• Korean journal of applied entomology
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• v.49 no.2
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• pp.115-121
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• 2010

The bean bug, Riptortus clavatus Thunberg (Hemiptera: Alydidae), is a pest of soybeans and tree fruits. It enters reproductive diapause during winter. We studied the effect of different combinations of temperature, day length, and treatment period on the termination of diapause in R. clavatus using adult females collected in October and November 2006. Ovarian development was used to determine diapause termination. The treatments were: (1) HTLD; $25^{\circ}C$, 14L:10D treatment for 1, 2, 3 weeks and 30 days, (2) HTSD; $25^{\circ}C$, 10L:14D treatment for 1, 2, and 3 weeks, (3) LTLD; $8^{\circ}C$, 14L:10D treatment for 1, 2, and 3 weeks followed by HTLD for 3 weeks, and (4) LTSD; $8^{\circ}C$, 10L:14D treatment for 1, 2, and 3 weeks followed by HTLD for 3 weeks. The HTSD treatments did not affect ovarian development, and resulted in no significant difference in the number of mature eggs in ovaries or the percentage of diapause-terminated females compared to the control females before treatment. The percentage of females that terminated diapause was significantly higher in the HTLD treatment than in the HTSD treatment. The HTLD treatment for more than 14 days increased the percentage of diapause-terminated females, accelerated the development of the ovaries, and increased the number of mature eggs in ovaries. Compared with the HTLD or HTSD treatments, the LTLD or LTSD treatments followed by the HTLD treatment accelerated ovarian development and increased the number of ovipositing females. The pre-LTSD treatment for 1 week was enough to increase the number of eggs oviposited.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.29 no.5
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• pp.557-566
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• 1996

An ecological study on pathogenic vibrios was done in the aquatic environments of southern coast of Korea during summer in 1995, to investigate the distribution and relationship between pathogenic vibrio and zooplankton. Furthermore, special emphasis was given to study on the efforts of zooplankton existence on the wintering of Vibrio cholerae in the aquatic region in Korea. During the study period, pathogenic vibrios were isolated from the samples such as V. parahaemolyticus, V. vulnificus, V. mimicus, and V. cholerae non O1, but V. cholerae O1 was not detected in any sample submitted in this study. Adsorption ratio of V. parahaemolyticus onto zooplankton was higher than that of E. coli. The efficiency of adsorption was found to be on the concentration of NaCl and other ions found in sea water. For example, adsorption ratio of V. parahaemolyticus were $75\%\;at\;5\%_{\circ}$ of NaCl solution and $55\%$ at same salinity of diluted sea water, but those were decreased as $20\%\;and\;7\%\;at\;15\%_{\circ}$ salinity of NaCl solution and diluted sea water, respectively. In addition, survival period of pathogenic vibrio was extended in the presence of live copepods at $25^{\circ}C$, but zooplankton existence has no significant effect on the survival rate at $5^{\circ}C$ in closed microcosm and also microalgae and dead copepods do not affect on the survival of V. parahaemolyticus. According to these experimental results, zooplankton has positive effects on the growth and survival rate of pathogenic vibrios in sea water during the summer season, but copepods have no significant effects on the growth and survival rate of them in winter season in Korea. Finally, authors suggest that V. cholerae is not able to over winter with zooplankton in adjacent sea water in Korea.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.1
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• pp.61-73
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• 2018

The objective of this study was to investigate the suitable method for rapid establishment of grassland according to forage species, mixed pastures and installation of mesh at 35 degree angle of cutting area in the middle region of Korea. In agronomic characteristics after wintering, vegetation coverage of Tall fescue(TF) was 74% in monoculture, which was the highest among 3 forage crops. Meanwhile average vegetation coverages of monoculture and mixed pasture were 67 and 92% in treated of mesh, which were 4 and 18% higher than untreated of mesh, respectively. In botanical composition, TF of monoculture and Orchardgrass(OG) and TF oriented mixed were indicated over 94% forage coverage. Meanwhile forage coverages Kentucky bluegrass(KBG) and Red top(RT) of monoculture and Perennial ryegrass(PRG) oriented mixture were 89, 81 and 92% in treated of mesh, which were 7, 6 and 5% higher than untreated of mesh, respectively. In forage productivity, dry matter yield(DMY) of TF(12,537kg/ha) and KBG(11,897kg/ha) of monoculture were significant(p<0.05) higher than RT(9,604kg/ha). Meanwhile DMY of OG(12,227kg/ha), TF(12,823kg/ha) and PRG(11,871kg/ha) oriented mixed were not significant difference(p>0.05). In forage quality of monoculture, in the first year, crude protein of KBG was 13.6%, which was the highest among 3 forage species. Also neutral detergent fiber(NDF) of TF was 56.5%, which was the lowest among 3 forage species. In mixed pasture, in the second year, NDF and acid detergent fiber of PRG oriented mixed were 56.5 and 34.3%, respectively, which was the lowest among 3 mixed pasture. In conclusion, forage species TF was more suitable on initial rootage and continuous forage coverage, OG and TF oriented mixed were more suitable on continuous forage coverage. Also the installation of mesh showed positive effects on initial rootage and maintain forage ratio.

• Korean Journal of Plant Resources
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• v.28 no.5
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• pp.608-615
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• 2015

Garlic (Allium sativum L.) has been used as both food and medicine in many cultures for thousands of years. Garlic cultivars are completely sterile and propagated through vegetative method. Collection of a large number of fertile accessions of these genus is needed to explore genetic variability. In order to investigate genetic variation among Allium species and its possibilities for direct cultivation in Korea, we characterized 12 accessions of A. longicuspis, flowering wild garlic which had collected from Central Asia, the main center of garlic diversity. Most of A. longicuspis accessions showed higher over-wintering and bolting rate, longer scape length and more number of bulbils than Korean landraces cultivar, Danyang and Euiseong, but A. longicuspis accessions exhibited smaller size of bulbs and bulbils. Most accessions of A. longicuspis had more number of cloves per bulb, except K229596 and K248824 than Korean landraces. All the accessions of A. longicuspis from Central Asia had complete bolters having many flowers and topsets in umbel. Further studies of A. longicuspis should focus on securing true seeds through removal of topsets and crosses among accessions to create the genetic variability.

• Journal of The Korean Society of Grassland and Forage Science
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• v.29 no.2
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• pp.111-120
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• 2009

There are barley, wheat, oat, rye and triticale winter cereal crops for whole crop silage. These small grains have been suitable to use for round-baled silage making as livestock feed. Studies were carried out to understand the growth and productivity of five winter cereals grown at paddy field in middle region of South Korea. The ratio of culm weight per plant were described by quadratic function for 5 winter cereals crops. The peak of culm ratio were 1 May in barley variety 'Youngyang', 5 May in wheat variety Keumkang', 10 May in rye 'Gogu'(Rye), 11 May in triticale variety 'Shinyoung' and 13 June in oat variety 'Samhan', respectively. The ratio of leaf per plant were linearly decreased by growing. In barley and oat, the ratio of spike weight per plant were linearly increased after heading, but in wheat and triticale, it were not accumulated at one time after heading and rapidly increased after fertilization. The ratio of spike weight per plant in barley was outstandingly higher than that of wheat, triticale, rye and oat, respectively. So, barley variety 'Youngyang' recommended for whole crop forage use was suitable for forage use because of high at ratio of the leaf and spike. The proper cutting date by the percentage of dry matter for baled-silage making, 30$[\sim}$40%, were 25 May in barley variety 'Youngyang', 25 May to 5 June in wheat variety 'Keumkang' and triticale variety 'Shinyoung', 15 May in rye 'Gogu' and 5 June in oat variety 'Samhan', respectively. The total aerial fresh weight accumulation at different cutting dates were described by quadratic function for barley, wheat and triticale. The forage fresh yield were peaked at 7 May in barley, 14 May in wheat, 17 May in triticale and late of May in oat, respectively. The dry matter yields of four small cereals were linearly increased after over-wintering. The yield at the date of proper harvesting time by water content for baled silage making were sequently high oat, barley, wheat, triticale and rye. The relative growth rate was relatively high in rye at early cutting but high in oat at late cutting. In barley, wheat and triticale, the rate were similar.

• Korean Journal of Medicinal Crop Science
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• v.1 no.2
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• pp.115-119
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• 1993

This study was carried out to determine optimum harvest time of in vitro multiplied tuber Pinellia ternata(Thunb.)Breit from 1990 to 1992. Tuber yield and its related traits were observed with four harvest times. Plant height was 7.2cm at 6 months and 19.3cm at 24 months after planting. The number of tubers per unit area was significantly increased with the passage of growing time after planting$(78\;tubers/m^2)$, those were increased by 2.3 times in 6 months, 5.6 times in 12 months, 13.3 times in 18 months and 20.0 times in 24 months. The tuber sizes(length, width and weight) were highly enlarged during 12 to 18 months after planting compared with before or after this time. There were smaller tubers and lower tuber yields with shorter growing period, while large tubers above 7.1mm and higher yields with longer growing. It was suggested that the optimum harvest time was 18 months after planting, before over wintering rather than next year of spring, 24months after planting.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.356-365
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• 2022

Agrivoltaic systems, also called solar sharing, stated from an idea that utilizes sunlight above the light saturation point of crops for power generation using solar panels. The agrivoltaic systems are expected to reduce the incident solar radiation, the consequent surface cooling effect, and evapotranspiration, and bring additional income to farms through solar power generation by combining crops with solar photovoltaics. In this study, to evaluate if agrivoltaic systems are suitable for viticulture, we investigated the microclimatic change, the growth of vines and the characteristics of grape grown under solar panels set by planting lines compared with ones in open vineyards. There was high reduction of wind speed during over-wintering season, and low soil temperature under solar panel compared to those in the open field. There was not significant difference in total carbohydrates and bud burst in bearing mother branches between plots. Despite high content of chlorophyll in vines grown under panels, there is no significant difference in shoot growth of vines, berry weight, cluster weight, total soluble solid content and acidity of berries, and anthocyanin content of berry skins in harvested grapes in vineyards under panels and open vineyards. It was observed that harvesting season was delayed by 7-10 days due to late skin coloration in grapes grown in vineyards under panels compared to ones grown in open vineyards. The results from this study would be used as data required in development of viticulture system under panel in the future and further study for evaluating the influence of agrivoltaic system on production of crops including grapes.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.15 no.2
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• pp.72-85
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• 2010

Seasonal variation in species composition of estuarine fauna in the Han River estuary was determined using monthly samples collected near Ganghwa Island by a bag net from February to December 2009. Total number of species was 86: 54 species of fishes, 16 species of shrimps of crustacean, 12 species of other crustacean such as craps and so on, 3 species of cephalopods and 1 species of jellyfish. Of a total of 86 species, Palaeman carinicauda (32.6%), Acetes japonicus (15.9%), Palaemon gravieri (9.9%), Portunus trituberculatus (7.7%) and Acetes chinensis (6.9%) were predominated in abundance. These 5 crustacean accounted for 73% of total. Abundance, biomass and diversity of Han River estuarine fauna were high in spring and autumn, indicating typical pattern of temperate area. Out of dominant species, the brackish residence species such as Coilia nasus, Chelon haematocheilus, Mugil cephalus, Synechogobius hasta, Lophiogobius ocellicauda, Tridentiger barbatus, Palaeman carinicauda, Palaemon gravieri were collected almost year-round and predominated in abundance. Coastal migratory fauna species such as Coilia mystus, Thryssa hamiltonii, Thryssa adelae, Sardinella zunasi, Engraulis japonicus, Portunus trituberculatus, Acetes japonicus, Collichthys lucidus, Pampus argenteus were most plentiful from spring through autumn. Their adult coastal migratory entered the estuary in spring and large numbers of their juveniles were grew in summer and autumn until moving out to deeper waters for over-wintering, indicating they use estuary as nursing ground. Diadromous fish such as Anguila japonica adults were collected in autumn during their downstream migration. Brackish fauna and crustacean, especially shrimps were predominant, and few contaminant indicator species collected in the Han River estuary, indicating this area maintains the characteristics of natural estuary ecosystem.

• Korean Journal of Weed Science
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• v.16 no.2
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• pp.88-99
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• 1996

In recent years dry direct-seeding of rice has been encouraged by the government and increasingly practiced by farmers in Korea. This has been bringing up an increased occurrence of weedy rites. Some farmers in the southern region dare to sow the rice before winter after harvest, while most farmers wish to sow as early as possible in the spring to secure the growing period, and to disperse the intensive labor in early May. The purpose of this study was to determine the feasibility of moving the sowing of rice to an earlier date under dry direct-seeding, and to elucidate the nature of emergence of an old strain of rice, weedy rites, and barnyardgrasses tinder this farming practice and their adaptive competence over present cultivate. The presently recommended rice cultivar, Dongjinbyo and an old rice strain, Dadajo which prevailed in early 1900s, almost could not emerge from soil deeper than 6cm and could emerge to only 5.3% at best from 1cm deep loamy soil field when the seeds were sown on Nov. 28. However, two strains of weedy rites being weedy for over 200 years emerged by 17.0 to 63.0% from the loamy and sandy clay loam field 1 to 6cm deep. Emergence of the weedy rites was greater in the loamy soil and at a shallow depth, and negligible from the soil depth of 9cm. Barnyardgrasses sown on Nov. 28 emerged by 13.4 to 51 % from the 1 to 3cm deep loamy soil, and 8.6 to 46.7% from the 1cm deep sandy clay loam. Echinochloa crus-galli var. crus-galli emerged more than var. praticola, and var. oryzicola least. Most of the non-emerged barnyardgrasses seem to have entered secondary dormancy. Seeding rice a month earlier than the season lowered the emergence of Dongjinbyo by ca. 10, 18, and 26%, respectively at 1, 3, and 6cm soil depths, indicating that moving the seeding date a month earlier is impractical. The old strain, Dadajo sown in the soil at a depth of 6cm responded similarly. However, the strain has shown a significantly higher ability in emergence from 9cm deep soil. Weedy rices sown a month earlier A month earlier sown weedy rices have shown very similar emergence rates at various soil depths to those sown on May 1. Barnyardgrasses have also shown similar emergence rates when sown between April 3 and May 1. Like barnyardgrasses, the old strain and weedy rices apparantly posessed a greater adaptability to emerge under lower temperatures, and from deeper soil ; Dongjinbyo${\leq}$ Echinochloa species in that order. However, emergence- speed under lower temperature(sown on April 3) was faster in the order of weedy rice