• The Plant Pathology Journal
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• v.33 no.4
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• pp.434-439
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• 2017

Incidence rates of diseases in kiwiberry orchards were investigated monthly from late June to late September in Gwangyang and Boseong in 2015 and 2016. The impact of postharvest fruit rot was investigated during ripening after harvest. Bacterial canker was only observed on one single tree in 2015, but black rot, powdery mildew, leaf spot and blight, and postharvest fruit rot diseases were problematic throughout the study period in both 2015 and 2016. Incidence rates of the diseases varied with kiwiberry cultivar, region and sampling time. Incidence rates of powdery mildew, leaf spot and blight diseases increased significantly during the late growing stages near fruit harvest, while black rot peaked in late August. Incidence rate of postharvest fruit rot on fruit without fruit stalks was less than half of fruit with fruit stalks, regardless of kiwiberry cultivars. Among the four cultivars, Mansu was relatively resistant to black rot and postharvest fruit rot diseases. In our knowledge, this is the first report of various potential pathogens of kiwiberry in Korea.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.629-636
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• 2019

This study was conducted to investigate the growth characteristics and yield of whole green rice grains during the ripening period. These were investigated using Hopumbyeo and Unkwangbyeo at two transplanting times and with two kinds of nitrogen fertilization. The transplanting times were May 30 and June 20, respectively, using 30-day seedling culture and transplanting conducted with 3 - 4 plants per hill in planting space of $15cm{\times}30cm$. During nitrogen fertilization, 9 kg and 18 kg was used, respectively. The harvest of the green whole rice grains was carried out on the 15th, 20th, 25th, 30th, and 40th day after the heading date. The clum length was greater with later planting and with application of more nitrogen. The rice yield was higher with nitrogen fertilization of 18 kg/10 a when transplanted on May 30 for Hupumbyeo, and for Unkwangbyeo, was higher at 9 kg/10 a nitrogen fertilization when transplanted on May 30. The protein content of Hopumbyeo was higher when the nitrogen fertilizer was 18 kg/10 a, and that of Unkwangbyeo was lower than that when transplanting on June 20. The greenness was not related to the nitrogen fertilization level when transplanted on May 20 but for later transplanting, the greenness was higher when the nitrogen application was increased, and the greenness was the greatest about 30 days after the heading date.

• ALGAE
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• v.29 no.3
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• pp.227-235
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• 2014

The red seaweed, Gracilaria tikvahiae McLachlan, was cultivated in open water farms in urbanized estuaries of Long Island Sound (26-30 psu of salinity) and New York City (20-25 psu), USA in 2011. Plants were harvested monthly from summer (August, $24^{\circ}C$) to fall (November, $13^{\circ}C$) and analyzed for total nitrogen, protein, and amino acid content. On a dry matter (DM) basis, nitrogen and protein significantly increased over the harvest period until October and then plateaued. Nitrogen increased from $22{\pm}1g\;kg^{-1}$ DM in August to $39{\pm}3g\;kg^{-1}$ DM in October (p < 0.001). Protein increased from $107{\pm}13g\;kg^{-1}$ DM in August to $196{\pm}5g\;kg^{-1}$ DM in November (p < 0.001). With two exceptions, amino acid concentrations expressed on a crude protein (CP) basis were similar over the harvest period. Essential amino acids accounted for $48{\pm}1%$ of all amino acids present with lysine and methionine averaging $56{\pm}2g\;kg^{-1}$ CP and $18{\pm}1g\;kg^{-1}$ CP, respectively. Histidine was underrepresented among essential amino acids and averaged $13{\pm}1g\;kg^{-1}$ CP. Taurine ranged from 2.1 to $3.2g\;kg^{-1}$ DM. With its moderate levels of lysine, methionine and taurine, ocean farmed G. tikvahiae has the potential of overcoming many nutrient deficiencies currently associated with terrestrial plant ingredients in alternative feeds for fish and shrimp.

• The Korean Journal of Food And Nutrition
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• v.32 no.4
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• pp.364-370
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• 2019

This study was conducted to select cultivars and determine the harvest period suited for the availability of biological activities in unripen apple. To analyze effective the components in the apple (Malus domestica), three cultivars, 'Summerking', 'Hongro', 'Fuji' were harvested from 40~50 days after full bloom to harvest time. Soluble solid content increased gradually by ripening but titratable acidity decreased with ripening regardless of the cultivars. The total phenol content significantly reduced with ripening from May 30 to July 30 (p<0.05). Substantially, the total phenol content of 'Hongro' in May 30 was four times higher than that of 'Summerking' in the same period and ten times higher than that of 'Hongro' in August 30. The total flavonoid content reduced with ripening regardless of cultivars (p<0.05) and that of 'Hongro' in May 30 was significantly highest (p<0.05). The ascorbic acid content was the highest in 'Hongro' in May 30 (p<0.05). The contents of tannin and ursolic acid significantly reduced with ripening from May 30 to July 30 (p<0.05), while no significant difference was observed between Hogro and Fuji after July 30. Therefore, 'Hongro' harvested in May 30 was considered to be best in the utilization of the effective components of immature apple.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.23 no.3
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• pp.250-259
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• 2010

The ability for energy harvesting via the piezoelectric effect was studied for a unimorph element such as piezo buzzer. A simple equivalent circuit was proposed to predict the energy generated based on the internal stress. Unimorphs with a metal-cavity were used as a driving device of the generation panel. Both the AC open voltage and DC output voltage as a function of pressure period and number of element were measured. For the unimorph generation circuit, DC output voltage varies with pressure period, reaching a maximum value at $470{\mu}F$. The maximum output voltage a according to load resistance was measured at $1M{\Omega}$. Data analysis of the DC output voltage and time constant indicated that number of piezoelectric element of optimum was 60~80. It was found that piezoelectric unimorph has the possibility to be used as the driving element of the electric generation.

• Journal of Ginseng Research
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• v.32 no.4
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• pp.337-340
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• 2008

Seedlings of North American ginseng (Panax quinquefolius L.) were grown to full canopy establishment and then leaflet or leaf removal at different times applied to determine the effects on plant growth and performance. Leaf removal at 47, 57, 69 and 78 days after seeding resulted in 82.1, 59.8, 41.3 and 29.8% reduction, respectively, in root dry matter (economic yield) ; this indicates that leaf removal during the early root growth period causes greatest reduction in root yield. Removal of 1, 2, and 3 leaflets at 42, 52, 62 and 70 days from seeding reduced root weight at harvest (80 days from seeding) linearly, particularly at earlier removal dates. The perennating bud formed on all roots and was not influenced by treatment. This would suggest that if leaf loss occurs after canopy establishment the plant will re-grow the next year after the obligatory dormancy period.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.349-355
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• 2018

This study was aimed at predicting the yield of paprika (Capsicum annuum L.) through analyzing the growth characteristics, yield pattern and greenhouse environment. In the greenhouse of the Gyeongnam area (667 m above sea level), the red paprika 'Cupra' and the yellow paprika 'Fiesta' were grown from July 5, 2016 to July 15, 2017. The planting density was $3.66plants/m^2$ and attracted 2 stems. During the cultivation period, the average external radiation of the glasshouse was $14.36MJ/m^2/day$ and the internal average temperature was controlled as $20.1^{\circ}C$. After 42 weeks of planting, the growth rate of 'Cupra' was 7.3 cm/week and that of 'Fiesta' was 6.9 cm/week. The first fruit setting of 'Cupra' appeared at 1.0th node and 'Fiesta' at 2.7th node. The first harvest of 'Fiesta' was 11 weeks after planting and 'Fiesta' was 14 weeks. Comparing the yield per 10 a until the end of the cultivation in July, 'Fiesta' was 19,307 kg, which was 2.4% higher than that of 'Cupra'. And the fruit weight ratio of over 200 g of 'Cupra' was 27.7% which was 7.7% higher than that of 'Fiesta'. The average required days to harvest after fruit setting of 'Cupra' was 72.6 days and 'Fiesta' was 63.8 days. According to the relationship between the average required days to harvest and the cumulative radiation (during from fruit setting to harvest), the more radiation increases the less required days to harvest increases after February. In terms of yield, 'Cupra' increased in yield as the cumulative radiation increased, while 'Fiesta' showed an irregular pattern. Cumulative radiation from fruit setting to harvest was negatively correlated with required days to harvest after February in both cultivars. But in relation to yield, there were difference between 'Cupra' and 'Fiesta'.

• Journal of Bio-Environment Control
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• v.13 no.2
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• pp.73-80
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• 2004

Two red pepper(Capsicum annuum L.) cultivars, 'Geumtap' and 'Bugang', were cultivated at main producing areas in Korea and harvested four times in 1998 and 1999. Length, weight, dry matter ratio and color of red peppers were measured at each harvest. The relations between external characteristics with regional climatic elements such as total accumulated air temperature, total amount of precipitation and duration of sunshine during the fruit growing periods were compared. Length and fruit weight decreased by delayed harvest. These characteristics were shown significant difference according to cultivars, but not to growing year. Dry matter ratio had a tendency to increase at the 3rd and 4th harvest. The red color as measured a${\times}$L values of pepper powder, increased with being later in harvesting, but the trend was uncertain. In fruit growth, fruit length showed a positive correlation with total accumulated air temperature in later growth period of fruits(from 1st to 20th day before harvesting), and fruit weight had relationships with accumulated air temperature and total amount of precipitation in later growth period of fruit. There was no relation between dry matter ratio and climate elements. The red color was shown high correlations with total amount of precipitation and duration of sunshine. There was highest coefficient of determination($r^2$) in all external characteristics.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.4
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• pp.331-339
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• 2010

Shrimp farming is the most important mariculture industry on the west coast of South Korea. However, it has suffered from mass mortality due to viral disease outbreaks and coastal pollution due to water discharge. This study developed an intensive shrimp culture method for outdoor ponds, without water exchange, which minimizes the chance of viral transmission from the environment, reduces coastal pollution by water discharge and enhances shrimp production. A culture trial was conducted in two high-density polyethylene (HDPE)-lined ponds with a $550\;m^2$ surface area. The ponds were stocked with postlarvae of Litopenaeus vannamei, the major farmed shrimp species in Korea, on July 10, 2007, and cultured for 90 days with no water exchange. The stocking density of the postlarvae (B.W. 0.0015 g) was $272\;ind./m^2$, which is eight times higher than in traditional pond culture in Korea. At harvest, the total production of ponds 1 and 2 was 1,362kg ($2.48\;kg/m^2$) and 1,282 kg ($2.33\;kg/m^2$), respectively. This is 20~22 times higher than the mean farmed shrimp production ($0.112\;kg/m^2$) in Korea and about eight times higher than in traditional ponds with a good harvest. Although there was no water exchange throughout the culture period, the mean concentrations of unionized ammonia and nitrite-nitrogen were as low as 0.038 and 6.0 mg/L, respectively. The feed conversion rate (FCR) was 1.38, which is 20~45% lower than that of traditional pond cultures. The high efficiency of the diet in this study is thought to be due to a well-managed feeding strategy and well-developed bioflocs used as diet additions for the shrimp. The final body weight of the shrimp at harvest was low (12.2~12.5 g), compared with that of traditional pond culture. This may have resulted from the combination of a short culture period, high density of shrimp, and low temperature. This study suggests that a super-intensive shrimp pond culture method using biofloc technology with no water exchange can minimize viral transmission via water exchange, reduce coastal pollution, and enhance shrimp production.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.4
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• pp.328-340
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• 1987

In order to clarify major reasons of a poor harvest, the Porphyra-cultivation ground was investigated in Kwangyang Bay in terms of the laver production per unit area, diseases, and fouling organisms from January to April in 1986. The laver production per unit area of the control station was more than that of the study area at 'Soppal' cultivation ground, while the difference at the cultivation groud using 'nets' seemed to be insignificant. The vertical attachment range of laver was directly associated with the production per unit area at 'Soppal' cultivation ground. The number of young thalli of 1-3 mm length was almost similar between control and study sites at 'nets' cultivation ground. Two kinds of diseases in cultured laver, the crape and shot hole, were prevalent during the study period. However, the affected thalli were gradually decreased at the end of the study period. Major fouling organisms attached to 'Soppal' were Balanus albicostatus, Enteromorpha prolifera, Capsosiphon fulvescens, and Scytosiphon lomentaria. In conclusion, the poor harvest of laver in 1986 may result from such following problems as the decrease in vertical attachment range of laver and fouling problems as the decrease in vertical attachment range of laver and fouling organisms at 'Soppal' cultivation ground, prevalence of certain diseases, changes in environmental conditions, arrangement and maintenance of facilities for laver cultivation.