• Horticultural Science & Technology
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• v.33 no.1
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• pp.47-54
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• 2015

This research was conducted to investigate the changes in moisture retention capacities of expanded rice-hull (ERH)-based root media and their influences on the growth of mother and daughter plants in vegetative propagation of 'Seolhyang' strawberry. The proportion of water at the container capacity of ERH medium was in the range of 20 to 23%. This range was lower than the 60 to 66% of strawberry-specialized medium, the 30 to 34% of soil mother material (SMM) and the 30 to 35% of loamy sand. The moisture content of ERH was reduced to 10 to 12% at 8 hours after irrigation, and there were large variations among replications of ERH medium. Among four kinds of root media formulated to contain ERH, the medium of ERH + coir dust (CD) (55 + 45%, v/v) had 26.5 and 32.5% water contents at 20 and 40 days after irrigation to daughter plants, respectively. The m edia o f ERH + sandy loam (S L) and E RH + S MM showed similar trends i n moisture r etention. The pH and EC i n the all root media tested were in the range of 6.7 to 7.1 and 0.03 to $0.08dS{\cdot}m^{-1}$, respectively. The pHs and ECs measured at 20 and 40 days after irrigation were not significantly different in each root medium. Among the root media formulated to contain ERH, the growth of daughter plants was the highest in the treatment of ERH + SL (55 + 45%, v/v). As the blending rate of coir dust was elevated in the ERH + CD media, moisture retention capacity increased gradually, but the growth of daughter plants became worse even though the medium showed higher moisture retention capacity than other root media tested. The growth of roots and aboveground tissues of daughter plants deteriorated in the root media formulated by blending ERH + perlite (PE) at various ratios. The results of this research suggest the optimum formulations of root media and management of moisture content in raising of strawberry daughter plants when ERH is a component of root media.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.1-10
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• 2015

This study was conducted in three years (7-9 years after planting) to investigate vegetative growth, yield, fruit quality, and return bloom for optimum crop load based on different planting densities of adult 'Fuji'/M.9 apple trees. As plant materials, 'Fuji'/M.9 apple trees planted at $3.5{\times}1.5m$ (190 trees per 10 a), $3.5{\times}1.2m$ (238 trees per 10 a), and $3.2{\times}1.2m$ (260 trees per 10 a) spacing and trained as slender spindles were used. The crop load was assigned to five different object ranges as follows: 55-64, 65-74, 75-84, 85-94, and 95-104 fruit per tree. TCA increment, total shoot growth, return bloom, yield per tree, and yield efficiency tended to increase as planting density decreased, and fruit weight and soluble solid content tended to increase as the object range of crop load decreased. Fruit red color tended to increase as shoot growth decreased. For apple trees planted with 238 trees and 260 trees per 10a, biennial bearing occurred when the crop load was over 85-94 and 75-84 fruits, respectively. However, biennial bearing did not occur when the crop load was 95-104 fruits in apple trees planted with 190 trees per 10a. Accumulated yield tended to increase as planting density and crop load increased, but that of biennial bearing did not show such a difference. Based on our results, optimum crop load recommendations are to set 95-104 fruits per tree in 'Fuji'/M.9 mature apple trees planted at 190 trees per 10a, 75-84 fruits per tree at 238 trees per 10a, and 65-74 fruits per tree at 260 trees per 10a.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.638-646
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• 2015

To increase the utility of seeds in plant resources, seeds of 6 Aster species(A. incisus, A. hayatae, A. koraiensis, A. scaber, A. spathulifolius, and A. yomena) were subjected to experiments to develop adequate methods for sprout production. To study optimum germination conditions, germination rates of the seeds were analyzed at different temperature (15, 20, 25, and $30^{\circ}C$) and light conditions. A longitudinal growth experiment was performed in dark conditions for 10 days. Seedlings, with optimum germination rate and longitudinal growth, were placed in the light for 0-3 days to seek the adequate greening periods. Sprouts grown under optimum environmental conditions were placed in vessels with or without ventilation, and stored under $4^{\circ}C$ and $10^{\circ}C$ to examine storage environment and period. As a result of this analysis, seeds were selected that germinated over 50% within 12 days. Longitudinal growth was promoted at $20-25^{\circ}C$, and optimum growth was obtained with 7-9 days. As greening days increased longitudinal growth was retarded, but orbital growth of radicles and cotyledons was promoted. Considering all these factors, greening treatment of 2 days showed the best results. In a storage ability experiment, the best result was achieved by storage in vessels without ventilation under $4^{\circ}C$. Ventilation prevented rotting of sprouts, but reduced moisture contents of sprouts. Most sprouts were fresh at $4^{\circ}C$ for 3-6 days. In particular, sprouts of A. hayatae and A. yomena had high keeping quality, and remained fresh over 3 days even at $10^{\circ}C$.

• Journal of Food Hygiene and Safety
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• v.30 no.3
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• pp.272-280
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• 2015

A simultaneous official method was developed for the determination of phorate and its metabolites (phorate sulfoxide, phorate sulfone, phorate oxon, phorate oxon sulfoxide, phorate oxon sulfone) in livestock samples. The analytes were quantified and confirmed via liquid chromatograph-tandem mass spectrometer (LC-MS/MS) in positive ion mode using multiple reaction monitoring (MRM). Phorate and its metabolites were extracted from beef and milk samples with acidified acetonitrile (containing 1% acetic acid) and partitioned with anhydrous magnesium sulfate. Then, the extract was purified through primary secondary amine (PSA) and C18 dispersive sorbent. Matrix matched calibration curves were linear over the calibration ranges (0.005-0.5 mg/L) for all the analytes into blank extract with $r^2$ > 0.996. For validation purposes, recovery studies were carried out at three different concentration levels (beef 0.004, 0.04 and 0.2 mg/kg; milk 0.008, 0.04 and 0.2 mg/kg, n = 5). The recoveries were within 79.2-113.9% with relative standard deviations (RSDs) less than 19.2% for all analytes. All values were consistent with the criteria ranges requested in the Codex guidelines. The limit of quantification was quite lower than the maximum residue limit (MRL) set by the Ministry of Food and Drug Safety (0.05 mg/kg). The proposed analytical method was accurate, effective and sensitive for phorate and its metabolites determination and it will be used to as an official analytical method in Korea.

• Journal of Food Hygiene and Safety
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• v.32 no.6
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• pp.493-499
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• 2017

This study was conducted to monitor the current status of pesticide residues and sulfur dioxide in a total of 91 functional rice products from February to October 2016. Multi class pesticide multiresidue methods of 220 pesticides was performed by the GC/ECD, GC/NPD, GC/TOF/MS, LC/PDA, and LC/FLD. As a result of analysis, the pesticides were detected in 3 samples, representing a detection rate of 3.3%. The kind of pesticides was propiconazole and isoprothiolane used for germicide in agriculture or plant growth regulator purposes. The detected levels were 0.0340~0.0566 mg/kg, which were under the MRL (Maximum Residues Limits). The contents of sulfur dioxide in 91 samples by the Monier-Williams method were not detected. Risk assessment of pesticides evaluated using human health exposure with the ratio of EDI (Estimated daily intake) to ADI (Acceptable daily intake). %ADI (the ratios of EDI to ADI) were 0.24~1.25% with safety level.

• Food Science of Animal Resources
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• v.30 no.2
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• pp.261-268
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• 2010

This study was conducted to investigate the effects of environmental temperature (ET; $21^{\circ}C$ and $32^{\circ}C$) and antibiotic substitute conditions on meat quality of chicken breast during cold storage. Seven treatments were as follows; T1, ET $21^{\circ}C$ + antibiotics (+); T2, ET $21^{\circ}C$ + antibiotics (-); T3, ET $32^{\circ}C$ + antibiotics (+); T4, ET $32^{\circ}C$ + antibiotics (-); T5, ET $32^{\circ}C$ + 0.1% Lactobacillus; T6, ET $32^{\circ}C$ + 0.1% medicinal plant extract; T7, ET $32^{\circ}C$ + 0.1% essential oil. T7 had a higher (p<0.05) pH at 72 h post-slaughter value when compared to the other treatments. The CIE $b^*$ value of treatments at ET $32^{\circ}C$ showed significantly (p<0.05) higher when compared to the treatments at $21^{\circ}C$. T7 also had significantly (p<0.05) lower TBARS values than the other treatments as the storage time increased. T6 contained significantly (p<0.05) higher extractability of salt-soluble protein contents than the other treatments. The results from SDS-PAGE showed that the actin protein decreased for ET treatments at $32^{\circ}C$. The concentration of actin protein was not significantly different among T1, T2 and T7. Therefore, these result suggested that the antibiotic alternative with essential oil was effective under the high environmental temperature ($32^{\circ}C$) for chicken meat production.

• Journal of Bio-Environment Control
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• v.10 no.1
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• pp.15-22
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• 2001

A soil temperature was known as extremely important factor in terms of measuring the values of the growth and yield of vegetable in the greenhouse. A low temperature water irrigation was had much trouble in its growth. This study was performed to analyze the effect of the heating water irrigation on the soil temperature and the growth of a cucumber within a greenhouse environment. Soil temperature was 5-7$^{\circ}C$ below to 10cm in depth and 2-3$^{\circ}C$ to 20cm when the irrigation water temperature was 13$^{\circ}C$ (non-warme water irrigation). Soil temperature was similar to irrigation water temperature at 5cm in depth and was 1.5-2$^{\circ}C$ below at 10cm when the irrigation water temperatures were 2$0^{\circ}C$, $25^{\circ}C$. The early growth rates of heating water irrigation were 109-110% in plant height, 107-108% in leaf number, 103% in node number compared with those of unheated water irrigation for 30 days after planting it. The rates of total yield were 115% in 2$0^{\circ}C$ water irrigation plots and 121% in $25^{\circ}C$ water irrigation plots while those of unheated water irrigation plots were.

• Journal of Bio-Environment Control
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• v.6 no.1
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• pp.1-14
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• 1997

This experiment was conducted to find out the compositions of nutrient solution for closed system in substrate culture of cucumber. Cucumber(Cucumis sativus L. cv. Eunsung baekdadagi) plants were grown in the substrates supplied with the nutrient solutions whose strengths were 1/2, 1, and 3/2 of the original concentration developed by National Horticultural Research Station in Japan. By increasing the nutrient concentrations, plant height decreased but leaf length, leaf width, and leaf number showed little differences. A number of marketable fruit and marketable yield were the highest in the concentration of 1 strength. The nutrient compositions of solution developed for closed system in cucumber substrate culture were N 11.4, P 3.3, K 6.0, Ca 4.5, and Mg 3.5 me.$\ell$$^{-1}$ during the vegetative growth period and N 10.4, P 3.3, K 5.0, Ca 4.5, and Mg 3,5 me.$\ell$$^{-1}$ during the reproductive growth period. To examine the suitability of nutrient solution developed in the above experiment, cucumber plants were grown in the substrates supplied with different solutions and concentrations - Yamasaki's nutrient solution(Yamasaki) of 1 S, nutrient solution of Research Station for Greenhouse Vegetable and Floriculture on the Netherlands(PTG) of 1 S, nutrient solution developed in the above experiment(SCU) of 1/2, 1, and 3/2 S. EC and pH in root zone changed little in the all treatments during growing period. As cucumber plants grew, the concentrations of N, P, and K in root zone decreased but Ca concentration increased. Net $CO_2$ assimilation rate of cucumber leaves was high in SCU of 1 and 3/2 S, and Yamasaki of 1 S. Growth of cucumber plants was the lowest in SCU of 1/2 S.

• Journal of Bio-Environment Control
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• v.13 no.1
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• pp.44-50
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• 2004

This experiment was conducted to investigate the effects of different levels of light intensity (100, 200, 400 ${\mu}mol\;{\codt}\;m^{-2}\;{\cdot}\;s^{-1}$, and natural light) on the growth and the fruit quality of cucumber(Cucumis sativus cv. Hyakunari-3). The results of this experiment indicated that plant height and length of lateral shoots were decreased under low light condition, but it was not significantly different among treatments. Leaf area and root weight were lowest under low light intensity(100 ${\mu}mol\;{\codt}\;m^{-2}\;{\cdot}\;s^{-1}$), but no significant differences were noted between 200 and 400 ${\mu}mol\;{\codt}\;m^{-2}\;{\cdot}\;s^{-1}$. Photosynthesis rate was decreased with reduced light intensity and total chlorophyll contents, root activity and xylem sap were also decreased under low light intensity, but there was no significant difference between 200 and 400 ${\mu}mol\;{\codt}\;m^{-2}\;{\cdot}\;s^{-1}$. From the SEM observation the erosion of the guard cells and closed stomata in low light treatment were shown and the size of stoma were small also the stomatal aperture were decreased with reducing the light intensity. Chlorosis in leaves and aborted-liked fruits were appeared under low light condition and Ca and Mg uptake in leaves were decreased by shading in proportion to the decrease of light intensity. Fruit yields were decreased by 65% under 400 ${\mu}mol\;{\codt}\;m^{-2}\;{\cdot}\;s^{-1}$, and by 80${\sim}$90% under 200 and 100 ${\mu}mol\;{\codt}\;m^{-2}\;{\cdot}\;s^{-1}$, compared to those under the natural light. This low intensity of light caused the sharp decrease in the early harvested yields within two weeks and the fruit yields of lateral shoots were greatly decreased.

• Journal of Oral Medicine and Pain
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• v.34 no.2
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• pp.169-177
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• 2009

Recently it is very interesting that the plant extracts use to prevent or treat the oral diseases. The present study was performed to observe the antibacterial effect on S. gordonii Challis, S. gordoii G9B, S. mutans GS5, S. sobriuns 6715, E. faecalis ATCC 4083, A. actinomycetem Y4, P. gingivalis A7A1-28, P. gingivalis W83, Pr. intermedia ATCC 25611, F. nucleatum KTCT 2488, C. albicans ATCC 18804 of Artemisa capillaris THUNB employing the viable cell counts. The results were as follows: 1. Minimum inhibitory concentration(MIC) and Minimum bactericidal concentration(MBC) of extracts of Artemisa capillaris THUNB for P. gingivalis A7A1-28, P. gingivalis W83, and Pr. intermedia ATCC 25611, which are the pathologic bacteria of periodontal diseases, was observed under 2%. 2. MIC of extracts of Artemisa capillaris THUNB for P. gingivalis A7A1-28 was determined to be 1.2% and MBC was determined to be 2.0% respectively. 3. MIC of extracts of Artemisa capillaris THUNB for P. gingivalis W83 was determined to be 1.4% and MBC was determined to be 2.0% respectively. 4. MIC of extracts of Artemisa capillaris THUNB for Pr. intermedia ATCC 25611 was determined to be 1.2% and MBC was determined to be 2.0% respectively. The overall results indicate that Artemisa capillaris THUNB used for this study has a strong antibacterial activity against P. gingivalis A7A1-28, P. gingivalis W83, and Pr. intermedia ATCC 25611, which are the periodontopathic bacteria. Therefore, the extracts of Artemisa capillaris THUNB can be used as a candidate for prevention and therapeutic agent against periodontal diseases.