• Korean Journal of Soil Science and Fertilizer
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• v.41 no.3
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• pp.177-183
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• 2008

Sodium is known to reduce a plant growth and yields. However, the relationships between physiological response of seedling and salinity stress caused by growing media are not well understood yet. We conducted experiments to investigate change of some parameters including Na, EC, moisture content in media under different air temperature ($15^{\circ}C$, $25^{\circ}C$), and the response of fruit-vegetables such as cucumber, oriental melon on saline conditions originated from horticultural substrate. Volumetric moisture content of media at $15^{\circ}C$ was 70%, but at $25^{\circ}C$ was decreased by 45% within 22 hrs, showing below optimal matric potential, approximately. During reaction time, the increase of Na concentration was significantly greater in saline substrate than in control. The decrease rate of Na concentration according to supplying irrigation water was higher in saline substrate than in control. $CO_2$ assimilation rate and transpiration rate of Korea melon grown in low temperature were decreased with a Na/cation ratio in hydroponic solution. Water saturation deficit was also increased significantly at $15^{\circ}C$ as compare to $25^{\circ}C$. Saline stress during nursery stage induced a reduction of seedling quality, growth and cucumber yield. The results suggest that the relationship between uncontrolled Na uptake of seedling from saline substrate and meteological condition is responsible for saline stress.

• Korean Journal of Microbiology
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• v.13 no.4
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• pp.143-156
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• 1975

A rotting bacterium was isolated from decayed root of ginseng (Panax ginseng Meyer), cultured purely, and its pathogenicity was confirmed by reinoculation test. The strain causing ginseng root rot was identified as Pseudomonas fluoresens biotype II. The strain was somewhat different from P.marginalis and P.talaasii, considering the number of flagella, pathotype and ability of indole production. The strain did not exhibit pathogenicity to other plants tested, such as red kidney bean(Phasolus vulgaris L.), soy bean (Glycine max Merr.), cucumber (Cucumis sativus L.) lettuce (Lactuca sativa L.) and cowpea bean (Vigna sinensis Savi.).

• Korean Journal of Soil Science and Fertilizer
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• v.30 no.2
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• pp.196-199
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• 1997

We studied the effect of inoculation of microorganisms known to produce plant growth promoting substances, on the growth and yield of cucumber(Cucumis sativa L.), through a field experiment. The microorganisms used were isolated from the forest soil and consisted of Micrococus sp., Baccilus sustilis, Enterobacter agglomerans, Baccilus megaterium, Pseudomonas putida, Cellulomonas sp. and Staphylococus xyposus. Fotr the multiplication, microorganisms were cultured in liquid media of Pseudomonas P and Sabouraud dextrose. Inoculation of microorganisms was done by spraying the culture media after the culture of them to soil and cucumber plants, three times during the growth of cucumber at the rate of 10l/ha. The inoculation of microorganisms tended to promote the growth of cucumber plant and increase the yield of it. No sign of significant improvement of soil chemical and physical properties were observed after the harvest of crop. The population of bacteria and actinomycetes tended to be higher in the inoculated plots than in not inoculated plots, while opposite was the case in the population of fungi.

• Research in Plant Disease
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• v.14 no.2
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• pp.117-121
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• 2008

To determine the economic threshold level of Meloidogyne incognita on cucumber in greenhouse conditions, cucumber seedlings(Cucumis sativa L. cv. 'Super Manchon') grafted on 'Jangsushintozoa'(Cucurbita maxima x Cu. moschata) were planted in wooden boxes($30{\times}40{\times}15cm,\;L{\times}W{\times}D$) under a plastic house in August 01 and harvested from Sep. 01-Oct. 30, 2006. The initial nematode population densities(Pi) in the wooden boxes were adjusted to 0, 10, 30, 100, 300, and 600 second-stage juveniles(J2)/100 $cm^3$ soil. The relationship of total fruit yield to Pi level could be adequately described by a linear regression equation, $Y=0.82-0.04{\cdot}Log_{10}$(Pi+1). Initial nematode densities(Pi) before planting in excess of 5 J2/1,000 $cm^3$ soil caused in total yields loss that is equivalent to the costs of granular nematicide application; Pi level in excess of 25 J2/1,000 $cm^3$ soil caused in total yields loss that exceed the costs for application of fumigants at current control costs. We propose two different management strategies depending on nematode densities, (i) application of non-fumigant granular nematicides for M. incognita Pi level of 5 J2/1,000 $cm^3$ soil and (ii) fumigant treatment with Pi level over 25 J2/1,000 $cm^3$ soil. Soil samples to determine population density of Meloidogyne spp. for advisory purposes should be taken several months before planting time, which allows a period of time enough for implementing management procedures.

• Korean Journal of Organic Agriculture
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• v.19 no.spc
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• pp.222-224
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• 2011

The effects of seawater on growth of lettuce(Lactuca sativa L.), leaf perilla(Perilla frutescens var. japonica Hara), red pepper(Capsicum annuum L.) and cucumber(Cucumis sativus L.) seedlings were investigated in the glass greenhouse. These effects were studied on seedlings, and diluted seawater (1%, 5%, 10%, 20%, 50%, 100% v/v) was sprayed enough on leaves. The tested four vegetable crops have well grown up to 10% diluted seawater, but the tested vegetable crops were damaged from increasing salt levels. Of these, lettuce was provided salt-tolerant vegetable crop and red pepper was considered salt-sensitive vegetable crop. The salt tolerance of vegetable crops is different between crops and complicated because of additional detrimental effects caused by accumulated ions or specific ion toxicities in their leaves. These results show that agricultural use of seawater may be benefit crop cultivation in organic farming system as well as in conventional farming system.

• Korean Journal of Weed Science
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• v.16 no.2
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• pp.160-170
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• 1996

Several physiological responses were investigated in plants treated with TOPE as a preliminary step to know its action site. Unlike photo-dependent diphenylethers, herbicidal activity of TOPE appeared slowly and its typical symptoms were both burning of leaf blades and abnormal division of meristem in grasses, Similarly, both leakage of cell electrolytes and the curling of cotyledon margin were also shown in cucumber(Cucumis sativus L.). Biosynthesis of chlorophyll in etiolated cucumber cotyledon was not inhibited directly by treatment of TOPE at low light intensity(5.5${\mu}$ mol $m^{-2}s^{-1}$ PAR) and protoporphyrin IX was not also accumulated. The contents of phytoene, phytofluene and ${\beta}$-carotene were abnormaly increased. Photosynthesis was inhibited only at high concentration. Mitochondrial respiration was inhibited at high concentration but rather increased significantly at 10${\mu}$M of TOPE. However, respiration inhibitors did not alleviate the two symptoms of TOPE in cucumber cotyledon. In the same experiments, using inhibitors of protein or nucleic acid biosynthesis, only one of the two symptoms was alleviated by chloramphenicol and cycloheximide. In contrast, both symptoms were alleviated by actinomycin-D and hydroxyurea, suggesting that nucleic acid metabolism might be preferentially related to the mode of action of TOPE. DNA, RNA and protein contents were accumulated in both cucumber cotyledon and rice (Oryza sativa L.) routs treated with TOPE, and the DNA of them was increased at first. Thus, it is conjectured that TOPE increase nucleic acid metabolism directly or indirectly, and then disturb various metabolic pathways causing abnormal physiological and morphological effects followed by final death.

• Korean Journal of Soil Science and Fertilizer
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• v.25 no.3
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• pp.242-248
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• 1992

This study was carried out to investigate the effects of root-zone temperature in hydroponics on the plant growth and nutrient uptake of lettuce(Lactuca sativa L), tomato (Lycopersicon esculentum Mill), and cucumber (Cucumis sativus L). Respiration rate in roots increased with increase in root-zone temperature. At $10^{\circ}C$ of root-zone temperature, respiration rate in lettuce root was higher than those in tomato and cucumber. Increasing rate of root respiration in tomato with increase in root-zone temperature was greater than those in lettuce and cucumber. The lowest dry weight and leaf area of the crops studied were obtained at $10^{\circ}C$ of root-zone temperature, but they were not different between 20 and $30^{\circ}C$. Increase in root-zone temperature generally resulted in increase in T/R ratio and net assimilation rate. At the low root-zone temperature, root growth and leaf area of tomato and cucumber were severely affected. Relative growth rates of lettuce and cucumber were also greatly reduced by the low root-zone temperature. Contents of N, P, K, Ca, and Mg in the crops increased as root-zone temperature increased from 10 to $20^{\circ}C$, whereas only Ca content in tomato and cucumber increased with increase in root-zone temperature to $30^{\circ}C$. Remarkably low contents of P and Mg in the crops were found at the low root-zone temperature. Inhibition of plant growth and nutrient uptake due to low root-zone temperature was much greater in cucumber than in lettuce and tomato.

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.963-974
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• 2015

This study was conducted to determine the effects of organic vegetable cultivation on the soil physical properties in 33 farmlands under plastic greenhouse in Korea. We were investigated 5~8 farms per organic vegetable crops during the period from August to November 2014. The main cultivated vegetables were leafy lettuce (Lactuca sativa L.), Perilla leaves (Perilla frutescens var. Japonica Hara), cucumber (Cucumis sativus L.), strawberry (Fragaria ananassa L.) and tomato (Lycopersicon spp.). We have analyzed soil physical properties. The measured soil physical parameters were soil plough layer, soil hardness, penetration resistance, three soil phase, bulk density and Porosity. The measurement of the soil plough layer, soil hardness and penetration resistance were carried out direct in the fields, and the samples for other parameters were taken using the soil core method with approximately 20 mm diameter core collected from each organic vegetable field. Soil plough layer was average 36 cm and ranged between 30 and 50 cm, and slightly different depending on the sorts of vegetable cultivation. The soil hardness was $0.17{\pm}0.15{\sim}1.34{\pm}1.02$ in the topsoil, $0.55{\pm}0.34{\sim}1.15{\pm}0.62$ in the subsoil. It was not different between topsoil and subsoil, but showed a statistically significant difference between the leafy and fruit vegetables. Penetrometer resistance is one of the important soil physical properties that can determine both root elongation and yield. The increase in density under leafy vegetables resulted in a higher soil penetrometer resistance. Soil is a three-component system comprised of solid, liquid, and gas phases distributed in a complex geometry that creates large solidliquid, liquid-gas, and gas-solid interfacial areas. The three soil phases were dynamic and typically changed in organic vegetable soils under greenhouse. Porosity was characterized as range of $54.2{\pm}2.2{\sim}60.3{\pm}2.4%$. Most measured soils have bulk densities between 1.0 and $1.6gcm^{-3}$. To summarize the above results, Soil plough layer has been deepened in organic vegetable cultivation soils. Solid hardness (the hardness of the soil) and bulk density (suitable for the soil unit mass) have been lowered. Porosity (soil spatial content) was high such as a well known in organic farmlands. Important changes were observed in the physical properties according to the different vegetable cultivation. We have demonstrated that the physical properties of organic cultivated soils under plastic greenhouse were improved in the results of this study.

• Korean Journal of Environmental Biology
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• v.36 no.4
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• pp.479-487
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• 2018

The purpose of this study is to analyze photochemical activity of nursery seedlings under drought stress, using chlorophyll fluorescence reaction analysis. Young nursery seedlings of tomato (Lycopersicon esculentum Mill.) and cucumber (Cucumis sativa L.), were grown under drought stress for 8 days. Analysis of chlorophyll fluorescence reaction (OJIP) and parameters, were performed to evaluate photochemical fluctuation in nursery seedlings under drought stress. Chlorophyll fluorescence reaction analysis showed maximal recorded fluorescence (P) decreased from the 5 day after treatment in tomato seedlings, while an amount of chlorophyll fluorescence increased at the J-I step. Thus, physiological activity was reduced. In cucumber seedlings, maximal recorded fluorescence (P) and maximal variable fluorescence ($F_V$) lowered from the 4 day after treatment, and chlorophyll fluorescence intensity of J-I step increased. Chlorophyll fluorescence parameter analysis showed electron transfer efficiency of PSII and PSI were significantly inhibited with decreasing $ET2_O/RC$ and $RE1_O/RC$ from the 5 day after treatment, in tomato seedlings and from the 4 day after treatment, in cucumber seedlings. $ET2_O/RC$ and $PI_{ABS}$ significantly changed. In conclusion, 6 indices such as $F_V/F_M$, $DI_O/RC$, $ET2_O/RC$, $RE1_O/RC$, $PI_{ABS}$ and $PI_{TOTAL}ABS$ were selected for determining drought stress in nursery seedlings. Drought stress factor index (DFI) was used to evaluate whether the crop was healthy or not, under drought stress. Cucumber seedlings were less resistant to drought stress than tomato seedlings, in the process of drought stress.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2020.08a
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• pp.42-42
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• 2020

오이(Cucumis sativa L.)는 1년생 초본의 덩굴성 박과 작물로 미숙한 과실을 다양한 식품 용도로 이용하고 있다. 오이는 시설재배기술 확립으로 연중 생산과 공급이 가능하나 내병성 품종개발이 필요한 실정이다. 또한 오이의 다양한 생리활성 물질에 대한 관심이 높아지고 있어 이를 위한 다양한 오이 자원이 필요한 실정이다. 본 연구에서는 국내외에서 수집한 오이 180자원의 형태적 특성을 분석하여 육종 소재로 활용하는데 있어 기초 정보를 제공하고자 하였다. 본 연구에서 사용된 오이 자원의 원산지는 조지아 98자원, 한국 37자원, 중국 28자원, 우즈베키스탄 17자원이었다. 오이 180자원은 모두 덩굴손을 가졌으며 자웅동주로 조사되었다. 착과습성은 주지형 83자원, 주지 및 측지형 97자원으로 조사되었고 절화당 자화수는 175자원이 2개로 조사되었으며 5자원은 1개로 조사되었다. 과형은 장원형 87자원, 단원형 92자원으로 대부분을 차지하였으며 과선단좁은형이 1자원 조사되었다. 과기부형태는 평평한 형태 83자원, 휘어진 형태 94자원으로 대부분이었으며 오목한 형태 1자원, 뽀족한 형태 2자원이 조사되었다. 과선단의 형태는 평평한 형태 148자원, 휘어지 형태 32자원으로 조사되었다. 오이 유전자원의 개화기는 60~80일로 평균 66.1일 이었으며 과실 성숙기는 33~68일로 평균 49.6일이었다. 국가별로 개화기는 62.4일(중국)~68.5일(한국), 과실성숙기는 48.3일(중국,조지아)~54.1일(우즈베키스탄)로 조사되었다. 본 실험에서 조사된 오이 유전자원의 형태적 특성은 오이 선발에 있어 기초 정보로 활용 가능할 것이며 추가적으로 농업형질, 내병성, 기능성 분석등의 오이 육종 프로그램을 위한 다양한 자원 평가 및 선발이 필요할 것이다.