• Horticultural Science & Technology
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• v.28 no.4
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• pp.535-539
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• 2010

The formation and elongation of runners, growth of runner plants, and transplant propagation rates of 'Maehyang' strawberry were investigated at various photosynthetic photon flux (PPF) levels. Strawberry plants having $3.1{\pm}0.4$ leaves and $7.0{\pm}1.1mm$ of crown diameter were used as propagules and were cultured for 35 days in 9 transplant production modules using fluorescent lamps as artificial lighting sources. Applied PPF levels were $137.4{\pm}2.1$, $217.0{\pm}1.0$, and $274.7{\pm}8.4{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ as measured on the surfaces of empty shelves. The numbers of runners and runner plants per propagule were the greatest at $280{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPF. The runner plant propagation rate was 0.27 plant/day/propagule at $280{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, which was significantly greater than that of conventional propagation methods. Results indicate that high PPF levels promotes the formation of runners and runner plants of strawberry and that the rapid propagation method with high PPF levels can be feasible for production of vigorous transplants in a closed transplant production system.

• Journal of Bio-Environment Control
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• v.14 no.1
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• pp.38-45
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• 2005

This research was conducted to determine the effect of fertilization programs on crop growth, nutrient uptake and yield of strawberry and salt accumulation in PE film house soil. To achieve these, experiments were conducted through two years with various fertilization program such as traditional fertilization(A), recommended fertilization of Rural development administration (B), Tochigi prefectural experiment station (C) and Nonsan strawberry experiment station (D), and control (E). In 1st year, statistical differences in growth characteristics were not observed among treatments except (E). Yield per 10 was the highest in (D) followed by (A), (B), (C) and (E) and there was the statistical difference between (D) and (E). In the 2nd year experiment, growth characteristics and yield showed similar trends to those of 1st year experiment. In the results of soil analysis of 2nd year, the soil pH of all treatments were in the acceptable range, while electrical conductivity of (A) and (D) were 2.36 and 2.19 %$dS{\cdot}m^{-1}$, respectively. After finishing of strawberry cultivation, nitrate concentration in soil solution of (A) and (D) were 74.6 and 65.0%$mg{\cdot}L^{-1}$ and Na in those were 3.71 and 3.53 $cmol+kg^{-1}$, respectively. Above results indicated that (A) and (D) were good fertilization program for strawberry cultivation, but those also resulted in accumulation of $NO_{3-}N$ and Na in PE house soil.

• Journal of Bio-Environment Control
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• v.25 no.4
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• pp.283-287
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• 2016

This study was conducted to examine the effects of defoliation levels during winter season on the yield and soluble solid contents of fruits. To achieve this strawberry 'Seolhyang' cultivated forcingly in the year of 2013 to 2014 as well as 2014 to 2015. The three treatments include periodical removing of leaves remaining 6 fully expanded leaves, those remaining 9 leaves, and only removing of old and infected leaves during the period from early December to end of February. In the early marketable fruit yield until the end of February and total marketable fruit yield, the treatment of non-defoliation was significantly higher than those of the treatment of 6 and 9 leaves in the year of 2014 to 2015 cropping season. Soluble solid contents of fruits among January and March increased significantly as the number of leaves get higher. Soluble solid contents were higher and stable around $12^{\circ}Brix$ in the treatment of non-defoliation. Assimilation of photosynthetic products into plant tissue are insufficient due to the lack of irradiation and short day in winter season forcing cultivation of strawberry. Thus, it is considered to manage the leaves with defoliation for only old and infected leaves from December to February for increasing of fruit yield and improvement of fruit quality.

• Journal of Bio-Environment Control
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• v.26 no.2
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• pp.49-55
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• 2017

The objective of this research was to investigate the effects of planting date, root pruning and uprooting on growth, yield and budding ratio of 'Seolhyang' strawberry (Fragaria${\times}$ananassa Duch.). Planting dates of plantlets with 60 ~ 70 days old were September 7th, September 14th and September 21th. Root pruning rates were controlled to 25% (RP 25) or 50% (RP 50) before transplanting. In the uprooting treatments, the plantlets were pulled out on root media and were replanted into same bed at 10 days (UR 10) and 20 days (UR 20) after transplanting. The delayed planting dates of plantlet resulted in the suppressed growth of plant, reduced yield, and slight earlier appearance of flower buds. The RP 50 treatment showed the lowest value among root pruning treatments in growth and yield, but appearance of flower buds slightly fall behinds. The UR 20 treatment only made flower budding earlier by 6 days than non-treatment. All of root stress treatment was appeared to decrease vegetative growth and yield except the RP 25 treatment. Above results imply that strong root stress was required to emerge second flower bud earlier but which reduced overall growth and yield in 'Seolhyang' strawberry.

• Current Research on Agriculture and Life Sciences
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• v.31 no.4
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• pp.265-271
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• 2013

The objective of this study was to find out the optimum number of fruiting per a flower cluster on 5 domestic strawberry cultivars (Fragaria${\times}$ananassa Duch.), 'Daewang', 'Ssanta', 'Okmae', 'Seolhyang' and 'Maehyang'. Therefore, three ways of fruit thinning, 4~5 fruiting, 7~9 fruiting and all fruiting per a flower cluster were compared. After fruit thinning, the first fruit weights were increased from the second flower cluster on 'Seolhyang' and 'Maehyang', but from the third one on 'Daewang' and 'Ssanta'. There was no difference in first fruit weight by the flower thinning ways on 'Okmae'. The mean fruit weights of all the cultivars were increased and sugar contents also were increased, but acidities were decreased. The peduncle lengths were shortened by fruit thinning, but there was no difference in number of leaf, petiole length and crown diameter. Marketable yields by 4~5 fruiting per a flower cluster than all the fruit setting were higher 4.3% and 6.6% respectively on 'Daewang' and 'Maehyang'. In contrast, the yields were higher 3.1%, 3.5% and 9.1% in 7~9 fruiting per a flower cluster than all fruiting on 'Ssanta', 'Okmae' and 'Seolhyang' respectively. As the result, we could improve the fruit quality and could increase marketable yield by fruit thinning with matching flowering characteristics of those strawberry cultivars.

• Horticultural Science & Technology
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• v.35 no.3
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• pp.381-386
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• 2017

'Jangha' is a new strawberry (Fragaria ${\times}$ ananassa Duch.) cultivar, which was released by the Highland Agriculture Research Institute in 2014. The 'Jangha' cultivar originated in 2008 from a cross between 'Goha' and 'Elsinore' that showed excellent ever-bearing characteristics, including continuous flowering habit and high soluble-solids contents under long-day and high temperature conditions. This cultivar was initially named 'Saebong No. 6' after examining its characteristics and productivity in summer culture from 2010 to 2012. After two regional adaptability tests in 2013-2014, 'Jangha' was selected from Saebong No. 6 as an elite cultivar. The general characteristics of 'Jangha' include semi-spreading type, elliptical leaves, and moderately vigorous growth. The fruit are conical in shape, and red in color. 'Jangha' plants have 21.4 leaves, 55.8 fewer than 'Flamenco' plants. The soluble-solids content of 'Jangha' was 8.9%, which was 1.2% higher than that of 'Flamenco'. The average fruit weight of 'Jangha' was about 11.7g and the marketable yield was $19,013kg{\cdot}ha^{-1}$, 141% higher than 'Flamenco'. 'Jangha' is suitable for summer season cultivation as a high soluble solids contents cultivar, because it shows continuous flowering habit under long-day and high temperature conditions.

• Horticultural Science & Technology
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• v.28 no.6
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• pp.948-953
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• 2010

We evaluated the bioactive compounds including carbohydrates (CH), organic acids (OA), ascorbic acid (AA), anthocyanin (AC), and ellagic acid (EA) in the achenes, epidermis, and flesh of fully ripe strawberry fruits of the 'Maehyang', 'Seolhyang', 'Keumhyang', 'Akiheme', and 'Red pearl' cultivars. The total contents of CH, OA, AA, and AC were significantly greater in the epidermis than in other tissues, while the EA content was significantly greater in the achenes than in other tissues. The AA content of the epidermis ranged from $49.1-69.2mg{\cdot}100g^{-1}$ FW and was significantly greater than the content of the flesh, while AA was not detected in the achenes of any of the tested strawberry cultivars. The AA contents of the epidermis and flesh of the 'Maehyang' were 69.2 and $42.2mg{\cdot}100g^{-1}$ FW, respectively, and were greater than those of the other cultivars. The AC contents in the epidermis and achenes of the 'Keumhyang' were $74.0mg{\cdot}100g^{-1}$ FW and $36.7mg{\cdot}100g^{-1}$ DW, respectively, greater than those of the other cultivars. The EA content of the achenes of the 'Seolhyang' was $215.5mg{\cdot}100g^{-1}$ DW, significantly greater than those of the other cultivars. Results indicate that the antioxidant levels and other chemical compounds of strawberry fruits vary significantly among different fruit tissues. Our results also suggest that the recently introduced Korean 'Maehyang', 'Seolhyang', and 'Keumhyang' contain higher levels of antioxidants than other major June-bearing strawberry cultivars. These cultivars are feasible selections for both growers and consumers.

• Journal of Bio-Environment Control
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• v.14 no.4
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• pp.280-283
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• 2005

The growth and yield of ever-bearing strawberry $(Fragaria{\times}ananassa\; Duch.)$ 'Pechika' were compared after transplant treatment in the raised hydroponic culture on highlands in summer season. The transplant production methods compared were whole plant refrigerated, outdoor over-wintered, pot-refrigerated, and 1 -year-old transplants. Growth increment at planting was the highest in pot-refrigerated transplants. C/N ratio of the pot-refrigerated transplants was 39.2 which was higher than 19.5 of 1-year-old transplants. However, the growth increment up to the first harvest were not different among the treatments. The first harvesting date of 1-year-old transplants was August 14, which was 5-9 days late than in the other treatments. The average fruit weight was highest in the 1-year-old transplants with 12.6 g. Marketable yield was the highest in the pot-refrigerated transplants, followed 1-year-old, plant refrigerated, and outdoor over-wintered transplants. Therefore, the pot-refrigerated transplants are recommended for marketable yield increase in ever-bearing strawberry cultured on highlands.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.432-436
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• 2012

This study was conducted to determine the optimal aeration rate for mass propagation of ever-bearing strawberry by bioreactor culture. The aeration rate was treated in four levels: 0.1 vvm (air volume/medium volume/min), 0.2 vvm, 0.3 vvm, and 0.4 vvm. In 0.2 vvm conditions, shoot length was the longest at 9.03 cm in bioreactor culture, leave numbers were 40.4 ea and fresh weight was 6,106 mg. Plant growth rate at 0.2 vvm condition was faster than other treatments. In the aeration condition, 0.2 vvm was most effective to increase aerial part growth and to decrease medium consumption. As the culture periods increased, the fresh weight also increased rapidly. After six weeks of cultivation, shoots were emerged with 10.4 ea per plantlet, resulting in developing a complete plant. As a result, the bioreactor culture system for mass propagation of strawberry is required to continuously supply the air by 0.2 vvm speed and cultivate at least for six weeks.

• Horticultural Science & Technology
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• v.32 no.5
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• pp.739-743
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• 2014

This work characterizes 'Yeolha', a new strawberry (Fragaria ${\times}$ ananassa Duch.) cultivar that was released by the Highland Agriculture Research Center, RDA, in 2013. This cultivar originated from a 2008 cross between 'Goha' and 'Elsinyo' and showed excellent ever-bearing characteristics including continuous a flowering habit under long-day and high temperature conditions. It was originally named 'Saebong No. 5' after examining its characteristics and productivity in summer culture from 2010 to 2013. After two regional adaptability tests in 2012, it was selected as an elite cultivar and renamed 'Yeolha'. The general characteristics of 'Yeolha' include a semi-spreading plant type, elliptic leaves, and strong vigor in growth. Its fruit is conical and red. T he s oluble s olids content of 'Yeolha' is 8 .6%, w hich is 0.6% h ig her than t hat of 'Flamenco', b ut f ruit hardness is lower than that of 'Flamenco'. The average fruit weight of 'Yeolha' is about 12.1 g and the marketable yield is $28,133kg{\cdot}ha^{-1}$, which is 117% higher than that of 'Flamenco'. 'Yeolha' is resistant against Fusarium wilt. In addition, 'Yeolha' is suitable for four-season cultivation as a high harvesting cultivar because it shows continuous flowering under long-day and high temperature conditions.