• Korean Journal of Weed Science
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• v.18 no.2
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• pp.154-160
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• 1998

This study was conducted to develop a foliar applied herbicide mixture covering wide spectrum weeds in dry direct seeded rice. Uniform precision central composite design(UPCCD) was employed to evaluate the effect of herbicide mixture among cyhalofop-butyl(cyhalofop), bispyribenzoxim and pyrazosulfuron-ethyl(pyrazosulfuron) having different weed control spectrum and to determine the best application rates of the three herbicide mixtures. The partial additive effect was observed in the mixture of cyhalofop and bispyribenzoxim with pyrazosulfron against Echinochloa crus-galli Beauv var crus-galli L., attributed to the negative interaction between cyhalofop and bispyribenzoxim system. Additive effect was observed in the mixture of bispyribenzoxim and pyrazosulfuron against Cyperus serotinus R. and Aneilema keisak H. but cyhalofop had no effect on these weeds. The most appropriate rate of the mixture of cyhalofop with bispyribenzoxim and pyrazosulfuron was 100 : 12 : 10g ai/ha exhibiting $ED_{90}$ against three weeds such as E. crus-galli, C. serotinus and A. keisak.

• Journal of The Korean Society of Grassland and Forage Science
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• v.37 no.2
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• pp.108-115
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• 2017

The aim of this study was to evaluate different herbicides in corn-soybean intercropping for optimum growth, yield and nutritive value of forage under Korean environment conditions. Herbicidal treatments were randomly applied over five plots, viz. (1) Control treatment: no herbicide; (2) Alachlor; (3) Simazine; (4) Pendimethalin and (5) Mixture of alachlor and simazine herbicides in RCBD have three replications. Results depicted that treated herbicides exhibited significant effect over control of weeds. Simazine herbicide alone or mixed with alachlor had adverse effects on soybean but enhanced (p<0.05) corn production in terms of survivability, dry matter and digestible nutrients yield. Corn-soybean coupling and total dry matter yield were greater (p<0.05) in pendimethalin. Simazine-alachlor mixture reduced (p<0.05) soybean height. Conclusively, simazine could not be suitable for corn soybean intercropping because of having an adverse effect on soybean component. Pendimethalin could maintain growth and yield of corn and soybean both components. Effect of alachlor was comparable to that of pendimethalin.

• Weed & Turfgrass Science
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• v.3 no.2
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• pp.110-113
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• 2014

The continuous use of acetolactate synthase (ALS) and acetyl-CoA carboxylase (ACCase) inhibitors has led to the selection of herbicide resistant barnyardgrass populations in direct-seeded rice fields of Korea. This study was conducted to identify herbicide resistant barnyardgrass biotypes and to determine the cross- and multiple-resistance of them. 25% of the population collected from Taeahn was partially resistant to ACCase inhibitors and 22% collected from Kimjae were partially resistant to ALS inhibitors. However, 8.2% of the population from both sites was resistant to ALS and ACCase inhibitors. Resistance to sulfonylurea herbicide, flazasulfuron was identified from two barnyardgrass accessions collected from both Taeahn and Kimjae. One barnyardgrass accession from both sites was resistant to ACCase inhibitor, sethoxydim. The cross-resistance to ALS inhibitors was identified at one barnyardgrass accession from Taeahn and at two accessions from Kimjae. Further, crossresistance to ACCase inhibitors was also identified at barnyardgrass accessions from Taeahn and Kimjae. Multiple-resistance to flazasulfuron and sethoxydim was determined at four barnyardgrass accessions from Taeahn and at six accessions from Kimjae. Therefore, the herbicide mixture and sequences within a growing season or the herbicide rotation with different modes of actions across growing seasons are recommended to control herbicide-resistant barnyardgrass in infested fields.

• Korean Journal of Weed Science
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• v.18 no.3
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• pp.197-204
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• 1998

This study was conducted to determine the activity of ALS, content of endogenous free amino acids and fatty acids affected by herbicide mixture of cyhalofop-butyl, pyribenzoxim and pyrazosulfuron-ethyl. $I_{50}$ values (concentration required for 50% inhibition of ALS activity) of pyribenzoxim herbicide on the activity of ALS in Echinochloa crus-galli and Cyperus serotinus in vitro were recorded at 4${\times}$100 nM and 5${\times}$10 nM, respectively, while $I_{50}$ values of pyrazosulfuron against E crus-galli and C. serotinus were 4.5${\times}$10 nM and 4${\times}$10 nM, respectively, and the mixture of two herbicides showed additive effect on ALS activity at the low application rate, and independent effect at the high application rates of two herbicides. The inhibition rates of the three herbicides mixture treatment on the three branch-chain amino acids such as valine, leucine and isoleucine were 74.6%, 66.6% and 57.9% in C. serotinus and 36.6% 51.1% and 48.1% in E. crus-galli, respectively. A little bit higher inhibitory effect on the three branch-chain amino acids in C. serotinus and E. crus-galli seedlings was observed in two herbicide mixture of pyribenzoxim with pyrazosulfuron than three herbicide mixture of cyhalofop with pyribenzoxim and pyrazosulfuron. The interaction among three herbicides showed non-antagonism on the amounts of endogenous free amino acids.

• Korean Journal of Weed Science
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• v.2 no.2
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• pp.146-151
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• 1982

Herbicide mixtures, butachlor + naproanilide, CG113 + naproanilide and benthiocarb + naproanilide were tested in order to control Sagittaria pygmaea Miq., one of the most serious perennial weeds in paddy field of Honam area. 92% of tuber of Sagittaria pygmaea Miq. was distributed within 9cm from the soil surface and number of emerged Sagittaria pygmaea Miq. increased until 40 days after rice transplanting but decreased thereafter. Number and dry weight of survived Sagittaria pygmaea Miq. were much less in butachlor + naproanilide, CG 113 + naproanilide and benthiocarb + naproanilide treatments than perfluidone and it was controlled by up to 95% by mixture treatments. Number of rhizome of Sagittaria pygmaea Miq. was decreased by all herbicide treatments and especially mixture treatment significantly reduced rhizome formation compared to perfluidone and 2.4 -D treatments. CG113 + naproanilide treatment caused phytotoxicity that tip of leaf sticked to leaf sheath curvedly in Indica ${\times}$ Japonica rice, Iri 358, but it was recovered within 10 days after herbicide treatment.

• Korean Journal of Weed Science
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• v.2 no.1
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• pp.20-30
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• 1982

A field experiment was conducted in 1981 at the Crop Experiment Station, Suweon, Korea, in machine transplanted paddy rice field, to study the effectiveness of single herbicide, mixture, and systematic application of herbicides on diversity of weed control spectrum. The rice variety planted was Taebaegbyeo, Indica ${\times}$ Japonica cross bred. Experimental field was dominated by Echinochtoa crusgalli, Eleocharis kuroguwai, and Scirpus hotarui, and importance values based on dry weight of these weeds were 89%, 5%, and 3%, respectively. The mixture or systematic treatments of herbicide were generally more effective than single herbicide applications on weed control. Coefficients of similarity based on floristic composition after herbicide application between Perfluidone (5G) and Chloromethoxynil (7G), and between Pertluidone (5G) and Bifenox (7G), and between Perfluidone (5G) and three types of Butachlor (6G) were low, and these sets seemed to be a good mixture herbicide in paddy fields. While, Perfluidone (5G) had low coefficient of similarity with other single herbicides tested. The information on coefficient of similarity could be used as parameter for selecting herbicides to increase the efficiency of herbicidal performance. Simpson's indices from Butachlor (3.5G)/SL-49 (7G), Butachlor (3.5G)/Pyrazolate (6G), and Perfluidone (5G) treatments were high, and these herbicide treatments tended to the weed community type simplified, while the indices from Perfluidone (5G) + Chloromethoxynil (7G), Butachlor (6G) fb Perftuidone (5G), and Butachlor (4G)/Naproanilide (6G) treatments were low, and these herbicide treatments caused to the community type diversified in terms of floristic composition.

• Korean Journal of Weed Science
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• v.6 no.1
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• pp.85-96
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• 1986

From the two differently located orchards (even-site with adult tree and slope-site with young tree), weed emergence and the effect of various orchard herbicides on them were comparatively experimented. Weed emergence was assessed in emergence frequency, biomass, relative frequency, and herbicide responses were checked with the variarions in the above weed emergence characters and the weeding values. Herbicides applied were paraquat, glyphosate, oxyfluorfen, napropamide and ustinex using the recommended rates, respectively. Weeds emerged were 7 life-forms, 23 families and 45 species. Among other families, weeds Umbelliferae, Commelinaceae, Gramineae and Polygonaceae couldn't classified in any similarly correlated cluster. However, according to "1-Q mode cluster analysis" of each herbicide performances, "paraquat or glyphosate" with "napropamide or oxyfluorfen" were selected as the most unrelated herbicide pairs expecting the best combination value in mixture model, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.4
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• pp.286-291
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• 2003

Monochoria vaginalis is one of the most troublesome resistant weeds in Korean rice culture. Thus, the objectives of this study were to evaluate the response of M. vaginalis resistant to sulfonylurea(SU) herbicides and to determine alternative herbicides for the control of resistant M. vaginalis in direct seeded and transplanted rice culture in Korea. In greenhouse studies, the resistant biotype was 31-, 38-, 3172-, and 7-fold more resistant to ben-sulfuron-methyl, cyclosulfamuron, imazosulfuron, and pyrazosulfuron-ethyl, respectively, than the susceptible biotype, indicating cross-resistance to the SU herbicides used in this study. Non-SU herbicides, butachlor, carfentrazone-ethyl, mefenacet, pretilachlor, pyrazolate, and thiobencarb, several SU herbicide-based mixtures, ethoxysulfuron plus fentrazamide, pyrazosulfuron-ethyl plus pyrazolate plus simetryn, and non-SU herbicide-based mixtures, pyrazolate plus butachlor, pyrazolate plus pretilachlor, simetryn plus molinate, carfentrazone-ethyl plus butachlor, and carfentrazone-ethyl plus thiobencarb can be used to control both the resistant and susceptible biotypes of M. vaginalis when applied before the second leaf stage. In the field experiment, the resistant biotype of M. vaginalis that survived from the paddy fields treated with a SU herbicide-based mixture could effectively be controlled by using mixtures of bentazone plus MCPA, bentazone plus mecoprop-P, and bentazone plus 2,4-D when applied at 2 or 4 main leaves. Our results suggest that the SU-resistant M. vaginalis had not developed multiple resistances to herbicides with different modes of action. In particular, bentazone plus MCPA and bentazone plus mecoprop-P were effective control measures after failure to control resistant M. vaginalis in Korean rice culture.

• Korean Journal of Weed Science
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• v.6 no.1
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• pp.76-84
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• 1986

All combinations of oxyfluorfen in 5 dosages and glyphosate in 4 dosages were used to assess the onto-drifting pattern of herbicide inactivation in three different type, such as check soil ($O^-M^-$), organic soil ($O^+M^-$), and micro-organism soil ($O^+M^+$). The plant used for bioassay was rape-hybrid. From the results, it was recognized that the herbicide inactivation is strongly achieved in order of $O^+M^+$ > $O^+M^-$ > $O^-M^-$ soil. Also, the inactivation of oxyfluorfen in soil tended to depend rather on soil microorganisms than organic matter, and to be promoted earlier by paraquat mixture than by that of glyphosate. Average 50 and 95% inactivated time (in days) of herbicides were getting shorten in order of $O^+M^+$, $O^+M^-$, $O^-M^-$, rather prolonged in mixture than in oxyfluorfen single treatment, and rather prolonged in high dose than in low dose, respectively.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1688-1689
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• 2011

A simple and rapid capillary electrophoresis method was developed for the quantitative analysis of common triazine herbicides. Cyclic voltammetry was employed to clarify the detection voltage which showed characteristic irreversible cathodic peaks. For the analysis, the mixture of triazine herbicides was applied in a microfluidic chip to determine the CE-separated peaks. Soil sample extracts were analyzed directly after drying and redissolution with the supporting electrolyte but without other pretreatment. The results were comparable to those obtained by HPLC with UV detection. Therefore, this method can be used in the rapid determination of pesticide/herbicide residues.