• The Plant Pathology Journal
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• v.39 no.4
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• pp.374-383
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• 2023

Capsicum annuum (CA) is grown outdoors across fields in Jeollabuk-do, South Korea. The weeds surrounding these fields were investigated regarding the infection of 11 viruses infecting CA during the year 2014-2018. In the reverse transcription polymerase chain reaction diagnosis, 546 out of 821 CA samples (66.5%) were infected by nine viruses, and 190 out of 918 weed samples (20.7%) were infected by eight viruses. Correlation analysis of the mutual influence of the viruses infecting CA and weeds during these 5 years showed that five viruses had significant positive correlations with the infection in both CA and weeds. Over the study period, the weeds infected by cucumber mosaic virus (CMV) in the previous year were positively correlated with the incidence of CMV infection in CA in the current year, although the correlation was lower for tomato spotted wilt virus (TSWV) compared to CMV. The CMV infection percent was 14.0% in summer annuals, 11.4% in perennials, and 7.8% in winter annuals. However, considering the overwintering period without CA, the infection percent was 5.2% higher in winter annuals and perennials than that in summer annuals, indicating that winter annual and perennial weeds served as the main habitats for insect vectors. The TSWV infection percent in weeds was 10.4% in summer annuals, 6.4% in winter annuals, and 6.2% in perennials. The weeds surrounding CA fields, acting as the intermediate hosts, were found to be the potent sources of infection, influencing the spread and diversity of CA-infecting viruses. The results of this study can contribute to prevent viral infection in agricultural fields.

• Weed & Turfgrass Science
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• v.6 no.3
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• pp.165-178
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• 2017

This study was carried out to investigate the characteristics of weeds occurring in paeony field in June and July, 2015 in Uiseong, Cheongsong of Kyungbuk province, and Hwasun, Jangheung, Gangjin of Jeonnam province. In total paeony field, there were 35 families and 105 species, including 30 species of Asteraceae, nine species of Poaceae, eight species of Polygonaceae, and each five species of Fabaceae and Convolvulaceae, By life style, there were 49 species of annuals, 27 species of winter annuals and 24 species of perennials. In Kyeongbuk province, 30 families and 75 species were found including 20 species of Asteraceae, seven species of Poaceae, six species of Polygonaceae, each four species of Brassicaceae, Fabaceae and Convolvulaceae, three species of Euphorbiaceae. By life style, there were 35 species of annuals, 21 species of winter annuals and 19 species of perennials. In Jeonnam province, 34 families and 88 species were found including 23 species of Asteraceae, seven species of Poaceae, eight species of Polygonaceae, six species of Fabaceae and four species of Scrophulariaceae. By life style, there were 43 species of annuals, 15 species of winter annuals and 25 species of perennials. Therefore, there are various occurrences of annual, annual, and perennial weeds in peony fields, and weed control system should be set up accordingly.

• Journal of Ecology and Environment
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• v.29 no.4
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• pp.353-360
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• 2006

Ecological correlates of flowering times often are examined to infer evolutionary mechanisms for flowering time diversities. We examined ecological characteristic associations such as growth habits and pollination modes with flowering times among 3,037 Korean angiosperms experiencing strong climatic seasonalities. We first examined taxonomic membership effects on flowering times across diverse taxonomic levels. Phylogeny constrained flowering times at all levels down to the genus level. We then analyzed the effects of ecological characteristics using subset data consisting of species randomly selected from each genus to control phylogenetic effects. The commonly observed patterns of early flowering of woody species in temperate regions existed. Spring flowering shrubs and trees, however, both being woody, were involved with biotic and abiotic vectors, respectively. In two herbaceous groups of annuals and perennials, annuals flowered later in the growing season than perennials although both herbs tended to be associated with abiotic vectors when flowering in autumn. These results support our hypothesis that species able to decouple vegetative and reproductive growth flower in spring's dry season, but species with different habits, even when they flower within the same season, are subjected to different selective pressures for efficient pollination.

• Weed & Turfgrass Science
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• v.6 no.2
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• pp.109-116
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• 2017

This study was carried out two surveys in 2015 to monitor weed occurrence and determine the most troublesome weeds in peach orchards of Korea. The first survey identified 56 taxa belonging to 23 families including 27 annuals, 11 biennials, and 18 perennials. Based on importance values, Conyza canadensis (5.12%), Plantago asiatica (4.17%), and Trifolium repens (3.86%) were the dominant weeds in the first survey (from April to June). Seventeen exotic weeds were identified in the first survey, including Conyza canadensis, Trifolium repens, and Chenopodium ficifolium. The second survey (from September to October) identified 42 weeds belonging to 19 families including 23 annuals, 5 biennials, and 14 perennials. According to importance values, Digitaria ciliaris (8.00%) was the most dominant weed, followed by Echinochloa utilis (6.61%) and Rorippa palustris (6.48%). There were 12 exotic weeds, including Taraxacum officinale, Rumex crispus, and Trifolium repens. Additionally, according to Braun-Blanquet's scale showed that the dominance value was level 1 (41.98% and 46.43%, respectively) in two surveys. Currently, 40% of the total surveyed peach orchards applied herbicides for weed control. These results could provide basic data to assist orchardists in selecting the most suitable weed management methods; thereby, reducing labor inputs and effectively lowering costs while improving fruit yields in peach orchards of Korea.

• Korean Journal of Agricultural Science
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• v.44 no.3
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• pp.325-331
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• 2017

This study was conducted to investigate the dominance and distribution of weed species in organic and conventional paddy fields. The organic paddy fields were maintained for organic farming for more than five years in Anseong, Gyeonggi province of Korea. According to the Braun-Blanquet method, 42 and 36 weed species were found in the organic paddy fields in 2015 and 2016, respectively, while 38 and 36 weed species were found in the conventional paddy fields in 2015 and 2016, respectively. As a result of two years' survey, 53 species from 24 families in the organic paddy fields were identified and classified as 32 annuals, 3 biennials and 18 perennials. In conventional paddy fields, 51 species from 24 families (30 annuals, 6 biennials, and 15 perennials) were identified. According to the classification by family, the most abundant weed species were Compositae (9 species), followed by Poaceae (8 species) and Polygonaceae (6 species) in organic paddy fields. In conventional paddy fields, Compositae (9 species) were the most abundant weed species, followed by Cruciferae (6 species), Poaceae, Polygonaceae, and Cyperaceae. This result indicates that the difference in diversity of weeds in paddy fields was influenced more by the agricultural environment than the type of cultivation. Our results could be used as a base data to control the occurrence of weed species in the paddy fields.

• The Korean Journal of Ecology
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• v.19 no.4
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• pp.341-351
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• 1996

In order to elucidate the differences in early successional development among similary aged old-fields having different soil nitrogen (N), caused by the land use history before at abandonment, the response of plant community along an experimental nitrogen gradient (control plot (No), plot NI with 5.8g $N/m^2$, plot N2 with 11.7g $N/m^2$ and plot N3 with 23.3g $N/m^2$) was investigated in a five-year-old abandoned field. Although the N content in soil among treatments was similar at the end of the growing season, N concentrations in plant tissue increased with the amount of N supplied. These results suggest that almost all the N contained in N-enriched soil might be absorbed by plants during the growing season after N supply. Vegetation tended to grow vigorously by nitrogen supply, and the standing biomass increased significantly in plots NI and N2 . Species richness of plants, especially of annuals and perennials, was more reduced than the control plot, and the species diversity was also reduced by N supply. The importance value (IV) of species by N supply differed in each species along the position on the successional sere: Artemisia princeps var. orientalis as the dominant species in this old-field decreased slightly; annuals as the earlier successional species decreased clearly along nitrogen gardients; Erigeron annuals as the earlier successional species and as a strong competitor with Artemisia princeps var. orientalis had the highest IV by small N supply; Miscanthus sinensis and Rubus crataegifolius as the later successional species increased by large N supply. These results suggest that old-fields with high soil N might show the structural and functional characteristics of the earlier successional stages, but community composition in those old-fields might be changed more quickly from the sarlier successional species than the later successional species.

• Journal of Ecology and Environment
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• v.43 no.2
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• pp.129-160
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• 2019

Background: Characterizing and describing soils and land use and make a suggestion for sustainable utilization of land resources in the Ethiopian Rift valley flat plain areas of Lake Chamo Sub-Basin (CSB) are essential. Objectives: To (1) characterize soils of experimental area according to World Reference Base Legend and assess the nature and extent of salinity problems; (2) characterize land use systems and their role in soil properties; and (3) identify best land use practices used for both environmental management and improve agricultural productivity. Methods: Twelve randomly collected soil samples were prepared from the above land uses into 120 composites and analyzed. Results: Organic carbon (OC) and total nitrogen (TN) were varied along different land uses and depleted from the surface soils. The soil units include Chernozems (41.67%), Kastanozems (25%), Solonchaks (16.67%), and Cambisols (16.67%). The identified land uses are annual crops (AA), perennial crops (PA), and natural forest (NF). Generally, organic carbon, total nitrogen, percentage base saturation (PBS), exchangeable (potassium, calcium, and magnesium), available phosphorus (P₂O₅), manganese, copper, and iron contents were decreased in cultivated soils. Soil salinity problem was observed in annuals. Annuals have less nutrient content compared to perennials in irrigated agriculture while it is greater in annuals under rainfed. Clay, total nitrogen, available phosphorus, and available potassium (K₂O) contents were correlated positively and highly significantly with organic carbon and electrical conductivity. Conclusion: Management practices that improve soil quality should be integrated with leguminous crops when the land is used for annual crops production.

• Asian Journal of Turfgrass Science
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• v.2 no.1
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• pp.59-64
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• 1988

This study was carried out to investigate the classification and the growing charicteristics of weed species in a newly formed lawngrass land. The results obtained are summarized as follows: 1)Weed population in a newly formed lawn field consisted of 30% of Gramineae, 15% of Compositae, and 12% of Leguminosae family. 2)Percentage of weed emergence between April and May was 39.4%. The same amount of weed emergence was observed at the period of September and October, where as the percentage was 21.2% at the period of March and April. 3)The population ratio of flowering date of weed species was in order of 48.5% July and August, 30.3% in May and July, 12.1% in March and April, and 9.1% in September and October. 4)Weed classification by life cycle showed 39.4% of biennials, 33.3% of annuals, and 27.3% of perennials. 5)Weed species were grouped according to the plant height. The ratios of each group were 33.3% of 20~40cm group, 27.3% of 40~60cm group, 24.2% of shorter than 20cm group, and 15.2% of taller than 60cm group.

• Asian Journal of Turfgrass Science
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• v.4 no.1
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• pp.31-41
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• 1990

About 117 weed species composed of 44 annuals, 26 biennials, and 47 perennials belonging to 36 families were identified from golf fields in both Anyang an Taegu country clubs on May and September, 1989. Graminae was the most widely occuring family covering 21 species, followed by 14 species in compositae, 8 species in leguminosae, polygonaceae and caryophyllaceae respectively, and 5 species in cyperacae etc. The highest numbers of weed species occured in the rough area in golf fields, followed by tee, fairway and green area in orders. The dominant weed species in golf fields based on importance value and frequency were Digitaria Sanguinalis, Poaannua, Polygonum aviculare, Trifohum repens, Plan tago asiatica, Capsella bursa-pastoris Rumx acetocella and Kyllinga brevifolia.

• Asian Journal of Turfgrass Science
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• v.7 no.2_3
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• pp.67-80
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• 1993

About 154 weed species composed of 31 annuals, 33 biennials, and 90 perennials belonging to 38 families were identified from golf courses in Dongrae, Joongmoon and Ora country clubs on June and September, 1992. Compositae was the most widely occurring family covering 30 species, followed by 28 species in Graminae, 12 species in Leguminasae and Rosaceae, respectively, and 7 species in Caryopbyllacese etc. The bighest number of weed species occurred in the out of bounds in three golf courses, The dominant weed species based on importance value and frequency were Hydrocotyle sibthorpioides, Poa annua, Cyperus rotundus, Oxalis corniculata, Digitaria sanguinalis and Artemisia prinseps.