• Korean Journal of Agricultural Science
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• v.40 no.3
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• pp.183-189
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• 2013

This study was conducted to evaluate the efficacy of herbicide mixtures of benzobicyclon and carfentrazone-ethyl in direct-seeding flooded rice. The efficacy of benzobicyclon mixtures and carfentrazone-ethyl mixtures was greater than that of pyrazosolfuron-ethyl + pyriminobac-methyl GR. Herbicide mixtures with benzobicyclon controlled average 97% and herbicide mixtures with carfentrazone-ethyl controlled average 95% 60 days after application. When compared with untreated control, no visual injuries were detected at single and double dosage of herbicide mixtures. The yield of rice increased in both benzobicyclon and carfentrazone-ethyl treatments when compared with pyrazosolfuron-ethyl + pyriminobac-methyl GR. Based on these data, combinations of these herbicides can be applied to provide effective weed management in rice field.

• Journal of Biosystems Engineering
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• v.23 no.4
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• pp.319-326
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• 1998

A herbicide applicator attached to a rice transplanter was developed to perform herbicide application and transplanting simultaneously. The prototype machine was composed of herbicide tank, discharge device, spinner, scattering plate and power drive. The application rate of the machine could be adjusted from 10 to 30 kg/㏊ and the application swath was 1.8m. According to the field test, application uniformity showed the range of 13.6~43.9％ in terms of CV(coefficient of variation) depending on the spinner speed, application height and shape of diffuser. The best uniformity could be achieved with the spinner speed of 30.8m/s and application height of 20cm. Field efficiency of the prototype was 4.7hr/㏊. Transplanting machine has field efficiency of 4.6hr/㏊ in Korea. By attaching the herbicide applicator, field efficiency became lowed only by 0.1hr/㏊, which was counted for filling time of herbicide. Simultaneous operation of transplanting and herbicide application had a of labor saying. The weed control efficacy was measured to be 96% in field when AC140 + Stomp and Londax + YRC was applied at the 65th day after transplanting. Nonanmae was treated by manual application to be compared to.

• Korean Journal of Agricultural Science
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• v.46 no.2
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• pp.405-416
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• 2019

Weeds are a serious problem in crop production. Use of synthetic herbicides is rapidly increasing in weed management worldwide including Korea. Herbicide application reduces the time spent on weed control. However, the evolution of resistance to herbicides in weeds has become widespread as a natural response to selection pressure imposed by agricultural management activities. If an herbicide with the same mechanisms of action is used repeatedly and intensively, it can rapidly select for a weed biotype that shifts toward difficult-to-control becoming a more tolerant weed and lead to the evolution of herbicideresistant weeds. Moreover, agricultural and biological factors have an important role in the development of herbicide-resistant weed populations. Mitigating the evolution of herbicide resistance in weeds relies on reducing selection through the diversification of weed control techniques. The resistance management of weeds in the future will strongly depend on intensive cropping systems. The current situation of intensive cropping systems with their heavy reliance on the efficacy of chemical weed control will not lead to significant containment of this problem. Therefore, management strategies need to overcome the further spread of herbicide resistance in weeds in Korean crop production. This review presents the current information on herbicide resistance in Korea and factors controlling the development of herbicide resistant weeds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.23 no.3
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• pp.19-30
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• 1978

Use of herbicides in Korean agriculture has increased rapidly in recent years accompanying with ever-increasing pressure of farm labor shortage. Herbicides occupied already the second place in the rank of pesticides consumption in 1977. The agricultural experiment stations have carried out over 50 trials of chemical weed control each year since 1968. These research works and registration trials contributed much to the present wide use of herbicides. The pesticide management act amended in 1977 requires reevaluation of pesticides for their efficacy every 5 year-term. However, the development of sound weed control program and recommendations has been hempered very much by the lack of qualified workers of weed control research in agricultural experiment stations and in the institute for pesticide registration trial. Critical review of the past research works on herbicide evaluation and the present status indicates strong need for 1) the characterization of the nature of local and national weed problem, 2) the improvement of ability of the staffs in charge of weed control research through appropriate training on the basics and experimental techniques, and 3) organization and activities of weed control research committee. Furthermore, the present article attempts to clarify commonly misled points in the establishment of herbicide evaluation plan, in the design and execution of field trials, and in the assessment of trial results of the past works from the viewpoint of the basic principles with some case studies for resolution of specific enigmas.

• Korean Journal of Weed Science
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• v.18 no.4
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• pp.281-285
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• 1998

This experiment was carried out to evaluate the effect of recycled paper mulch on weed occurrence and the growth and yield of rice in dry-seeded paddy field. Mulch papers with basis weight of 105, 110, 115g/$m^2$ were fabricated from recycled corrugate container. It took about 80 days after mulching for the mulch papers to reach 50% decomposition, showing no significant differences among types of mulch paper. Paper mulching was very effective in controlling the paddy weeds at early stage of rice growth, but the efficacy of weeds control decreased a little at late season. However the efficacy was still higher than the plot using herbicide. The paper mulch plot showed rice yield similar to the weed control plot using herbicide. It could be concluded that paper mulch can be used as an alternative for non-herbicidal weed control and ensure as high yield as the conventional weed control method using herbicide in dry-seeded rice field.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.24 no.2
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• pp.89-103
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• 1979

The compatibility of herbicide use for soybean cultivation was evaluated from the field and pot trials. Comparing with the check plot, the effects of herbicides at their several doses on the phytotoxic stability of crop plants and on the weeding efficacy were studied. Statistically significant differences were found among the doses, and not among herbicides and interactions between herbicide and dose. Risks on the compatibility for crop plant and weeding efficacy were recognized from the excess-dosed treatments of herbicides tried.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.387-392
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• 2007

The effect of mixed treatments of wood vinegar and sulfonylurea-based herbicides on weed control, yield and yield components, and quality of rice was investigated. Two herbicides were tested namely: imazosulfuron-ethyl+thiobencarb[ethyl-1-(2-chloroimidazo[1,2-$\alpha$]pyridin-3-ylsulfonyl)-3-(4,6-dimethoxypyrimidin-2-yl) urea+S-4-chlorobenzyl diethyl(thiocarbamate)], and bensulfuronmethyl+butachlor [methyl $\alpha$-[(4,6-dimethoxypyrimidin-2-ylcarbamoyl)sulfamoyl]-o-toluate+N-butoxymethyl-2-chloro-2',6'-diethylacetanilide]. The experiment was carried out in a randomized complete block design with 3 replications and 5 treatments. Treatments used were recommended(RH: 100%) and half-recommended(HRH: 50%) application rates of each herbicide. Half-recommended application rates were combined with 1 mL wood vinegar $500mL\;water^{-1}$(500) and 1 mL wood vinegar $1000mL\;water^{-1}$(1000) wood vinegar. Plots for no herbicide treatments were also prepared and used as control. Results showed that wood vinegar significantly increased efficacy of HRH in bensulfuron-methyl+butachlor while high efficacy was already obtained in HRH treatment of imazosulfuron-ethyl+thiobencarb. Wood vinegar did not improve the efficacy of imazosulfuron-ethyl+thiobencarb but improved rice yield. Significantly similar rice yields were obtained in the HRH+1000 WV and RH treatments of both herbicides. There were no significant variations in the yield components among the treatments; however, differences in yield can be attributed to the variations in the spikelet number and ripening ratio. Data on rice quality analysis did not show clear trend on the effects of the treatments on grain appearance and nutritional quality.

• 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.41 no.1
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• pp.17-22
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• 2014

This study was conducted to evaluate the efficacy of formulations and application timings of imazosulfuron+fentrazamide in rice field. Weeding efficacy of imazosulfuron+fentrazamide SC (75+300 g a.i./ha) was more than 95% except Bidens tripartita. The efficacy of this formulation was not related to its formulations but was highly related to application timing. Herbicide application before 5 days after transplanting was best timing to get a maximum weed control. Systemic application before and after transplanting was much higher than single application for weed control. Second leaf stage of Echinochloa spp. and sulfonylurea resistant Monochoria vaginalis was controled over 90% in the imazosulfuron+fentrazamide SC (75+300 g a.i./ha). Based on these data, imazosulfuron+fentrazamide can be applied to provide effective weed control especially in the field infested with herbicide resistant M. vaginalis.

• Korean journal of applied entomology
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• v.22 no.2 s.55
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• pp.147-159
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• 1983

In general, herbicides have been classified according to selectivity, mobility. time of application, methods of application, mode of action and chemical property and structure. However, there was no generally accepted classification system for practical use in the field. The primary processes affected by the majority of herbicides are the growth process through cell elongation and/or cell division, the photosynthetic process specifically the light reaction, the oxidative phosphorylation and the integrity of the membrane systems. The usual approach in the study of the mechanism by which herbicides kill or inhibit the growth of plants is to initially determine the morphological phototoxicity systems, The mechanism by which a herbicide kills a plant or suppresses its development is actually the resultant effect of primary and secondary(or side) effects. In most instances, the death of the plant is due to the secondary effects. To induce the desired response, a herbicide must be able to gain entry into the plants and once inside, to be transported within the plant to its site(s) of activity in concentrations great enough. Obstacles to the entry and movement of herbicides in plants are generally classified by leaf and soil obstacles, translocation obstacles and biochemical obstacles, and these obstacles are also strongly influenced by plant species and by environmental factors such as light, temperature, rainfall and relative humidity. And hence, in most instances, results obtained from laboratory or greenhous vary from those of field experiment. Author attempted to classify herbicides from the field experiment using the two-dimensional ordination analysis to obtain practical information for selecting effective herbicides or to choose effective herbicide combinations for increasing herbicidal efficacy or reducing the chemical cost. Based on this two-dimensional diagram, desired herbicides or combinations were selected and further investigated for the interaction effects whether these combinations are synergistic, additive or antagonistic. From the results, it was concluded that these new approach could possibly be give more comprehensive informations about effective use of herbicide than any other systems.