• Journal of Bio-Environment Control
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• v.15 no.4
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• pp.377-384
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• 2006

This study was conducted to investigate the effects of chemical application and amout of soil moisture on low temperature stress of cucumber seedling under the greenhouse conditions. When chilling treatments ($2^{\circ}C$) were begun at 07:00AM, survival rates of seedlings of two conditions; -0.3 bar and -5.5 bar were 28.3% and 83.3% respectively. But when chilling treatments were begun at 6:00PM - even the soil moisture condition was -0.3 bar - the survival rate was above the 87%. When reducing the soil moisture from -0.3 bar to -9.0 bar, ABA content in leaf was inc.eased by 6.5fo1d. Spraying of abscisc acid (ABA) before or after the chilling significantly increased the survival rates of seedlings, decreased the amounts of leaking electrolytes and prevented the yield reductions. ABA application on the soil before the chilling appeared to be more effective than the application after the chilling with foliar spray. Spraying of ABA ($10^{-5}M$), urea (0.2%) or $KH_2PO_4$ was effective in counteracting the low temperature, which causes growth deterioration and yield reduction in cucumbers.

• Proceedings of the Korean Society of Organic Agriculture Conference
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• 2009.12a
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• pp.298-298
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• 2009

유기농업 토양에서 합리적인 유기물 관리를 위한 기초자료로 활용하기 위하여 밭토양에서 동일한 유기물을 9년간 연용하면서 옥수수의 건물량의 연차간 변화량을 조사하였다. 처리는 무비구(WF)를 비롯하여 화학비료 단용처리(CF), 화학비료 및 돈분왕겨퇴비 혼용(CF+CPR) 두었으며, 유기자원별로는 돈분왕겨퇴비(CPR), 채종유박(RC), 볏짚퇴비(CRS), 녹비(GM) 등 7처리를 두었고, 작물의 생산성은 줄기와 알곡을 포함한 총 건물량에 대하여 화학비료 단용구를 대조로 하여 상대비교하였다. 옥수수의 생육은 파종후 52일 및 수확기에 볏짚퇴비구와 녹비처리구에서 가장 양호하였다. 9년차 옥수수 총 건물량은 화학비료구 1,226kg/10a 대비 녹비처리구에서 121%로 높았으나 볏짚퇴비구 97%, 채종유박 92% 돈분왕겨퇴비 80%로 낮았으며, 무비구의 경우 24%의 수량을 보였다. 양분의 흡수량은 녹비처리구에서 11.8kg/10a로 화학비료구에 비하여 낮았으나 다른 유기자원 처리구보다 높았다. 질소 이용율은 녹비처리구 61.1%로 화학비료구 61.6%와 동일한 수준을 보였다. 화학비료구에 대한 상대적인 수량은 녹비처리구에서 5년차까지 증가하다가 6년차부터 점차 감소하는 경향(y=$-2.044x^2$+25.302x+51.402, $R^2$=0.8571)이었으며, 볏짚퇴비구도 7년차까지는 수량이 증가하다가 8년차부터 감소하는 경향(y=$-1.0621x^2$+13.091x+63.59, $R^2$=0.6643)을 보였다. 유기질비료구와 돈분왕겨퇴비구는 완만한 감소경향을 보였으나 무비구는 급격히 감소하는 경향이지만 점차 감소폭이 좁아지는 경향(y=$0.4584x^2$-9.5544x+69.221, $R^2$=0.8777)을 보였다.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.2
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• pp.174-180
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• 2014

This study was conducted to know the effect of low radiation during grain filling stage of rice on its grain yield, components, physicochemical properties and palatability, compared to the effect of natural light. Ripened grain ratio, 1000 grain weight of brown rice, milled rice yield of Mipum, Hopum, and Sindongjin were reduced as the shading treatments become higher. After harvest, physicochemical properties of rice influencing eating quality were investigated. Protein content of milled rice was increased, but palatability was decreased by shading treatments. Change of milled rice proteins and palatability due to shading treatments were found to be less in Mipum than that in Hopum and Sindongjin. With regard to amylogram properties, shading treatments resulted in a significant decrease in peak trough final breakdown viscosities of rice flour, though it increased pasting temperature and setback viscosity. The degree of the 55% shading effect was more intensive than the 35% shading effect in changes of ripened grain ratio, 1000 grain weight of brown rice, milled rice yield and milled rice protein.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.1
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• pp.97-103
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• 1986

In order to investigate the important morphological traits, and grain yield and its components on basis of regional variation of barley plant, Olbori was tested at 3 locations Suwon, Daejeon and Jinju for 3 years. It needed seven days around 15$^{\circ}C$ of daily average temperature for seed emergence. 104 to 144 days for Daejeon and 135 to 142 for Jinju after sowing are needed for productive tillers according to the different sowing dates, and % of productive tillers were ranged on 37-77%, showing higher value at the southern region. Young spike elongated slowly at early stage, and after floret differentiation it appeared rapid development with 1.05-1.95 mm elongating per day. Analysis of variance indicated that only number of kernels/spike showed significant differences among locations, but every traits related to grain yields revealed the significant differences among different sowing dates. Little differences between locations existed on grain yield but its large variation appeared between sowing dates, especially indicating more variation at northern regions.

• Korean Journal of Soil Science and Fertilizer
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• v.14 no.3
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• pp.157-162
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• 1981

The studies we re carried out to examine the effect of soil improvement agents, such as lime, wollastonite and phosphate, in reducing the damage caused by hydrogen fluoride gas to the vegetative growth of rice. The yield loss, damage rate of the plant leaves, the fluoride of the plants were measured. The results obtained are summarized as follows : 1. The best results were obtained a treatment of lime and wollastonite. 2. The rice yield was not significantly increased by the soil improvement agents. 3. The fluoride content of the plants was positively correlated with yield loss and damage rate during vegetative growth.

• Research in Plant Disease
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• v.19 no.3
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• pp.196-200
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• 2013

This study was carried out to investigate yield loss due to soybean leaf spot disease caused by Cercospora sojina Hara and to determine the economic threshold level. The investigations revealed highly significant correlations between disease severity (diseased leaf area) and yield components (pod number per plant, total grain number per plant, total grain weight per plant, percent of ripened grain, weight of hundred seed, and yield). The correlation coefficients between leaf spot severity and each component were -0.90, -0.90, -0.92, -0.99, -0.90 and -0.94, respectively. The yield was inversely proportional to the diseased leaf area increased. The regression equation, yield prediction model, between disease severity (x) and yield (y) was obtained as y = -3.7213x + 354.99 ($R^2$ = 0.9047). Based on the yield prediction model, economic injury level and economic threshold level could be set as 3.3% and 2.6% of diseased leaf area of soybean.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.1
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• pp.69-75
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• 1985

Field experiments were performed to obtain the basic information of flowering order and variation of yield characteristics by capsule position in sesame. Flowering order was advanced regularly about one day interval from 5th capsule-setting node to upper node. Developing order of flowers at the same nodes, the chief bud was generally flowered eariler than side buds, 3 days below 8th node, 2 days from 9th to 16th node, and 2 - 3 days above 17th node. The number of capsule per plant and total grains were 98% from 1st to 16th capsule - setting node, but the number and the weight of matured grain were 99% from 1st to 13th node. The weight of matured grain among nodes was the heaviest at 5th capsule - setting node. The variation of yield characteristics among nodes was higher than individual plants. Yield characteristics of 6th node was shown lowest variation in comparision with those of other nodes.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1656-1660
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• 2006

도시 주변의 급격한 택지개발, 도시 인구의 집중, 대규모 계획단지의 개발은 유역의 유출특성에 큰 영향을 주게 되고, 도시화가 진행됨에 따라 불투수 표면이 증가되고 침투율이 감소됨으로써 유출계수의 증가요인이 되고 있다. 이에 따라 유역의 자연 저류지 기능이 저하되고, 우수가 하천으로 유입되는 시간이 단축됨으로써 첨두홍수량 뿐만 아니라 유출총량의 증대를 초래하여 도시 주변의 중소하천 유역에서는 막대한 재산 및 인명 피해가 발생하고 있다. 이러한 도시화로 인해 증가된 유출량을 저감시키는 구조적 방안으로 대부분 강우 유출수를 일시 저류하여 유출량을 조절하는 우수유출 억제시설이 권장되고 있으나, 이들 시설에 대한 수리학적 침수방어능력이 명확히 규명되지 못한 실정이다. 본 연구의 목적은 도시지역 침수방지 대책 수립에 필요한 On/Off-Line 저류지의 평가 및 설계에 기존 부정류 모형들의 모의가능성을 평가 비교하고, 가상하도와 실제하도에 적용하여 모형을 검보정 함으로서 저류지 해석의 실용화 모형을 확립함에 있다. 본 연구 결과는 도시지역에 적용할 수 있는 도시홍수방어시스템의 일환으로 구축함으로써, 도시지역에서 저류지 홍수저감효과를 평가하는 등 침수재해와 연계된 구조적 대책 수립에 필요한 기초자료로 활용하고자 한다. 본 연구에서 연구된 저류지 모형을 이용하여 On-Line 및 Off-Line 저류지에 적용한 결과 두 종류의 저류지 모두 홍수방어를 위해 이용될 수 있었다. On/Off-Line 저류지 모두 첨두유량이 발생할 경우 어느정도의 첨두값의 감쇠를 발생시킬 수 있는 것으로 판단된다. 그러나 저류지 상류단의 수위감소는 저류지로 유출로 인해 저류지 상류 하도부에서 유속의 증가를 발생시켰고 이로 인해 수위는 저류지가 존재하지 않는 경우보다 낮게 나타나고 있다. On-Line 저류지의 경우 Off-Line 의 경우에 비해 수위, 유량이 저류지의 상류단에서 크게 나타났다. On-Line 저류지의 경우 Off-Line 의 경우에 비해 같은 값의 첨두홍수량을 저류하기 위해서 상대적으로 넓은 저류면적이 필요한 것으로 나타난다. 대등한 수위감소값의 홍수저감효과를 발휘하기 위해서 본 연구에서는 On-Line 저류지 면적은 Off-Line 저류지에 비 두배 이상이 필요한 것으로 보여졌다.

• Korean Journal of Weed Science
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• v.31 no.2
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• pp.134-145
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• 2011

The objectives of this study were to investigate fitness difference in growth and rice yield in herbicide-transgenic rice overexpressing Myxococcus xanthus and Arabidopsis thaliana protoporphyrinogen oxidase (Protox) genes and non-transgenic rice. We also aimed to determine whether these fitness differences are related to ALA synthesizing capacity, accumulation of terapyrroles, reactive oxygen species, lipid peroxidation, and antioxidative enzymes at different growth stages of rice. Plant height of the transgenic rice overexpressing M. xanthus (MX) and A. thaliana (AP37) Protox genes at 43, 50, and 65 days after transplanting (DAT) was significantly lower than that of WT. Number of tiller of PX as well as MX and AP37 at 50 and 65 DAT was significantly lower than that of WT. At harvest time, culm length and yield of MX, PX and AP37 and rice straw weight of MX and AP37 were significantly low compared with WT. The reduction of yield in MX, PX, and AP37 was caused by spikelets per panicle and 1000 grain weight, ripened grain, spikelets per panicle, 1000 grain weight, and ripened grain, respectively. On the other hand, 135 the reduction of yield in MX, PX, and AP37 was also observed in another yearly variation experiment. The reduction of rice growth in MX, PX, and AP37 was observed in seedling stage as well as growth duration in field. There were no differences in tetrapyrrole intermediate Proto IX, Mg-Proto IX and Mg-Proto IX monomethyl ester, reactive oxygen species ($H_2O_2$ and ${O_2}^-$), MDA, antioxidative enzymes (SOD, CAT, POX, APX, and GR) and chlorophyll between transgenic lines and wild type, indicating that accumulated tetrapyrrole intermediate and other parameters were not related to growth reduction in transgenic rice. However, ALA synthesizing capacity in MX, PX, and AP37 at one day after exposure to light and 52 DAT was significantly lower than that of WT. Further study is required to elucidate the mechanisms underlying the growth and yield difference between transgenic and WT lines.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.408-421
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• 1989

The effects of seeding and clipping termination dates, and seeding and fertilizer rates on forage and grain yields were evaluated in 1989 harvest year for dual production of forage and grain of naked and malting barleys in Cheju province. In the experiment I, 'Saessalbori' (naked barleY)1 and 'Doosan 22' (malting barley) were seeded on Sept. 21, Oct. 12 and Nov. 2, respectively. An unclipped(grain-only) treatment that was planted on Nov. 2 was included for check. In the experiment II, the two above cultivars were planted at seed rate of 14, 20 and 26 and kg/l0a. Fertilizer rates were 9-6-12, 17-13-8 and 22-16-11 (N-P$_2$O$\sub$5/-K$_2$O) kg/l0a. Seeding dates were Oct. 13 and Nov. 7 for clipped treatments and grain -only treatment(seeding rate: 14kg/l0a, N-P$_2$O$\sub$5/-K$_2$O=9-6-12 kg/l0a), respectively. All treatments in both experiments were harvested for grain yield. In Saessalbori, survival following forage removal was 100％ regardless of seeding and clipping termination dates, and seeding and fertilizer rates. In Doosan 22, survival percenage decreased with increasing seeding and fertilizer rates when plants was clipped in January to Febuary. Forage yield of two cultivars increased with early planting and delays in clipping termination and tended to increase as seeding and fertilizer rates were increased. Crude ash and fat were not affected by seeding and fertilizer rates, and clipping date. Crude protein increased with an increase in fertilizer rate and decreased with delays in clipping date. N free extract tended to increase with delaying clipping date and decreased with increasing fertilizer rate. Earlier planting resulted in earlier heading and maturity. Clipping slightly delayed heading of Saessalbori and greatly delayed that of Doosan 22. Maturity of Doosan 22 was delayed 3 to 5 days by increased fertilization. Clipping shortened culm length more severely in Doosan 22 than in Saessalbori. The later the clipping termination, the shorter the culm length. The number of spikes per m$^2$ and the number of kernels per spike were not affected by clipping in Saessalbori while those of Doosan 22 were decreased with delays in clipping termination. Delaying forage harvest resulted In a reduction in grain yield. However, final clipping on Feb. 27 reduced grain yield of Saessalbori by only 6-11 ％ compared to the grain-only treatment. In Doosan 22, forage harvest after Dec. 28 resulted in 6 to 66％ reduction of grain yield. The data indicate that grazing of naked and malting barleys until late Feb. and late Dec., respectively, might not reduce grain yields when planted on mid-Sept. to mid-Oct.