• Korean Journal of Agricultural Science
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• v.42 no.2
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• pp.93-98
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• 2015

This study was conducted to evaluate the efficacy of herbicide in winter cereal crops, barley and wheat. The efficacy of soil-applied herbicides, linuron EC and pendimethalin, thiobencarb GR was greater than that of butachlor EC. Linuron EC controlled average 95% and pendimethalin, thiobencarb GR controlled average 97% within 150 days after soil-applied treatment. When compared with untreated control, no visual injuries were detected at single and double dosage of linuron EC and pendimethalin, thiobencarb GR. The yield of barley increased in linuron EC and wheat increased in pendimethalin, thiobencarb GR treatments when compared with butachlor EC. The efficacy of foliage treatment, bentazone+propanil ME was greater than that of bentazone SL. Bentazone+propanil ME controlled average 96% in barley and 97% in wheat, within 30 days after foliage treatment. When compared with untreated control, no visual injuries were detected at single and double dosage of bentazone+propanil ME. The yield of barley and wheat increased in bentazone+propanil ME treatments when compared with bentazone SL. Based on these data, combinations of these herbicides could be applied to provide effective weed management in barley and wheat field.

• Korean Journal of Agricultural Science
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• v.35 no.2
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• pp.119-126
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• 2008

This study was carried out to find the botanical characters and effect of weed control for herbicides treatment after barley sowing. Barley variety used in study was "Yuyeon", hood-type awn for whole crop forage use, which developed at RDA in 2004. Sowing date was on 10th October, 2007, and was drilled as $60{\times}20cm$. Herbicides were treated on 2th day after barley sowing. Measured items were number and kinds of weeds at each treatment and growth characteristics and grain yield in barley. Cerastium holosteoides var. hallaisanense among weeds surveyed at tillering stages in Butachlor treatment were highly appeared, but Alopecurus aequalis var. amurensis did not appeared while Alopecurus aequalis var. amurensis was 39 plants and Capeslla bursa-pastoris was 37 plants in check. Occurrence of the Capeslla bursa-pastoris at primary survey and Cerastium holosteoides var. hallaisanense in ripening stage were high, while Alopecurus aequalis var. amurensis did not emerged. Botanical characteristics of barley each as plant height, number of tillers and spiklets per plant. surveyed at ripening stage were higher than check. Grain yield per 10a was the highest at Alachlor among treatments, while dry matter of leaf and culm were similar among treatments. Therefore, effect of yield increasing of barley by herbicide after sowing was reconfirmed through this study. Especially, effect of Alachlor was lightly high compared with others.

• Korean Journal of Weed Science
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• v.7 no.2
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• pp.208-219
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• 1987

Newly developed several herbicides were evaluated as paddy rice herbicide at the Yeongnam Crop Experiment in 1986. And also, the general situation of rice cultivation between Korea and Japan was compared. Twenty-nine herbicides of the total 59 herbicides were used as paddy rice field in Korea while these were 100 and 187, respectively, in Japan. Among paddy rice herbicides, butachlor was the most important herbicide in both countries. However, the degree of concentration to a particular herbicide was greater in Korea compared to Japan; consumption rate of single butachlor to the total herbicide were 66.5% for Korea and 11.9%r for Japan, respectively. Pyrazolate, pyrazoxyfen and quinclorac were the most promising hebicides in pressed-type rice nurserybed in terms of herbicidal efficacy and phytotoxic effect. For transplanted paddy rice field, single application of NC-311 or combining applications of NC-311 with butachlor or quinclorac gave excellent results at the weed community that was dominated by Echinochloa crus-galli, Aneilema japonica, Ludwigia prostrata, Scirpus hotarui, Cyperus serotinus, Potamogeton distinctus and Eleocharis kuroguwai. Particularly the above combining applications maintained their excellent herbicidal effect up to 3 leaf stage of E. crus-galli without arising herbicidal phytotoxicity. Pyrazolate and three sulfonyl urea herbicides (DPX-5384, NC-311 and CGA 142464) exhibited very high safety against rice. However, Japonica type rice cultivar was a little bit more sensitive than Indica/Japonica type rice cultivar. On the other hand, the effect of these herbicides against E. crus-galli was very strong. Herbicidal effect against E. crus-galli was enhanced through shoot absorption for sulfonyl urea herbicides and root abosorption for pyrazolate and quinclorac, respectively.

• The Korean Journal of Pesticide Science
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• v.2 no.2
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• pp.119-125
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• 1998

A nation-wide fact-finding survey was done to provide the basic information for establishing the rational weed control scheme in paddy rice. A total of 445 respondents including 273 farmers and 172 pesticide dealers was involved in this survey. Dominant weeds in rice paddy field were Echinochloa crus-galli, Eleocharis kuroguwai, Sagittaria pygmaea, Sagittaria trifolia, etc.. Preferred herbicides widely used by farmners were ranked in the following order; butachlor 5GR, pyrazosulfuron-ethyl + molinate 5.07GR, molinate + cinosulfuron 5.08GR, meanwhile, those recommended by pesticide dealers were; pyrazosulfuron-ethyl + molinate 5.07GR, molinate + cinosulfuron 5.08GR, and butachlor 5GR. The guidelines to choose the preferred herbicides was primarily based on the experience, which was occupied about 45%. Approximately 56% of the farmers followed the recommended herbicide dosage and 43% of them applied the herbicides before weed germination (pre-emergence treatment). In addition, most farmers applied herbicides at least two times with systematic application schedule. Application method of granular formulation was broadcasting by hand, while that of sprayable ones was by high-pressure sprayer. Some farmers answered that they had experienced phytotoxicity in the crop by applied herbicides, of which higher experience was observed from the farmers who applied by high-pressure sprayer. It was analyzed significantly that the feasible herbicides to cause phytotoxicity in rice at farmer's level were butachlor 5GR, esprocarb + pyrazosulfuron-ethyl 5.07GR and bensulfuron-methyl + molinate 5.17 GR.

• Korean Journal of Weed Science
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• v.4 no.2
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• pp.179-187
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• 1984

This experiment was carried out to clarify the effect of herbicide chlormethoxynil 7G, CNP 9G and butachlor 3.5/pyrazolate 6G on weed control and seedling growth in rice seedbed. Different quantities of the herbicides were applied as soil incorporation or surface broadcasting. At earlier sowing annual grasses such as Echinochlva spp. and Alopecurus spp. were dominated, but Cyperus spp. were dominated at later sowing. Weed suppression by herbicides was greater in soil incorporation than in broadcasting and chlormethoxynil 7G and CNP 9G application (30kg/ha) showed about 70% weed control, while butachlor 3.5/pyrazolate 6G (10-20kg/ha) showed 90 to 100% weed control. At lower rate of butachlor 3.5/pyrazolate 6G (10kg/ha) emergence ratio, healthy seedling ratio and relative growth rate of rice were higher, and phytotoxicity was lower than in the others.

• Korean Journal of Weed Science
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• v.3 no.2
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• pp.199-207
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• 1983

To select appropriate herbicides for adzukibean and mungbean, a series of experiments was carried out in both field and pot from 1980 to 1983. Tolerance to the herbicides tested was highest in soybeans and followed by mungbean and adzukibean in the order. Pre-emergence herbicides showed relatively low phytotoxicity were chlorambem, linuron, and metribuzin for adzukibean and alachlor and butachlor for mungbean. Post-emergence herbicides showed no external phytotoxicity for adzukibean and mungbean were alloxydim, Dowco 453, fluazifop, etc.. For mungbean, terbutryn (1.5 kg, a.i./ha) which is pre-emergence herbicide showed the best weeding control efficacy but some possible phytotoxicity. Among post-emergence herbicides, acifluorfen (300 g, a.i./ha) showed the best weeding efficacy with no yield reduction though some phytotoxicity which recovered within 20 days. Compared to single herbicide application, the mixture or systemic treatments of herbicides showed much higher weeding control efficacy and seed yields: the systemic treatments of linuron (500 g, a.i./ha) / Dowco 453 (180 g, a.i./ha) or linuron (500 g, a.i./ha) / fluazufop (260 g, a.i./ha) for adzukibean and the mixture treatment of alachlor (1.31 kg, a.i./ha) / acifluorfen (150 g, a.i./ha) for mungbean, respectively.

• Korean Journal of Environmental Agriculture
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• v.7 no.2
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• pp.124-129
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• 1988

Prolonged aquatic toxicity tests (7-days) of six pesticides to the freshwater fish Oryzias latipes were performed to confirm the adequacy of the exposure times, 48-hr or 96-hr, which has been required by the protocols for the aquatic acute toxicity test. The toxicity curves were plotted for each chemical, and the significance of the difference between lethal threshold concentrations and 48-hr or 96-hr LC50's was analysed statistically. The lethal threshold concentrations of butachlor, fenobucarb, and chlorothalonil were clearly defined on the 5th day, 2nd day, and 2nd day at 0.53mg/1, 10.3mg/l, and 0.085mg/1, respectively. But the toxicity curves of alachlor, diazinon, and iprobenfos continued with no threshold for 7 days. Four out of six test pesticides failed to show the threshold concentration during the 96-hr exposure time. Therefore, the results of the acute toxicity test using 48-hr or 96-hr exposure time would not describe the ideal toxicity of pesticides. It is recommended that the prolonged exposure should be continued long enough to define the threshold adequately.

• Korean Journal of Environmental Agriculture
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• v.9 no.1
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• pp.1-8
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• 1990

The effects of soil environmental conditions on the degradation rates of fenitrothion(O-O-dimethyl O-4-nitro-m-tolyl phosphorothioate) in soils under flooded conditions were examined in the laboratory. Fenitrothion was degraded rapidly and the half life period was within 4 days. Furthermore the degradation was mere rapid under flooded conditions than under upland conditions. The decomposition rate was varied with soils and soil temperatures. Fenitrothion degraded more slowly at 30ppm than at l0ppm. Repeated applications of fenitrothion in soils accelerated the degradation rates. The degradation remarkably increased with amendment of rice straw. However, degradation rates ,were virtually unaffected by the addition of the mixed-fertilizer, the fungicide IBP and the herbicide butachlor. The population of fenitrothion-degrading microbes, which were counted by MPN method, always corresponded with the degradation rates in the soils.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.738-746
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• 1995

Greenhouse studies were carried out to find the difference of growth, weed competition and herbicides response in barley(Hordeum vulgare L. emend Larnark) under foggy and non-foggy condition. Plant height, leaf stage, leaf width and shoot fresh weight of barley under foggy condition were greatly increased, while heading rate ripening rate and number of grains per panicle of barley were reduced. Weed emergence based on fresh weight was much greater under foggy than that under non-foggy condition. Plant height of barley under foggy condition was increased comparing with non-foggy condition and significantly reduced with increasing the duration of weed competition, while 1,000-grain weight of barley reduced by the early competition(0∼20 days). Among the herbicides treated, butachlor and thiobencarb inhibited growth of barley under foggy than non-foggy condition. Plant height of barley treated of herbicides under foggy condition was ever increased but 1,000-grain weight of barley was reduced. Weeding efficacy(75-90%) by shoot fresh weight of weeds under foggy condition at 25 days after application was lower 3 to 15% than that under non-foggy condition.

• Applied Biological Chemistry
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• v.33 no.2
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• pp.133-137
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• 1990

The effects of soil environmental conditions on the rate of degradation of fungicide IBP (Iprobenfos, S-benzyl O, O-diisopropyl phosphorothioate) in the soils under flooded condintions were examined in the laboratory. IBP in soil was degraded more slowly under flooded conditions than under upland conditions. The degradation greatly varied among soils, and the degradation rate was negatively correlated with the content of soil organic matter. Degradation of IBP was influenced by the soil temperature and the amount of IBP applied. The rate of degradation in soil was remarkably inhibited by the amendment of rice straw but not affected by the treatment of mixed-fertilizer, and insecticide fenitrothion and herbicide butachlor. The degradation of IBP was assumed to be due to microorganisms, especially aerobic microbes, as no degradation was observed in sterilized soil.