• Proceedings of the Turfgrass Society of Korea Conference
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• 2011.02a
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• pp.75-78
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• 2011

• Asian Journal of Turfgrass Science
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• v.20 no.2
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• pp.157-165
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• 2006

This study was initiated to investigate herbicidal selectivity margin with annual bluegrass and bentgrass according to growth stages through herbicidal spectrum of bispyribac-sodium and therefore to examine application possibility to prevent annual bluegrass selectively. The herbicidal efncacy by pre-emergence application was generally low. But a high herbicidal efficacy was observed over 90% for Shehpherd's purse. Foliar treatment resulted in a higher herbicidal efficacy in all tested plants except dallisgrass, lovegrass, curled dock and bentgrass as compared with pre-emergence application. We found bispyribac-sodium could be used as a selective weeding chemical between annual bluegrass and bentgrass. In regard to dose-responses to the growth stage, annual bluegrass was more susceptible to bispyribac-sodium than bentgrass for the same dosage. Particularly, bispyribac-sodium application in inflorescence emergence stage showed a greater herbicidal selectivity margin of 6.8 times with annual bluegrass over creeping bentgrass after 28 days from the application. These data demonstrated that annual bluegrass was more sensitive to bispyribac-sodium over creeping bentgrass.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.2
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• pp.131-136
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• 2005

This study was conducted from March 21 to July 7 in 2004 at JeJu Island to investigate the influences of seed-ing rates (4, 6, 5, 10 and 12 kg/10a) on creeping bentgrass vegetation. The result obtained were summarized as follows; plant height was getting longer as seeding rate increased from 4 to 12 kg/10a, Although it was no significance from 10 to 12 kg/10a. Root length, Minolta SPAD-502 chlorophyll reading value, leave and root weight increased as the plant height increased. The degree of land cover and density of creeping bentgrass also increased as seeding rate increased from 4 to 12 kg/10a, and the degree of land cover and density of weed decreased. The number of weed species on decreased as increasing of seeding rate. Then ranking of the dominant weeds were Digitaria adscendens, Chenopodium album var. centrorubrum md Poa annua (at 4 kg/10a seeding rate), Digitaria adscendens, Chenopodium album var. centrorubrum and Stellaria media (at 6 kg/10a seeding rate). Chenopdium album var. centrorubrum, Poa annua and Digitaria adscendens (at 8 kg/10a seeding rate), Digitaria adscendens, Chenopdium album var. centrorubrum and Steilaria media (at 10 kg/10a seeding rate), Chenopdium album var. centrorubrum, Digitaria adscendens and Stellaria media (at 12 kg/10a seeding rate). These results showed that the optimum seed-ing rate is 10 kg/10a for growth of creeping bentgrass in volcanic ash soils of Juju island.

• Weed & Turfgrass Science
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• v.2 no.1
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• pp.76-81
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• 2013

This study was performed to find the effective post-emergence herbicides to control of Poa annua that has already emerged from the soil in Kentucky bluegrass. A total of 8 treatments consist of various post-emergence herbicides applied at recommended concentration or lower concentration than recommended concentration to prevent Kentucky bluegrass injury in this study. Methiozolin showed the least injury in Kentucky bluegrass during 40 days after treatments and there were no footprints by methiozolin in creeping bentgrass green during 20 days. However, Poa annua control was 60.4%, which was less than those of other 7 treatments in this study. Both of asulam sodium and iodosulfuron plus asulam sodium exhibited the higher Poa annua control of 81.7% and 82.2% respectively without serious injury in Kentucky bluegrass during 40 days, and they showed a slight footprints damage in creeping bentgrass green. On the other hand, critical Kentucky bluegrass injuries and the vivid and numerous footprints were occurred in treatments of trifloxysulfuron-sodium, foramsulfuron, rimsulfuron and flazasulfuron, even though they were applied with only 1/4 of recommended concentration. Methiozolin is available to reduce gradually Poa annua population on Kentucky bluegrass without severe turfgrass damage. Asulam sodium or iodosulfuron plus asulam sodium could be useful to remove Poa annua by spot treatment but it is prohibited to spray directly on green even spot.

• Asian Journal of Turfgrass Science
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• v.21 no.1
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• pp.39-49
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• 2007

Bispyribac-sodium is a new-type herbicide that prevents the occurrence of annual bluegrass by the suppression of anthesis and inflorescence emergence on the bent green. The greenhouse experiment was conducted to investigate interaction effect of the bispyribac-sodium with 21 soil- and foliar-applied herbicides in regards of herbicidal activity of annual bluegrass. The remarkable synergism was not found on the combination of bispyribac-sodium with benfluralin, pendimethalin, oryzalin, siduron, chlorphtalim, isoxaben, bifenox, tenylchlor, indanofan, bentazone, imazosulfuron, imazaquin, halosulfuron-methyl and limsulfuron. However, mixture of bispyribac-sodium with mecoprop, triclopyr, metsulfuron-methyl, cyclosulfamuron, pyrazosulfuron-ethyl and pyributicarb produced greater synergism of herbicidal activity when compared with unmixed, single application. Phytotoxicity was low on bentgrass green and fast recovery was observed. In future, it would be strongly necessary to do research to Investigate the effect of bispyribac-sodium combination with other herbicides under various environment and management practices on-site bentgrass green.

• Asian Journal of Turfgrass Science
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• v.20 no.1
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• pp.77-82
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• 2006

Annual bluegrass(Poa annua L.) is a problem weed that is very difficult to control on golf courses. There are some reasons that make Poa annua such a difficult weed to be controled. One of these reasons is this plant's ability to reproduce its seed even under stressful conditions. Another reason is its adaptation to low mowing heights. Above all things, the greatest competitive advantage of Poa annua is its genetic diversity. Generally, Poa annua is a bunch type and annual type cool-season grass, but some types act as weak perennials and have stolons. There has been much research on controlling annual bluegrass in golf course turf with chemical and cultural techniques. This research has been conducted for more than 85 years. There has been some progress in controlling some types of Poa annua, but these methods have not been successful on every biotype. Among all of the techniques, Roundup ready creeping bentgrass has the most promise of controlling the diverse types of Poa annua. Roundup ready bentgrass is capable of tolerating the effects of Roundup(glyphosate) while it kills other plants including Poa annua. By using this new technology, we can make Poa annua free greens, tees, and fairways.

• Weed & Turfgrass Science
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• v.5 no.3
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• pp.177-180
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• 2016

This study was conducted to identify problematic weed species in grape orchard fields to establish basic information for suitable weed control. Surveys of weed species occurring in grape orchards were conducted in Chungnam province including Daejeon and Sejong of Korea from April to June and from September to October in 2015. From the surveys, 50 weed species belonging to 23 families (33 annuals and 17 perennials) were identified. In the first survey, the most dominant weed species by the importance values was Poa annua (7.07) followed by Echinochloa crus-galli (6.56), Digitaria ciliaris (6.43) and Capsella bursapastoris (5.63). In the second survey, Rorippa palustris (9.59), Eclipta alba (9.13), Digitaria ciliaris (7.68) and Poa annua (7.68) were dominant. Different weed species and dominance patterns were detected according to weed control methods in the grape orchards. Seven weed species belonging to six families were identified in the field in which herbicides were being used as a weed control method. However, most weed species (21 species belonging to 9 families) were occurred in the mowing + tillage fields. These surveys provide information about seasonal variations of weeds species occurred in grape orchards and impact of different weed control methods on the weed occurrence.

• Asian Journal of Turfgrass Science
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• v.15 no.1
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• pp.15-20
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• 2001

Two types of annual bluegrass have been reported, and those consist of annual type (Poa annua ssp. annua) and perennial type (Poa annua ssp. reptans). As a weed, annual bluegrasses are commonly found in putting greens and fairways in many golf courses. Due to its strong competitiveness such as tremendous seed reproduction rate a year, prostrate growth habit, and no herbicide availability, annual bluegrasses have been considered as one of the most hard-to-control weeds in turf management systems. A growth chamber study was conducted to determine seed dormancy and to understand seed germination characteristics of annual bluegrass (Poa annua ssp. annua). Freshly harvested seeds showed 80 and 55% germination at 30 and $35^{\circ}C$, respectively, indicating that the optimum temperature of annual bluegrass is $30^{\circ}C$. However, the seed germination occurred only under light condition at any given temperature. This result demonstrated that light is prerequisite for the seed germination, and no primary dormancy of annual bluegrass seed exists. Secondary seed dormancy induced by unfavorable temperatures and dark condition was broken through 4 to 6 wk-storage at $4^{\circ}C$ with moisture, and the stored seeds germinated at $20^{\circ}C$ even under the dark. In red and far-red light trial, fresh seeds resulted in 40% germination under red while no seed germination occurred under far-red light condition, indicating that phytochrome Pr and Pfr could be related to annual bluegrass seed germination. When the far-red light replaced the red the germination was recovered, but this reversibility did not reach to the germination level under the red light only. This result implied that other lights than red and far-red would play an important role on seed germination of annual bluegrass.

• Korean Journal of Weed Science
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• v.31 no.2
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• pp.212-219
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• 2011

The water dispersible granule flupoxam showed over 95% of weeding effect on the annual weeds of Poaceae such as Poa annua L., Digitaria ciliaris (Rets.) Koel and broad-leaf weeds. Efficacy of treatment had been lasted over 120 days in the $2kg\;ha^{-1}$ when it was treated from March to April while lasted over 180 days when it was treated from September to October. Because the flupoxam has a high soil absorptivity, a perfected herbicide layer is formed. This results in perfect weeding effect regardless of the presence or absence of thatch. Because the flupoxam has a different mechanism of action from the conventional herbicides such as dinitroanilines, pyridines, and carbamates, it is very effective with the alternative spray. Phytotoxicity symptoms was not observed and/or produced antocyan in new leaves in the landscape trees around the lawngrass by flupoxam treatment.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.237-242
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• 2011

The 2011 Japanese Society of Turfgrass Science was divided in oral presentation, sectional meeting and small symposium, and the total 55 subject was announced. The oral presentation was reported physiological ecology of turf, disease and weed; field management; pesticidal activity and spectrum of new turf pesticides. Above all, there was presentation that investigated control method of necrotic ring spot of new turf disease and Cyperus brevifolius, annual bluegrass and mouse-ear chickweed. In addition, the control effect of new registration fungicide (Furametpyr) and herbicides (S-metolachlor, Flucetosulfuron and Foramsulfuron) were announced. There was various information interchange through 4 kinds of subjects of a golf course, ground turf, a urban park greens and ground cover plants greening by the sectional meeting, and the genetic resource of turfgrass discussed by small symposium. Specially, park greens sectional meeting was announced about the radioactive material contaminated on mechanism and effectively removal method of the radioactivity contaminant from public park, school ground and domestic lawn.