• Current Research on Agriculture and Life Sciences
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• 제7권
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• pp.117-125
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• 1989

벼잎선충(線蟲) 방제(防除)를 위(爲)한 볍씨의 온탕침적조건(溫湯浸績條件), 벼품종간(品種間)의 저항성(抵抗性) 정도(程度), 피해경율(被害莖率)과 수량감소(收量減少) 정도(程度) 등을 구명(究明)하기 위(爲)해 시험(試驗)한 결과(結果)를 요약(要約)하면 다음과 같다. 볍씨 온탕침법(溫湯浸法)에 의(依)한 선충(線蟲) 방제효과(防除效果)는 $61^{\circ}C$에서 10-15분간(分間) 처리(處理)하였을때 가장 좋았다. 벼잎선충(線蟲)에 대한 품종간(品種間)의 피해경율(被害莖率)은 통일형(統一型) 품종(品種)의 경우 White tip 증상(症狀)이 나타나지 않았고 일본형(日本型) 품종(品種)들은 대부분 White tip 증상(症狀)이 잘 나타났는데 그 중(中)에서도 오태(五台)벼와 부광벼는 각각(各各) 95.6%, 81.8%의 높은 피해경율(被害脛率)을 보였다. 그러나 볍씨내 선충밀도(線蟲密度)에 있어서는 통일형(統一型), 일본형(日本型) 품종(品種) 모두 벼 10g당 100마리 이상(以上) 검출되었다. White tip 증상(症狀)이 나타나지 않았던 통일형(統一型) 품종(品種)들도 선충(線蟲) 접종구(接種區)에서는 수량(收量) 및 수량구성요소(收量構成要素)가 감소(減少)되는 품종(品種)이 많았고 일본형(日本型) 품종(品種)에서는 피해경율(被害莖率)이 높았던 오태(五台)벼와 부광벼는 40% 가까운 수량감소율(收量減少率)을 보였으며 전체적(全體的)으로 통일형(統一型) 보다는 일본형(日本型) 품종(品種)에서 수량구성요소(收量構成要素)와 수량(收量)의 감수정도(減收程度)가 높게 나타났다. 일본형(日本型) 품종(品種) 중(中) 영덕(盈德)5호(號)는 접종구(接種區)에서 White tip 증상(症狀)이 전혀 나타나지 않았고 수량(收量)도 감소(減少)되지 않아 벼잎선충(線蟲)에 대하여 저항성(抵抗性) 품종(品種)으로 생각된다.

• Weed & Turfgrass Science
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• 제1권4호
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• pp.31-37
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• 2012

담수직파재배에서 사마귀풀과 자귀풀 경합밀도에 따른 벼 수량감소 정도를 예측하고 제초제 사용여부 결정을 위한 경제적 방제수준을 설정하여 저투입, 친환경적인 정밀 잡초관리 체계를 확립하고자 시험을 수행하여 얻어진 결과는 다음과 같다. 쌀수량 감소정도는 사마귀풀의 경우 경합밀도가 $m^2$당 8본일 때 8%, 96본일 때 45% 이었고 자귀풀의 경우 $m^2$당 8본일 때 20%, 96본일 때 77% 이었다. 벼와 잡초의 경합에 따른 쌀수량 예측모델은 사마귀풀의 경우 Y=553.2 kg/(1+0.00913X) $R^2$=0.912 이었고 자귀풀의 경우 Y=567.9 kg/(1+0.04434X) $R^2$=0.961 이었다. 초종별 경제적 방제수준은 사마귀풀의 경우 $m^2$당 3.0본 이었고, 자귀풀의 경우 $m^2$당 0.6본 이었다.

• 한국응용곤충학회지
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• 제23권3호
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• pp.153-157
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• 1984

포장조건하에서 수잉기와 출수기에 벼멸구를 인위적으로 가해시킨 후 출수후 고사시기별로 수량수율을 조사하여 다음과 같은 결과를 얻었다. 1. 출수후 23일경에 고사된 벼는 무접종구에 비하여 등숙율은 $32.2\~37.5\%$ 현미천립중은$ 3.2\~3.5g$ 감소되었다. 2. 고사시기가 같아도 수잉기부터 가해구는 출수기부터 가해구보다 등숙율 현미천립중, 현미수량이 낮았다. 3. 고사된 벼의 감수율은 무접종에 비하여 고사시기에 따라 $24\~62\%$였으며 출수후 고사일수(X)와 수량(Y)간에는 다음과 같은 관계가 있었다. o 수잉기이후가해 : $\hat{Y}=10.145X-16.374(r=0.9726^{**})$ o 출수기이후가해 : $\hat{Y}=9.792X+26.936(r=0.8850^{**})$.

• 한국잡초학회지
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• 제30권1호
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• pp.43-49
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• 2010

본 시험은 2008년에 경상북도 농업기술원 벼 재배포장에서 최근 담수직파답에서 제초제 저항성 잡초로 가장 문제시 되고 있는 잡초 중 올챙이고랭이를 대상으로 잡초 밀도별 벼와의 경합력을 구명하고 Rectangular hyperbola 모델을 기초로 잡초의 밀도에 따른 쌀 수량 감소를 예측하여 경제적인 방제 필요수준을 구명하고자 실시하였다. 잡초를 완전 방제 했을 경우를 가상한 벼 수량은 올챙이고랭이에서 10a당 466kg으로 피의 457kg보다 다소 높았으며, 벼와 잡초의 경합력은 올챙이고랭이에서 0.00188로 피의 0.02402 보다 낮았고, 수량 예측식은 올챙이고랭이가 y = 466/(1+0.00188x), $R^2$ = 0.933, 피가 y = 458/(1+0.02402x), $R^2$ = 0.973로 나타났다. 제초제 구입 비용을 10a당 12,492원, 제초제 살포 인건비를 9,936원, 쌀의 가격을 kg당 2,000원, 제초제 방제가 95%로 적용하여 구한 경제적 피해 한계 밀도는 잡초 완전 방제시 수량이 10a당 466kg이고 잡초 1본당 수량 감수정도가 0.001884인 올챙이고랭이는 평방미터당 13.4본, 잡초 완전 방제시 수량이 458kg이고 잡초 1본당 수량 감수 정도가 0.02402인 피는 평방미터당 1.07본이었다.

• 한국작물학회지
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• 제60권3호
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• pp.355-365
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• 2015

Environment-friendly growth enhancers for rice are being promoted to reverse the negative impact of intensive chemical-based and conventional rice farming on yield sustainability and environmental problems. Several rhizosphere microorganisms and pyroligneous acids (PA) had demonstrated beneficial influence on growth, yield and grain quality of rice. Since most of the previous study had evaluated the effect of PGPR and PA on paddy rice singly, the effect of combined application of these on the growth and yield of paddy rice and on some soil chemical properties were determined. A four factorial pot experiment was conducted to evaluate the effect of PGPR, PA in combination with fertilizers and on different soil types. There were 54 treatment combinations including the control with three replications under complete randomized design. Plant growth parameters were evaluated using standard procedures during tillering and heading stages. Rice yield and some soil chemical properties were determined at harvest. Results showed that inoculation of Bacillus licheniformis and Fusarium fujikuroi enhanced plant growth by increasing the plant height which could be ascribe to its ability to promote IAA and GA production in plants. Inoculation of Rhizobium phaseoli enhanced chlorophyll content indicative to its ability to improve the N nutrition. However, these plant growth benefits during the vegetative stage were override by the fertilizer application effect especially during the maturity stage and grain yield. High fertilization rates on coarse-textured soil without nutrient loss resulted to high available nutrients and consequently high yield. Wood vinegar application however improved nutrient availability in soil which could be beneficial for improving soil quality. Further evaluation is necessary to fully assess the potential benefits that could be derived from inoculation of these organisms and wood vinegar application in different soil environment especially under different field conditions.

• 한국농공학회지
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• 제28권3호
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• pp.79-88
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• 1986

Drought occurs most frequently and severely around transplanting season of the rice plants in Korea. Shortage of water due to drought for the paddy fields often delays transplanting, and less often the rice plants are subjected to water stress after delayed transplanting. The present study aimed at quantification of the rice crop loss due to delayed transplanting, different inten3ity of water stress, and the combined effect of delay in transplanting followed by water stress for better use of limited water for irrigation under drought. The rice variety Chucheong, a japonica, and Nampung, an indica x japonica, were grown, transplanted to 1/200 a plastic pots, and subjected to different timing of transplanting and degree of water stress under a rainfall autosersing, sliding clear plastic roof facility with completely randomized arrangement of 5 replications. The results obtained are summarized as follows: 1.Twelve days or 22 days delay in transplanting without water stress reduced rice yield by 25% and 43% in the japonica variety, and by 15% and 60% in the indica x japonica variety. 2.The 10 days or 20 days water stress developed without irrigation after drainage in the rice plants transplanted at proper time lowered the water potential at the paddy soil 10cm deep to -4 bar, and -12 bar and caused rice yield reduction by 14%, and 45% in the japonica variety and by 8%, and 50% in the indica X japonica variety. 3.The 12 days delay in transplanting and 10 days or 20 days water stress reduced rice yield by 39% and 59% in the japonica variety, and by 38% and 52% in the indica x japonica variety. The 22 days delay in transplanting plus 10 days water stress caused yield reduction by 76%, i.e. meaningless yield, in both varieties. 4.The intermittent irrigation just to wet the soil body for 10 days after 10 days water stress without irrigation increased rece yield by 12 to 16% compared to the rice plants water stessed without irrigation continuously for 20 days in both varieties respectively. 5.The above results suggest strongly 1) to transplant the rice plants at proper .time even with some water stress rather than delay for sufficient water from later rainfall, and 2) to distribute insufficient irrigation water to broader area of transplanted rice with limited irrigation for better use of limited irrigation water. A greater sensitivity of japonica variety to a moderate water stress than the indica X japonica variety during initial rooting and tillering stage was noticed. To cope with frequent drought in rice culture, firstly the lasting time of transplanting without yield reduction should be clarified by region and variety, and secondly a scheme of rational distribution of limited water should be developed by region with better knowledge on the varietal distribution of limited water should be developed by region with better knowledge on the varietal responses to varying intensity of water stress.

• 한국잡초학회지
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• 제32권1호
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• pp.44-51
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• 2012

본 시험은 2010년 경상북도 농업기술원 벼 시험재배 포장에서 잡초발생 예찰 시스템 구축의 일환으로 최근 담수 직파답이 늘어나면서 벼 재배시 문제잡초인 피와 너도방동사니를 대상으로 잡초 밀도별 벼와의 경합력을 구명하고 Rectangular hyperbola 모델을 기초로 잡초의 밀도에 따른 쌀 수량 감소를 예측하고 경제적인 방제 필요수준을 구명하고자 본 시험을 실시하게 되었다. 피와 벼와의 밀도 경합에 따른 쌀수량 예측식은 y=507kg/(1+0.001734x), $R^2$=0.867이고, 너도방동사니는 y=560kg/(1+0.001883x), $R^2$=0.933으로 나타났다. 표 6은 재료 및 방법에 제시한 바와 같이 Cousens(1987)에 의해 개발된 계산식(2)을 이용하여 벼와 잡초와의 경합에 있어서 당해연도 경제적 한계 허용밀도를 산출하여 나타내었다. 그 결과, 제초제 구입비용은 ha당 150,280원(2010년)이었고, 제초제를 살포하는데 소요되는 인건비 등은 ha당 99,360원, 쌀의 kg당 가격은 1,605원, 제초제의 방제가는 95%로 적용하였을 때 경제적 한계 허용 밀도는 잡초 완전 방제시 쌀 수량이 5.07톤이고 1본당 수량 감수 정도가 0.001734인 피는 평방미터당 2.3본, 잡초 완전 방제시 쌀 수량이 5.60톤이고 1본당 수량 감수 정도가 0.001883인 너도방동사니는 평방미터당 15.5본이었다. 이와 같은 결과로 볼때 잡초의 벼에 대한 경합력이 높을수록 경제적 한계 허용 밀도의 본수는 줄어들었고, 경합력이 낮았던 잡초는 경제적 한계 허용 밀도의 본수가 증가되는 경향이었다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2022년도 추계학술대회
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• pp.288-288
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• 2022

Rice is an important staple in the world. And drought is one of the important constraints that negatively affect yield loss and grain quality of rice. CRISPR/Cas9 is a new breeding strategy that can improve the characteristics of rice quickly and accurately. CRISPR/Cas9 is a novel approach that can reliably harvest rice yields in response to a rapidly changing climate. In addition, there is no externally inserted DNA left in genome-editing rice, and it is receiving attention as being able to take responsibility for future food because its characteristics are continuously improved. In the future, high levels of drought resistant in water-constrained environments will be required, which will reduce yield loss. OsSAP was genome-editing with CRISPR/Cas9 in rice. A different line number was assigned to each panicle, and the generation advanced by applying the ear-to-row method. Genome-editing rice has improved drought resistance in drought conditions. Also, in genome-editing rice, the target sequence was homozygous in the 0 generation, and the coefficient of variation of heading date, number of tiller, and 1,000-grain weight was very small in 2 generation. In the era of rapidly changing climate change, CRISPR/Cas9 presents a new breeding strategy that can rapidly and accurately improve agronomic traits of major food crops as well as rice. CRISPR/Cas9 is applied together with traditional breeding to develop into a new breeding strategy, it is suggested that food can be obtained stably in response to climate change.

• Journal of Biosystems Engineering
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• 제3권1호
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• pp.20-36
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• 1978

The effect of binder kicking forces on the shattering losses of paddy rice, which has been widely understood as an outstanding loss factor in harvesting with a binder, were experimentally assessed in this thesis.Through the field tests the optimum time of harvest, in terms of grain moisture contents, was found by considering harvesting losses for two rice varieties, harvested by two different binders, at four or five grain moisture levels.A device was designed and manufactured to apply various kicking forces to the bundles and was used in the bundle kicking tests. It was intended to find out the optimum range of kicking force to minimize the kicking losses. Based on the study, modification of the existing binder kicking mechanism was suggested. The following is a summary of the results of this thesis. 1. In Suweon 258 variety, as the grain moisture content is reduced, so the cutting loss and the kicking loss increase. The grain losses range from 0.77 to 0.82 percent of total field yield for the cutting loss, from 1.83 to 2.01 percent for the kicking loss, and from 2.60 to 2.83 percent for the field loss, when the moisture content is about 22 percent. 2. In Jinheung variety , the field losses increased as the grain moisture content decreased . When the moisture content was 20 percent, the field loss, cutting loss and kicking loss was 0.42-0.49 % , 0.30-0.35, and 0.12 -0.14% of the total field yield, respectively. 3. The difference in the field loss , cutting loss, and kicking loss for the two binders was 0.23% , 0.05% and 0.18% respectively in Suweon 258 variety, and 0.07% , 0.02% and 0.05% respectively ini Jinheung variety. The grain losses for binder B were slightly higher than those for binder A. 4. In the statistical analysis of each variety , the kicking force and the moisture content of the grain, and its interaction were all highly significant at 1% level by T test .The optimum kicking force was found to be in the 3.0-0.4kg range. This does not interrupt the binder operation, while ioses are kept to an acceptale level. 5. To reduce the kicking force of the eXlstmg binder mechanism, the speed of rotation of the kicking arm needs to be redued by increasing the number of driving sprocket teeth, and the position and gear ratio of the knotter-bill and driving bevelgear have to be change to give a !motter-bill speed of 1110 rpm. It is also desirable to attach a belt conveyor which smoothly carries the bundle to the ground. 6. The optimum harvesting time cased on maximum field yield was found to be at a grain moisture content of around 22 percent for Suweon 258 variety, and 20 percent for Jinheung variety. Tota] field yield and field yield at the time amounted to 9, 812.5 kg/ha, 9, 302. 5kg/ha respectively for the Suweon 258, and 7, 819.5 kg/ ha, 7, 158.7 kg/ha respectively for the Jinheung variety.

• 한국작물학회지
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• 제63권2호
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• pp.120-130
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• 2018

Improvement in rice grain yield has been approached by means of genetic amendment, cultural management, and environmental adaptation. Subjecting the plant during the grain filling period to an appropriate environment plays a key role in achieving a high grain yield in temperate rice. Field experiments were conducted for two consecutive years with two planting times to assess the relations among grain filling traits, loss of leaf activity during the ripening period, and the grain yield of temperate japonica rice with wide environmental variation. Higher grain yields were attained in 2017 than in 2016 and with late planting than with early planting. The high grain yield accompanied a comparatively lesser increase in grain weight at the early filling stage but more gain in grain weight occurred during the late filling stage. Final grain weight correlated positively with grain filling duration but negatively with grain filling rate. Extended grain filling duration was associated with higher cumulative temperature and cumulative solar radiation for an effective grain filling period. The reduction in SPAD value ${\times}$ leaf dry weight from heading to harvest significantly correlated with final grain dry weight in a positive manner. No significant relation was found between grain filling duration and the decrease in SPAD value ${\times}$ leaf dry weight during the grain filling period. The results suggest that grain filling duration and loss of leaf activity during ripening independently contribute to environmentally induced yield improvement in temperate japonica rice.