• Horticultural Science & Technology
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• v.32 no.3
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• pp.303-309
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• 2014

The purpose of this study is to suggest indicators and proper standards to forecast the sensory quality of 'Hongisul' grape. Further, this study determines the optimum fruit load of 'Hongisul' grape reflecting consumer preference. Among several quality attributes, identified through instrumental and sensory evaluation, soluble solid-acid ratio was the most useful indicator of consumer preference for 'Hongisul' grapes. The ideal soluble solid-acid ratio for marketable grapes was found to be higher than 86.3. Analysis on the effects of fruit load control on fruit quality revealed a negative correlation where the latter increased as the former decreased. This trend is common for all grape species. The field with a fruit load of $1,400kg{\cdot}10a^{-1}$ exhibited a soluble solid-acid ratio of less than 86.3, uneven coloring and slow softening texture at the mature stage. However, fruit quality proved excellent in the field with a fruit load of $1,200kg{\cdot}10a^{-1}$ or less. It is therefore proposed that fruit load should be controlled to $1,200kg{\cdot}10a^{-1}$ or less when growing 'Hongisul' grapes to produce high quality grapes. We believe that this result can be used as a standard in judging harvest time and evaluating fruit quality.

• Horticultural Science & Technology
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• v.17 no.2
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• pp.111-114
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• 1999

Experiments were conducted to select the optimum cultivars which are adaptable to South Korea through estimating the differences in daughter plant production and growth response among seven strawberry cultivars. In the vegetative stage, Nyoho, Akihime and Suhong produced more daughter plants than other cultivars whereas Akaneko and Tochinomine, which developed less runners, showed better condition in runner vigorness. The quality of daughter plants derived from forcing cultivars was uniform in general. Even though there was no significant differences in rooting among cultivars, runners from Akaneko and Tochinomine developed more roots and fresh weight of roots than other cultivars. In the forcing cultivars, Akihime showed the most excellent plant vigorness, yield and highest sugar content of fruits and also was 5 days faster than Nyoho in flowering date. However, the fruit tended to be softened. In the semi-forcing cultivars, Tochinomine was excellent in vigorness, firmness, sugar content of fruits and the average of fruit weight but low in flower numbers per cluster and late in the emergency of second flower cluster. Although Akaneko showed highest in sugar/acid ratio and rich in flavour, lighting treatment was recommended to this cultivar for early harvest because of softness of fruits.

• Korean Journal of Food Science and Technology
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• v.17 no.5
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• pp.331-335
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• 1985

Series of study were conducted to develop a method for longterm storage of chest-nut with preserving it's taste and freshness. Experiments were carried out with Korean chest-nut (Castanea crenata var. Okkwang) sealed in polyethylene (P.E) film stored under the ambient and low temperature. Summarized results are as follow: After the harvest, $CO_2$ produced by chest-nut at the early storage was increased with temperature increase. Q10 mg/kg/day, the temperature index of $CO_2$production, by chest-nut ranged 2.4-2.7. It was available to store chest-nut in good condition with 8-15% total loss upto the following may at the ambient temperature sealed in 0.03 mm P.E. film, and upto the following july at the low temperature if sealed in 0.03 or 0.05 mm P.E. film. Throughout the period from one month after the innitiation upto the end of the storage, the rate of $CO_2$and $O_2$ was maintained near the optimum condition for the CA storage of chest-nut. The taste of chest-nut was improved during the storage due to increased reducing-sugar and decreased wate soluble tannin. However, the taste become bitter and unacceptable from the early stage of the storage when used the thicker P.E. film (than above mentioned) for the sealing.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.497-503
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• 2018

A strawberry variety 'Arihyang' was derived as an artificial cross between 'Tochiotome' and 'Seolhyang' in 2014. The seedling and line selections were conducted from 2014 to 2015. Preliminary and advanced yield trials of '14-5-5,' which was the final selected line, were conducted from 2015 to 2017. 'Arihyang' is suitable for forced cultivation and has strong plant vigor, uniformly large-sized fruit, and a high yield compared to those of the check variety, 'Seolhyang' and 'Maehyang.' Especially, vitamin C was at a significant level, which was approximately 15% higher than that of 'Seolhyang.' The average number of flowers per first flower cluster was 10.5, which could reduce the labor of thinning fruit. Its fruit has a conical shape, dark red color, and glossy skin. The fruit was of good quality but has recommendations for harvest at the fully ripened stage. 'Arihyang' has intermediate resistant to phytophthora crown rot, but is susceptible to powdery mildew, gray mold, anthracnose, and fusarium wilt. It is reguired to manage major diseases and pests using optimum cultivation techniques and chemical control.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.768-776
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• 2010

This study was conducted to predict number and fresh weight of leaves, and total leaf area of a single-stemmed rose 'Vital' based on the accumulated thermal units, and to develop a model of shoot development for the prediction of the time when the flowering shoot reaches a phenological stage in a plant factory system. The base temperature ($T_b$), optimum temperature ($T_{opt}$), and maximum temperature ($T_{max}$) were estimated by regressing the rate of shoot development against the temperature gradient. The rate of shoot development ($R$, $d^{-1}$) for the phase from cutting to bud break (CT-BB) was best described by a linear model $R_b$ ($d^{-1}$) = -0.0089 + $0.0016{\cdot}temp$. The rate of shoot development for the phase from bud break to harvest (BB-HV) was fitted to the parabolic model $R_h$ ($d^{-1}$) = $-0.0001{\cdot}temp^2$ + $0.0054{\cdot}temp$ - 0.0484. The $T_b$, $T_{opt}$, and $T_{max}$ values were 5.56, 27.0, and $42.7^{\circ}C$, respectively. The $T_b$ value was used in the thermal unit computations for the shoot development. Number of leaves, leaf area (LA), and leaf fresh weight showed sigmoidal curves regardless of the cut time. The shoot development and leaf area model was described as a sigmoidal function using thermal units. Leaf area was described as LA = 578.7 $[1+(thermal units/956.1)^{-8.54}]^{-1}$. Estimated and observed shoot length and leaf fresh weight showed a reasonably good fit with 1.060 ($R^2=0.976^{***}$) and 1.043 ($R^2=0.955^{***}$), respectively. The average thermal units required from cutting to transplant and from transplant to harvest stages were $426{\pm}42^{\circ}C{\cdot}d$ and $783{\pm}24^{\circ}C{\cdot}d$, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.32 no.3
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• pp.295-303
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• 1999

An experiment was conducted to evaluate the possibility of using basic oxygen furnace (BOF) slag as a soil conditioner in rice paddy field. In 1997, rice (Oryza sativa B. cv. Dongjinbyeo) crop was cultivated under different application rates of BOF slag at three different places, Inandong Sunchon city, Youjunglee Bosung province, and Nampyung Najoo city. In each paddy field, five treatments, four application rate of BOF slag (0, 4, 8, $12Mg\;ha^{-1}$) and one application rate of lime ($2Mg\;ha^{-1}$) were tried with three replications. Plant height, number of tillers per hill, leaf area per hill, leaf dry weight, calm dry weight or shoot dry weight per hill were measured five times at the interval of seven days. Chemical contents of rice plants and soil were also measured at the same sampling date Yield were estimated by harvesting $6.6m^2$ per experimental unit and yield components were measured by sampling 10 plants per experimental unit at the harvest date. Application of BOF slag hardly affected contents of soil organic matter, available phosphate and potassium in soil. Soil pH and contents of Ca, Mg, Fe and $SiO_2$ enhanced as BOF slag rate increased. Enhancement of soil pH by ROF slag treatment appeared to be closely related with increase in soil Ca content. Application tate of $2Mg\;ha^{-1}$ of lime showed almost the same effect, in increase of soil Ca content as application rate of $4{\sim}8Mg\;ha^{-1}$ of BOF slag, Fe content in soil decreased sharply as time passed after slag treatment and stabilized more or less at the later sampling date. Contents of inorganic matter in plant such as total nitrogen, phosphate, potassium and Mg were not affected by BOF slag treatment. However, contents of Ca, Fe, and $SiO_2$ in plants increased as slag rate became higher. The growth of rice plants with BOF slag treatment was more or less slower but continued persistently up to the later growth stage, so that growth of plants with BOF slag treatment was almost the same nr even greater than that of control or lime treatment. However, BOF slag rate of $12Mg\;ha^{-1}$ seemed to be too high because all the measurements of plant, growth at this rate showed lower values than those of other treatments at all the sampling dates. Treatments of BOF slag $4Mg\;ha^{-1}$ or $8Mg\;ha^{-1}$ showed higher rough rice yield than other treatments, so that the optimum BOF slag ratein rice paddy field seemed to be in the rage of $4{\sim}8Mg\;ha^{-1}$.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.424-431
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• 2017

This study was conducted to set the optimum nutrient solution concentration by growth stage for new strawberry cultivars 'Berrystar' and 'Jukhyang'(Fragaria ${\times}$ ananassa Duch. cvs. 'Berrystar', 'Jukhyang') grown through hydroponics to improve the quality and yield. Three different EC levels were applied to the nutrient solution. The treatment levels were 0.7, 1.0 and 1.3 times higher than the nutrient concentration standard for 'Seolhyang' based on the 'Manual for strawberry cultivation' of Rural Development Administration. Based on the results, there were no significant differences in growth of 'Berrystar' by EC level. 'Jukhyang' showed the most vigorous growth grown in 1.3 times higher nutrient concentration. While the growth of 'Berrystar' and 'Jukhyang' grown in higher EC level has leaves with more chlorophyll concentration. However the quantum yield of leaves was not affected by the treatments. On the treatment with 1.3 times higher EC level, the weight, length, width and firmness of 'Berrystar' and 'Jukhyang' were significantly high. The sugar contents of the harvest analyzed by HPLC did not differed particularly, but the percentage composition of reducing sugar and non-reducing sugar were presented differently depending on the treatments. Marketable fruit yield increased as nutrient concentration increases. However, there were no large differences by treatments. Meanwhile, 'Jukhyang' showed significant difference by nutrient concentration and had the largest yield for a treatment grown in 1.3 times higher EC level. Based on these results, it is recommended to provide the same nutrient solution concentration level to the nutrient concentration standard of 'Seolhyang' for 'Berrystar', and the 1.3 times higher level for 'Jukhyang'.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.3
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• pp.259-270
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• 1985

Meteorological year variations for rice crop from 1973 to 1984 were compared by using air temperature and sunshine hour for nursery period, cooling index for reproductive stage and meteorological yield productivity index for ripening period. The most optimum transplanting date and heading date for crop yield based on real transplanting date-grain yield relationship or heading date-grain yield relationship, meteorological yield productivity index and actual results showed good agreement each other. Around May 26 for transplanting and August 10 for heading were the most optimum date in Indica/Japonica hybrid cultivars while these were about June 8 and August 23 for Japonica cultivars, respectively. On the other hand, theoretical late limiting heading date for safe ripening were August 20 for Indica/Japonica hybrid cultivars and August 30 for Japonica cultivars, respectively, for both methods, cumulative temperature method during ripening with 80% believable frequency and meteorological yield productive index method having 1000(kg/10a) yielding potential. Based on the yield forecast trial, the highest values of photosynthetic efficiency, 2.5%, and crop growth rate, 23g/㎡/day, were recorded during 30 days before rice heading. Considering the photosynthetic efficiency and solar radiation, the potential crop growth rate was more or less 30g/㎡/day and the biological grain yielding potential in a existing cultural practices was approximately 900-1000(kg/10a) in Milyang weather condition. To increase further yielding potential, either photosynthetic efficiency or harvest index or both should be improved by manipulating appropriate canopy architecture, plant spacing, fertilizer, chemical, etc.

• Korean Journal of Soil Science and Fertilizer
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• v.33 no.6
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• pp.493-497
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• 2000

An experiment was conducted to evaluate the possibility of using basic oxygen furnace (BOF) slag as soil conditioner in soybean upland field. In 1997, soybean (Glycine max L. cv. Eunha) crop was cultivated under different application rates of BOF slag at an experimental field of Chonnam Rural Development Administration in Nampyung, Najoo city. Five treatments, four application rates of BOF slag (0, 4, 8, $12Mg\;ha^{-1}$) and one application rate of lime ($2Mg\;ha^{-1}$) were tried with three replications. Plant height and shoot dry weight per plant were measured five times during the growth period. Chemical contents of soybean plant tissues and soil were also measured at the same sampling date. Yield were estimated by harvesting $6.6m^2$ per experimental unit and yield components were measured by sampling 10 plants per experimental unit at the harvest date. In upland soil, application of BOF slag rarely affected contents of total nitrogen, organic matter, available phosphate and potassium in soil. Soil pH, and contents of Ca and Fe in soil became higher as BOF slag rate increased. Enhancement of soil pH by application of BOF slag appeared to be closely related with increase in soil Ca content. Application rate of $2Mg\;ha^{-1}$ of lime showed almost the same effect in increase of soil Ca content as application rate of $4{\sim}8Mg\;ha^{-1}$ of BOF slag. Slag treatment hardly affected the contents of total nitrogen, $P_2O_5$, CaO, $K_2O$ and MgO in the shoot of soybean plants. Soybean plants under treatments of BOF salg showed better growth from the earlier growth stage compared with those of control treatment, and at the later growth stage, their growth was even superior to that of lime treatment. BOF slag rate of $8Mg\;ha^{-1}$ showed the highest soybean yield with $1,232kg\;ha^{-1}$. which was $330kg\;ha^{-1}$ or 37% higher than the yield of control with $902kg\;ha^{-1}$, As a result, BOF slag appeared to be useful material as a soil conditioner as well as nurient source for Ca and Fe in upland soybean fields, and its optimal rate for higher yield seemed to be around $8Mg\;ha^{-1}$.

• Korean Journal of Soil Science and Fertilizer
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• v.43 no.6
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• pp.1018-1023
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• 2010

Climatic change was observed and analyzed in view of impacts on agricultural ecosystem, inter alia on rice cropping. The changed climate gave rise to earlier transplanting of rice seedling and later harvest after 40 years. Also phenological change and prolonged growth duration was observed. The meteorological data was selected from the standardized climatological data of 30 year normals of 1960s and 2000s, which were published by Korea Meteorological Administration. Development stages and growing periods of rice crop were compared by analyzing critical and optimum temperatures of each growth stage during these two periods. The first appearance date of $15^{\circ}C$ was ranged from Apr. 29 to May 23 in the year-normals of 1960s and it varied from Apr. 24 to May 16 in the normals of 2000s. The difference of the first appearance date of $15^{\circ}C$ was 0~10 days earlier in the year-normals of 2000s than the 1960s. The last harvesting date was determined to be the last appearance date of mean air temperature $15^{\circ}C$. The difference in the last appearance date of $15^{\circ}C$ was 1 to 13 days later in the year-normals of 2000s than in 1960s. The plant height of a rice variety, Hwayoung-byeo was 101~109 cm in 4 local areas, Seoul, Kangneung, Kwangju and Daegu. The plant height became 1~4 cm taller under warm condition. Rice grain yields estimated with daily weather data for the year-normals of 1960s and 2000s were 453~580 kg $10a^{-1}$ and 409~484 kg $10a^{-1}$ respectively. Rice grain yield of the former period was 50~100 kg $10a^{-1}$ higher than that hat in the later period.