• Title/Summary/Keyword: population dynamics

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Biological Control of Garlic Blue Mold using Pantoea agglomerans S59-4 (Pantoea agglomerans S59-4를 이용한 마늘 푸른곰팡이병의 생물학적 방제)

  • Kim, Yong-Ki;Hong, Sung-Jun;Jee, Hyung-Jin;Park, Jong-Ho;Han, Eun-Jung;Park, Kyung-Seok;Lee, Sang-Yeob;Lee, Seong-Don
    • The Korean Journal of Pesticide Science
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    • v.14 no.2
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    • pp.148-156
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    • 2010
  • S59-4 isolate was evaluated as a potential biocontrol agent using in vivo wounded garlic bulb assay. When the spore suspension ($10^5$ spores/$m\ell$) of Penicillium hirsutum was co-inoculated with cell suspension of S59-4 isolate on wounded garlics, the isolate showed high suppressive effect to disease development. The isolate was identified as Pantoea agglomerans S59-4(Pa59-4) through Biolog system. Furthermore, soaking garlic bulbs in the suspension of Pa59-4 significantly reduced garlic decay caused by P. hirsutum. The optimal concentration of Pa59-4 for controlling garlic blue mold was $10^7\sim10^8$ cfu/$m\ell$. And suppressive effect of Pa59-4 on garlic storage decay reduced as inoculation concentration of Penicillium hirsutum increased. In addition in order to investigate population dynamics of Pa59-4 on application site of garlic cloves, two antibiotic markers, pimaricin and vancomycin were selected. Bacterial density of Pa59-4 on the wounded garlic cloves increased continuously both under room temperature condition and low temperature condition until 30days after application of Pa59-4, meanwhile that of Pa59-4 on intact garlic cloves increased until 15days after application of Pa59-4 and thereafter decreased continuously. Two culture media for mass-production of Pa59-4, LB medium and TSB medium, were selected. By-product of bio-fungicide formulated by mixing white carbon and bacterial suspension of Pa59-4 suppressed by 40 to 50% garlic blue mold. Above results suggest that Pa59-4 be a promising control agent against garlic blue mold.

Survival Rate on the Small Cyprinidae by PIT Tagging Application (소형 잉어과 어류의 PIT tag 적용을 위한 생존율 평가)

  • Jang, Min-Ho;Yoon, Ju-Duk;Do, Yuno;Joo, Gea-Jae
    • Korean Journal of Ichthyology
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    • v.19 no.4
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    • pp.371-377
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    • 2007
  • The passive integrated transponder (PIT) telemetry is a useful method for investigating fish population dynamics, community structure and migration. It can be applied for small fishes (TL<100 mm) because of its tiny size and light weight. The survival rate of PIT tag was investigated on 4 small size cyprindae fish species, Carassius gibelio langsdorfi (n=34, standard length; $91.9{\pm}0.9mm$, body weight; $21.2{\pm}0.9g$), Hypophthalmichthys molitrix (n=16, SL; $75.1{\pm}0.9mm$, BW; $6.0{\pm}0.2g$), Pseudorasbora parva (n=30, SL; $51.4{\pm}1.1mm$, BW; $2.7{\pm}0.2g$) and Phoxinus phoxinus (n=37, SL; $70.6{\pm}1.4mm$, BW; $8.2{\pm}0.5g$) under age 1 for applicability and effectiveness. We used three type tags including a small (length 11.0 mm, diameter 2.1 mm, weight 0.088 g), middle (20 mm, 3.5 mm, 0.102 g), large (30 mm, 3.5 mm, 0.298 g) size. After 30 days of tag insertion, survival rate of 117 individuals were 58.1% (large tag, 50.0%; middle tag, 57.5%; small tag, 61.4%). Survival rates varied between three types of tags because the abdominal cavity of each individual was different size. The death was due to surgical damage. If we apply tagging systems on field research of the Korean freshwater fish, the PIT tag will be effective method for analyzing fish ecology.

CHILDREN WITH CHRONIC CONVULSIVE DISORDER AND THEIR FAMILIES (경련성 질환 환아와 가족)

  • Cho, Soo-Churl;Kim, Boong-Nyun
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.13 no.1
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    • pp.67-75
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    • 2002
  • Objectives:This study was conducted to investigate the degree of psychopathologies of the family members of children with chronic convulsive disorder and evaluate the structures and dynamics of those families. Methods:The participant patients and family members were recruited from the population attending the outpatient clinic of department of pediatric neurology in Seoul National University Hospital in Korea. All the patients had idiopathic chronic convulsive disorder. Any patient with mental retardation, pervasive developmental disorder and gross brain pathology was excluded. As controls, normal students were chosen and their sex, age, achievement, socioeconomic status were matched to patients. The author interviewed the children and their family members twice and obtained informations about patient-parent relationship, patient-sibling relationship and others. For in-depth evaluation, we used family environment scales(FES), symptom Checklist-90-revised(SCL-90-R), self administered dependency questionnaire for mother(SADQ). Results:After interviewing with the parents of epileptic children, overprotection of parents, hostile feeling of siblings toward index children were higher than controls. The parental conflict was also more expressed than control families. According to results from FES, the scores of the subscales of expression, achievement-orientation, intelligence-orientation and active recreation were significantly lower than control group. The epileptic children showed higher dependency to parents especially in affection, communication and traveling areas of SADQ than control group. Maternal psychopathologies evaluated by SCL-90-R were much higher than the mothers of controls. According to T scores of SCL-90-R, about 40% of mothers with epileptic children had the risk of clinically significant depressive or anxiety disorders. Conclusion:These results suggested that the family members of epileptic children had more relationship problems and psychopathologies than control group and some mothers might have clinically significant depressive or anxiety disorders. so, effective psychiatric family interventions are needed for resolution of conflict and psychopathologies of family members.

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Radionuclide Cisternographic Findings in Patients with Spontaneous Intracranial Hypotension (자발성 두개내 저압 환자의 방사성 동위원소 뇌조조영술 소견)

  • Jung, Dong-Jin;Kim, Jae-Seung;Ryu, Jin-Sook;Shin, Jung-Woo;Im, Joo-Hyuk;Lee, Myoung-Chong;Jung, Sun-Joo;Moon, Dae-Hyuk;Lee, Hee-Kyung
    • The Korean Journal of Nuclear Medicine
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    • v.32 no.6
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    • pp.482-489
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    • 1998
  • Purpose: Radionuclide cisternography may be helpful in understanding pathophysiology of postural head-ache and low CSF pressure in patients with spontaneous intracranial hypotension. The purpose of this study was to characterize radionuclide cisternographic findings of spontaneous intracranial hypotension. Materials and Methods: The study population consists of 15 patients with spontaneous intracranial hypotension. Diagnosis was based on their clinical symptoms and results of lumbar puncture. All patients underwent radionuclide cisternography following injection of 111 to 222 MBq of Tc-99m DTPA into the lumbar subarachnoid space. Sequential images were obtained between 112 hour and 24 hour after the injection of Tc-99m DTPA. Radioactivity of the bladder, soft tissue uptake, migration of radionuclide in the subarachnoid space, and extradural leakage of radionuclide were evaluated according to the scan time. Results: Radionuclide cisternogram showed delayed migration of radionuclide into the cerebral convexity (14/15), increased soft tissue uptake (11/15), and early visualization of bladder activity at 30min (6/10) and 2hr (13/13). Cisternography also demonstrated leakage site of CSF in 4 cases and 2 of these were depicted at 30min. Epidural blood patch was done in 11 patients and headache was improved in all cases. Conclusion: The characteristic findings of spontaneous intracranial hypotension were delayed migration of radionuclide and early visualization of the soft tissue and bladder activity. These scintigraphic findings suggest that CSF leakage rather than increased CSF absorption or decreased production may be the main pathophysiology of spontaneous intracranial hypotension. Early and multiple imaging including the bladder and soft tissue is required to observe the entire dynamics of radionuclide migration.

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Bacterial Community Dynamics during Swine In vitro Fermentation Using Starch as a Substrate with Different Feed Additives for Odor Reduction

  • Alam, Md.J.;Jeong, C.D.;Mamuad, L.L.;Sung, H.G.;Kim, D.W.;Cho, S.B.;Lee, K.;Jeon, C.O.;Lee, Sang-S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.25 no.5
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    • pp.690-700
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    • 2012
  • The experiment was conducted by in vitro fermentation and bacterial community analysis to investigate the reduction of odorous compounds in response to the use of feed additives (FA) during carbohydrate overload in growing pigs. Soluble starch at 1% (control) and various FA at 0.1% Ginseng meal (FA1); Persimmon leaf (FA2); Gingko nut (FA3) and Oregano lippia (FA4) were added to fecal slurry and incubated anaerobically for 12 and 24 h. In vitro parameters and microbial diversity of the dominant bacteria following fermentation were analyzed using Denaturing Gradient Gel Electrophoresis (DGGE), band cloning and sequencing of the V3 region. Results showed that total gas production increased with the advancement of incubation (p<0.05). pH values of FAs and control groups were decreased except the FA4 group which increased somewhat from 12 to 24 h (p<0.05). Ammonia nitrogen ($NH_3$-N) and $H_2S$ gas concentrations were comparatively lower in both stages in FA4 treatment than in the other groups (p<0.05). Hence, $NH_3$-N concentrations in liquid phases were increased (p<0.05) from 12 to 24 h, but the trend was lowest in FA4 than in the other groups at both stages. The total VFA production was comparatively lower and butyrate levels were moderate in FA4 group than in the the other groups during both stages (p<0.05). Indirect odor-reducing compounds such as $NO_2$, $NO_3$ and $SO_4$ concentrations were higher in the FA4 and FA3 than in the other groups at 24 h (p<0.05). After fermentation, ten dominant bands appeared, six of which appeared in all samples and four in only the FA4 treated group. The total number of DGGE bands and diversity was higher in the FA4-group compared to other groups. Additionally, similarity indices were lowest (71%) in the FA4, which represented a different bacterial community compared with the other groups. These findings indicate that $NH_3$-N, $H_2S$ and VFA production was minimal, and pH was also better in the FA4 group than in the other groups. Furthermore, the conversion of odor-reducing indirect compounds or their intermediates was higher in the FA4 group in compared to the other groups. FA4 group generated less odorous products and more indirect products by in vitro fermentation at 24 h, and their microbial pattern appeared to differ from that of the other groups. These findings suggest that this particular FA could change the microbial population, which may have a beneficial effect on odor reduction. It is recommended that the oregano lippia may be supplied to growing pigs as FA along with excess carbohydrate sources to reduce the production of odorous compounds.

Ecophysiological Studies on the Population Dynamics of Two Toxic Dinoflagellates Alexandrium tamarense and Alexandrium catenella Isolated from the Southern Coast of Korea -I. Effects of Temperature and Salinity on the Growth (남해연안해역에서 분리한 유독와편모조류 Alexandrium tamarense와 Alexandrium catenella의 개체군 변화에 관한 생리.생태학적 연구 -I. 수온과 염분의 변화에 따른 성장 특성)

  • Oh, Seok-Jin;Park, Ji-A;Kwon, Hyeong-Kyu;Yang, Han-Soeb;Lim, Weol-Ae
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.15 no.2
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    • pp.133-141
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    • 2012
  • Effects of temperature and salinity on the growth of the toxic dinoflagellate $Alexandrium$ $tamarense$ and $A.$ $catenella$ isolated from the southern coast of Korea were examined in the laboratory. Growth experiment was conducted under the following combinations of temperature and salinity; 10, 15, 20, 25 and $30^{\circ}C$, 10, 15, 20, 25, 30 and 35 psu at a constant irradiance of 300 ${\mu}mol$ photons $m^{-2}s^{-1}$. Temperature and salinity conditions for maximum growth rate were indicated as follows: temperature $15^{\circ}C$ and salinity 30 psu (0.31 $d^{-1}$) in $A.$ $tamarense$, temperature $25^{\circ}C$ and salinity 30 psu (0.36 $d^{-1}$) in A. catenella. Temperature and salinity ranges for optimum growth condition of two species were $10{\sim}20^{\circ}C$, 25~35 psu and $120{\sim}30^{\circ}C$, 25~35 psu, respectively. The result of two-factor ANOVA indicated significant effects (P<0.001) of temperature and salinity on the growth rate, and two species were more effected by a temperature than a salinity on the growth. In addition, prediction equations were obtained through the multiple regressions of the specific growth rates as ${\mu}=0.04+0.0193T-0.0339S- 0.0005T^2+0.0021S^2+0.00073TS-0.000022T^3-0.000038S^3+0.00000086TS^2-0.0000255T^2S$ in $A.$ $tamarense$ and ${\mu}=1.01-0.1288T-0.0778S+0.0067T^2+0.0038S^2+0.00204TS-0.0001T^3-0.000059S^3-0.0000131TS^2-0.0000392T^2S$ in $A.$ $catenella$. Correlation coefficient between experimental values and simulated values was highly indicated. These results seem to provide information for understanding the spreading mechanism of $A.$ $tamarense$ and $A.$ $catenella$.

Occurrence and distribution of ALS inhibiting herbicide-resistant weeds in the paddy field of Gyeongnam province (경남지역 ALS 저해 제초제 저항성 논잡초의 발생 및 분포)

  • Lee, Yong Hyun;Shim, Soo Yong;Kim, Jin-Won;Lee, Jeongran;Park, Kee Woong;Lee, Jeung Joo
    • Weed & Turfgrass Science
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    • v.7 no.3
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    • pp.209-218
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    • 2018
  • This study was carried out to investigate the occurrence and distribution of ALS inhibiting herbicide-resistant weeds and to estimate the appeared areas of resistant weeds in the paddy fields of Gyeongnam province of Korea in 2017 and 2018 using a soil assay method. Compared with the 2012 survey, this study showed that the infested ratio of ALS inhibiting herbicide-resistant weeds increased from 1.0% to 66.8% and the infested area increased from 876 ha to 49,008 ha. The infested area of ALS inhibiting herbicide-resistant weeds was estimated in Ulsan-si (8.4%), Hapcheon-gun (8.3%), Haman-gun (7.9%), Goseong-gun (7.9%), Hadong-gun (7.3%), Jinju-si (7.2%), Changnyeong-gun (7.0%), Gimhae-si (6.4%), Miryang-si (5.5%), Busan-si (4.9%), Uiryeong-gun (4.6%), Namhae-gun (4.3%), Geochang-gun (4.2%), Changwon-si (3.8%), Geoje-si (2.9%), Yangsan-si (1.8%), Sancheong-gun (0.9%) and Tongyeong-si (0.4%), and the herbicide resistant weeds was not occurred in Hamyang-gun. The most dominant ALS inhibiting herbicide-resistant weeds in paddy fields were Monochoria vaginalis, followed by Echinochloa oryzicola, Lindernia dubia, Scirpus juncoides, Ludwigia prostrata, Cyperus difformis, Sagittaria trifolia and Rotala indica. ALS inhibiting herbicide-resistant M. vaginalis, L. dubia, and E. oryzoides occurred throughout Gyeongnam province, and ALS inhibiting herbicide-resistant S. trifolia and R. indica were only found in Gimhae-si. Therefore, these results will be utilized to estimate population dynamics of ALS inhibiting herbicide-resistant weeds and provide proper management practices in the paddy fields of Gyeongnam province.

A Multi-agent System to Assess Land-use and Cover Changes Caused by Forest Management Policy Scenarios (다행위자시스템을 이용한 산림정책별 토지이용 변화와 영향 분석)

  • Park, Soojin;An, Yoo Soon;Shin, Yujin;Lee, Sooyoun;Sim, Woojin;Moon, Jiyoon;Jeong, Gwan Young;Kim, Ilkwon;Shin, Hyesop;Huh, Dongsuk;Sung, Joo Han;Park, Chan Ryul
    • Journal of the Korean Geographical Society
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    • v.50 no.3
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    • pp.255-276
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    • 2015
  • This paper presents a multi-agent system model of land-use and cover changes, which is developed and applied to the Gariwang-san and its vicinity, located in Pyeongchang and Jeongseon-gun, Gangwon province, Korea. The Land Use Dynamics Simulator (LUDAS) framework of this study is well suited for representing the spatial heterogeneity and dynamic interactions between human and natural environment, and capturing the impacts of forest-opening policy interventions to future socio-economic and natural environment changes. The model consists of four components: (1) a system of human population, (2) a system of landscape environment, (3) decision-making procedures integrating human(or household), environmental and policy information into forest land-use decisions, and (4) a set of policy scenarios that are related to the forest-opening. The results of model simulation by different combination of various forest management scenarios are assessed by the levels of household income, ecosystem service value and income inequality in the study region. As a result, the optimal scenario of forest-opening policies in the study region is to open the forest to local residential community for the purpose of recreation, considering the distinctive topographical feature. The model developed in this research is expected to contribute to a decision support system for sustainable forest management and various land-use policies in Korea.

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Development of animal protein(feed for fry) utilizing the rumen ciliates (제1위 섬모충(rumen ciliates)을 이용한 동물성 단백질(치어용 사료) 개발)

  • Jee, Cha-ho;Hyun, Gong-yool
    • Korean Journal of Veterinary Research
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    • v.35 no.2
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    • pp.327-336
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    • 1995
  • This study was carried out to develop the animal protein(feed for fry) that was isolated, purified and lyophilized the rumen ciliates from the healthy rumen contents which have $10^5-10^6/g$ ciliates and were discarded in abattoirs. The rumen ciliates are non-pathogenic, anaerobic and the weight of this protozoa is 2% of rumen content. The rumen protozoan and bacterial proteins both have a biological value for rats of 80-81, which is higher than the 72 of brewer's yeasts. Furthermore, the true digestibility and net protein utility of the protozoan protein are 91 and 73, much higher than those of bacterial(74 and 60) or yeast(84 and 60) proteins. The amino acids of rumen protozoa is nutritionally superior than the others. The size of rumen ciliates is $30-200{\times}20-110{\mu}m$ and so we had isolated and purified the rumen ciliates from the rumen contents by the physical methods. The purified rumen protozoa was lyophilized with freezing dryer. The results of this experiment were as follows : 1. Population dynamics of protozoan ciliates in slaughtered rumens; % of samples which small ciliates were predominated was 82.5%(52/63) and that of large ciliates was 17.5%(11/63). 1) predominant species of small ciliates were Entodinium ovinum and E nanellum. 2) predominant species of large ciliates were Epidinium ecaudatum and Diploplastron affine. 2. The lyophilized rumen ciliates which were isolated and purified from 1 kg of rumen content at the pH 6.2-6.8 was about 7.0 gram. 3. The nutrient analysis of lyophilized rqmen ciliates(LRC) was as follows: 1) Proximate analysis of the LRC and the composition of fry feed; moisture 8.05%(below 10.0), protein 35.37%(45), fat 5.39%(4.5), fiber 1.23%(below 2.5), ash 2.25%(below 15.0), Ca 0.26%(below 2.0), P 0.14%(below 1.1), energy 4,608.11(fish meal 5000 cal/g) 2) Amino acids (% in crude protein) of the LRC and the rotifer(Brachionus plicatilis); Arg 5.19%(4.50), His 2.50%(1.55), Ile 5.29%(3.45), Leu 8.11%(5.85), Lys 10.34%(6.15), Met 2.25% (0.85), Phe 5.66%(3.80), Thr 5.14% (3.45), Val 4.18%(3.90), Ala 4.13%(3.35), Asp 13.26%(8.25), Glu 16.62%(9.20), Gly 4.23%(3.10), Pro 3.25%(5.05), Ser 4.85%(3.85), Tyr 5.04%(3.05) 3) Fatty acids(% in fat) of the LRC and the rotifer(biological feed ; Brachionus plicatilis); myristic acid(C14:0) 3.27%(0.3), myristoleic acid(C14:1) 0.83%(-), palmitic acid(C16:0) 39.11% (23.5), palmitoleic acid(C16:1) 2.81%(2.0), stearic acid(C18:0) 9.36%(5.6), oleic acid(C18:1) 25.54%(3.5), linoleic acid(C18:2) 15.05%(32.9), linolenic acid(C18:3) 1.74%(9.8). Judging from the above investigated results, the analytical data of proximate analysis, amino acids, fatty acids of the purified and lyophilized rumen protozoa are reasonable for the feed of freshwater fishes(fry and fingerling). But it was disappointed of our expectation that the crude protein of lyophilized rumen ciliates contains low percentage, it was thought that because of the small ciliates(starch digester) in beef cattle rumens which were administered the concentrated feed, is much difficult to isolate and purify than the large ciliates(fiber digester).

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A Survey of Weed Occurrence on Paddy Field in Korea (국내 논잡초 발생분포조사)

  • Ha, Huen-Young;Hwang, Ki Seon;Suh, Su Jeoung;Lee, In-Yong;Oh, Young-Ju;Park, Jungsoo;Choi, Jun-Keun;Kim, Eun Jeong;Cho, Seung Hyun;Kwon, Oh-Do;Im, Il-Bin;Kim, Sang-Kuk;Seong, Deok-Gyeong;Chung, Young-Jae;Lee, Wook-Jae;Kim, Chang-Seok;Lee, Jeongran;Park, Jae-Eup;Park, Kee Woong
    • Weed & Turfgrass Science
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    • v.3 no.2
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    • pp.71-77
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    • 2014
  • Surveys of weed species in paddy fields were conducted in Korea to identify weed occurrence from June to September 2013. Total 3,434 sites of paddy fields in 155 City/Gun, eight Provinces were investigated. From the nation-wide survey, 90 weed species in 28 families were identified and classified to 52 annuals, 3 biennials and 35 perennials. Based on the occurrence ratio, the most weed species belonged to Poaceae (18 species). 17, 8 and 6 weed species belonged to Cyperaceae, Scrophulariaceae and Polygonaceae, respectively, and these 49 weed species in the most four families accounted for 54% of total weed occurrence. The most dominant weed species in Korean paddy fields were Echinochloa spp. (17.4%), followed by Monochoria vaginalis (12.4%), Eleocharis kuroguwai (7.8%), Bidens tripartite (9.27%), Scirpus juncoides (6.2%) and Sagittaria sagittifolia (6.1%). This information could be useful for estimation of future weed occurrence, weed population dynamics and establishment of weed control methods in paddy fields of Korea.