• Journal of Bio-Environment Control
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• v.24 no.4
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• pp.296-300
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• 2015

This study was conducted to investigate optimal crop loads of 'Jinok' grape for unheated plastic house culture. The crop loads of 'Jinok' grapes were managed to be 1.3, 1.8, 2.2, 2.4, and 2.6t per 10a from 2012 to 2014. We measured vine growth and berry qualities. Crop loads were not significantly affected on plant height, trunk diameter, shoot length, and the internode length of 'Jinok'. However, the maturation of berries was delayed when the crop load was higher. And the harvest date was earlier about three weeks in an unheated plastic house compared to in an open field. The average berry weight was decreased by the higher crop load although higher crop loads made higher yields showing the lowest weight at 342g with the treatment of 2.6t per 10a and the highest weight at 363g with the treatment of 1.3t per 10a. Also, the soluble solids content showed a tendency that higher crop loads brought to lower degree Brix. The contents of P, K, Ca, and Mg in grape leaves and shoots were not significantly different by crop loads. To sum up, when crop loads were under the 2.4t per 10a, the berries were harvested as a marketable fruit having $15^{\circ}Brix$ in the cultivar 'Jinok' grape. This result could help to increase grower's benefit having improved quality of fruit for the sustainable production by the established cultivation techniques for the newly developed cultivar 'Jinok'.

• Journal of Bio-Environment Control
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• v.26 no.3
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• pp.175-180
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• 2017

This study was conducted for the domestic new cultivar to expand cultivation area and sustainable production. The new domestic cultivar, 'Jinok' and control cultivar, 'Campbell Early', had been investigated on vine growth and fruit quality by different cultivating conditions as open field, rain shelter and unheated plastic house. The growth period of 'Jinok' was faster than 'Campbell Early'. The harvesting date of 'Jinok' was on 13th of Aug. faster than 'Campbell Early' which was on 17th of Aug., and it was on 25th and 29th of Aug. for 'Jinok' and 'Campbell Early' on field cultivation, respectively. The growing length and width of new shoots were similar among the cropping systems. In the result of fruit characteristic evaluation, the soluble solids content of the 'Jinok' and 'Campbell Early' cultivating on the unheated plastic house were $15.4^{\circ}Brix$ and $15.9^{\circ}Brix$, respectively. In the open field condition, those were $15.9^{\circ}Brix$ and $15.8^{\circ}Brix$, respectively. The titratable acidity and chromaticity were similar among the treatments. In the appearance of past and disease, Phomopsis blight was occurred on mid of June and in the end of cultivation period on about early Aug., the damage by Phomopsis blight was the lowest about 14% in the unheated plastic house cultivation on the 'Jinok' cultivar and it was 39% in the open field condition. However, in the open filed cultivation for 'Campbell Early', Phomopsis blight was highly occurred about 49%. During this period, or the end of cultivation, it is necessary for the intensive control.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.431-438
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• 2012

The developmental time of the nymphs of Myzus persicae was studied in the laboratory (six constant temperatures from 15 to $30^{\circ}C$ with 50~60% RH, and a photoperiod of 14L:10D) and in a green-pepper plastic house. Mortality of M. persicae in laboratory was high in the first(6.7~13.3%) and second instar nymphs(6.7%) at low temperatures and high in the third (17.8%) and fourth instar nymphs(17.8%) at high temperatures. Mortality was 66.7% at $33^{\circ}C$ in laboratory and $26.7^{\circ}C$ in plastic house. The total developmental time was the longest at $14.6^{\circ}C$ (14.4 days) and shortest at $26.7^{\circ}C$ (6.0 days) in plastic house. The lower threshold temperature of the total nymphal stage was $3.0^{\circ}C$ in laboratory. The thermal constant required for nymphal stage was 111.1DD. The relationship between developmental rate and temperature was fitted nonlinear model by Logan-6 which has the lowest value on Akaike information criterion (AIC) and Bayesian information criterion (BIC). The distribution of completion of each developmental stage was well described by the 3-parameter Weibull function ($r^2=0.95{\sim}0.97$). This model accurately described the predicted and observed occurrences. Thus the model is considered to be good for use in predicting the optimal spray time for Myzus persicae.

• Korean journal of applied entomology
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• v.51 no.4
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• pp.421-429
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• 2012

The developmental time period of Aphis gossypii was studied in laboratory (six constant temperatures from 15 to $30^{\circ}C$ with 50~60% RH, and a photoperiod of 14L:10D) and in a cucumber plastic house. The mortality of A. gossypii in the laboratory was high in the 2nd (20.0%) and 3rd stage(13.3%) at low temperature but high in the 3rd (26.7%) and 4th stage (33.3%) at high temperatures. Mortality in the plastic house was high in the 1st and 2nd stage but there was no mortality in the 4th stage at low temperature. The total developmental period was longest at $15^{\circ}C$ (12.2 days) in the laboratory and shortest at $28.5^{\circ}C$ (4.09 days) in the plastic house. The lower threshold temperature at the total nymphal stage was $6.8^{\circ}C$ in laboratory. The thermal constant required to reach the total nymphal stage was 111.1DD. The relationship between the developmental rate and temperature fit the nonlinear model of Logan-6 which has the lowest value for the Akaike information criterion(AIC) and Bayesian information criterion(BIC). The distribution of completion of each development stage was well described by the 3-parameter Weibull function ($r^2=0.89{\sim}0.96$). This model accurately described the predicted and observed outcomes. Thus it is considered that the model can be used for predicting the optimal spray time for Aphis gossypii.

• Korean Journal of Soil Science and Fertilizer
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• v.45 no.2
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• pp.135-142
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• 2012

Exchangeable cations are often overestimated especially in salt-affected soils due to the presence of high levels of soluble ions in soil solution. Thus, quantitative analysis of the soil exchangeable cation based on ammonium acetate extraction method {(Exch. Cation)$_{total}$} requires additional process to remove the free ions (pre-washing) in soil with distilled water or alcohol {(Exch. Cation)$_{pw}$} or subtraction of the soluble ion contents from the total exchangeable cations {(Exch. Cation)$_{ref}$}. In this research, we compared the three different methods for the determination of exchangeable cations in soils affected by different types of salt accumulation such as the soils from upland, plastic film house, and reclaimed tidal land. In upland soils, non-saline and non-sodic soils, the regular ammonium acetate extraction method did not have any problem to determine the content of exchangeable cations without any additional process such as the pre-washing method or the subtraction method. However, the contents of exchangeable cations in the salt-affected soils might be determined better with the pre-washing method for the plastic film house soils and with the subtraction method for the reclaimed tidal land soils containing high Na.

• Horticultural Science & Technology
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• v.18 no.5
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• pp.599-604
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• 2000

This experimemt was conducted to determine the effect of ridge-up bed with different height (0, 20, 40, 60 cm) on the fruit quality of 'Miyagawa Wase' satsuma mandarin cultivated in a plastic film house. Soil moisture was measured at the soil depths of 10, 30, and 60 cm for each height of ridge-up bed. The time required to reach the condition, -1.4 Mpa at 30 cm deep in soils, which are supposed to be the ideal soil moisture potential and soil depth for high quality satsuma mandarin production, was 100, 60, and 30 days for 20, 40, and 60 cm ridge-up bed, respectively, and more than 100 days for 0 cm. Peel chromaticity by 'a' value was increased as the ridge-up height went up, so that plants grown at the bed with 60 cm height had 11 degree higher value than those of plants grown at the bed with 0 cm height. The 'a/b' values also had a similiar trend as value 'a'. The reducing sugar level of the fruit juice, which was composed of glucose and fructose, was increased as the height of ridge went up, showing significant difference between the ridge heights. The sucrose level had the same trend as the reducing sugar level although the difference between the ridge heights were not significant. Generally, the soluble solid level is considered to be representing the fruit quality. It had 11.4, 12.1, 12.5, $12.8^{\circ}Brix$ for 0, 20, 40, and 60 cm ridge-ups, respectively, showing $1.4^{\circ}Brix$ difference between 0 and 60 cm ridges. Acidity basically showed the same result as that of the soluble solid level depending on the height of the ridges.

• Horticultural Science & Technology
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• v.18 no.5
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• pp.605-611
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• 2000

This experiment was conducted to examine the effects of foliar application of ethychlozate and ethyclozate mixed with different calcium formulae (clef-non, suical, cell-bine, and calcium acetate monohydrate) on the fruit quality and peel puffing of 'Miyagawa Wase' satsuma mandarin cultivated in a plastic film house. Foliar application of ethychlozate mixed with clef-non or suical showed a result that the 'a' value of peel chromaticity was increased, which are supposed to accelerate peel coloration without peel puffing. The reducing sugar levels of fruits in control, ethychlozate, ethychlozate+celef-non, ethychlozate+suical, ethychlozate+cell-bine, and ethychlozate+calcium acetate monohydrate treatment were 4.98, 5.30, 5.59, 5.00, 5.20, and 4.27%, respectively. Especially, in the case of ethychlozate mixed with clef-non, the reducing sugar level was 0.61% higher than that of control. Sucrose and total sugar content also had a similar trend as that in the reducing sugar contents. The sugar contents of fruits in various ethychlozate treatments mixed with different calcium formulae except those in ethychlozate treatment or ethychlozate treatment mixed with calcium acetate monohydrate were higher than $12^{\circ}Brix$. Especially, the treatment of ethychlozate treatment mixed with clef-non showed the highest sugar content with $12.7^{\circ}Brix$. The ratio of soluble solids to acidity also showed the similar tendency, but there was no significant difference in acidity among the treatments.

• Journal of Bio-Environment Control
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• v.7 no.3
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• pp.259-267
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• 1998

This study was carried out to investigate the effect of mulching materials on the fruit quality of Miyagawa Early Satsuma Mandarin in the plastic house. The mulching time was 10 days after water irrigation breakage. The mulching materials used, in order of decreasing light reflectivity, were; micro-perforated vinyl sheets, non-woven fabric film, porous black P.E. film and non-mulching(control). Peel coloration by a values in the treatment of the micro-perforated vinyl sheets showed a 6.93 increase over the control group. The a/b values were similar to this trend, but there were no significant difference among the mulching treatment groups. The glucose level of fruit juice was much higher in the mulching treatment groups as compared with that of the control group, but there was no significant difference among the mulching treatments. Fructose content in the treatment of the micro-perforated vinyl sheets a 0.31mg%.m $L^{-1}$ increase over the control group. This group also showed a 1.36%.m $L^{-1}$ increase in sucrose and a similar increase trend in total sugar. The Brix value was 0.9 $^{\circ}$Brix higher in the micro-perforated vinyl sheet group(12.4 $^{\circ}$Brix) than in the control group(11.5 $^{\circ}$Brix) which result in a significant increase with micro-perforated vinyl sheet usage. However, the acidity level did not differ significantly among mulching treatments.

• Journal of Bio-Environment Control
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• v.4 no.2
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• pp.125-130
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• 1995

Observations on the seedling growth of red pepper responding to different temperature(10, 20, 3$0^{\circ}C$) and light intensity(5, 15, 25 klux) were made in the growth Chamber during 7 weeks. The results obtained were as follows; 1. Best results of the combinations of temperature and light intensity were obtained from the combinated treatment of 3$0^{\circ}C$ and 25klux. At all of the temperature levels in this experiment, the more the light intensity is high, the more the growth is favor, but at low temperature below 2$0^{\circ}C$ and low light intensity below 15 klux, the growth of red pepper seedlings was decreased markedly. 2. Multiple regression polynomial equations of the characteristics of red pepper seedlings grown in the different combinations of temperature and light intensity fitted well in the plant height, number of leaves, leaf area, stem dry weight and shoot dry weight. 3. Multiple regression polynomial equation to the shoot dry weight was partial differentiated and diagrammatized the response surface using its theoretical value. Light intensity affected more to the shoot dry weight in the temperature below 2$0^{\circ}C$ but above 2$0^{\circ}C$ the role of the temperature showed greatly influence however, interaction effects of light intensity and temperature showed strongly.

• Journal of Bio-Environment Control
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• v.20 no.3
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• pp.204-210
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• 2011

This experiment was conducted to investigate the effect of water states (water, osmotic potential and turgor pressure) of fruit vesicle and leaf on soluble solids and organic acid contents of fruits of 'Shiranuhi' mandarin hybrid, M16 A line during the fruit maturing season in plastic house cultivation. The 'Shirauhi' grafted on 'Swingle citrumelo', strong strength of rootstock, produced fruit with lower soluble solids and organic acid content than 'Trifoliate' orange rootstock. The fruits vesicle water potential and turgor pressure measured before dawn in 'Swingle citrumelo' were higher tendency than the 'Trifoliate' orange, but osmotic potential values were lower than the 'Trifoliate' orange. The changes of leaf water potential were very similar to the fruit. The results suggest that in the 'Shirauhi' fruits grafted on two rootstocks changes of soluble solids and organic acid content of the fruit were influenced by the leaf water potential and the osmotic potential of the fruit vesicles, which might be caused by the difference of root distribution between two rootstocks.