• 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.

• 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.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.437-441
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• 2012

This study was conducted to find out the optimum container for increasing acclimatization rate of in vitro mass propagated plantlets of Ever-bearing strawberry (Fragaria ${\times}$ ananassa Duch.) via bioreactor. Four types of containers were used such as transparent plastic container (TPC), plug tray (PT), I-pot (IP), and black vinyl pot (BVP). Number of date maintaining soil water content above 10% was five days in TPC, three to four days in BVP, two days in PT, and one day in IP. Survival rate of plantlets was 80% in BVP, 70% in TPC, 55% in IP, and 15% in PT. In TPC, growth increment of plantlets was the greatest among all the tested containers and the lowest in IP. Numbers of runner per plant were 3.3 in BVP, 2.9 in TPC, 1.6 in PT, and 1.2 in IP. Total cost was 44,405,300 won/10 a in BVP, resulting in reducing more 6,659,400 won/10 a than IP's (51,064,700 won/10 a). Around 102,718 plants/10 a were produced by using BVP, suggesting that 30,265.1 plants/10 a more could be produced than IP (72,452.9 plants/10 a). Production cost per plant was 432.3 won in BVP, resulting in reducing 272.5 won than IP's (704.8 won). As a result, BVP was appropriate for acclimatization of in vitro plantlets through bioreactor system.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.41-45
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• 2014

This study was conducted to investigate the effects of crown numbers on growth and yield of ever-bearing strawberry (Fragaria ${\times}$ ananassa Duch.) 'Goha' cultivar. Strawberry seedlings were planted with $55{\times}30cm$ distance on April 29, and the randomized block experimental was designed by putting the crown numbers by 1, 3, 5 and crown-unremoved as the control. At the early growth stage, as the numbers of crown decreased, the size of leaf became larger and inflorescence diameter became thicker. Plant height became higher as the number of crown increased at the final harvesting time. Fresh weight of crown-unremoved plants was 118 g, showing 77.2 g higher than that of plants with one crown. Numbers of the developed inflorescence of plants with five crowns and crown-unremoved was 20.1, whereas 6.8 of plants with one crown, resulted in 13.3 more crowns. However, crown number did not significantly affect the fruit quality. As the crown number increased, the average fruit weight was lighter and the marketable fruit rate was shown to decrease significantly. The marketable yield of crown-unremoved plants was $17,372kg{\cdot}ha^{-1}$, showing 68% higher than plants with one crown. Therefore, crown management without thinning crowns was recommended and inflorescence thickness less than 3 mm should be removed for successful production of ever-bearing strawberry 'Goha' cultivar during summer season.

• The Korean Journal of Mycology
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• v.37 no.1
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• pp.117-119
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• 2009

Rhizopus soft rot caused by Rhizopus stolonifer occurred on strawberry (Fragaria ${\times}$ ananassa) in the plastic boxes in Jinju City Wholesale Market of Agricultural Products at Gyeongnam province in Korea on April 2008. The infected fruits were rapidly softened, water soaked and finally rotted. The symptoms were mainly occurred through wounds at harvest time. The colony color was white, cottony to brownish black after fully matured and numerous sporangiospores were formed on sporangia. The optimum growth temperature of the fungus was $30^{\circ}C$ on potato dextrose agar. Sporangia were globose or hemispheric shape of white color at initial stage and gradually changed with black color of $82{\sim}195{\mu}m$ in size. Sporangiophores were $12{\sim}25{\mu}m$ in width. Columella were hemispheric in shape, and $70{\sim}92{\mu}m$ in size. Sporangiospores were irregular round or oval in shape, brownish-black in color and $9{\sim}21\;{\times}\;7{\sim}8{\mu}m$ in size. This fungus formed stolones and rhizoid on PDA. On the basis of symptom, mycological characteristics and pathogenicity of the fungus, the causal fungus was identified as Rhizopus stolonifer (Ehrenb.) Vuill.

• Journal of Bio-Environment Control
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• v.27 no.2
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• pp.111-116
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• 2018

This study were carried out to evaluate the efficiency of using burn-type $CO_2$ generators in greenhouse for cultivation 'Seolhyang' strawberry ($Fragaria{\times}ananassa\;Duch.$) during winter season. The concentration of $CO_2$ was 200 to $600{\mu}mol{\cdot}mol^{-1}$ in the control, and 800 to $1,100{\mu}mol{\cdot}mol^{-1}$ in using burn-type $CO_2$ generator between 6 and 11 hours. At other times, it was observed that at similar concentration in the control and using burn-type $CO_2$ generator. Measured greenhouse air temperature inside the of using burn-type $CO_2$ generator was $2{\sim}3^{\circ}C$ higher than the control at 6 ~ 10 am. There was no temperature difference between treatments after 11 o'clock. Plant height, leaf length, leaf width, root diameter, fresh weight, and dry weight were not different between treatments. The marketable yield (kg/10a) of using burn-type generator were 4,131 kg, which was 519 kg higher than the control. Therefore, the total fruit yields increased 17% compared to the control.

• Journal of Plant Biotechnology
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• v.47 no.3
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• pp.242-247
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• 2020

This experiment was performed to determine the concentration of coconut water that is most effective in promoting the growth of 'Maehyang' strawberry in tissue culture. Cultivars in this experiment consisted of 'Maehyang' grown in the presence of 0, 20, 40, 60, 80, 100 ml·L^-1 of coconut water which was added to a medium mixed with BA 0.5 mg·L^-1 and IBA 0.1 mg·L^-1. Morphological variation tests and SSR detection with coconut water were conducted to determine variations in proliferation. The proliferation rate of 'Maehyang' strawberry improved with the coconut water treatment compared to non-treatment. In particular, the proliferation rate with 100 ml·L^-1 coconut water treatment increased by about 4 times. When 'Maeyang' was treated with 100 ml·L^-1 of coconut water, two morphological variants occurred without genetic variation. Therefore, the results suggest that 100 ml·L^-1 of coconut water can be used to mass-produce "Maeyang" strawberry without causing genetic variations.

• Horticultural Science & Technology
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• v.33 no.3
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• pp.443-447
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• 2015

Fragaria ${\times}$ ananassa (Duch.) cultivars, 'Wongyo 3 115' a nd 'Wongyo 3 116', we re bre d as a n inte rme diate parent l ine using heterosis of $F_1$ hybrids in octoploid strawberry. These two new cultivars were developed as inbred lines ($S_9$ generation) propagated from both seed and runners/stolons. 'Wongyo 3115', an inbred line derived from the 'Benihoppe' cultivar, has a semi-upright plant shape showing a vigorless growth habit, weaker than the original 'Benihoppe' cultivar; it has early flower bud differentiation and produces 10 flowers per cluster when grown from healthy seed. 'Wongyo 3115' has low yields of conical type fruit with pink colored skin; average fruit weight is approximately 11 g. The important characteristic of 'Wongyo 3115' is its excellent fruit firmness, firmer than the original variety. 'Wongyo 3116', an inbred line derived from the 'Doyonoka' cultivar, has an upright plant shape, vigorless growth habit, weaker than that of the original 'Doyonoka' cultivar; it has early flower bud differentiation and produces 8 flowers per cluster when grown from healthy seed. 'Wongyo 3 116' has oblate type fruits with red skin and an ave rage weight of approximately 12 g. The important characteristics of 'Wongyo 3116' are excellent fruit shape and higher yield than other inbred lines, although it produces small fruits compared to the original cultivar. Both cultivars have excellent taste, high sugar/acid ratio, and good texture. In regards to disease and pest resistance, 'Wongyo 3115' and 'Wongyo 3116' have a tendency to be sensitive to powdery mildew, anthracnose and the two-spotted spider mite.

• Journal of Bio-Environment Control
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• v.17 no.3
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• pp.238-245
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• 2008

This study was carried out to investigate the effect of magnesium (Mg) concentrations in nutrient solution on growth of and nutrient uptake by 'Maehyang' strawberry. Tissue analysis based on dry weight and petiole sap were also conducted to determine the threshold level in plants when Mg deficiency disorders developed in strawberry plants. In the Mg deficient plants, the spotted yellowing or yellowing area developed on the interveinal area of mature leaves. The dark brown color also developed on the interveinal area of mature leaves with marginal browning or marginal necrosis. The response in dry weight production of 'Maehyang' strawberry to elevated Mg concentrations in nutrient solution was quadratic and the equation is y=6.84+1.7533x-$0.9278x^2$ $(R^2=0.1081^{***})$. But the Mg contents in tissue increased lineally with the equation of y=0.1764+0.1275x $(R^2=0.8307^{***})$. The trends of fresh weight production and Mg concentrations in petiole sap were also quadratic (y=24.127+7.3565x-$1.125x^2$, $R^2=0.2314^{^***}$) and linear (11.954+5.793x, $R^2=0.6869^{***}$), respectively. To prevent growth suppression, the Mg concentrations based on dry weight of above ground tissue and in petiole sap should be in the range of 0.30 to 0.65% and 19 to $40mg{\cdot}kg^{-1}$, respectively, fer the commercial production of 'Maehyang' strawberry.

• Horticultural Science & Technology
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• v.30 no.6
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• pp.784-787
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• 2012

'Gwanha' is new strawberry (Fragaria ${\times}$ ananassa Duch.) cultivar, which was released by Highland Agriculture Research Center, Rural Development Administration, in 2011. In 2007, this cultivar was originated from a cross between 'Sucambodiaberry' and 'Selva' that showed excellent ever-bearing characteristics including continuous pink flowering habit under long-day and high temperature condition. It was named 'Saebong No.4' after examining its characteristic and productivity in summer culture from 2009 to 2011. After characteristic and productivity test in 2011, 'Gwanha' was selected as an elite cultivar. The general characteristics of 'Gwanha' include spreading type, middle vigor, elliptic leaf, and long cluster in growth. The fruit shape is wedge, and the red fruit is edible and unique among the domestic ornamental strawberry cultivars. Flower color of 'Gwanha' is pink, and flower cluster is more appearance than 'Pinkpanda'. The average fruit weight of 'Gwanha' is about 7.8 g and the marketable yield is relatively low because of low marketable rate. It is resistant against fusarium wilt. 'Gwanha' is suitable for four season cultivation as an ornamental strawberry cultivar because it shows continuous flowering habit under long-day and high temperature condition.