• Korean Journal of Environmental Agriculture
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• v.5 no.2
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• pp.130-134
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• 1986

This study was performed to determine the aquatic toxicity of 3 chemicals(butachlor, trichlorfon, and BPMC) to 3 teat organisms (fish, crustacean, and algae) which represent each trophic level in freshwater ecosystem, and to compare the sensitivity of these organisms to 3 chemicals with short-term test. Scenedesmus subspicatus, unicellular algae, was the most sensitive species of 3 organisms to butachlor and the ratio between least and most sensitive organisms was 5.7. Moina rectirostris, freshwater invertebrate, was also more sensitive organism than S. subspicatus and Oryzias latipes to trichlorfon and BPMC, and their ratios were 260,000 and 5,090. As a result, remarkable differences were observed in the sensitivities among the test organisms with different chemical structure and mode of action of the chemicals. Therefore, it is recommended that a set of tests on different species, including the representative species of fish, invertebrate, and algae, should be required in short-term aquatic toxicity test for chemicals introduced into the Korean environment.

• Korean Journal of Weed Science
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• v.4 no.2
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• pp.188-193
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• 1984

Interactions of herbicide mixtures were assessed for effective control of annual and perennial paddy weeds by isobole method(90% control) using Echinochloa crusgalli Beauv. var. oryzicola Ohwi, Scirpus hotarui Ohwi, Sagittaria pygrnaea Miquel, and Cyperus serotinus Rottb which are dominated in the paddy field of Korea. Mixture of butachlor and pyrazolate showed additive effect for control of E. crusgalli Beauv. var. oryzicola Ohwi, S. hotarui Ohwi and C. serotinus Rottb, but synergistic effect for control of S. pygmaea Miquel. Interaction of bifenox and bromobutamide showed synergistic effect to E. crusgalli Beauv. var oryzicola Ohwi and C. Serotinus Rottb, but slightly antagonistic effect to S. pygmaeo Miquel.

• Korean Journal of Weed Science
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• v.6 no.2
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• pp.154-161
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• 1986

Since herbicide damage has been occurred in subirrigated rice seedbed in Korea, the use of crop safener is required to reduce crop injury. Field studies were conducted to evaluate safening effect of 1,8-naphthalic anhydride (NA) and CGA 123'407 (4, 6-dichloro-2-phenyl-pyrimidine) against four kinds of paddy herbicides applied to subirrigated vinyl-covered rice seedbed. NA as a seed dressing at 0.5% (W/W) was effective in reducing rice injury from butachlor, pretilachlor, chlormethoxynil and benthiocarb, and increased number of seedling established, plant height, and dry weight of rice seedlings, while growth inhibition and stand loss were observed at 1% NA. Pretilachlor slightly decreased number of seedlings established and inhibited growth of rice seedlings. But pre-mix combination of pretilachlor (2%) and CGA 123'407 (0.5%) reduced rice injury caused by pretilachlor alone and increased number of seedlings established and dry weight of rice seedlings. The results indicate that NA and CGA 123'407 would permit the safe application of butachlor, pretilachlor, chlormethoxynil, and benthiocarb in subirrigated rice seedbed.

• Korean journal of applied entomology
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• v.16 no.3 s.32
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• pp.149-154
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• 1977

Effect of Simazine(2-chloro-4,6-bis (ethylamino)-s-triazine), Nitrofen (2, 4-dichloro-4' -nitrodi­phenylether), Propanil (:3, 4-dichloropropionanilide), and Butachlor (2-chloro-2, 6-diethyl N-(buthoxy­menthyl) acetanilide on urea hydrolysis and subsequent nitrification was investigated in an upland soil incubated at $20\pm1^{\circ}C$. 1. All the herbicides tested had no effect on the hydrolysis of urea to ammonia at the recommended rates. Butachlor, at ten and fifty times the recommended rate, and Nitrofen, at fifty times the recommeded rate, depressed urea hydrolysis, resulting in reduction of ammonia. But the depressive effects were temporary, disappearing soon. Simazine and Propanil had no detrimental effect on urea decomposition at all the treated rates. 2. Also, all the chemicals tested had no effect on the nitrification process at the recommended rates. At higher concentrations of ten and fifty times the recommended rate Butachlor and Nitrofen inhibited the oxidation of nitrite, and propanil long inhibited the oxidation of ammonium to nitrite, but was inactive against nitrite oxidizer. These inhibitive effects of the chemicals, however, disappeared in the later period of incubation. Simazine had no effect on the nitrification process at all the treated rates. 3. The trend of change in soil pH of both the treated and untreated plots well reflected the change of soil nitrogen forms during incubation. No direct effect of the chemicals on soil pH was obserbed.

• Korean Journal of Weed Science
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• v.5 no.1
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• pp.35-42
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• 1985

This study was carried out to investigate the effect of environmental factors affecting emergence and control of Sagittaria pygmaea Miquel in greenhouse. Emergence of S. pygmaea delayed as the amount of rice straw increased. When the tuber was sowned at 5 to 7㎝ soil depth the emergence of S. pygmaea delayed more in the hard condition of soil than that of the soft condition the large size tuber of S. pygmaea showed less control rate than the small size one at the rate of 2 to 3㎏ prod/10a of butachlor-naproanilide mixtures. The tubers of S. pygmaea seeded at the deeper soil depth decreased weeding efficicy of this mixture. Butachlor-naproanilide mikture showed higher weeding effects at the high temperature and at 2 to 4cm depths of water management than those of the low temperature and at 0cm and 6cm water depths. Weed control rate increased as the rate of butachlor-naproanilide mixture increased. The rate of 4㎏ (prod.)/10a showed good weed effect regardless of application times till 7.5 leaf stage of S. pygmaea. Tuber production of S. pygmea increased as the application time of mixture delayed.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.314-317
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• 2008

본 연구에서는 백탄과 흑탄에서 농약의 제거 능력을 비교하였고, 연속 실험을 통하여 시간의 경과에 따른 농약의 제거율 변화를 평가하는 것을 목적으로 하였다. 실험에 사용된 농약은 Simazine, Diazinon, Fenitrothion, Butachlor, Malathion이다. 회분식 실험 결과에 따르면, 흑탄과 백탄 양을 0.1g, 1g, 10g, 50g씩 증가시킬수록 각 농약 성분의 제거율이 높아지는 것으로 나타났으며, 농약성분에 따른 제거율을 보면, Malathion과 Butachlor는 혹탄에서 상대적으로 잘 제거가 되는 것으로 나타났다. 하지만 Diazinon은 흑탄의 회분식 실험, 연속식 실험 모두 상대적으로 낮은 제거율을 보였다.

• Current Research on Agriculture and Life Sciences
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• v.17
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• pp.65-70
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• 1999

This study was conducted to develop a simple selection method for herbicide-resistance weeds. Two methods, designated "seedling method" and "stem node method" were employed for screening of barnyardgrass against propanil and butachlor. In the seedling method, shoot and root growth of barnyardgrass were significantly inhibited at quarter of the recommended herbicide rate, while in the stem node method, the similar inhibition was obtained at half of the recommended rate. Thus, it was concluded that the seedling method is more simple and quick method to evaluate response of barnyardgrass to propanil and butachlor compared to stem node method.

• Applied Biological Chemistry
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• v.26 no.1
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• pp.53-57
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• 1983

Butachlor incubated for certain periods of time under the simulated, rather aerobic, rice-paddy conditions of two different soils exhibited two major degradation products. 2,6-diethyl-N-(butoxymethyl) acetanilide and a new product C in all cases, and a relativly small amount of another new product D named tentatively as 8-ethyl-2-hydroxy-N-(butoxymethyl)-3,4-dihydroquinoline in some cases. The supposedly microbial degradation seemed to proceed with incubation periods to some extent. An anaerobic incubation in the previous investigation showed 2,6-diethyl-N-(butoxymethyl) acetanilide as the major product, whereas the new product C with m/z 291 turned out to be the major one in the present condition. Structural elucidation of the products was done based on the fragmentation patterns of the given mass spectra and a possible pathway for their formation was postulated.

• Korean Journal of Weed Science
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• v.3 no.1
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• pp.69-74
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• 1983

The behaviour of mixtures of herbicides was determined to obtain the basic informations about effective herbicide use, enhancing herbicidal efficacy and reducing the chemical cost. Fourteen herbicides with 91 mixed combinations were evaluated by Limpel et al method at the Echinochloa crus galli Beauv-Monochuria vaginalis Presl.-Scirpus hotarui Ohwi (importance values of these weeds were 63%, 16% and 10%, respectively) community type. Thirty eight mixed combinations showed the antagonistic response. Among these 14 mixed combinations including chlormethoxynil + naproanilide mixture were greater than 11% in antagonistic effect. On the other hand, 40 mixed combinations including chlormethoxynil + SW751 mixture showed additive response (${\pm}2%$). For synergistic response, 13 mixed combinations were belonged to this group. Particularly, 3 mixed combinations, chlormethoxynil + butachlor, chlormethoxynil + bifenox and nitrofen + ACN/MCPB/nitrofen mixtures were greater than 11% in synergistic effects. The mixture of thiobencarb + oxyfluorfen was analyzed by isobole technique. This mixture showed the synergistic response and the interaction index was approximately 2. The most optimum mixtur for inducing 90%n weed suppression was 0.012 kg ai/ha for oxyfluorfen and 0.45 kg ai/ha for thiobencarb.

• The Korean Journal of Pesticide Science
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• v.18 no.1
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• pp.14-20
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• 2014

This study is aimed to search the possibility of developmental toxicity test using the zebrafish from the pesticide. We selected herbicides alachlor and butachlor, reported for fish toxicity, and insecticide fipronil reported for the high fish toxicity and the honey bee risk among the pesticides with high usability for the examples of the pesticides in this experiment. In this study, we showed those effects on the zebrafish embryo development by exposing different kinds of pesticide with different concentration and exposed time periods. As a result, the rates of hatching and abnormality of the zebrafish embryo after treatments of alachlor were increased in 24-48 hpf group, and the juvenile fishes in every group exposed to $40{\mu}M$ or more of alachlor displayed sever morphological changes such as bent tails, edema and activity failures. In case of the butachlor, the rates of hatching and the abnormality in 24-48 hpf group were higher than the other groups exposed in different time periods. The fatality before hatching was high in $40{\mu}M$ or more of butachlor treatment, and entire zebrafish embryos in 48 hpf group died before hatching. All the living juvenile fishes showed morphological changes as like as the treatment of alachlor. The rate of hatching and the survival of the zebrafish embryo by the fipronil were higher than other pesticides. However, morphological changes such as bent tails were observed from the most of living juvenile fishes. Therefore, the effects of three different pesticides with different concentrations and exposing time periods on the development of zebrafish embryos showed that all the pesticides effects were proportional to the concentration, and exposing time periods may cause the morphological abnormality.