• The Plant Pathology Journal
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• 제39권4호
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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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• 제6권3호
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• pp.165-178
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• 2017

작약 밭에서 잡초의 발생 특성을 파악하기 위하여 2015년 6-7월에 경북 의성, 청송, 전남 화순, 장흥, 강진 등의 지역에서 조사한 결과를 보면 다음과 같다. 전체 작약 밭에서는 국화과 30종, 벼과 9종, 마디풀과 8종, 콩과, 메꽃과 각각 5종, 십자화과, 현삼과 각각 4종을 포함하여 35과 105종이 발생하였다. 생활형별로는 일년생 49종, 월년생 23종, 다년생 33종이었다. 우점도가 큰 잡초는 바랭이, 쇠비름, 명아주, 피, 깨풀 등의 순이었다. 경북지역에서는 국화과 20, 벼과 7, 마디풀과 6, 십자화과 4종, 콩과 4종, 메꽃과 4종, 대극과 3종을 포함하여 30과 75종이 발생하였다. 상위 2개 과에 포함하는 잡초가 31종으로 44.7%를 차지하였다. 생활형별로는 일년생 35종, 월년생 21종, 다년생 19종이었다. 우점도가 큰 잡초는, 쇠비름, 깨풀, 명아주, 속속이풀, 피 등의 순이었다. 전남지역에서는 국화과 23종, 벼과 7종, 마디풀과 8종, 콩과 6종을 포함하여 34과 88종이 발생하였다. 생활형별로는 일년생 43종, 월년생 20종, 다년생 25종이었다. 우점도가 큰 잡초는 바랭이, 쑥, 쇠비름, 망초, 명아주, 개여뀌, 피 등의 순이었다. 이와 같이 작약 재배지에서 일년생, 월년생 및 다년생 잡초가 다양하게 발생하고 있어 이에 따른 잡초방제 체계가 설정되어야 할 것으로 생각된다.

• Ecology and Resilient Infrastructure
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• 제5권2호
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• pp.94-104
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• 2018

The Soyangho Reservoir in Korea has a large drawdown zone, with an annual maximum water level fluctuation of 37 m due to dam operations to maintain a stable water supply and control flooding, especially during the monsoon period. The floristic composition, distribution and biomass of the major plant communities in the drawdown zone of the Soyangho Reservoir were assessed in order to understand their responses to the wide water level fluctuation. Species richness of vascular plants was low, and species composition was dominated by herbaceous annuals. Principal coordinates analysis using both flora and environmental data identified slope angle and the distance from the dam as important factors determining floristic composition. The species richness was low in the steep drawdown zone close to the dam, where much of the soil surface was almost devoid of vegetation. In shallower slopes, distant from the dam plant communities composed of mainly annuals were found. The large fluctuation in water level exposed soil where these annuals could establish. An overall biomass of 122 t (metric tons) Dry Matter was estimated for the reservoir, containing ca 3.6 t N (nitrogen) and ca 0.3 t P (phosphorus); the role of the vegetation of the drawdown zone in carbon sequestration and water pollution were briefly discussed.

• The Korean Journal of Ecology
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• 제19권4호
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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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• 제43권2호
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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.

• Weed & Turfgrass Science
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• 제4권3호
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• pp.236-242
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• 2015

제주도의 밭을 대상으로 141지점을 선정하여 조사를 진행하였다. 제주도 밭에 발생하는 외래잡초 조사결과 18과 50속 64종 2변종, 총 66분류군의 외래잡초가 조사되었고 동계작물 재배지에서는 18과 45종, 하계작물 재배지에서는 16과 50종, 다년생 작물 재배지에서는 17과 39종이 출현하였다. 외래잡초의 생활형은 하계일년생 잡초가 39.4%, 동계일년생은 잡초는 36.4%, 하계일년생과 동계일년생이 모두 가능한 잡초는 7.6%, 다년생 잡초는 16.7%로 분석되었다. 특히 하계작물 재배지에서 하계일년생 잡초의 비율이 높았다. 종의 과별 분포순위는 국화과, 벼과, 아욱과가 우점하는 것으로 분석되었으나 다년생 작물 재배지에서는 아욱과는 출현하지 않았다. 제주도의 동계작물 재배지에서 우점하는 외래잡초는 흰명아주, 청비름, 개쑥갓, 냄새냉이, 들개미자리였고 하계작물 재배지에서는 흰명아주, 청비름, 개쑥갓, 방가지똥이었다. 다년생 작물 재배지에서는 큰망초, 선풀솜나물, 개쑥갓, 흰명아주로 조사되어 다른 작물과 차이를 보였다. 제주도 전체 밭에서 발생하는 외래잡초의 우점종은 흰명아주, 청비름, 개쑥갓, 큰망초, 방가지똥 등으로 분석되었다. 제주도에 발생하는 외래잡초의 발생정보는 밭의 지속적인 관리방안을 수립하는데 도움이 될 것이다.

• Journal of Ecology and Environment
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• 제29권4호
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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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• 제6권2호
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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.

• 농업과학연구
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• 제44권3호
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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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• 제9권1호
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• pp.73-78
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• 1986

The effects of density and soil nutrient regime on competition between individuals in pure and mixed populations of two annuals. Chenopodium album and Digitaria sanguinalis were investigated at the level of enegy allocation. Seedling emergence of two species was extremely high (>90%) in both pure and mixed culture irrespective of the density and nutrient regime, but percentage of seedling establishment or fertile plant became gradually low with increasing density owing to 'self-thinning'. The mean plant dry weight was significantly reduced with increasing density and decreasing soil fertility. The dry matter production of D. sanguinalis in mixture was markedly greater than in pure culture under medium and high density. Also, as considered the number of seed production as reproductive allocation, relationship between them and the number of seed production per plant showed a similar tendency. Therefore, these results indicated that D. sanguinalis had a greater competitive advantage than C. album and energy allocations to variious organs were regulated by plastic response rather than determined genetically.