• Weed & Turfgrass Science
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• v.3 no.1
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• pp.19-28
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• 2014

Research was initiated in greenhouse to investigate effects of polymer, calcium, perlite and chitosan on the growth of Kentucky bluegrass (KB). A total of 24 treatment combinations were used in the study. Treatments were made of water-swelling polymer (WSP), calcium, perlite, and chitosan in soil organic amendment (SOA). Significant differences were observed in germination rate, turfgrass coverage, turfgrass density and top growth among treatments. Germination rate, density and plant height varied with time after seeding. A proper mix of WSP is considered to be lower than 3% for turfgrass coverage and density. Regarding survival capability and top growth, however, it was good under 6%. Overall KB growth was more influenced by calcium and perlite than chitosan. Calcium and perlite were the most effective elements for early survival capacity and turfgrass density, respectively. But no effect was found by chitosan. Top growth increased with three elements, being perlite > calcium > chitosan. The chitosan was effective in early germination, but there was no effect on top growth until 3 weeks, when compared with others. A further study is needed for investigating the effect of these materials on the growth characteristics in mixtures of sand and SOA before a field application.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.176-187
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• 2015

The weed flora in the Codonopsis lanceolata upland fields were surveyed in Hoengseong and Jeju in May, August, and October of 2014. The objectives of this study were to use the survey data for establishing weed control methods and to bring awareness of possible problematic weeds occurred in C. lanceolata upland fields in Korea. Altogether 207 weed species of 47 families were identified, of which 87 were annual, 47 species were biennial and 73 were perennial. Based on the morphological characteristic of the leaves, 182 species were broad leaves, 18 species were grasses, and 7 species were sedges. The dominance was highest in the Artemisia princeps followed by Digitaria ciliaris, Commelina communis, Persicaria longiseta and Echinochloa crus-galli etc. Fifty-nine species were exotic weeds with 29% of a total presence, of which Erigeron annuus was highest, followed by Crassocephalum crepidioides, Bidens frondosa, Hypochaeris radicata etc. In the PCA plot, weeds presented in the C. lanceolata upland fields of Hoengseong were divided into three groups, E. annuus, Sigesbeckia pubescence and C. communis communities and those of Jeju were divided into four groups, C. crepidioides-Cyperus iria, Spergula arvensis, Poa annua and Youngia japonica communities.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.268-277
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• 2015

Organic fertilizer preparation was developed with organic materials to improve growth and qualities of cool-season turfgrass species. Organic fertilizer preparation were contained with essential macronutrient elements and organic matter for growth of cool season turfgrass. Four preparations of organic fertilizers were tested on creeping bentgrass (Agrostis palustris Huds) cultivar Penn-A1 and Kentucky bluegrass (Poa pratensis L.) mixed cultivars (Midnight 33%, Moonlight 33%, and Prosperity 33%) by one time application on fifty days after sowing. Two species of cool season turfgrasses were evaluated on turfgrass coverage, growth on NDVI (Normalized Difference Vegetation Index) and qualities from fall season to spring season in sod producing farm. It were found significantly difference found on turfgrass coverage, turf color, chlorophyll contents and growth increase on two species of cool season turfgrasses. Turfgrass coverage, chlorophyll content, turf color and growth increase of organic fertilizer preparation were significantly increased on creeping bentgrass cultivar and Kentucky bluegrass mixed cultivar for six time investigation in spring season. These results may indicate that the use of some preparation is beneficial for sod producing sod and turfgrass management.

• Asian Journal of Turfgrass Science
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• v.22 no.2
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• pp.133-140
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• 2008

The growth of root and shoot normally decline dramatically in mid-summer of Korea, moreover the cool-season turfgrassgrass eventually wither to death over $30^{\circ}C$. The increase of air temperature also drives the heat of soil, that makes stress on root system. The heat stress affects physiological mechanisms of hormonal unbalance that stimulates shoot growth, photosynthesis, and transpiration. To solve those problems, many studies have been carried out to control soil moisture and OM content to decrease soil temperature for dissolving the growth retardant by heat stress. This study initiated to analyze the change of soil temperature with soil moisture, and the effect of soil depth and moisture content on heat transmit and thermal changes on turfgrass growth(productivity, green color, and damage by dryness and high temperature). Kentucky bluegrass plots prepared with 25%, 33%, 40% soil moisture treatments. Soil temperature was measured every five min. with four thermo-sensors at 12 and 2 cm soil depth. The most acceptable growth showed at 33% soil moisture, but the worst result showed at 40%. The soil moisture seriously affected on the growth of Kentucky bluegrass, however the quality of turfgrass may acceptable if we can control soil moisture down to 33% when the flooding season of monsoon.

• Weed & Turfgrass Science
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• v.5 no.2
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• pp.71-81
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• 2016

This study was conducted to investigate the weed occurrence and distribution on the orchard fields (apple, pear, peach, grape) at 387 sites in Chungbuk province of Korea from May to September in 2015. From the result of this survey, 200 weed species in 47 families were identified and classified to 82 annuals, 40 biennials and 78 perennials. Based on the occurrence ratio, the most dominant weed species in Chungbuk province orchard fields were higher in order of Digitaria ciliaris (4.12%), Echinochloa crus-galli (3.60%), Stellaria aquatica (3.45%), Artemisia princeps (3.07%) and Chenopodium album (3.06%). The composition of major occurred weed families, Compositae, Poaceae, Leguminosae and Cyperaceae were 21, 9, 6 and 6%, respectively. Coefficient of similarity between a various orchards based on the degree of dominance were ranged from 68.7-91.8%. The most important weed species at apple, peach, grape was Digitaria ciliaris while these for pear was Poa annua. Fifty-one exotic weed species were also identified. The results of this study could be useful information for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods on the orchard fields in Chungbuk province of Korea.

• Journal of Korean Society of Forest Science
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• v.98 no.5
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• pp.609-617
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• 2009

This study was conducted to investigate ecological indicators of forest degradation after forest fire and clear-cutting in the Siberian larch (Larix sibirica Ledeb.) stand of Mongolia. The species abundance and biodiversity indices were higher in burned and clear-cut stands than those of reference stand, but boreal understory species, such as Vaccinium vitis-idaea, Pyrola incarnata, Linnea borealis and Maianthemum bifolium, completely disappeared and was replaced by sedge species, such as Carex duriuscula, C. lanceolata, C. pediformis, Poa attenuata and P. pratensis. During the research period, temperature increased by an average of $1.6^{\circ}C$ in burned stand and $1.7^{\circ}C$ in clear-cut stand compared to reference stand, but RH sharply decreased up to 15.7% in clear-cut stand. This result indicates that Larix sibirica stand became warmer and drier after forest fire and clear-cutting, and contributed to the abundance of sedge and grass species in the understory. Moreover, intense occupation of tall sedge grass after forest fire and clear-cutting had a vital role as obstacle on natural regeneration of Larix sibirica. The similarity of species composition between reference and burned stands was higher (73.6%) than between reference and clear-cut stands (63.8%). Soil moisture significantly decreased after forest fire and clear-cutting, and the extent of decrease was more severe in the clear-cut stand. The chemical properties at soil organic layer were significantly affected by forest fire and clear-cutting but not the mineral horizons. Inorganic nitrogen of the forest floor significantly decreased in the clear-cut stand ($1.1{\pm}0.4mg{\cdot}kg^{-1}$) than that of the burned ($4.5{\pm}2.3mg{\cdot}kg^{-1}$) and reference stands ($5.0{\pm}2.3mg{\cdot}kg^{-1}$). Available P of the forest floor significantly increased after fire, whereas it decreased after clear-cutting. These results indicate that existence of boreal understory vegetation, and changes in soil moisture and available P are distinct attributes applicable as ecological indicators for identifying forest degradation in Mongolia.

• Korean Journal of Environment and Ecology
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• v.32 no.1
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• pp.1-22
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• 2018

The purpose of this study is to provide the baseline data for conservation and management of Korean forest ecosystem by surveying and analyzing the vascular plants distributed from Gitdaebaegibong to Cheonghwasan in Baekdudaegan Mountains. The results are as follows. The numbers of vascular plants in the whole survey section were summarized as 771 taxa including 103 families, 379 genera, 623 species, 4 subspecies, 121 varieties and 23 forms. There were 377 taxa in A-section, 395 taxa in B-section, 278 taxa in C-section, 325 taxa in D-section, 534 taxa in E-section, and 406 taxa in F-section. The rare plants were 32 taxa including Megaleranthis saniculifolia, Rodgersia podophylla, Iris ensata var. spontanea, and Gastrodia elata. In IUCN Red List categories, there were 1 taxon of CR, EN, and DD each, 11 taxa of the VU, and 18 taxa of the LC. The Korean endemic plants were 26 taxa including Asarum versicolor, Clematis fusca var. coreana, Vicia chosenensis, Stewartia pseudocamellia, Carex okamotoi, and Luzula sudetica var. nipponica. The specific plants by floristic region were 143 taxa including 3 taxa of grade V, 12 taxa of grade IV, 41 taxa of grade III, 42 taxa of grade II, and 45 taxa of grade I. The naturalized plants were 41 taxa including Rumex crispus, Ailanthus altissima, Erechtites hieracifolia, Erigeron annuus, and Poa pratensis. The invasive alien plants were 4 taxa including Rumex acetocella, Sicyos angulatus, Ambrosia artemisiifolia, and Aster pilosus. The plants adaptable to climate change were 43 taxa including 14 taxa of endemic plants, 2 taxa of southern plants, and 27 taxa of northern plants.

• Korean Journal of Environment and Ecology
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• v.17 no.3
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• pp.201-209
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• 2003

This study was carried out to select proper species fur early stage replantation in forest road cut-slope. From one to fifteen years elapsed forest roads in four regional areas of Gyeongsangnam-do and Jeollanam-do, sample plots were selected, and their vegetations and environmental factors were investigated. Invaded species and plant coverage have increased with elapsed years. The occurrence rate of herbs have decreased, while the occurrence of trees have increased with elapsed years. The ordination analysis showed that distribution of species was influenced by the elapsed year, the slope angle of the cut-slope, elevation, and the direction angle of the cut-slope. Dactylis glomerata, Poa pratensis, Amorpha fruticosa, Lespedeza sp., Artemisia princeps var. orientalis, Duchesnea chrysantha, Miscanthus sinensis, Pueraria thunbergiana, Zanthoxylum schinifolium, Rhus chinensis, and Weigela subsessilis were considered as proper species for replantation in forest road cut-slope, besides the species used already. Seventy seven family, 190 genus, 233 species, 38 variety, and 271 species in total were counted as invaded plant species in the survey zone. Naturalized plants were 18 species. Invaded species are, with high frequency first, Rubus crataegifolius, Artemisia princeps var. orientalis, Zanthoxylum schinifolium, Pueraria thunbergiana, Pinus densiflora, Lespedeza maximowiczii, Lysimachia clethroides, Lespedeza bicolor, Youngia denticulata, Miscanthus sinensis, and Erigeron annuus.

• The Korean Journal of Mycology
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• v.44 no.3
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• pp.196-200
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• 2016

Symptoms of summer patch were observed on Kentucky bluegrass (Poa pratensis L.) cv. "Midnight II" from mid-June in 2015 in Seoul, Korea. The symptoms appeared as leaf blight, root rot, and frog-eye patch, which are typical of summer patch. To identify the causal agent of these symptoms, a pathogen was isolated from diseased leaves and roots, and the cultural, morphological, and phylogenetic characteristics were analyzed. The isolate reached 50-60 mm on potato dextrose agar (PDA) after 10 days as a white-grey mycelium with septa, and became olive-green or brown from the center. Phialide-like structures were observed at the ends of hyphae, and conidia were rarely observed. A phylogenetic analysis was conducted based on large subunit (LSU) and RNA polymerase II large subunit (RPB1) sequences. According to this analysis, the isolated pathogen was confirmed to be Magnaporthiopsis poae. In a pathogenicity test, summer patch symptoms were observed at 20 days after inoculation using the same grass cultivar. This is the first report of summer patch disease caused by M. poae on cool season grass in Korea.

• Weed & Turfgrass Science
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• v.5 no.1
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• pp.5-9
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• 2016

This survey was conducted to identify weed occurrence and to investigate weed management methods in the apple orchard fields in Chungnam province including Daejeon and Sejong from April to June and from September to October, 2015. In this survey, 64 weed species in 27 families including 39 annuals and 25 perennials were identified. Based on the importance values, the most dominant weed species in the first survey was Poa annua (6.51), followed by Veronica didyma (5.36), Plantago asiatica (5.36). In the second survey, Stellaria media (5.73), Digitaria ciliaris (5.36), and Rumex crispus (5.18) were dominant. When the 64 weed species were classified by family, the most abundant weed species belong to Compositae (12 species), followed by Poaceae (7 species), Polygonaceae (6 species), and Cruciferae (6 species). These 31 weed species in the most occurred four families accounted for 48% of total weed occurrence. Based on the questionnaire survey in which weed management methods in the apple orchard were asked, applied mowing + herbicide, mowing + tillage, and mowing + sod-culture was methods commonly conducted in apple orchard fields.