• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.2
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• pp.47-61
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• 2000

Agroclimatic zoning was done for paddy rice culture in North Korea based on a simulation experiment. Daily weather data for the experiment were generated by 3 steps consisting of spatial interpolation based on topoclimatological relationships, zonal summarization of grid cell values, and conversion of monthly climate data to daily weather data. Regression models for monthly climatological temperature estimation were derived from a statistical procedure using monthly averages of 51 standard weather stations in South and North Korea (1981-1994) and their spatial variables such as latitude, altitude, distance from the coast, sloping angle, and aspect-dependent field of view (openness). Selected models (0.4 to 1.6$^{\circ}C$ RMSE) were applied to the generation of monthly temperature surface over the entire North Korean territory on 1 km$\times$l km grid spacing. Monthly precipitation data were prepared by a procedure described in Yun (2000). Solar radiation data for 27 North Korean stations were reproduced by applying a relationship found in South Korea ([Solar Radiation, MJ m$^{-2}$ day$^{-1}$ ] =0.344 + 0.4756 [Extraterrestrial Solar Irradiance) + 0.0299 [Openness toward south, 0 - 255) - 1.307 [Cloud amount, 0 - 10) - 0.01 [Relative humidity, %), $r^2$=0.92, RMSE = 0.95 ). Monthly solar irradiance data of 27 points calculated from the reproduced data set were converted to 1 km$\times$1 km grid data by inverse distance weighted interpolation. The grid cell values of monthly temperature, solar radiation, and precipitation were summed up to represent corresponding county, which will serve as a land unit for the growth simulation. Finally, we randomly generated daily maximum and minimum temperature, solar irradiance and precipitation data for 30 years from the monthly climatic data for each county based on a statistical method suggested by Pickering et a1. (1994). CERES-rice, a rice growth simulation model, was tuned to accommodate agronomic characteristics of major North Korean cultivars based on observed phenological and yield data at two sites in South Korea during 1995~1998. Daily weather data were fed into the model to simulate the crop status at 183 counties in North Korea for 30 years. Results were analyzed with respect to spatial and temporal variation in yield and maturity, and used to score the suitability of the county for paddy rice culture.

• Korean Journal of Agricultural and Forest Meteorology
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• v.13 no.3
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• pp.123-139
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• 2011

It is expected that identification and lists of $C_4$ plants in specific regions are useful not only for the ecological researches that are related to vegetation phenology and succession but also as an index of climate change. In this review, $C_4$ plants growing in South Korea were listed and their life forms were investigated. In addition, we discussed the influences that climatic change and the $C_4$ plants exerted on plant ecosystem. Photosynthetic pathway types ($C_3$ and $C_4$) for the plant species in South Korea were determined by reviewing the scientific literatures published between 1971 and 2010. Of the total 4476 species in 1123 genera and 197 families, 206 species (4.6%) in 84 genera (7.5%) and 21 families (10.7%) were identified as $C_4$ plants (including $C_3$-$C_4$ intermediate plants). Among the identified $C_4$ species, 53 species (25.7%) in 26 genera and 15 families were classified as Dicotyledoneae, while 153 species (74.3%) in 58 genera and 6 families were classified as Monocotyledoneae. The majority of the $C_4$ species belong to four families: Chenopodiaceae (15 species), Amaranthaceae (13 species), Gramineae (102 speceis) and Cyperaceae (45 species). With respect to life form composition of 206 $C_4$ species, Th-$R_5$-$D_4$-t was most dominant: 95 species (46.1%) were included in Th, 123 species (59.7%) in $R_5$, 179 species (86.9%) in $D_4$, and 122 species (59.2%) in t. The projected increase in temperature due to climate change may provide better conditions for the growth of $C_4$ plants. Such a result will have considerable impacts on the interspecific competition between $C_3$ and $C_4$ plants, the distribution of $C_4$ plants, plant phenology, and plant diversity.

• Korean Journal of Ecology and Environment
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• v.51 no.4
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• pp.259-267
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• 2018

This study was conducted to confirm phenological response of main deciduous woody species in Korea according to elevated temperature. Based on seeds collected from the same place, 39 woody species were cultivated in field (control) and in greenhouse (treatment) that was maintained above base temperature ($4.8^{\circ}C$). And then, we observed phenotype change of leaves focused on phenological response and explained relation with their current distribution area. As a result, initiation period of leaves unfolding was 1st~3rd, May in control. It was 13, December~7, January in treatment. Period of leaves yellowing was 11~26, October in control. It was 30, October~13, November in treatment. Consequently, initiation period of leaves unfolding was faster by 119~140 days and period of leaves yellowing was slower by 3~32 days since elevated temperature. Period of leaves growth increased in treatment by 148 days than control. Quercus mongolica and Quercus serrata that cultivated in treatment was changed as evergreen trees which have grown up continuely during one year. Also, initiation period of leaves unfolding of Sorbus alnifolia in treatment was faster than in control. However, difference of the period between control and treatment was smallest. Because period of yellowing leaves was moved ahead. Phenological response of leaves according to elevated temperature had no relation of type of their current distribution area. This is the result of acclimation due to elevated temperature during the winter and suggests that the phenotype of leaves of 39 deciduous woody species is more sensitive to the current growth condition than to the past growth condition.

• Research in Plant Disease
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• v.16 no.3
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• pp.266-273
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• 2010

Bacterial pustule of soybean (Glycines max) caused by Xanthomonas axonopodis pv. glycines is one of the most prevalent bacterial diseases of soybean. This bacterium shows strong pathogenicity to the plants and distributes throughout Korea. However, no good control measures including bactericides and resistant cultivars are available to control the disease in Korea. Therefore, this study was conducted to develop chemical control method against soybean bacterial pustule. The present study was undertaken to find out the growth inhibitory effect bactericides (8 antibiotics, 2 copper compounds, quinoline, 18 agro-chemicals) on bacterial pustule pathogen. Antibiotics test showed that tetracycline and streptomycin sulfate significantly suppressed the growth of bacterial pustule pathogen. Also, application of oxolinic acid was found to be effective for pathogen inhibition. However, vancomycin, polymyxin B sulfate and copper compounds did not show the positive suppressive effect on growth of the pathogen. Among the eighteen agro-chemicals, streptomycin sulfate + oxytetracyclin (18.8 + 1.5%) WP, oxytetracycline (17%) WP and oxolinic acid (20%) WP were found to be effective for the inhibition of the pathogen in vitro. The selected 5 agro-chemicals were also applied on soybean in field and their control effects against the soybean bacterial pustule were tested. The foliar application of streptomycin sulfate + oytetracyclin WP and oxytetracycline WP on the naturally infected soybean (Taekwangkong) showed high control value (above 70%). Therefore, it is concluded that the bactericides used in this study showed strong inhibitory effect to soybean bacterial pustule and they can be recommend to farmers to control the disease.

• Korean Journal of Agricultural and Forest Meteorology
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• v.5 no.3
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• pp.185-190
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• 2003

This study was conducted to examine rice growth duration by analyzing agricultural climatic conditions at different latitudes in unified Korea. The climatic conditions of nine sites from Wunggi (latitude 42N) to Jeju (latitude 31N) were examined in this study. The rice growth duration of various cropping patterns was determined by analyzing consecutive days when effective daily mean air temperature was suitable for rice growth from the first seeding date to the last maturing date. The rice growth duration in Wunggi located in North Korea was available 138 days for machine transplanting, 115 days for direct seeding on dry paddy cultivation, and 97 days for direct seeding on a flooded surface with cultivation after seeding. On the other hand, the rice growth duration in Kwangju (latitude 35N) located in South Korea was 195 days for machine transplanting, 180 days for direct seeding on dry paddy cultivation, and 170 days for direct seeding on a flooded surface cultivation after seeding.

• Proceedings of the KSRS Conference
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• 2007.03a
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• pp.43-48
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• 2007

본 연구는 벼 군락의 분광반사율 지표를 측정할 수 있는 인공광원을 사용하는 능동형 광학 센서인 GNDVI 를 활용하여 생육시기별 식생지수와 엽 질소함량과의 관계를 구명하여 벼 군락의 엽 질소함량을 추정하고자 하였다. 농업과학기술원 답작 포장에서 공시품 종인 추청벼를 이용하여 난괴법 3반복으로 시험구 배치를 하고 질소 4수준 3반복으로 실험을 수행하였다. 벼 생육시기별 GNDVI 와 엽 질소함량과의 관계를 2년 간 (2005, 2006)의 자료를 통하여 분석해 보았다. 2005년의 경우 벼 생육시기동안 9시기의 GNDVI값과 그 당시 시료를 샘플링하여 분석한 엽 질소함량과의 관계를 벼 출수전과 출수후로 구분하여 분석해 본 결과 GNDVI 값은 출수전 ($r=0.78^{***}$ n=60) 보다 출수후 ($r=0.89^{***}$, n=59) 가 엽 질소함량과의 상관계수가 높았다. 2006년은 20시기동 안 생육시기별 식생지수와 엽 질소함량과의 상관 분석한 결과 착근기 (6월 5일) $r=0.84^{***}$, 유수분화기 (7월 11일) $r=0.95^{***}$, 출수기 (8 월 16일) $r=0.87^{***}$, 수확기 (10월 13일) $r=0.90^{***}$ 으로 출수전의 경우 7월 11일이 상관계수가 가장 높았고， 이 결과는 2005년 동일시기 (7월 11일) 식생지수와 벼 엽 질소함량과의 상관계수가 가장 높았던 ($r=0.91^{***}$) 것과 일치하였다. 벼 생육시기 변화에 따른 식생지수와 엽 질소 흡수량과의 관계를 살펴보았는데 벼 출수전의 경우 GNDVI는 7월 11일 에 엽 질소 흡수량과의 상관계수 ($r=93^{***}$)가 가장 높은 결과를 보였고 출수후의 경우에는 시기에 따라 상관계수가 고르게 높게 나타났다. 엽 질소함량과의 상관관계가 높았던 2005년，2006년 7월 11일 식생지수 데이터를 함께 이용하여 엽 질소함량과의 관계를 추정식으로 작성하였다. GNDVI를 이용하여 2005년과 2006년 실측한 엽 질소함량 값과 추정 값을 비교해 본 결과 2005년과 2006년의 결정계수가 각각 0.88, 0.94로 2006년이 더 예측률이 높게 나타났다. GNDVI 값을 이용하여 엽 질소함량 추정값과 실측값을 비교해 본 결과 결정계수가 0.86으로 추정값과 실측값이 근접하게 분포하였다.

• Journal of Korean Society of Forest Science
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• v.62 no.1
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• pp.1-18
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• 1983

Sum of daily mean temperature, sum of daily mean relative humidity and sum of daily mean duration of sunshine during the growing season (March-October), and daily mean temperature, daily mean relative humidity and daily mean minimum temperature during the dormant season (November-February) were obtained respectively from the climactic data recorded at 26 different standard stations for 30 years from 1951 to 1980, to provide a method for proper selection of tree species suitable to a certain site. They were also marked on the map of Korea. The whole country was divided into 6 regions by trend of temperature variation and the regression equations for each region were produced to estimate the sum of daily mean temperature of the growing season and the sum of daily mean minimum temperature of the dormant season in a certain site where tree plantings are planned. The natural range of distribution of each species was expressed by the sum of daily mean temperature and daily mean minimum temperature on the basis of "Horizontal and vertical distribution of the Korean woody plants" reported by Chung and Lee (1965).

• Korean journal of applied entomology
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• v.23 no.1 s.58
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• pp.49-55
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• 1984

This study was carried out to investigate the biological performance of the brownplanthopper, Nilaparvata lugens Stal, reared on rice plants at different growth stages; maximum tillering, booting, heading with and without panicles, and milking. The results obtained are as follows: The rice plants at the maximum tillering stage gave the best in the longevity, oviposition period, and the total number of oviposited eggs for the macropterous females, and the worst with the booting stage. For the brachypterous females, however, the best results were obtained from the rice of which their panicles had removed after heading. There was no significant difference in the hachability of eggs and the developmental period of the nymphs in the next generation, but the nymphal mortality was the highest with the milking stage and the lowest with the maximum tillering and heading stage without panicles. The longest life span was shown in males derived on the maximum tillering stage, and the shortest for milking(macropterous type) or booting (brachypterous type) stages. Coefficientes of variances in longevity and number of eggs for the adults emerged from heading stage without panicles were lower than those with panicles intact, and such trend was more obvious in brachypterous adults, especially for the females. The biological performances of the BPH have close relationship with the translocated organic material at the feeding site which showed considerable difference with the growth stages of the rice.

• Journal of Ginseng Research
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• v.32 no.3
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• pp.270-274
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• 2008

A bacterium isolated from contaminated white ginseng was identified using API kit and electron microscope. This isolate was determined as rod shaped bacterium having about 1.0 ${\mu}m$ in diameter and 2.0 to 6.0 ${\mu}m$ in length. It had motility by peritrichous flagellum. The isolate had ${\beta}-galactosidase$, arginine dihydrolase and ornithin decarboxylase. It did not have ability not only to use citrate as sole carbon source and but also to produce $H_2S$. However, it could ferment glucose, manitol, sorbitol, rhamnose, arabinose and amygdalin. From these obserbations, the isolate was identified as Citrobacter sp. Ginseng saponin was added to culture of Citrobacter sp. in order to investigate saponin's influence on its growth. The strain was incubated at $38^{\circ}C$ for 3 days after addition of 0.05, 0.5, 2.0 and 4.0% (w/v) of saponin, respectively and the growth rates was investigated. The relative bacterial growth inhibition rates showed 28.6, 66.7, 92.4 and 97.7%, respectively, when compared with saponin non-treated group. These results suggest that the growth of Citrobacter sp. is inhibited by saponin in a concentration-dependent manner.

• Korean Journal of Soil Science and Fertilizer
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• v.22 no.4
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• pp.285-289
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• 1989

Interrelationships between yields of Burley 21 variety and meteorological factors such as precipitation, duration of sunshine, and evaporation in Suweon, Chungju, Daegu, and Jeonju were investigated during the growing seasons from 1976 to 1985. Cultivation period from the 41st to the 60th day after transplanting which showed the highest transpiration by the tobacco plant was corresponding to relatively dry season in Korea from the middle of May to early of June. The meteorological factors during the middle stage of the tobacco growth, especially the 41st to the 80th day after transplanting, seemed to have higher correlation with tobacco yield, than any other periods. This result implied that the middle stage of the growth when tobacco plant consume more soil moisture by transpiration proved to be a important growth stage having a great influence upon tobacco productivity.