• Asian Journal of Turfgrass Science
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• v.12 no.3
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• pp.173-182
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• 1998

This study was conducted to evaluate the effect of plant growth inhibitors on "Penncross" creeping bentgrass in the green of golf course for increasing the summer quality. Chlormequat chloride (C) 250$\times$, 500$\times$, 1000$\times$, daminozide (D) 50$\times$, 100$\times$, 200$\times$, paclobutralzol (P) 1000$\times$, 2000$\times$, 4000$\times$, trinexpac-ethyl (T) 1000$\times$, 2000$\times$, 4000$\times$, uniconazole (U) 25$\times$, 50$\times$, 100$\times$ with three concentrations, respectively, were applied to creeping bentgrass. The leaf length, leaf width, and internode length of stolon were inhibited by all plant growth retardants applied as compared to that of control in which D-50, T-2000, and trinexpac-ethyl were the most effective among treatments on the inhibition of leaf length and internode length of stolen, respectively. Leaf thickness increased more in the treatments of C-250, D-50. T-2000 and T-4000 than any other treatments. On the other hand, shoot density which was represented by number of leaves per unit area was found to be the highest in P-2000 and P-4000 treatment. In this case, all plant growth retardants with no significant differences showed increase of 15-20% in density as compared to control. Total dry weight increment was higher in P-2000 and P-4000 while leaf dry weight increment was higher in T-4000. and U-25 and 50 than other treatments. According to the visual evaluation for the purpose of turf quality measurement, it was found that paclo-butralzol, trinexpac-ethyl and uniconazole were not suitable for green maintenance and extension because of making leaves to yellow. In conclusion, it was postulated that C-250, D-50, and T-4000 had possibility to use practically in the green area of golf course.lf course.

• Asian Journal of Turfgrass Science
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• v.12 no.3
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• pp.225-236
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• 1998

The white grubs in turfgrass were investigated from 15 golf clubs in 7 provinces and 2 metropolitan cities. 12 white grub species were collected and 11 species in 8 genera including oriental beetle, Anomala orientalis were identified but 1 species was not identified. The oriental beetle grub was the most serious pest in turfgrass out of them. The brown chafer, Adoretus tenuimaculatus was widely distributed species collected from 6 golf clubs, Maladera castanea was collected from 5 golf clubs and A. orientalis, Holotrichia kiotoensis, and M. orientalis were collected from 4 golf clubs. The white grubs, their density, and distribution depth were also observed at tee, fairway, and green from Yongweon, Daegu, and Dongrae golf clubs. A. orientalis was dominant species in overwintering season but A. tenuimaculatus was dominant one in unoverwintering season. The density of white grubs was low in the green compared with tee or fairway. Distribution depth was different depending on season in Daegu and Dongrae golf clubs but not different in Yongweon golf club. Although there showed no differences in white grub species depending on turfgrass but density was different, that is, A. tenuimaculatus was abundant in Zoysia matrella while A. orientalis abundant in Poa pratensis. The density of A. orientalis grubs was higher in older golf courses but there showed no differences in white grub species depending on the age of golf club.

• Korean Journal of Weed Science
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• v.12 no.4
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• pp.387-392
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• 1992

For reducing the residual effects of Quinclorac to followed-by crops of paddy rice, three tests by different soil improvers, different cultural performances with tillage and application of composts, and cultivation of different depletion crops were evaluated, respectively. Among seven soil improvers, activated carbon, composts and perlite showed significant promisable feasibility to reduce phytotoxicity of tomato seedlings as affected by Quinclorac residuals, And comparing to untreated check, the application of tillage and composts prior to transplanting of tomato seedling could helpful to reduce Quinclorac residuals in the soil, but tomato and lettuce, most susceptible crops to Quinclorac, were not remarkably protected by those cultural performances. Also among cultivation of depletion crops just after rice harvest, Italian ryegrass, tall fescue, rape and oats engaged to deplete and reduce Quinclorac residuals for tomato seedling growth, however alfalfa and hairy vetch, relatively susceptible plants to Quinclorac were not promisable.

• Journal of Korea Water Resources Association
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• v.47 no.10
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• pp.973-983
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• 2014

This study focused on the selection of appropriate plant species of VFS (vegetative fiter strips) and the assessment of VFS effects for reducing NPS (non-point source) pollution from uplands. The experimental field was constructed with 1 control and 6 treated plots in the upland area of $1,500m^2$ with 5% slope which is located in Gunwi-gun, Gyeongbuk province. Six vegetation including Chufa, Common crabgrass, Barnyard grass, Turf grass, Tall fescue, Kenturky bluegrass, were applied to install VFS systems during the study period from June 2011 to Dec. 2012. The results of this study showed that 6.1~77.8% in runoff and 15.6~90.3% in TS, 49.9~96.6% in T-P, and 6.7~91.1% in T-N were reduced from the VFS treated plots. Generally high reduction effects were observed from TS, T-P, T-N, and SS, while BOD, TOC, and $NO_3^-$ showed low reductions. The best vegetation type was Turf grass showing higher reduction effects of NPS pollutions and having relatively easier maintenance efforts compared to other vegetations selected in this study. Based on these results, VFS technique found to be an effective management practice for reducing agricultural NPS pollutions in Korean upland conditions. Further study needs to be performed through various field experiments with long term monitoring in order to develop a design manual of VFS system for practical applications.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.5
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• pp.314-325
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• 2002

The effects of arbuscular mycorrhizal (AM) fungus (Glomus intraradices) on plant growth and N metabolic responses were examined in perennial ryegrass plants exposed to drought-stressed or well-watered condition. Mycorrhizal inoculation improved significantly leaf water potential, dry mass and P content. Drought stress increased significantly nitrate concentration in roots where the increase was much less in AM than non-AM. Drought stress decreased the concentration of soluble proteins in non-AM shoots, whereas non-significant decline occurred in AM shoots even under drought condition. The concentrations of ammonia and proline in drought stressed non-AM plants significantly increased, while mycorrhizal inoculation lowered significantly ammonia and proline accumulation. The decrease in leaf dry weight in drought stressed-plants was significantly correlated to the increase in ammonia (p<0.01) and proline concentration (p<0.01). These results suggested that the increased P content and N assimilation by mycorrhizal inoculation may be associated with drought stress tolerance, showing the moderating effects on shoot growth inhibition and ammonia accumulation in drought stressed-plants.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.4
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• pp.498-505
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• 2010

To evaluate the effectiveness of AMF on the growth of horticultural crops, we compared mycorrhizal and non-mycorrhizal plants, lettuce (Lactuca sativa L.), that were inoculated with AMF propagules. As compared to the AMF- seedlings, in AMF+ seedlings at 3 weeks after sowing, the number of leaves increased 9%, leaf fresh weight increased 59%, leaf area increased 58%, and leaf length and width increased 21-22%, and chlorophyll content increased 2%. Furthermore, at 9 weeks after sowing, compared to the AMF- plants, in lettuce plants inoculated with AMF at the sowing and transplanting stages, the number of leaves increased 21% and 18%, leaf fresh weight increased 51% and 41%, root fresh weight increased 56% and 47%, and chlorophyll content increased 18% and 19%, respectively. Further this experiment indicated that the growth responses of lettuce plants inoculated with AMF during transplanting were similar to those inoculated with AMF during sowing. The results imply that the AMF infection timepoint is not important. The P content in the leaves of lettuce plants inoculated with AMF during transplanting was significantly higher (217%) than that of leaves from lettuce plants not inoculated with AMF. In contrast, the P content of the leaves of lettuce plants inoculated with AMF during the sowing stage was similar to that of leaves of control lettuce plants. In this experiment, P and chlorophyll content in AMF+ lettuce plants were higher than in AMF- plants, indicating that the photosynthetic rate was improved with AMF inoculation.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.3
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• pp.179-186
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• 2009

Relation between soil salinity and forage yield of five upland crops such as sudan grass, sesbania, barnyard grass, corn and soybean was studied in the three reclaimed lands of Korea during two years from 2007 to 2008. Although plant number emerged was obtained satisfactory by desalting treatment, further growth of crops was sharply affected by re-salting process according to soil drying. Soil salinity varied place by place and changed constantly, crop growth was differently responded to soil salinity according to the specific conditions of the reclaimed lands. In the Iweon reclaimed land with higher soil water conductivity and sandy soil texture, crop growth and yield sharply decrease with increase of soil salinity. Relation between soil salinity and crop growth and yield was well expressed as logarithmic function. Surface soil EC to reach at 50% of growth reduction to the tallest height of crops was $5dS\;m^{-1}$ for soybean, $6dS\;m^{-1}$ for corn and $7dS\;m^{-1}$ for sudan grass, sesbania, and barnyard grass by logarithmic function. In the Hwaong and Yeongsangang reclaimed lands with low soil conductivity and finer soil texture, plant growth response to salt stress was statistically vague by mixing of harmful influence from flooding and wet injury. However, it is observed that crop growth and yield on the place of lower salinity was better than crop growth on the place of higher salinity. It is accordingly concluded that flooding control during summer rainy season is vary important as well as desalting process for good growth of soiling and forage crops in the newly reclaimed land from tidal flat.

• Asian Journal of Turfgrass Science
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• v.26 no.1
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• pp.54-59
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• 2012

This study was conducted to evaluate to the effect of liquid fertilizer with saponin (SLF) and liquid fertilizer with amino acid (ALF)on the growth of creeping bentgrass. In creeping bentgrass, turf color index, chlorophyll index, dry weight and shoot number were measured. It was hardly affected by SLF and ALF applications in investigation of chemical properties of the soil. By applying SLF and ALF, turf color index and chlorophyll index in 2SLF and 2ALF were increased more than CF, and shoot number and root length in 2SLF, ALF and 2ALF were higher than CF. In correlation coefficient among growth factors of creeping bentgrass, turf quality was significantly different in root length, shoot number, dry weight, and content of N and K in turf tissue (P<0.05), N content of tissue was significantly in root length, shoot number and dry weight (P<0.05), and K content was significantly in shoot number and dry weight (P<0.05). These results suggested that application of functional liquid fertilizers such as SLF and ALF was expected to replace compound fertilizer in turf management and that applied SLF and ALF was stimulated the uptake of N and K into turf so that turf qualities were improved by enhancing growth shoot and root of turf.

• Journal of Environmental Science International
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• v.24 no.11
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• pp.1501-1511
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• 2015

As essential trace elements, copper and zinc play important roles in many physiological events in plants. In excess, however, these elements can limit plant growth. This study selected a heavy metal-tolerant plant by analyzing seed germination and biomass of alfalfa (Medicago sativa), canola (Brassica campestris subsp. napus var. nippo-oleifera), Chinese corn (Setaria italica), and a sorghum-sudangrass hybrid (Sorghum bicolor ${\times}$ S. sudanense), and determined heavy metal uptake capacity by analyzing biomass, chlorophyll a fluorescence, and heavy metal contents under high external copper or zinc levels. The seed germination rate and biomass of the sorghum-sudangrass hybrid were higher under copper or zinc stress compared to the other three plants. The plant biomass and photosynthetic pigment contents of the sorghum-sudangrass hybrid seedlings were less vulnerable under low levels of heavy metals (${\leq}50ppm$ copper or ${\leq}400ppm$ zinc). The maximum quantum yield of PSII ($F_v/F_m$) and the maximum primary yield of PSII ($F_v/F_o$) decreased with increasing copper or zinc levels. Under high copper levels, the decline in $F_v/F_m$ was caused only by the decline in $F_m$, and was accompanied by an increase in non-photochemical quenching (NPQ). The $F_v/F_m$ declined under high levels of zinc due to both a decrease in the maximum fluorescence ($F_m$) and an increase in the initial fluorescence ($F_o$), and this was accompanied by a marked decrease in photochemical quenching (qP), but not by an increase in NPQ. Accumulations of copper and zinc were found in both aboveand below-ground parts of plants, but were greater in the below-ground parts. The uptake capacity of the sorghum-sudangrass hybrid for copper and zinc reached 4459.1 mg/kg under 400 ppm copper and 9028.5 mg/kg under 1600 ppm zinc. Our results indicate that the sorghum-sudangrass hybrid contributes to the in situ phytoremediation of copper or zinc polluted soils due to its high biomass yield.

• Journal of Animal Environmental Science
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• v.8 no.1
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• pp.35-42
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• 2002

This study was carried out to determine the effect of chemical fertilizer and two fermented types of pig slurry on the total dry matter yield and quality of sorghum $\times$ sudangrass hybrid (Sorghum bicolor L. Moench) and chemical properties of soil after harvest in Jeju area. Three treatments consisted of chemical fertilizer (CF) 200kg 7kg Nha $^1$, aerobic fermented pig slurry (PS)200kg 7kg Nha $^1$, and aerobic fermented pig slurry treated with probiotics (PS+P) 200kg 7kg Nha $^1$were arranged in a randomized block design with three replications. The results obtained are summarized as follows. The heights of plant applied fermented pig slurry were slightly taller than those of plants applied chemical fertilizer during early growing stage, but there was no difference among treatments when the plants were harvested. The total forage dry matter yields were in the range of 14,848~ 15,42kg/ha, but they were not significantly different. Also, CP, NDF, ADF and mineral contents in the forage(% of DM basis) did not differ among treatments. The pH of soil was ranged from 5.35 to 5.63, but it was not significantly different. However, the content of available $P_2O_5$ of soil was higher(P<0.05) in chemical fertilizer treatment than that of soil in fermented pig slurry treatments. The content of K was higher(p<0.05) when ffrrmented pig slurry treated with probiotics was applied after the 1st harvest. but it was not different among treatments after the and harvest.