• Korean Journal of Agricultural and Forest Meteorology
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• v.1 no.2
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• pp.127-134
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• 1999

This study was performed to obtain the basic data to present rational silvicultural tending plan. It makes these widely distributed pine-oak mixed stand and each of pure stand in middle province on object of this study and do comparative analysis of light condition about stand parameter and natural regeneration according to each slope(north, west and south) conditions of location in central part of South Korea. Sample plots for pine-oak mixed stand and pine and oak pure stand were established on each of southern, northern and western slopes based upon site and growth conditions of the slope. Sample plot was a circle of 0.05ha with a diameter of 25.24 m. A sample plot has between 30 and 40 tree in it. Total 23 sample plots were established; 9 pure pine stands, 8 pine-oak mixed stands. and 6 pure oak stands across lower, middle, upper parts of slopes. Relative light intensity within a stand was' measured by crown- photo(fish-eye lens; 180$^{\circ}$) system through fish-eye lens and by comparing each plot with the denuded through PAR-sensor. The crown closure ratio of pure pine stand (75%) shows much lower than that of mixed stand (90.9%) and pure oak stand (93%). The relative light intensity within a stand showed an opposite result. The crown closure of mixed stands tended to become gradually low as the slope moves from the north to the south, but the relative light Intensity within the stand tended to rise. By analyzing the relationship between the relative light intensity within a stand and stand parameter, light intensity within a stand tended to decrease as the diameter and N/ha increase. Number of oak seedlings and light intensity within a stand is in a straight-line regression relation. In particular, the number of oak seedlings was the highest in mixed stands on the southern slope. But no single pine seedling was found. The unfavorable conditions of l0cm thick litter layer and low relative light intensity in a stand (ranging between 4% and 8%) is considered to prevent pine seeds from germinating.

• Journal of Korean Society of Forest Science
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• v.95 no.6
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• pp.680-689
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• 2006

Introduction of the Special Account for Balanced National Development (SABND) which was represented top-down in 2005 have previous national budget distribution system between central and local government change. A local autonomous entities can choose freely the favorite programs within the total programs in SABND so they can use limited budget efficiently, After induction of this system, budget of the Forest Programs in SABND in 2006 compare to last year has increased by 24.5 percent. That is three times higher than the average rate of total SABND budget, 8.1 percent. This study surveyed propriety of the Forest Programs and hereafter their budget prospect with local government officials in forest sector, 68.7 percent of the respondents recognized that the inclusion of the Forest Programs in SABND is proper. The most preferred Forest Programs are making Urban Forests and their Management and making Facilities for Forest Recreation. And the most non-preferred Forest Programs are complementing the Lumberyard Facility of the Forestry Association, making the Exhibition of Wood Products and making the Base for the Seedling Production. When Forest Programs are adjusted in the future, these programs above mentioned should be exempted from the SABND. because the non-preferred programs as well as the small budget programs On the prospect of the future budget, 81.1 percent of the local government officials in forest sector answered that it will be the same with the current or increasing, In the short term, the budget of the Forest Program in SABND is expected to increase.

• Journal of Bio-Environment Control
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• v.24 no.2
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• pp.51-56
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• 2015

The objective of this study was to evaluate the effect of silicate fertilizer on growth, physiology and abiotic stress tolerance of Chinese cabbage seedlings. Five silicate concentrations (8, 16, 32, 64, and 128mM) and control (non-treatment) were applied to Chinese cabbage seedlings twice a week. Three weeks after application of silicate treatment, seedlings were used for treating abiotic stresses and were assessed for growth and physiological characteristics. Growth parameters significantly increased in 8, 16, and 32mM treatments except 64 and 128mM. Total root surface area, total root length, and number of root tips increased in 8, 16 and 32mM treatments, but they decreased in treated seedlings with 64 and 128mM of silicate. The highest growth parameters and root morphology were observed in 8mM treatment. As for the effect on the seedling physiology, transpiration rates decreased while stomatal diffusive resistance increased to increasing silicate concentration. The application of silicate reduced the electrical conductivity, heating and chilling injury index at high and low temperatures. Silicate enhanced drought tolerance of Chinese seedlings by delaying the starting time of wilting point. The starting time of wilting point in the control was 3 days after discontinuation of irrigation, while in the 8, 64 and 128mM of silicate treatments were 4 days, and the 16 and 32mM treatments were 5 days. All plants were wilted after 5 days in control without irrigation whereas it showed in 8mM treatment after 6 days, in 16, 32, 64, 128mM treatments after 7 days.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.373-381
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• 2011

This study was carried out to investigate the growth and physiological responses to shading treatment of 1-year-old containerized seedling of Quercus myrsinaefolia. Experimental process was conducted in a facility that consisted of compartments under the lighting control with full sunlight and shading (35%, 55% and 75% of full sunlight). Height and root collar diameter growth were high in the seedlings under both 35% and 55% shading. Regardless of shading level, root collar diameter growth lasted for more than 4 weeks compared to height growth. Highest H/D ratio was observed in the seedlings under 35% shading as 4.31, and the lowest ratio was 3.63 under 75% shading. It was found that seedlings under 55% shading showed highest dry mass production, which was followed in seedlings under 35% shading. In case of leaf dry weight ratio (LWR) after shading treatment, the highest value was 0.53 under 55% shading, and followed in seedlings under 35% shading as 0.52. But root dry weight ratio (RWR) was highest as 0.36 under 75% shading (highest level of shading). In terms of shading treatment, it was found that the higher level of shading had a tendency toward the higher content of chlorophyll a and the higher total chlorophyll content in the leaves of Quercus myrsinaefolia, but there was no significant difference in the content of chlorophyll b depending on the level of shading. It was found that high photosynthesis and transpiration rate were more correlated with high level of shading than full sunlight, but the rates of seedlings had a tendency to be higher under 35% and 55% shading than under 75% shading. The results on growth and physiological responses to different shading levels of 1-year-old containerized seedlings of Quercus myrsinaefolia could be useful in setting up the optimum light intensity for growth, and in estimating the shade tolerance of the species.

• Korean Journal of Plant Resources
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• v.27 no.1
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• pp.80-88
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• 2014

This study was carried out to understand the effect of sowing date on growth characteristics, flower duration of a total of 6 domestic rapeseed cultivars, "Sunmang", "Tammiyuchae", "Tamlayuchae", "Naehanyuchae", "Yongsanyuchae" and "Hallayuchae" with different sowing dates (25 Sept., 5 Oct., 15 Oct., 25 Oct., 5 Nov.) in Muan, Jeollanamdo, Republic of Korea. The results obtained were summarized as the follows: The number of seedling stand after overwintering was decreased in all 6 cultivars. It changed little until 5 Oct., and then showed continuously largely decrease as the sowing date being delayed. As the sowing date was being delayed, plant height was decreased while Silique length and thousand seed weight were increased. Seed yield in all 6 cultivars decreased almost linearly with late sowing date. In correlation analysis between the delaying sowing date and growth characteristics, it was inversely correlated with plant height ($r=-0.769^{**}$), No. of branches/plant ($r=-0.760^{**}$), No. of siliqua/panicle ($r=-0.631^{**}$) and seed yield ($r=-0.946^{**}$), while showed a positive correlation with silique length (r=0.635), seed diameter ($r=0.629^{**}$) and thousand grain weight ($r=0.422^*$). No. of seeds/silique and seed set percentage were not significantly correlated with the delaying sowing date. The flower duration was long in order of Sunmang, Tammiyuchae, Yongsanyuchae, Naehanyuchae, Hallayuchae and Tamlayuchae. Varietal variation of flowering date was larger with early sowing date than with delaying sowing date. The range of flower duration across all cultivars was from 1 day of Tamlayuchae to 14 days of Sunmang according to the sowing date, and the end flowering date was able to be extended from 2 to 9 days, compared to normal date of end flowering.

• Journal of The Korean Society of Grassland and Forage Science
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• v.34 no.1
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• pp.1-8
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• 2014

Field studies were conducted from the years 2009 to 2012 in order to determine the cultivation limit as well as to evaluate the characteristics and forage production of warm season grass in Korea. Two bermudagrass [Cynodon dactylon (L.) Pers.] cultivars, two bahiagrass (Paspalum notatum Flugge) cultivars and a Kleingrass [Panicum coloratum L.] cultivar were compared for forage production and quality in the mid-southern regions of Korea. The experimental design was a randomized block design (RBD) with three replications. The number of days to seedling emergence for bremudagrass and bahiagrass was observed as approximately 12 days and 28 days after seeding, respectively. In Kwangju, the heading dates of bahiagrass and kleingrass were 21 August and 10 July, respectively,. Warm season grass did not winter in the mid-regions (Kimjea, Cheonan) of Korea. All of the Bermudagrass cultivars had higher dry matter (DM) than bahiagrass at the first harvest. The dry matter yield of kleingrass was usually greater than the other entries at all study sites. Peak forage DM production of bermudagrass and bahiagrass cultivars occurred in June and July, respectively. The contents of crude protein (CP) and total digestibility nutrient (TDN) for bermudagrass cultivars were usually greater than the other entries at all study sites. Further, acid detergent fiber (ADF) and in vitro DM digestibility (IVDMD) were similar across all cultivars.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.228-235
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• 2009

Growth and branch characteristics of 35 half-sib families were surveyed in a seedling seed orchard of Quercus acutissima at ages 10 and 12. The averages of height, DBH (diameter at breast height), branch height, crown width, branch angle and stem straightness at age 12 were 9.96 m, 14.50 cm, 1.04 m, 6.80 m, $18.82^{\circ}$ and 2.58, respectively. Families of 075 and 052 showed superior height growth and 0511 and 0517 were inferior ones. For DBH growth, 075 and 0413 were best families and 0725 and 0511 were inferior families. Pearson's product moment and Spearman's rank correlation coefficients were all positive for all growth traits except branch angle at ages 10 and 12. This result showed that the families with good height and DBH growth were also superior in stem straightness. In ANOVA, there was a highly significant difference among families in height, DBH, cylindric volume and stem straightness. Branch height, crown width and branch angle were also significantly different among families. Family heritability was higher than individual heritability at ages 10 and 12. Height, DBH and stem straightness were under strong genetic control, showing high family heritability. This implies that high genetic gain could be expected by family selection. Expected genetic gain for each trait was estimated based on the family selection. The highest genetic gain was expected for the traits of branch angle, height and DBH because of the large phenotypic standard deviation and the high family heritability. The growth performance and branch characteristics were weighted by the magnitude of genetic variation and heritability. The weighted values were then subjected to estimate family breeding values. This family breeding value would be applied as a criterion in the genetic thinning of the seed orchard.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.1018-1023
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• 2010

Climatic change was observed and analyzed in view of impacts on agricultural ecosystem, inter alia on rice cropping. The changed climate gave rise to earlier transplanting of rice seedling and later harvest after 40 years. Also phenological change and prolonged growth duration was observed. The meteorological data was selected from the standardized climatological data of 30 year normals of 1960s and 2000s, which were published by Korea Meteorological Administration. Development stages and growing periods of rice crop were compared by analyzing critical and optimum temperatures of each growth stage during these two periods. The first appearance date of $15^{\circ}C$ was ranged from Apr. 29 to May 23 in the year-normals of 1960s and it varied from Apr. 24 to May 16 in the normals of 2000s. The difference of the first appearance date of $15^{\circ}C$ was 0~10 days earlier in the year-normals of 2000s than the 1960s. The last harvesting date was determined to be the last appearance date of mean air temperature $15^{\circ}C$. The difference in the last appearance date of $15^{\circ}C$ was 1 to 13 days later in the year-normals of 2000s than in 1960s. The plant height of a rice variety, Hwayoung-byeo was 101~109 cm in 4 local areas, Seoul, Kangneung, Kwangju and Daegu. The plant height became 1~4 cm taller under warm condition. Rice grain yields estimated with daily weather data for the year-normals of 1960s and 2000s were 453~580 kg $10a^{-1}$ and 409~484 kg $10a^{-1}$ respectively. Rice grain yield of the former period was 50~100 kg $10a^{-1}$ higher than that hat in the later period.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.341-354
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• 2021

A large part of Gapyeong is occupied by Korean pine (Pinus koraiensis) and Japanese larch (Larix kaempferi) plantations. Abies holophylla stands are scattered throughout Gapyeong, but little information on their distribution is available. This study explored the potential of succession from planted species to native A. holophylla in plantations. Trees were inventoried and regeneration of A. holoplhylla and stand management history were examined in Korean pine, Japanese larch, and A. holophylla-dominated stands. The importance percentage of A. holophylla was the highest among species with a range of 36.1% to 79.1% in all stands and the density of A. holophylla in understory (DBH <2 cm or <1.3 m height) ranged from 50 to 5,820 trees ha^-1. Non-metric multidimensional scaling classified stands into four types, AN, AP, AM, and P. The AN type showed a reverse J-shape DBH distribution, which was similar to that in natural A. holophylla stands. Both AP and AM types included Korean pine plantations with A. holophylla seed trees within stands. For AP, A. holophylla competed with planted species in overstory and deciduous broadleaved species in understory. The AM type was once thinned from below, thus stem density in the mid DBH classes was lower than upper or lower DBH classes. The P type consisted of plantations without A. holophylla seed trees. However, understory regeneration of A. holophylla was abundant through seed supply from A. holophylla in adjacent stands. Plantations with A. holophylla seed trees within or in adjacent stands showed vigorous natural regeneration of A. holophylla, highlighting the potential for succession from planted species to native A. holophylla in the Gapyeong area. Further studies can help develop techniques to restore plantations to native species-dominated natural stands using ecological succession.

• Korean Journal of Breeding Science
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• v.49 no.4
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• pp.420-427
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• 2017

'Pungwonmi', a new sweetpotato variety, was developed for table use by Bioenergy Crop Research Institute, National Institute of Crop Science (NICS), RDA in 2014. This variety was derived from the cross between 'Benisatsuma' and 'Luby3074' in 2006. The seedling and line selections were performed from 2007 to 2009, and preliminary and advanced yield trials were carried out from 2010 to 2011. The regional yield trials were conducted at five locations from 2012 to 2014, and it was named as 'Pungwonmi'. This variety has cordate leaf shape, and its leaves, stems, nodes, and petioles are green. Storage root of 'Pungwonmi' has an elliptical shape, red skin, and light orange flesh. 'Pungwonmi' was moderately resistant to fusarium wilt, and resistant to root-knot nematode. Dry matter content was 31.2%, and texture of steamed storage root was intermediate. Total sugar content of raw and steamed storage roots of 'Pungwonmi' was higher than that of 'Yulmi'. ${\beta}$-carotene content of 'Pungwonmi' was 9.1 mg/100g DW. Yield of marketable storage root over 50 g of 'Pungwonmi' was 24.3 MT/ha under the early season culture, which was 46% higher than that of 'Yulmi'. The number of marketable storage roots per plant was 2.8 and the average weight of marketable storage root was 156 g under the optimal and late season culture. Marketable storage root yield of 'Pungwonmi' was 24.1 MT/ha under the optimum and late season culture, which was 26% higher than that of 'Yulmi'. (Registration No. 6428).