• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.2
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• pp.195-201
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• 1983

This study was conducted to find out the damage of rice root nematodes on rice and determine the economic injury level. In pot experiments, rice root nematode, Hirschmanniella imamuri, suppressed the growth and reduced yield of a rice, Milyang 23, above critical levels. Tillering was depressed above 5, 000 nematodes per pot inoculum levels. Heading was also delayed by 6 days when inoculum level was above 20, 000. Weight of roots and grain yield in rice plants which inoculated with 20, 000 nematodes/pot were reduced by 41% and 31%, respectively. Economic injury level of rice root nematode appeared to be 1, 500 nematodes per 30g of fresh root on Aug. 30.

• Korean Journal of Weed Science
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• v.15 no.2
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• pp.115-120
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• 1995

This experiment was conducted in the paddy field to investigate the influence of bensulfuron (methyl-2-[[[[[(4,6-dimethoxypyrimidin-2-yl)amino]carbonyl]amino]sulfonil]methyl]benzoate)+butachlor (N-(butoxymethyl)-2-chloro-2',6'-diethyl acetanilide) and bensulfuron+mefenacet(2-(1,3-benzothiazol-2-yloxy)-N-methylacetanilide) for seedling age of rice with Dongjinbyeo of medium-late-maturing variety, Hwaseongbyeo of medium-maturing variety and Namwonbyeo of early-maturing variety. Two herbicide applications interfered with the early growth of all rice varieties, the root was especially damaged more than the shoot. The phytotoxicity of bensulfuron+butachlor and bensulfuron+mefenacet was not significant statistically and the phytotoxicity of these herbicides for seedling age was apt to be similar, also. Twenty and 35days seedlings of Dongjinbyeo and Hawseongbyeo had more growth amount than 8days seedlings, but Namwonbyeo had opposite trend. The number of maximum tillers in the plots applied herbicides were fewer than untreated control but, the percentage of productive tillers was higher than those. Heading date for Namwonbyeo was delayed 2, 1-2 and 2-3days on 35, 20 and 8days seedlings by herbicide application, respectively.

• 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.

• Proceedings of the KSRS Conference
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• 2006.03a
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• pp.193-197
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• 2006

지상측정 및 위성영상탑재 광학센서를 이용하여 벼 주요 생육시기에 대한 군락의 엽질소 함량을 추정하였다. 6월부터 10월에 걸쳐 주요 생육시기 $5{\sim}6$회에 걸쳐 Orbview 및 QuickBird와 같이 4m 이하의 고해상도 다중영상을 취득하였다. 위성영상 취득일에 가능한한 맞추어 인공광원을 사용하는 2종의 능동형 광학 (G)NDVI 센서를 이용한 벼 군락의 반사특성을 측정하였으며 동시에 식물체 샘플링을 통한 생육량, 엽면적지수, 엽질소 함량 등을 분석하였다. 시기별 영상의 분광반사특성 및 (G)NDVI와 벼 생육량 및 엽질소 함량과의 관계를 알아보기 위해 상관분석 및 회귀분석을 수행하였다. 지상센서 및 위성영상 유래 (G)NDVI의 값을 서로 비교해 보면 전체적으로 지상센서를 이용하여 측정한 (G)NDVI값이 위성영상 유래 (G)NDVI값보다 크게 나타났다. 하지만 두 센서 모두 엽면적지수 변화에 따른 (G)NDVI의 변화를 살펴보면 엽면적지수가 2 정도가 될 때까지는 함께 증가하다가 2보다 커지면서는 변화가 없이 머무르는 경향은 같게 나타났다. 엽면적지수의 변화는 군락의 엽질소함량 변화와 선형적인 관계($R^2=0.80$)로 나타났다. 분얼기부터 성숙초기까지의 자료를 이용하여 지상센서 및 위성영상 유래 (G)NDVI를 이용한 벼 군락의 엽질소 함량과의 관계를 살펴보니 지수함수적 관계($R^2=0.90$)로 나타났다. 위성영상 유래 (G)NDVI를 이용한 벼 군락의 엽질소 함량 추정식을 이용하여 신평면 최고쌀 생산단지에 대한 엽질소 함량 지도를 작성하였다.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.4
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• pp.503-510
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• 2012

Microwave radar can penetrate cloud cover regardless of weather conditions and can be used day and night. Especially a A ground-based polarimetric scatterometer operating at multiple frequencies can continuously monitor the crop conditions. We analyzed scattering characteristics of rice and soybean using pauli decomposition method. Surface scattering (${\alpha}$) is the dominant component over the entire stages for all bands and pauli decomposition value was the highest for L-band. Double bounce scattering (${\beta}$) and volume scattering (${\gamma}$) were approximately equal for C-band and volume scattering was higher than double bounce scattering for X-band in rice field. In soybean, double bounce scattering becomes higher than volume scattering during the R2 stage (DOY 224) and there was a significant difference between the two components after the R4 stage (DOY 242) for L-band. The maximum growth stage of soybean can also be detected using L-band double bounce scattering. The peak of double bounce effect coincides with the peak of growth biophysical variables on DOY 271. We found that pauli decomposition can provide insight on the relative magnitude of different scattering mechanisms during the rice and soybean growth cycle.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.471-474
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• 2002

This experiment was conducted to investigate the response of rice growth and grain yield to night illumination. Three cultivars Heugjubyeo (early maturing), Hwaseongbyeo (medium maturing), and Ilpumbyeo(mid-late maturing) were tested under different light intensities ranging 1.0 to 20.0 lux (0.3 to 5.6 $1\mu\textrm{W}$ $cm^{-2}$). Awn length of all cultivars became longer as night illumination intensity increased; 4.09 cm under 10-20 lux compared to 1.93cm under 2 lux in Hwaseongbyeo. However culm and spike length ere not affected by night illumination. Night illumination delayed flowering by 3 days in Heugjinjubyeo, 5 days in Hwaseongbyeo, and 9 days in Ilpumbyeo at 10-20 lux compared to that at 2 lux. Grain yield was reduced by 10.0% in Heugjinjubyeo, 17.7% in Hwaseongbyeo, and 20.7% in Ilpumbyeo at 10-20 lux compared to 2 lux condition.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.67-72
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• 2006

This experiment was carried out to identify rice varieties suitable for growing under low N-fertilization levels. Eighteen rice varieties were grown at 5.5 kg and 11 kg/10a nitrogen levels in 2004-2005 in Taegu, Korea. Several varieties like Ilmibyeo, Nampyeongbyeo, Sindongjinbyeo, Dongjin 1 and Donganbyeo yielded more than 470 kg/10a. Low N-fertilization level (5.5 kg/10a) decreased yields of Junambyeo and Donganbyeo by more than 10%. However, the decrease in yield was not significant in Surabyeo and Hwayeongbyeo compared with the 11 kg/10a N-fertilizer treatment. Improved grain quality, chemical properties and palatability was noted in some rice varieties. In terms of rice yield and grain quality, Donganbyeo, Ilmibyeo, Ilpumbyeo, Dongjin 1, Saechoocheongbyeo and Saegyehwabyeo were selected as premising rice varieties for growing under low N-fertilization levels.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.5
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• pp.562-568
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• 1995

Changes in rice yield and soil chemistry of dry seeded rice in double cropping of rice and barley were investigated at National Yeongnam Agricultural Experiment Station during 5 years (1990-1994). Barley straw added or removed dry seeding had safe rice seedling stand for good rice production. However, the coefficient of variation of seedling stand by year was higher than dry seeding in rice single crop. Rice seedling height was slightly reduced by barley straw incorporation. However, it recovered soon as rice growing progressed. Heading time delayed 4 days in flat seeding method but not in high-ridged seeding method which imply that. this is more safe seeding technology than flat seeding method. Comparing to rice single crop, barley straw added dry seeding increased rice yield by 2∼19%(Average of 5 years: 8%) from second year due to higher panicle and spikelet number. Contents of organic matter was 2.71% in 1990. In 1994, it decreased 2.61% for rice single crop, while increased 3.02% and 3.41% for barley straw removed or added field, respectively. Rice grain quality was not significantly different among cropping patterns.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.2
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• pp.99-106
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• 2011

Here we reported an analyzing result for the relationship between climatic variables and rice(c.v. Odaebyeo and Ilpumbyeo) yield characteristics (including some growth characteristics) based on a long-term observed data at GARES and at KMA for rice and weather, respectively. Most of crop parameters investigated, such as heading date, culm height, panicle number $m^{-2}$, grain number $panicle^{-1}$ ripening rate, 1,000 grain weight and yield were strongly affected by wind velocity and relative humidity, as well as by daily mean air temperature, precipitation, sunshine hours and daily variations in air temperature depending on variety and crop developmental stages. Air velocity and relative humidity had not been studied as climatic variables affecting on the characteristics of rice growth and yield, however, they turned out to affect all the characteristics of rice investigated, especially ripening rate and yield, as much as any other climatic variables in this study. Air velocity appeared to affect highly the culm height and yield of Odaebyeo and ilpumbyeo. Relative humidity appeared to affect highly grain number and ripening rate of Odaebyeo and yield of Ilpumbyeo. Consequently Rice yield revealed to increase in the climatic conditions of high air velocity and low relative humidity.

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.485-489
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• 2011

In previous reports, the treatment of Bacillus amyloliquefaciens strain EXTN-1 showed a broad diseasecontrolling spectrum to the plant diseases caused by viral, bacterial, and fungal pathogens as well as the promotion of plant growth. In mechanisms of EXTN-1, treatment of EXTN-1 increased oxidative burst in early stage and induced the expression of resistance genes, PR-1a, PDF1.2. Mechanism involved in induced systemic resistance by EXTN-1 was revealed as simultaneous activation of SA and JA or ethylene metabolic pathways. The purpose of this study was to determine whether B. amyloliquefaciens EXTN-1 has a similar effect on rice plant against Rice stripe tenuivirus (RSV) under greenhouse conditions. When rice seeds were soaked in B. amyloliquefaciens strain EXTN-1, rice plants showed significant systemic resistance against RSV as well as promoted growth. In the case of plant growth, in 30-day old plants treated with B. amyloliquefaciens EXTN-1, the heights, weights, and lengths of roots increased by 12.6%, 9.8%, and 16.0%, respectively confirming the effects of PGPR. When the induced systemic resistance to RSV was examined, in 20-day old plants were treated with B. amyloliquefaciens EXTN-1, the heights, weights, and lengths of roots increased by 8.4%, 10.9%, and 4.8%, respectively compared to the control. Induced systemic resistance was more prominent in susceptible cultivars - Chucheong and Ilpum compared to the resistant cultivar, Nakdong.