorac, cyhalofop-butyl, penflusulfuron-methyl, pyrimisulfuron-methyl, bispyribac-sodium, oxadiazon, propargite, bentazon, 2,4-D sodium, clopyralid, and isoxaflutole. Among these, quinclorac, cyhalofop-butyl, penflusulfuron-methyl, pyrimisulfuron-methyl, bispyribac-sodium, oxadiazon, and propargite are used to control barnyardgrass and other grassy weeds such as Echinochloa crus-galli.

[0005] With the long-term use of herbicides in rice paddies, barnyard grass and Echinochloa crus-galli have developed increasingly serious resistance to mainstream pesticides. Studies by Ma Guolan et al. found that barnyard grass populations monitored in 70 rice-growing areas across my country (Hubei, Anhui, Ningxia, Heilongjiang, Hunan, Jiangxi, and Jiangsu) all exhibited varying degrees of resistance to penflusulfuron-methyl, with 50.0% showing high-level resistance, 47.1% showing medium-level resistance, 2.9% showing low-level resistance, and no susceptible populations. In Ningxia, barnyard grass samples showed overall medium-to-high resistance to cyhalofop-butyl. Penflusulfuron-methyl and bispyribac-sodium have developed severe resistance in the Dongting Lake rice-growing area. Resistance to quinclorac in barnyard grass is now widespread in various rice-growing regions of my country. Zuo Pingchun et al. determined the sensitivity of weeds to oxaziclomefone by measuring the activity of ACCase in different barnyard grass populations collected from Liaoning, Heilongjiang, Hunan and Jiangxi provinces. The results showed that some populations had reduced sensitivity to oxaziclomefone, with relative resistance multiples of 33.8, 30.1 and 14.9, respectively, indicating that these three barnyard grass populations had developed resistance to oxaziclomefone.

[0006] Currently, there are not many herbicides that can effectively control *Echinochloa crus-galli*, mainly aryloxyphenoxypropionate (APP) herbicides, such as quizalofop-p-ethyl, cyhalofop-butyl, and oxadiazon. Cyhalofop-butyl and oxadiazon are widely used in rice paddies in China. Existing research indicates that accase inhibitor-resistant *Echinochloa crus-galli* has become quite serious in some areas of Shanghai. In 2017, it was reported that *Echinochloa crus-galli* populations collected from the middle and lower reaches of the Yangtze River had developed strong resistance to cyhalofop-butyl, with a relative resistance multiple of 75.8. In addition, cyhalofop-butyl-resistant *Echinochloa crus-galli* populations were also found in Hunan Province, with the highest relative resistance multiple reaching 11.0.

[0007] This demonstrates the severity of herbicide resistance in barnyard grass and Echinochloa crus-galli, and the urgent market demand for highly effective herbicides.

[0008] The emergence of herbicide-resistant weeds in paddy fields, especially cross-resistant and multi-resistant weeds, has brought new challenges to weed control. Currently, the management of herbicide-resistant weeds in paddy fields is still in its early stages. It mainly relies on switching to other herbicides and manual weeding. At present, there are not many herbicides available for replacement, and clodinafop-propargyl is becoming one of the options.

[0009] Regarding the dosage of active ingredients in existing herbicides, the registered dosage of 20% cyhalofop-butyl for direct-seeded rice fields is 25-35 ml / mu, which corresponds to 75-105 g / m of active ingredient. -2 Anhui Shalongda has registered a dosage of 300-400 ml / mu for 45% propargite in direct-seeded rice fields, which corresponds to an effective ingredient content of 2025-2700 g / m. -2Zhejiang Tianfeng has registered a dosage of 60-100 ml / mu for 25% quinclorac acid in direct-seeded rice fields, which corresponds to an effective ingredient content of 225-375 gHM. -2 The registered dosage of 10% oxazolidinone in the United States for direct-seeded rice fields is 70-80 ml / mu, which is equivalent to 105-120 g / m². -2 The registered dosage of 100g / L bispyribac-sodium for direct-seeded rice fields is 15-25 ml / mu, which corresponds to an active ingredient concentration of 22.5-37.5g / mu. -2 Corteva's registered dosage of 25g / L penoxsulam for use in rice paddies is 40-80 ml / mu, which corresponds to 15-30g g / L of the active ingredient. -2 The dosage of 10% pyrimimethoxam registered by Anhui Lantian Agriculture for direct-seeded rice fields is 20-30 ml / mu, which corresponds to 30-45 g / m of active ingredient. -2 . Summary of the Invention

[0010] Purpose of the invention: The present invention aims to provide an application of a highly active herbicide containing clodinafop-propargyl and a safener, which does not exhibit resistance, in the control of weeds in paddy fields.

[0011] Technical solution: The application of the herbicide containing clodinafop-propargyl and a safener in the control of weeds in paddy fields according to the present invention, wherein the herbicide uses clodinafop-propargyl and a safener as active ingredients, and the mass ratio of clodinafop-propargyl to the safener is 1:0.25 to 1:100.

[0012] Preferably, the mass ratio of the acetamiprid to the safener is 1:0.25-3.

[0013] Preferably, the minimum dosage of the clodinafop-propargyl for controlling weeds in paddy fields is 10 g / m³. -2 .

[0014] Preferably, the weeds are weeds with two or more leaves.

[0015] More preferably, the weeds are 2-4 leaf weeds.

[0016] More preferably, the weeds are barnyard grass and Echinochloa crus-galli.

[0017] Beneficial effects: Compared with the prior art, the present invention has the following significant advantages: (1) The herbicide has no resistance because clodinafop-propargyl has never been used in rice. The present invention is the first to apply clodinafop-propargyl to rice, so there is no resistance; (2) The herbicide has high activity and no cross-resistance. High activity is manifested in low dosage, with a minimum of 10 g / m³. -2Clothiamethoxam can control weeds, which suggests that it exhibits cross-resistance with other ACC herbicides. If clothiamethoxam is resistant to other ACC herbicides, then the application rate of clothiamethoxam in rice will be relatively high. Detailed Implementation

[0018] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0019] Clothiamethoxam, chemically known as 2-propynyl-(R)-2-[4-(5-chloro-3-fluoro-2-pyridinoxy)phenoxy]propionate, belongs to the aryloxyphenoxypropionic acid class of herbicides and is an inhibitor of acetyl-CoA carboxylase (ACCase) synthesis.

[0020] Quizalofop-P-ethyl, also known as quizalofop-P-ethyl, is 1-methylhexyl(5-chloro-8-quinolinoxy)acetic acid ester. Quizalofop-P-ethyl can be used to improve plant acceptance of the herbicide quizalofop-P-ethyl, accelerate the detoxification of quizalofop-P-ethyl in grains, and can be used as a safener.

[0021] The herbicide is implemented as follows in controlling weeds in paddy fields:

[0022] The first phase aims to determine whether clodinafop-propargyl exhibits selectivity in rice and barnyardgrass.

[0023] The experiment began with a high dosage of clodinafop-propargyl, and the dosage was continuously adjusted downwards based on the feedback from each trial. This phase of the experiment ultimately revealed that clodinafop-propargyl exhibits selectivity for rice and barnyardgrass at certain dosages.

[0024] The second phase investigated the safety of clodinafop-propargyl mixed with different amounts of a safener (detoxifying quinal), as well as its effectiveness in controlling barnyardgrass. The experiment designed to study the effects of different dosages and ratios of clodinafop-propargyl and the safener on weed control in paddy fields, as Examples 1-7.

[0025] The third stage involves repeated verification in multiple locations, which is also a verification of cross-resistance.

[0026] Example 1

[0027] In the herbicide, the ratio of clodinafop-propargyl to safener is 1:0.25, and the application rate of clodinafop-propargyl is 15g per hectare.

[0028] Example 2

[0029] In the herbicide, the ratio of clodinafop-propargyl to safener is 1:0.5, and the application rate of clodinafop-propargyl is 15g per hectare.

[0030] Example 3

[0031] In the herbicide, the ratio of clodinafop-propargyl to safener is 1:1, and the application rate of clodinafop-propargyl is 15g per hectare.

[0032] Example 4

[0033] In the herbicide, the ratio of clodinafop-propargyl to safener is 1:2, and the application rate of clodinafop-propargyl is 15g per hectare.

[0034] Example 5

[0035] In the herbicide, the ratio of clodinafop-propargyl to safener is 1:3, and the application rate of clodinafop-propargyl is 15g per hectare.

[0036] Example 6

[0037] In the herbicide, the ratio of clodinafop-propargyl to safener is 1:1, and the application rate of clodinafop-propargyl is 10g per hectare.

[0038] Example 7

[0039] In the herbicide, the ratio of clodinafop-propargyl to safener is 1:1, and the application rate of clodinafop-propargyl is 30g per hectare.

[0040] When the dosage of clodinafop-propargyl is 15gghm -2 At two ratios of 1:0.25 and 1:0.5 (Examples 1 and 2), rice still suffered from herbicide damage. When the ratio of herbicide to safener was 1:1, 1:2, and 1:3 (Examples 3-5), the mortality rate of 2-4 leaf barnyardgrass and Echinochloa crus-galli was over 95%, and there was no significant difference in weed control efficacy and safety among different ratios. This also indicates that the safener did not significantly reduce the efficacy of the herbicide. In addition, the effect of the ratio of clodinafop-propargyl to safener on rice yield was also observed at the rice harvest period at 1:1, 1:2, and 1:3. The results showed that rice yield was not affected, which is the same result as the fact that clodinafop-propargyl has no effect on wheat yield. The reasons may be twofold: First, due to the action of the safener, the rice's vegetative organs were not damaged, and all functions were normal. Second, the herbicide was applied early, and there was still a considerable amount of time before harvest, so the residual clodinafop-propargyl had already been metabolized in the rice plant. Therefore, it can be concluded that 15 g / ha of clodinafop-propargyl plus 15 g / ha of safener can effectively control 2-4 leaf weeds in paddy fields.

[0041] Based on the conclusions of the second phase of the trial, repeated trials were conducted in multiple locations. The results showed that 15g / ha of clodinafop-propargyl plus 15g / ha of safener can effectively control 2-4 leaf weeds in paddy fields, thus proving that clodinafop-propargyl does not exhibit cross-resistance with other ACC class herbicides.

[0042] When 10 g / ha of clodinafop-propargyl + 10 g / ha of safener was applied (Example 6), it was only effective against barnyardgrass and Echinochloa crus-galli with less than 2 leaves, with a mortality rate of about 30%.

[0043] Meanwhile, for barnyardgrass and Echinochloa crus-galli with more than 4 leaves, when the ratio of clodinafop-propargyl to safener is 1:1, the dosage of clodinafop-propargyl is 15 g / m³. -2 At that time (Example 3), the weed mortality rate was approximately 70%. When the amount of clodinafop-propargyl reached 30 g / m³... -2 The mortality rate reached over 95% in Example 7.

Claims

1. The application of a herbicide containing clodinafop-propargyl and a safener in controlling weeds in paddy fields, characterized in that, The herbicide uses clodinafop-propargyl and a safener as active ingredients, with a mass ratio of clodinafop-propargyl to safener of 1:1, 1:2, or 1:

3. The application rate of clodinafop-propargyl is 15g per hectare. The weeds are barnyard grass and Echinochloa crus-galli. The safener is quinoline.

2. The application according to claim 1, characterized in that, The weeds are those with two or more leaves.

3. The application according to claim 1, characterized in that, The weeds are 2-4 leaf weeds.