• Korean Journal of Weed Science
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• v.8 no.2
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• pp.114-123
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• 1988

• Weed & Turfgrass Science
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• v.5 no.4
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• pp.225-229
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• 2016

This study was conducted to investigate the herbicidal efficacy of up granule formula of benzobicyclon mixtures, benzobicyclon + azimsulfuron + oxaziclomefone up granule (BAO UG) and benzobicyclon + bensulfuron-methyl + fentrazamide up granule (BBF UG) to control annual and perennial weed species in a rice paddy field. Four annual weed species including Echinochloa crus-galli L. and three perennial weeds were dominated in the experimental field. Application of BAO UG and BBF UG was highly effective to control both annual and perennial weed species. No phytotoxic effect was observed in the rice based on the plant height, the number of tillers, and culm and panicle length. Finally, rice yield in the BAO UG and BBF UG treatment was as much as that in the hand weeding. This study indicates that self-dispersible floating formula of benzobicyclon mixtures can be applied to control both annual and perennial weed species in rice paddy fields and contribute to save labor costs.

• Korean Journal of Agricultural Science
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• v.41 no.2
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• pp.113-117
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• 2014

This study was conducted to evaluate the efficacy of benzobicyclon mixtures by using Remote-controlled aerial application (RCAA) to control annual and perennial weeds in rice paddy field. Eight annual weed species including Echinochloa crus-galli L. and three perennial weeds were dominated in the experimental field. Application of benzobicyclon mixtures using RCAA was highly effective to control both annual and perennial weed species. When compared with untreated control, no visual injuries were detected at single and double dosage of benzobicyclon mixtures. Finally, rice yield in the benzobicyclon mixtures was as much as that in the hand weeding. This study indicates that benzobicyclon mixtures using RCAA can be applied to control both annual and perennial weed species in rice paddy field.

• Korean Journal of Agricultural Science
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• v.39 no.4
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• pp.473-476
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• 2012

The experiment was conducted to investigate the herbicidal efficacy of imazosulfuron mefenacet by using remote-controlled aerial application (RCAA) to control annual and perennial weeds in rice paddy field. Eight annual weed species including Echinochloa crus-galli L. and three perennial weeds were dominated in the experimental field. Application of imazosulfuron mefenacet using RCAA was highly effective to control both annual and perennial weed species. No phytotoxic effect was observed in the rice based on the plant height and the number of tillers. Finally, rice yield in the imazosulfuron mefenacet treatment was as much as that in the hand weeding. This study indicates that imazosulfuron mefenacet using RCAA can be applied to control both annual and perennial weed species in rice paddy field.

• Korean Journal of Weed Science
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• v.3 no.2
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• pp.246-251
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• 1983

In recent years weed flora have been changed to perennial dominance in paddy field being affected by the cropping systems and cultural practices. The perennial weeds are difficult to be controlled with annual herbicides which occupy 94% of total consumption of herbicides. The weeds competed more with rice plants in early tillering stages in machine transplanted field. For the reasonable and effective weed control, it is advisable to use single ai herbicides in hand transplanting field, but combined and mixed herbicides should be applied in machine transplanting field.

• Korean Journal of Weed Science
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• v.12 no.4
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• pp.309-316
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• 1992

• Korean Journal of Weed Science
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• v.12 no.3
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• pp.230-260
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• 1992

The paper was reviewed the research results on weed dynamics and effective control methods in direct-seeded rice crop. Direct seeding method resulted in drastic increment of weed growth compared to transplanting method and also changed in troublesome weed flora. Two to three fold more weeds were harvested at the direct seeded rice and weed flora of dominant species shifted toward $C_4$type grass weeds. Some of the important troublesome weeds in direct seeded rice were Echinochloa crus-galle, Oryza saliva ssp spontanea, Leptochloa chinensis. Setaria viridus. Digitaria adsendens, Sesbania exaltata, Aeschynomene indica, Algae, etc. Yield loss due to weed competiton was about 40-60% for water-seeded and about 70-100% for dry-seeded rice while these for transplanted rice were about 25-35% for mechanical transplanting and about 10-20% for manual transplanting, respectively. Integrated weed management concept was neede to approach weed control effectively. Several cultural technologies were very effective to suppress the weed growth. These were tillage operation, water management, seeding date and seeding rate. Crop residues of barley, rice, wheat, oat and italian ryegrass were also effectivly suppressed the paddy weeds particularly to Potamogeton distiuctus, a perennial broadleaf weed. A pathogen of Epicoccosorus nematosporus identified from Eleocharis kuroguwai was an excellent potential bioagent to control the most troublesome perennial sedge weed of E. Kuroguwai without arising any detrimental effect. The herbicidal efficacy of this pathogen was as high as bentazon herbicide. Plant growth regulator of paclobutrazol (pp-333) was another possible alternative to reduce the herbicide use. In current, herbicide exhibited the most conspicuous results to control weeds in direct-seeded rice even though the application technologies were not fully established. Recommendations for herbicide application were suggested for in both water-and dry-seeded rice in USA, Japan and Korea, respectively. To make better and comprehensive recommendations further studies on weed ecology and herbicide development were emphasized.

• Korean Journal of Weed Science
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• v.14 no.4
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• pp.258-264
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• 1994

The weed survey in lowland rice field in 1992 was conducted to identify weed population change as affected by different elevation, soil type and cultivation pattern at Gangweon province. There were more perennial weeds in plain and east coastal area while more annual weeds in mid alpine and alpine area. Meanwhile, perennial weed species was more dominant at ordinary and sandy soil but annual weed species was more dominant at poorly drained soil. In general, hand and machine(30 day old seedling) transplanting would result in higher dominant weed species of perennial while there was more annual weed species in machine (10 day old seedling) transplanting and dry seeding, respectively. Also, annual weed species was more predominant at spring plowing time compared to autumn plowing time. Particularly, there was change in dominant weed species with time. In 1971 annual weed species was more predominant but perennial weed species was highly dominant in 1981 and 1992.

• Korean Journal of Weed Science
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• v.1 no.1
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• pp.21-29
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• 1981

Nationwide survey of weed population in paddy rice field was conducted from 1760 fields all around Republic of Korea in 1981. The weed species observed include 2 species of grasses, 7 species of sedges, and 18 species of broadleaf weeds, and the dominant weed species were Monochoria vaginalis, Sagitraria trifolia, Potamogeton distinstus, Sagittaria pygmea and Cyperus serotinus. More and many weeds were growing in single cropped field than double cropped field. In single cropped fields, weed population was reduced when autumn plowing was conducted. In double cropped fields, more weeds were growing in barley or wheat grown fields than vegetable gown fields. Among the five paddy soil types, more weeds were growing in saline soils and poorly drained soils than others. The proportion of annual and perennial weeds in national average was 44% and 56%, and perennials became more dominant in central part of the peninsula. Autumn plowing and double cropping appeared to reduce the perennial weed population, however, the increased perennial weed population, presumably due to continuous use of herbicides which controls mostly annuals, seemed to an urgent problem to be solved.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.21 no.1
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• pp.20-23
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• 1976

Distribution of underground organs of perennial weeds in soil and ecological control measure were evaluated. Tubers of Cypers serotinus and Sagittaria pygmaea were mostly presented in a shallow depth of 0 to 5cm, however, Potamogeton distinctus's bulbs and Eleocharis kuroguwai's tubers were distributed in the soil at 10 to 20cm. A 20cm autumn plowing was, to some extent, effective to reduce Potamogeton distinctus. The herbicide, avirosan at 3kg/10a alone, was extremely effective in controlling Potamogeton distinctus.