• 한국환경농학회지
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• 제15권2호
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• pp.207-216
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• 1996

인공산성비의 pH가 낮아질수록 고추씨의 발아에 걸리는 시간은 단축되었으며 발아율은 향상되었으나 어린 싹에게는 매우 치명적인 영향을 미쳤다. 어린 고추모는 이미 자란 식물체에 비하여 산성비에 훨신 더 민감하게 작용하였다. 산성비의 전형적인 가시피해증상은 잎에 나타나는 흰색 반점이었으며, 빗물의 pH가 낮을수록 더 빨리 더 심하게 나타났다. 고추의 역병은 일반적으로 인공산성비 처리구에서 대조구보다 빨리 발병하였으나, 인공산성비의 pH가 아주 낮을 때는 다른 처리구에 비하여 오히려 병의 발생이 줄어들었다. 인공산성비 처리중에 역병을 접종하였을 때는 처리 전에 접종하였을 때보다 병이 더 빨리, 더 심하게 나타났다. 역병의 발생이 가장 심했던 것은 역병의 접종시기와는 관계없이 pH 4.0 또는 4.5인 빗물을 처리하였을 때였다.

• 한국정밀공학회지
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• 제31권1호
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• pp.43-50
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• 2014

This paper introduces a robot platform which can do weeding while traveling between rice seedlings stably against irregular land surface of a paddy field. Also, an autonomous navigation technique that can track on stable state without any damage of the seedlings in the working area is proposed. Detection of the rice seedlings and avoidance knocking down by the robot platform is achieved by the sensor fusion of a laser range finder (LRF) and an inertial measurement unit (IMU). These sensors are also used to control navigating direction of the robot to keep going along the column of rice seedling consistently. Deviation of the robot direction from the rice column that is sensed by the LRF is fed back to a proportional and derivative controller to obtain stable adjustment of navigating direction and get proper returning speed of the robot to the rice column.

• Journal of Biosystems Engineering
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• 제37권3호
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• pp.201-208
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• 2012

Purpose: This study was conducted to develop a vegetable transplanting robot which transplants seedlings from a nursery tray to a plant pot using its four fingers. Method: The robot consists of the transplanting part, nursery tray moving part, plant pot moving part, main frame and controller. Two moving parts are controlled by the photo sensor and servo motor. The transplanting part was composed with two components; transporting device using E-MY2H(SMC Corp., Japan) for controlling finger position accurately and finger for transplanting the seedling. Results: Head lettuce using the transplanting robot was transplanted in 21 days after sowing based upon the seed shape measurement and removing examination. The optimal finger shape was thin pin type because it caused minimum damage to the roots of seedlings. Conclusions: The four inclined pin type was applied to remove the seedlings from the nursery tray. In addition, the transplanting capacity of the developed robot was 2800 pots per hour and the rate of success was 99% and above.

• The Korean Journal of Ecology
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• 제25권6호
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• pp.371-377
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• 2002

Leaves of two-week old seedlings of tomato (Lycopersicon esculentum) were treated with various concentrations (0, 0.2 and 0.4 $\mu$g/1) of 2,4,5-trichlorobiphenyl (PCB-29) and subsequent growth of seedlings, symptoms of oxidative stress and activities of antioxidant enzymes were investigated. Compared with the non-treated control, foliar application of PCB-29 decreased both biomass and superoxide ($O_2$) radical production but increased hydrogen peroxide production and lipid peroxidation such as malondialdehyde (MDA) formation with increased activities of superoxide dismutase (SOD), ascorbate peroxidase (APX) and guaiacol peroxidase (GPX). Further studies on the isozymes of SOD, peroxidase (POD) and APX showed that all three isozymes of SOD such as Mn-SOD, Fe-SOD and Cu/Zn-SOD, two among four isozymes of POD and all three isozymes of APX were selectively increased in response to PCB. Therefore, we suggest that a possible cause for the reduction of seedling growth by PCB exposure is the oxidative stress including over production of hydrogen peroxide and the selective expression of specific isozymes of some antioxidant enzymes.

• 한국작물학회지
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• 제44권1호
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• pp.4-10
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• 1999

This study was conducted to determine the effects of NaCl stress on nitrogen, ${NH_4}^+$, and ${NO_3}^-$ content of 4 barley cultivar seedlings that were cultured for 10 and 30 days with different NaCl levels (0, 50, 100, and 150 mM) contain-ing 1/4 Hoagland solutions. The sodium ion content in the shoot of barley seedlings sharply increased with an increase of NaCl concentration. After 30 days of NaCl treatment, the sodium content of the shoot at 150 mM NaCl was 27 times higher than in non-saline conditions. The sodium content in the root linearly increased with increasing NaCl concentration. Nitrogen content in the shoot linearly increased with increasing NaCl concentration, but nitrogen content in the root declined above the point where the $Na^+$ content was 3.0 mM/g $Na^+$ in the barley seedling. ${NO_3}^-$ content also decreased with increasing NaCl concentration. ${NH_4}^+$ content in the shoot decreased with NaCl condition, but its content in the root increased with NaCl condition. A positive correlation between ${NO_3}^-$ and ${NH_4}^+$ content was found in the shoot, but their relationship was negative in the root.

• 한국작물학회지
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• 제46권4호
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• pp.284-288
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• 2001

Water deficit is a serious constraint to soybean [Glycine max L. (Merr.)] production in rainfed regions of Asia, Africa, and America. This study was conducted to develop a simple and effective screening method for drought tolerance in soybean. Fifteen soybean cultivars, eight identified to be drought-tolerant and seven drought-sensitive in previous studies, were used for the evaluation of drought tolerance under the new screening conditions. The seedling screening method was consisted of a treatment in a PEG solution and drought treatment in parafilm-layered pots. 5-day-old seedlings were treated in a 18% PEG solution for 4 days and their wilting and hypocotyl browning were recorded. Three seedlings grown in a parafilm-layered pot containing peat moss were drought-stressed by withholding water from the third day after seedling emergence, and root and seedling growth were examined. Degree of drought tolerance were rated based on seedling vigor in the PEG solution and drought-stressed parafilm-layered pots, and also on the penetration ability of roots through parafilm layer. Most of seedlings of the drought-tolerant cultivars showed higher vigour and root penetration than those of the drought-sensitive cultivars under the new screening conditions. Our results indicate that the new method can be used as a simple and effective screening procedure for drought tolerance in soybean breeding programs.

• 농업과학연구
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• 제4권1호
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• pp.94-104
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• 1977

수도재배(水滔栽培)에 기계이앙(機械移秧)을 실시(實施)하기 위(爲)하여 조생통일외(早生統一外) 3개(固) 품종(品種)을 4월(月) 16일(日)부터 10일(日) 간격(間隔)으로 3회(回) 상자육묘(箱子育苗)하고 40일묘(日苗)를 이앙기(移秧機)로 이양(移秧)하였던 바 묘(苗)의 생육(生育)과 기계이앙후본답(機械移秧後本畓)에서의 수도(水滔)의 생육(生育)과 수량(收量)을 조사(調査)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 40일묘(日苗)의 초장(草長)과 엽수(葉數)는 관행육묘(慣行育苗)에 비(比)해 상자육묘구(箱子育苗區)에서 현저(顯著)히 짧은 경향(傾向)이었으며 상자육묘(箱子育苗)의 경우 물못자리 상자육묘구(箱子育苗區)의 초장(草長) 및 엽수(葉數)가 밭못자리구(區)보다 현저(顯著)히 길었다. 2. 40일묘(日苗)를 단근(斷根)하여 발근력(發根力)을 시험(試驗)한 결과(結果) 상자육묘구(箱子育苗區)의 발근력(發根力)은 관행육묘구(관行育苗區)의 발근력(發根力)에 비(比)해 현저(顯著)히 낮았다. 한편 같은 상자육묘구(箱子育苗區)에서는 물못자리 상자육묘구(箱子育苗區)의 묘(苗)의 발근력(發根力)이 밭못자리에 비(比)해 높은 경향(傾向)이었다. 3. 본시험(本試驗)에 공시(供試)된 유일계(流一系) 품종(品種)은 상자육묘(箱子育苗)의 경우 못자리에서 25~30일(日) 경(頃) 부터 잎의 상부가 황변(黃變) 내지 황적색(黃赤色)으로 변(變)하고 생육(生育)이 거의 정지(停止)되는 현상(現像)을 나타내었다. 4. 상자육묘(箱子育苗)의 기계이앙구(機械移秧區)는 관행육묘이앙구(慣行育苗移秧區)에 비(比)해 활착(活着)이 5~7일(日) 이상(以上) 지연되었으며 출수기(出穗期)도 품종(品種)에 따라 차이(差異)가 있으나 대체로 5~7일(日) 지연되었다. 5. 정조수량(正粗收量)은 유신(維新)의 관행재배구(慣行栽培區)에 비(比)해 모두 약간의 감수(減收)를 보였는데 기계이앙구내(機械移秧區內)에서는 5월(月) 26일(日) 이앙(移秧)의 경우 통일(統一)의 수량(收量)이 가장 높았고 6월(月) 15일(日)의 수량(收量)은 밀양(密陽) 15호(號)가 가장 많았으며 기계이앙재배(機械移秧栽培)를 위(爲)한 품종(品種)의 선택(選擇)은 중요(重要)한 것으로 인정(認定)된다. 6. 수도이앙기(水滔移秧機)로는 $3.3m^2$당(當) 이앙주수(移秧株數)를 73주(株)부터 108주(株)까지 조정(調整)이 가능(可能)하며 파종밀도(播種密度)가 균일(均一)하면 결주율(缺株率) 1% 미만(未滿)의 작업정도(作業精度)로 인력이앙작업(人力移秧作業)에 비(比)하여 2조(條)의 경우 5~6배(倍)의 이앙작업능률(移秧作業能率)을 올릴 수 있으므로 단작지대(單作地帶)에서는 실용화(實用化)가 용역(容易)하리라 믿는다. 7. 이모작지대(二毛作地帶)에서는 이앙시기(移秧時期)가 한정(限定)되어 있으므로 적절(適切)한 품종(品種)의 선택(選擇)과 상자묘(箱子苗)의 육묘기술(育苗技術)이 개발(開發)된다면 수량(收量)은 감소(減少)없이 이앙작업(移秧作業)의 기계화(機械化)가 무난(無難) 할 것으로 전망(展望)된다.

• 한국식품저장유통학회:학술대회논문집
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• 한국식품저장유통학회 2003년도 춘계총회 및 제22차 학술발표회
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• pp.97.2-98
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• 2003

The main objective of this study was to investigate the patterns of glucosinolates (3-butenyl isothiocyanate, total glucosinolates) in different parts of young seedling and seeds on Korean Chinese cabbages 55 days and Winter pride cultivars. For determination of glucosinolates, two cultivars of Chinese cabbages seeds and different parts of 1-day-old, 3-day-old, 5-day-old, and 7-day-old seedlings were used for analytical sample preparation provided with an anion exchanges column, and measured by GC and UV-Visible Spectrophotometer. 3-Butenyl ITC concentration was the highest in the cotyledon and the hypocotyl parts of 55 days cultivar seedling. In the cotyledon part of Winter pride cultivar seedling, 3-butenyl ITC amount was increase to 3-day-old seedling and then reduced. The cotyledon of 55 days cultivar contained the highest concentration of total glucosinolates while those were increased in the hypocotyl and decreased by degrees in the root. Total glucosinolates amounts were increased to 5-day-old seedling and then decreased in the cotyledon and the hypocotyl parts of seedling on Winter pride cultivar. There was no significant difference in the root part. In the seeds, both of 3-butenyl ITC and total glucosinolates, 55 days cultivar concentration was higher than Winter pride cultivar. The study has shown the variability in 3-butenyl ITC and total glucosinolates concentrations among cultivars, growth stages, and parts.

• 한국산림과학회지
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• 제97권5호
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• pp.540-546
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• 2008

Enrichment planting has been used as one of the promising restoration techniques to accelerate the natural restoration process of secondary forests or logged-over forests in Myanmar, The objectives of this study were to examine the growth performances of two commercial species such as Teak (Tectona grandis Linn f.) and Padauk (Pterocarpus macrocarpus Kurz) in response to different canopy opening treatments and to examine the suitability of these species in enrichment planting activities for the restoration of degraded tropical forests in Myanmar. In this study, split plot design was applied, and three levels of canopy openings were experimented. The survival rate and height growth of two species were measured four times with 6 month interval. The root collar diameter (RCD) was also measured in the last assessment. Although the survival rate of seedlings was not significantly different among the three treatments (p>0.05) as well as between two species (p>0.05) for all consecutive measurements, height (p<0.05) and RCD were significantly different (p<0.001) among the treatments, T. grandis seedlings thrived best under complete canopy opening (i.e., 5 m width canopy opening with strip-clear cutting) while P. macrocarpus seedlings under partial canopy opening (without felling of marketable tree species). Because this study is concerned with only for young stage of seedlings, continuous assessment and follow-up tending activities are needed to verify the species suitability and optimum width of canopy opening for enrichment planting activities in restoration of degraded forests of Myanmar.

• BMB Reports
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• 제31권3호
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• pp.221-226
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• 1998

Phosphorylation of phytochrome may play important functional roles to control plant photomorphogenesis. Many attempts have failed to identify the protein kinase that phosphorylates phytochrome in vivo. It has been reported that a polycation-stimulated protein kinase activity was associated with the purified phytochrome. However, it is not known if the kinase activity is an intrinsic property of phytochrome or whether it comes from a contaminant of the purified phytochrome. In the present study, three protein kinases that phosphorylate phytochrome have been identified from etiolated oat seedlings. A polycationstimulated protein kinase that had very similar enzymatic properties with that associated with the purified phytochrome was identified in the cytosolic extract. It phosphorylated several contaminant proteins in the kinase preparation as well as phytochrome and had a broad substrate specificity. A CK II-type protein kinase phosphorylated phytochrome and the exogenously added casein. It is likely that this kinase may not be a feasible candidate for the kinase phosphorylating phytochrome in vivo since the content of the kinase seemed to well exceed the content of phytochrome in the etiolated oat seedlings. Another protein kinase that had unique enzymatic properties phosphorylated phytochrome very specifically and seemed to be present in a small quantity in the etiohlted seedlings. It is expected that one of three kinases may be responsible for the phytochrome phosphorylation in vivo.