• 농업과학연구
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• 제47권2호
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• pp.305-313
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• 2020

Root hair development has the potential to increase crop yields and at the same time to decrease fertilizer use, which will be required in the next 30 years to meet the demand for crop-derived commodities in a world with decreasing available natural resources. Root hair defective six (RHD6) encoding a basic helix-loop-helix transcription factor, is associated with root hair differentiation, and its roles are root hair initiation and elongation. Grass plants, rice and Brachypodium have been used as model plants to study the gene function of the root hair defective six like (RSL) subfamily which is orthologous to AtRHD6. The RSL subfamily has an identical gene function with AtRHD6 which is involved with root hair differentiation as well. Plants with longer root hairs within a species should have an improved Pi uptake efficiency; therefore, we would expect that a plant with a high Pi uptake could contribute to increasing the plant yield. We achieved increased root hair length by manipulating the RSL subfamily genes. It is expected that in these transgenic plants, the long root hairs would be sufficient to improve the Pi uptake and hence improve biomass and yield component (tiller, spikelet number, and spikelet weight) of the plant. Here, we demonstrate that Brachypodium transgenic plants overexpressing the BdRSL subfamily genes have an improved biomass and grain yield. The result of this study could be applied to important crop plants like rice.

• Journal of Biosystems Engineering
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• 제7권2호
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• pp.36-44
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• 1983

Farm population was rapidly decreasing due to shift of the people from farm sector to the non-farm sector caused by the economic growth of the country. Especially, a great shortage of farm labor in busy farming period in June and October is becoming a serious problem in maintaining or promoting land productivity. The peak of labor requirement in summer is caused by rice transplanting and barley harvesting. In order to reduce the restrictions imposed on farm management by the concurrence of labor requirement and the lack of labor, the experimental study for mechanization of barley harvesting has been carried out in the fields. 1. The machines for barley harvesting were knap-sack type reapers, windrow reaper (power tiller attachment), binder and combine. The order of higher efficiency of machine for barley harvesting was combine, binder, windrow reaper (WR), knapsack type reaper 1(KSTR1), and knap sack type reaper 2(KSTR2; mist and duster attachment). 2. The ratio of grain loss for the manual, binder, and combine plot was about four percent of total field yield. 3. The total yield of barley in 35 days and 40 days harvesting after heading were 514 kg and 507kg per 10 ares respectively. The yield of 35 days-plot was higher than other experimental plots. 4. The lowest yield was recorded in 30 days-plot due to the large quantity of immatured grains and having lighter 1000-grain weight. The ratio of immatured grains was 2.66 percent and 1000-grain weight was 29.4 grams. 5. The total harvesting cost of the windrow reaper was 10,178 won per 10 ares. It was the lowest value compared to other machines. The next were combine, binder, KSTR1, KSTR2, and manual in sequence. As a result, the optimum time of barley harvesting for mechanization was 35-40 days after heading. Combine, binder, and windrow reaper were recommended as the suitable machines for barley harvesting in the work efficiency. However, in total harvesting cost, the windrow reaper was the most promising machine for barley harvesting.

• 한국작물학회지
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• 제68권4호
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• pp.246-261
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• 2023

현시대 우리나라 자포니카 벼 품종의 조기이앙 한계온도를 밝히기 위하여, 2020~2023년 시험포장, 2020~2021년 포트육묘상자, 2022~2023년 인공기상실에서 수행한 연구 결과는 다음과 같다. 1. 포장시험에서 출수 조기화 효과가 나타나는 온도는 이앙부터 10일간 평균기온 12.0~12.4℃, 출수 조기화 효과는 없지만 생장 증가 효과가 나타나는 온도는 11.4~11.6℃로 분석되었으며, 2020~2021년 이앙부터 10일간 평균기온의 출수 조기화와 출수기 생장 증가 효과는 3 품종에서 동일하였다. 2. 10일 후 이앙 대비 최초 신근 발생 날짜는 이앙부터 10일간 평균기온 9.1℃ 이상, 이앙 후 엽록소 함량 증가 개시 날짜는 10.5℃ 이상, 최초 분얼 발생 날짜는 11.6℃ 이상에서 빨랐다. 3. 포트육묘상자 시험과 포장시험에서 나타난 최초 신근 발생, 엽록소 함량 증가 개시, 최초 분얼 발생 시기의 조만은 이앙시기 비교 조합에 따라 다른 양상으로 나타났으며, 최초 분얼 발생 시기의 조만이 조기이앙 한계온도 평가를 위한 생육 초기 지표로 실용적이었다. 4. 일교차 10℃ 조건에서 신근은 평균기온 10℃에서도 대부분의 개체에서 발생하였고, 식물체 고사 현상은 평균 기온 10℃에서도 나타나지 않았으며, 처리 당시 대비 처리 후 30일의 건물중은 10~11℃ 이상에서 증가하였고, 처리 후 30일 엽록소 함량은 11~12℃에서 처리 당시 수준이나 그 이상으로 높았다. 5. 항온 조건의 동일 평균기온에 비하여 일교차 10℃의 변온 조건에서는 신근 발생 속도가 빠르고 비율이 높았으며, 고사 식물체 비율이 낮고, 처리 후 30일 건물중과 엽록소 함량이 높아, 낮에 높아진 온도의 생장 촉진 효과가 밤에 낮아진 온도의 생장 억제 효과보다 크게 나타났다. 6. 종합적으로, 우리나라 자포니카 벼 품종의 출수 조기화에 효과적인 조기이앙 한계온도는 이앙부터 10일간 평균기온 12.0~12.4℃ 사이, 출수 조기화 효과는 없지만 출수기 생장 증가에 효과적인 한계온도는 11.4~11.6℃ 사이였고, 분얼 발생 시기의 조만이 생육초기 조기이앙 한계온도의 평가지표로 실용적이었으며, 기온 처리 시험 결과는 포장시험 결과에 대한 분석을 뒷받침하였다.

• Asian Journal of Innovation and Policy
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• 제6권1호
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• pp.58-84
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• 2017

This article aims at demonstrating location specific approach for agricultural technology promotion and adoption in improving the livelihood of the small farmers in the haor basin and coastal belt of Bangladesh. Innovative technologies that have potentials are initially screened by ex-ante investigation and instrumented by the business model canvas, which is used as a bottom-up approach for sustainability of the adoption of proposed technology innovations. Village-level extension farmers, sub-district extension officers and farmers' cooperative are the unique and central features to the business models and forward linkages. Extension service, power tiller, low-lift pump, sunflower, shallow tube well, quality seed, forward linkage for farmed duck eggs, live ducks and open catch fish etc. are the suggested potential technology innovations for the small farmers. The technology adoption business model can be reinvented for different locations within or beyond the country considering the local agricultural problems and prospects for greater sustainability.

• The Plant Pathology Journal
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• 제27권3호
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• pp.249-256
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• 2011

Tall fescue (Schedonorus phoenix Scop.) is resistant to abiotic and biotic stresses through a symbiotic relationship with Neotyphodium coenophialum. However, this endophyte has been considered detrimental since it produces toxic alkaloids to animals. It is vital to understand mutuality between these two to maximize positive impact of the endophyte on agri-ecosystem. Little research has been conducted on endophyte transmission mechanism in planta. To provide basic information related to endophyte transmission, an experiment was conducted to examine the effect of endophyte genotype and water stress on endophyte transmission by imposing soil moisture deficits at different stages of panicle development. There was water stress effect on endophyte frequency but not on concentration, whereas endophyte genotype significantly influenced endophyte concentration in pseudostem of tall fescue at boot stage. Reproductive tillers showed greater endophyte frequency and concentration. Endophyte frequency in florets or seeds depended on position within panicle. There was no drought effect on endophyte concentration, but showed the effect of endophyte genotype on endophyte concentration in florets and seeds. Overall endophyte concentration in seeds was higher. From this study, we may conclude that although water stress reduced endophyte frequency in vegetative tiller, water stress does not have effect on endophyte transmission, suggesting that drought is not an important factor controlling the endophyte transmission from plant to seed. Endophyte genotype and seed position in a panicle affected endophyte transmission, indicating that these two factors are involved in endophyte transmission and may determine seed transmission of endophyte in tall fescue.

• Journal of Biosystems Engineering
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• 제33권4호
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• pp.224-229
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• 2008

This study was aimed to minimize the impact force and vibration transmitted to the transporting materials from the trailer and wheel shaft by installing the leaf spring suspension device at the space between the wheel shaft and frame of power tiller trailer. The developed trailer equipped with leaf spring suspension device was compared to the existing trailer without suspension device, in order to identify the vibration absorption effect of the leaf spring. The results of this study could be summarized as follows; (1) The length and the maximum bending amount of the leaf spring were designed as 1,000 mm and 42 mm, respectively, considering the possible space for installing at below the trailer. When 4 leaf springs were installed on both wheel shafts, the allowable maximum load was identified as 9,418 N. (2) The average vibration accelerations for the frequency less than 20 Hz, where the severe transporting loss could be represented, were $0.017\;m/s^2$ and $0.133\;m/s^2$ for the developed and the existing trailer, respectively, showing the vibration absorption effect of about 87%. And the average vibration accelerations on the driver's seat for the frequency less than 20 Hz were $0.01\;m/s^2$ and $0.20\;m/s^2$ for the developed and the existing trailer, respectively, which showed the similar vibration absorption effect. (3) The change of the average vibration accelerations for the frequency from 20 Hz to 80 Hz showed the similar tendency with the result for the frequency less than 20 Hz, but the effect for developed trailer was reduced slightly. And the effect of vibration absorption for the above 80 Hz was reduced highly. However, by installing the leaf spring suspension device at the trailer, the low frequency below 40 Hz, which could affect on transporting loss severely, could be reduced highly. (4) The maximum vibration acceleration for the frequency less than 20 Hz were $0.027\;m/s^2$ and $1.267\;m/s^2$ for the developed and the existing trailer, respectively. And the change of maximum acceleration between 20 Hz and 120 Hz was showed similar tendency with the result for the frequency less than 20 Hz, but the width of change was reduced highly.

• 농업과학연구
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• 제28권1호
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• pp.8-17
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• 2001

분얼형 옥수수 자식계통의 식물학적 특정, 유전적 거리를 조사하여 새로운 교잡종 육성을 위한 기초자료를 얻고자 실험 한 결과를 요약하면 다음과 같다. 1. 개화기에 있어서 조사된 20계통 중 K15가 가장 빨랐고 K07이 가장 늦은 개화소요일수를 보였다. 2. 간장과 착수고는 비슷한 경향으로 보며 K04가 가장컸고, K15가 가장 작은 것으로 나타났다. 3. 상관 분석 결과 분얼수는 개화기 및 출사기와 고도의 부의 상관을 보였으며, 100립중은 개화기, 이삭높이와 고도의 부의 상관을 가지고 있다. 4. RAPD 분석 결과 17개의 BAND가 나타났고 이중 1개 만이 monomolpic band를 보였으며, primer 당 평균 4개의 loci를 보였다. 5. 유전적 거리와 식물학적 특성간에는 개화기, 분얼수, 엽장과 100립중에서 관련이 있었다.

• 한국작물학회지
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• 제65권3호
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• pp.172-181
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• 2020

고시히카리는 도열병과 쓰러짐에 약하지만 밥맛 좋은 쌀로 유명하고, 육성된 지 60년이 넘은 지금까지도 일본에서 가장 많이 재배되는 품종이다. 고시히카리에 도열병에 강하면서 생육이 빠른 백일미를 교배한 RIL집단(KBRIL)에서 도열병 저항성에 대한 유전분석을 수행하여 저항성 유전자의 염색체 상 위치를 규명하고, 고시히카리의 우수한 미질을 보유하면서 도열병에도 강한 계통을 선발하기 위해 본 연구를 수행하였다. 주요 결과는 다음과 같다. 1. 고시히카리×백일미 RIL 394계통과 모·부본의 도열병 저항성(전주, 남원) 및 주요 농업형질을 조사하고, 유전 분석을 위해 사용된 142계통으로 총 130개 SNP 마커, 1,272.7cM의 유전자지도를 작성하였다. 도열병 저항성 QTL 분석 결과 전주에서는 1번 염색체의 qBL1.1이, 남원에서는 전주와 동일한 qBL1.1과 추가로 2번 염색체의 qBL2.1이 탐지되었다. 2. RIL 394계통의 qBL1.1과 qBL2.1 유전자형을 도출하고 각 QTL의 백일미 대립인자 집적에 의한 도열병 저항성 강화 효과를 관찰하였다. 전주에서는 qBL1.1의 경우에만 백일미 대립인자 집적에 의하여 도열병 저항성이 강화되었다. 반면 남원에서는 qBL1.1, qBL2.1 모두 백일미 대립인자가 집적될 때 도열병 저항성이 강화되었다. qBL1.1, qBL2.1은 출수기, 간장, 수장, 수수를 포함한 주요 농업형질에는 영향을 미치지 않았다. 3. 고시히카리×백일미 RIL 394계통 중에서 출수기와 간장을 기준으로 고시히카리와 유사하면서 도열병에 약/강한(KS/KR) 계통과 백일미와 유사하면서 도열병에 강한(BR) 계통을 각 15계통씩 선발하였다. KR 그룹은 완전 미율이 가장 우수하여 밥맛 검정, 수량성 등 추가조사를 통해 고시히카리의 우수한 밥맛을 지니면서 도열병 저항성을 보유한 고품질 밥쌀용 품종개발에 활용할 계획이다. 또한 BR그룹은 미질이 우수하면서 출수가 빠른 고품질 품종 개발에 유용할 것으로 기대된다.

• Current Research on Agriculture and Life Sciences
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• 제11권
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• pp.43-54
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• 1993

본(本) 실험(實驗)은 벼에 있어서 냉해(冷害)로 인(因)하여 매년(每年) 막대한 수확량(收穫量)의 감소(減少)를 생육시기별(生有時期別) 생장조절제(生長調節劑) 처리(處理)에 의한 재배적(栽培的) 방법(方法)을 통하여 그 피해(被害)를 감소(減少)시키고, 생장조절제(生長調節劑)에 대한 벼의 생리학적(生理學的) 활동(活動)과 농업적(農業的) 특성(特性), 수량구성요소(收量構成要素), 근활력(根活力), Chlorophyll 함량(含量) 등(等)의 변화(變化)를 통하여 수확량(收穫量)에 관계(關係)는 요소(要素)를 규명(糾明)하고, 벼 재배(栽培) 방법(力法)에 있어서 기초(基礎) 자료(資科)로써 이용(利用)하고자 실시(實施)하여 얻은 실험결과(實驗結果)는 다음과 같다. 저온(低溫)조건하에서 처리(處理)된 모든 생장조절제(生長調節劑)는 농도(濃度)에 관계(關係)없이 초장(草長), 분니 등의 벼 생유지연(生有遲延)을 다소 경감(輕減)시켰으며, 특(特)히 ABA는 농도(濃度)에 관계(關係)없이 초장(草長), 분니수등에 있어서 다른 생장조절제(生長調節劑)보다 그 효과(效果)가 두드러진 것을 알 수 있었다. 저온(低溫) 조건하(條件下)에서의 chlorophyll함량(含量)은 무처리구(無處理品)에 비하여 감소(減少)되나 식물생장조절제(植物生長調節劑)를 처리(處理)함으로써 Chlorophyll함량(含量)이 증가(增加)되었고, 또한 근활력(根活力)도 chlorophyll함량(含量)과 같은 경향(傾向)을 나타내었다. 생육(生有) 초기(初期)의 생장(生長) 조절제(調節劑)의 처리(處理)는 수량(收量) 구성요소(構成要素)의 감소(減少)를 경감(輕減)시켜 주었으며, 이는 수량(收量)에 직후(直接) 영향(影響)을 미쳐 냉해(冷害)로 인(因)한 수량감소(收量減少)를 경향(經向)시켰으며, 특(特)히 Abscissic acid처리(處理)의 효과(效果)는 뚜렷하게 나타났다. 그러나 저온하(低溫下)에서 수잉기때 생장조절제(生長調節劑) 처리(處理)는 영양생장(營養生長)에 별다른 효과(效果)를 나타내지 않았으나 수량구성요소(收量構成要素)에는 다소 영향(影響)을 미쳐 수량(收量)에 관여(關與)하는 것으로 나타났다. 저온조건하(低溫條件下)에서의 생장조절제(生長調節劑)의 처리(處理)는 처리시기(處理時期)에 따라 다소 차이(差異)가 있지만 수량손실(收量損失) 경감(輕減)에 크게 영향(影響)을 미친 것으로 사료(思料)된다.

• Journal of Biosystems Engineering
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• 제34권3호
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• pp.140-146
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• 2009

The garlic, along with the red pepper, is one of the major seasoning vegetables in Korea. Garlic clove planting is one of the most laborious operations. Labor cost is the main source of high production cost of the garlic. Because of the geometrical uniqueness and irregularity of garlic cloves, mechanization of garlic clove planting is very difficult. To overcome price competition against the imported garlic, however, there has been a need of development of a clove metering device and a planting device for the garlic clove planter. Computer simulation, laboratory tests and field tests were conducted to develop a garlic clove planter. This research was conducted to drop garlic cloves into a soil holes through a drum bucket metering system and a rotary type planting system. Followings are the major achievements from this study. 1. The metering device consisted of a drum, a guide, a bucket and a bucket cover. Opening positions of the metering hopper were evaluated at different positions and trajectories of planting hoppers. The simulation showed that the optimum positions of hopper was -15${\sim}$0 mm in the x direction. 2. When the planter was tested under different soil textures and water contents, the best performances were obtained in a upland field with 29.1% water content and a paddy field with 18.3% water content where single clove metering and missing rate were 88.4% and 1.3%, and 90.7% and 2.0%, respectively.