• Korean Journal of Environmental Biology
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• v.20 no.1
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• pp.25-34
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• 2002

The halophytes were investigated on Gyeonggi Bay from Aug. 1999 to Oct. 2001. The survey was conducted at 38 areas including natural salt marshes, dunes, abandoned salt farms and bank areas. During this study 46 species of halophytes were collected in the areas. Among the halophytes the following 7 species were found at natural salt marshes only; Triglochin maritimum L, Carex scabrifolia Steud., Salicornia herbacea L., Suaedu australis (R. Br.) Moq., S. martima Dum., S. japonica Makino, S. malacosperma Hara, on the other hand 8 species at dunes only; Glehnia littoralis Fr. Schm., Cnidium japonicum Miq., Messerschmidia sibirica L., Ixeris repens A. Gray, Corispermum stauntonii Miq., Vitex rotundifolia L. fil., Ischaemum anthephoroides Miq., Carex kobomugi Ohwi. The distributions of halophytes in each regions are as the followings : Isl. Gyodong-do 21 species, Isl. Seokmo-do 10 species, Isl. Ganghwa-do 28 species, Isl. Jangbong-do 16 species, Isl. Sin & Si-do 10 species, Isl. Daemuui-do 23 species, Isl. Deokjeok-do 23 species, Isl. Ijak-do 10 species, Isl. Yeongheung-do 29 species, Soyra 25 species, Isl. Daebu-do 15 species, Ssangsong-ri 6 species, Hogok-ri 16 species, Maehyang-ri 10 species.

• Mycobiology
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• v.43 no.3
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• pp.354-359
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• 2015

Blossom blight in strawberry was first observed in a green house in Nonsan, Damyang, and Geochang areas of Korea, between early January to April of 2012. Disease symptoms started as a grey fungus formed on the stigma, which led to the blossom blight and eventually to black rot and necrosis of the entire flower. We isolated the fungi purely from the infected pistils and maintained them on potato dextrose agar (PDA) slants. To test Koch's postulates, we inoculated the fungi and found that all of the isolates caused disease symptoms in the flower of strawberry cultivars (Seolhyang, Maehyang, and Kumhyang). The isolates on PDA had a velvet-like appearance, and their color ranged between olivaceous-brown and smoky-grey to olive and almost black. The intercalary conidia of the isolates were elliptical to limoniform, with sizes ranging from $5.0{\sim}10.5{\times}2.5{\sim}3.0{\mu}m$ to $4.0{\sim}7.5{\times}2.0{\sim}3.0{\mu}m$, respectively. The secondary ramoconidia of these isolates were 0- or 1-septate, with sizes ranging betweem $10.0{\sim}15.0{\times}2.5{\sim}3.7{\mu}m$ and $8.7{\sim}11.2{\times}2.5{\sim}3.2{\mu}m$, respectively. A combined sequence analysis of the internal transcribed spacer regions, partial actin (ACT), and translation elongation factor 1-alpha (TEF) genes revealed that the strawberry isolates belonged to two groups of authentic strains, Cladosporium cladosporioides and C. tenuissimum. Based on these results, we identified the pathogens causing blossom blight in strawberries in Korea as being C. cladosporioides and C. tenuissimum.

• Journal of Environmental Science International
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• v.29 no.3
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• pp.219-228
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• 2020

The purpose of this study was to investigate the effects of defoliation treatment on the growth and yield of strawberries. There was a remarkable growth in the above-ground part and root of untreated strawberry plants possibly due to higher amount of photosynthesis, while overall plant growth was suppressed as the level of defoliation treatment increased. In both the "Seolhyang" and "Maehyang" cultivars examined, defoliation treatment resulted in small fruits and a low number of fruits per plant. Notably, 50% defoliation significantly reduced the number of fruits per plant to 8.2, compared to 13.8 in untreated plants. Defoliation treatment also negatively influenced the fruit quality including color, sugar content, and solid-acid rate. However, no significant changes in fruit firmness was observed in either cultivar. Therefore, retaining enough leaves without defoliation treatment can be important to increasing fruit yield, producing high quality fruits and saving labor required for defoliation.

• Horticultural Science & Technology
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• v.31 no.5
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• pp.633-639
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• 2013

Fungicide applications are required to prevent the strawberry from Botrytis fruit rot and powdery mildew that infect open strawberry flowers, however, their effects of fungicides on pollen germination of strawberry have been rarely documented, particularly those from recently developed active fungicidal ingredients. In this study we have evaluated the effects of 24 commercial fungicidal formulations and 6 organic materials on pollen germination in 3 strawberry cultivars using in vitro assays. Pollens from strawberry had higher germination rates on agar with sucrose of 18% and $25^{\circ}C$ than other tested conditions. Pollen germination rates of cvs. Seolhyang, Maehyang, and Kumhyang at 18% sucrose and $25^{\circ}C$ were 15.3, 18.4 and 30.7%, respectively. Pyraclostrobin, azoxystrobin, kresoxim-methyl, dichlofluanid, iminoctadine tris, and sulfur showed the strongest inhibitory efficacy with the germination rates of more than 93.8% compared to the no-fungicide control. Germination was not significantly affected by simeconazole and procymidone. This in vitro germination study may provide information useful for selecting fungicides in flowering stage to strawberry farmers.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.753-767
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• 2020

The commercial value of strawberries is affected by various factors such as their shape, size and color. Among them, size determined by weight is one of the main factors determining the quality grade of strawberries. In this study, image technology was developed to predict the weight of strawberries using the shape characteristics of strawberry cultivars. For realtime weight measurements of strawberries in transport, an image measurement system was developed for weight prediction with a charge coupled device (CCD) color camera and a conveyor belt. A strawberry weight prediction algorithm was developed for three cultivars, Maehyang, Sulhyang, and Ssanta, using the number of pixels in the pulp portion that measured the strawberry weight. The discrimination accuracy (R2) of the weight prediction models of the Maeyang, Sulhyang and Santa cultivars was 0.9531, 0.951 and 0.9432, respectively. The discriminative accuracy (R2) and measurement error (RMSE) of the integrated weight prediction model of the three cultivars were 0.958 and 1.454 g, respectively. These results show that the 2D imaging technology considering the shape characteristics of strawberries has the potential to predict the weight of strawberries.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.432-438
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• 2013

A study was conducted to examine the effect of maturity and precooling ($60%/0^{\circ}C$ and $80%/4^{\circ}C$), and light illumination on the storage life of 'Maehyang' strawberry meant for export. Fruits at 60% and 80% ripened stage were harvested from a commercial greenhouse in Jinju on April 3, 2012. Harvested fruits were transported to the precooling system within 30 minutes. Transported fruits were precooled the $4^{\circ}C$ for 2 hours and $0^{\circ}C$ for 5 hours by a forced draft cooling system, and then stored at $6^{\circ}C$. During the storage, the fruits were examined for their changes in hardness, soluble solid content, quality grade, acidity, Hunter value, weight loss, and the incidence of gray mold (Botrytis cinerea) at an interval of two days from April 5 to April 17. Hardness was decreased until 7th days and it was changed to increase at 9th days. Treatment of 60% maturity, $0^{\circ}C$ precooling and no light illumination of strawberry were shown the highest value in freshness. The soluble solid content harvested in 80% maturity strawberry was higher than 60% maturity strawberry until the third day. Quality grade decreased rapidly in 80% maturity stage with light illumination strawberry in comparison to the 60% maturity stage of strawberry. Hunter value 'L' and 'a' showed a rapid change in 60% maturity stage of strawberry. Weight loss decreased rapidly in 80% maturity, $0^{\circ}C$ precooling, and no light illumination of strawberry treatments. Gray mold incidence was found the most at 60% maturity, $4^{\circ}C$ precooling, and light illumination of strawberry. The results from our study indicate that effectiveness for keeping the freshness of strawberry was best achieved by harvesting in low maturity, precooling at $0^{\circ}C$, and with no light illumination.

• Journal of Bio-Environment Control
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• v.17 no.3
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• pp.231-237
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• 2008

Objective of this research was to investigate the effect of calcium concentrations in the fertilizer solution on growth and development of Ca deficiency in 'Maehyang' strawberry (Fragaria $\times$ ananassa Duch.). The margins of the youngest leaves were scorched and they developed a cupped shape as they were expanded in Ca deficient plants. The vein area of the youngest leaves became brown when the deficiency became severe. The quadratic responses were observed in dry weight production to elevated Ca concentrations in fertilizer solutions with the highest growth in 4.5 mM treatment. The regression equation was y=2.4026+1.0209x-$0.098x^2$ $(R^2=0.3546^{***})$. However, tissue Ca contents increased lineally as the Ca concentrations in fertilizer solutions were elevated (y=1.2108+0.1333x, $R^2=0.9189^{***}$). In changes of the fresh weight and Ca concentrations in petiole sap, fresh weight production showed quadratic responses to elevated Ca concentrations in fertilizer solution, but Ca concentration increased lineally. The equations in changes of fresh weight and Ca concentrations were y=9.273+4.882x-$0.4245x^2$ $(R^2=0.4935^{***})$ and y=52.311+3.2917x $(R^2=0.6918^{***})$, respectively. When the concentration of calcium at which plant growth was retarded by 10% is regarded as critical concentration level, the calcium contents based on dry weight of above ground plant tissue and in petiole sap should be in the range between 1.6 to 2.25% and 63 to $79mg{\cdot}kg^{-1}$, respectively.

• Journal of Bio-Environment Control
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• v.29 no.1
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• pp.80-88
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• 2020

This study was conducted to examine the effect by application method and concentration of the indole-3-butyric acid (IBA), which is auxin-based plant growth regulator, on the growth and runner plants production of strawberry in the greenhouse. The seedlings of strawberry were transplanted in the pot (150 ×135 × 90 mm) filled with coir medium on April 12, 2019. The IBA was applied with a foliar spray or drench as 50, 100, 150, and 200 mg·L^-1 (50 mL per plant), respectively. The treatment was started on April 29, 2019. The foliar spray and drench treatment of IBA were repeated at 2-week intervals for 9 weeks from the start date of treatment. At 9 weeks after treatment, the petiole length of mother plants was the shortest in the control. The number of runner plants showed a tendency to decreased in the foliar spray. The number of lateral buds showed a tendency to decreased in the IBA treatment, and the least in the foliar with 100 mg·L^-1. There was not significantly difference in the fresh and dry weights of the first and second runner plants. However, in the third runner plants, the fresh and dry weights were the greatest in the drench with 100 mg·L^-1. Therefore, when considering the growth of third runner plants and lateral bud suppression, the drench with the 100 mg·L^-1 could be better application method and concentration of IBA treatment for growth of the third runner plants and runner plants production of strawberry, and the results can be used as a basic research of plant growth regulator application to save the labor force and enhance the seedling quality in strawberry seedling stage.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.780-783
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• 2012

A new strawberry cultivar (Fragaria ${\times}$ ananassa Duch.) 'Okmae' was developed from a cross between 'Toyonoka' and 'Maehyang'. This cultivar has a good fruit quality and suitable number of flowers per cluster for labor saving in fruit thinning. 'Gyoengnam No. 1' was selected as an elite line with vigorous plant growth, higher soluble solids content and fruit firmness after examining its characteristics and productivity in forcing cultures from 2007 to 2009. Farmer's field trial of 'Gyoengnam No. 1' was conducted in 2010 and it was registered as 'Okmae' thereafter. The general characteristics of 'Okmae' are vigorous growth habit, erect plant type, less number of leaf and elliptic leaf shape. 'Okmae' has long peduncle and 9-10 flowers per flower cluster which need less labor for fruit thinning. Fruits of 'Okmae' are conical having a bright red and glossy skin color. Although 'Okmae' has a smaller average fruit number per plant of 21.9 than that of the control cultivars, it's possible to produce high yield because of greater fruit weight of 26.0 g. 'Okmae' showed a high soluble solids content of $11.6^{\circ}Brix$, low acidity of 0.37%, and high firmness of $14.5g{\cdot}mm^{-2}$. It is sensitive to anthracnose and powery mildews, but high-quality strawberry can be harvested by using effective control measure.

• Korean Journal of Food Science and Technology
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• v.38 no.5
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• pp.642-647
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• 2006

Yeast selection and the sterilization methods of strawberry juice were optimized for making strawberry wine. In addition, changes in the physicochemical characteristics of the wine during its fermentation were estimated. Maehyang and Yukbo cultivars of strawberry were tested for wine making; they contained 9.8 and 9.3% soluble solids and 0.59 and 0.58% titratable acidities, respectively. Among six yeasts tested, the Wg-15 and Sc-51 strains were selected based on the alcohol yield in the strawberry wine. Alcohol and soluble solid contents following heat treatment ($85^{\circ}C$, 10 min) or $K_2S_2O_5$ (200 ppm) treatment for sterilization were 7.10-7.20% and 5.60-5.80%, respectively, and no differences were observed between the Wg-15 and the Sc-51 strains. However, the flavor of wine produced following heat treatment was slightly better than that following $K_2S_2O_5$ treatment. The greatest amounts of alcohol were produced after 2 days of fermentation at $26^{\circ}C$. The alcohol content in wines produced with 12, 14, and 16% sugar content in the initial stages were 5.1, 6.0-6.2, and 7.5-7.7%, and the soluble solid contents were 3.9-4.3, 4.1-4.3, and 5.0-5.3%, respectively; no significant differences were observed between the Wg-15 and the Sc-51 yeast strains. For making strawberry wine, we proposed that the sugar content of Maehyang or Yukbo cultivars be adjusted to 16% soluble solids in the initial stages with heat treated at $85^{\circ}C$ for 10 min and fermentation with the Wg-15 or Sc-51 yeast strains at $26^{\circ}C$ for 8 days.