• Horticultural Science & Technology
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• v.29 no.4
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• pp.288-292
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• 2011

This study was undertaken to evaluate the yield and petiole burst occurrence rate of ever-bearing strawberry by controlling crown numbers per plant and the first flower cluster for summer production at highland. The cultivar 'Flamenco' was planted on April 20 and split-plots were designed by managing the number of crown per plant in the main plot and the removed and non-removed first flower cluster in the sub-plot. Uptaken mineral amount of the plants showing petiole burst were higher than normal plants. Plants with one crown per plant showed 62-65% petiole burst rate in contrast to plants with three crowns per plant which showed 57-58% petiole burst. Date of initiation of the second flower cluster with less crown and removed first flower cluster was delayed. The flower clusters number of the plants managed with one crown per plant was 5.6, compared with 9.2 flower clusters of plants with three crowns per plant. The first harvesting with removed first flower cluster was delayed around 42-44 days. Aa a result, the yield performance of plants with two or three crowns per plant was 11,183-11,733 $kg{\cdot}ha^{-1}$ and the amount 65-75% higher than that of plants with one crown and removed first cluster.

• Horticultural Science & Technology
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• v.32 no.1
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• pp.100-104
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• 2014

This study was conducted to determine the optimal MS medium strength to improve sprouting rate of apical meristem of strawberry 'Seolhyang' in vitro. Strawberry apical meristems at size (0.2 mm to 0.3 mm) with leaf primordials were cultured on the MS media with four strength levels, ($1/4{\times}$, $1/3{\times}$, $1/2{\times}$, and $1{\times}$) and the sprouting rate and growth characteristics were evaluated after eight weeks after cultivation. Shoot rate of 'Daewang' apical meristems was 93.6%whereas 'Seolhyang' apical meristems were sprouted with 31.6% on $1{\times}$ MS medium strength. Different sprouting rates were observed in 'Seolhyang' apical meristem with 31.6% in $1{\times}$ medium, 75.0% in $1/2{\times}$ medium, and 94.4% in $1/3{\times}$ medium. The sprouting rate was improved with the decrease of medium strength, but the shoot rate in $1/4{\times}$ medium decreased up to 54.5%. Shoot length was 0.9 cm in $1{\times}$ medium, 1.2 cm in $1/2{\times}$ medium, 1.6 cm in $1/3{\times}$ medium, and 1.9 cm in $1/4{\times}$ medium. Shoot length was longer as medium strength decreased and numbers of leaves and roots were not significant differences among the medium strengths. As a result, sprouting rate was highest and plant growth was best in $1/3{\times}$ MS medium compared to the others.

• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.178-184
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• 2019

Strawberry ($Fragaria{\times}ananassa$) is one of the most important and popular fruit crops in the world, and 'Sulhyang' is one of the principal cultivars cultivated in the Republic of Korea for the domestic market. The growth and flower induction in strawberry is the process which influences directly on fruit bearing and yield of this crop. In this study, effect of benzyladenine (BA), gibberellic acid ($GA_3$), and salicylic acid (SA) on growth and flower bud induction in strawberry 'Sulhyang' was investigated. The 3-week-old runner plants, grown in 21-cell propagation trays, were potted and cultivated in growth chambers with $25^{\circ}C/15^{\circ}C$ (day/night) temperatures, 70% relative humidity (RH), and light intensity of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ photosynthetic photon flux density (PPFD) provided by white light emitting diodes (LEDs). The runner plants were treated with one of three concentrations, 0 (control), 100, and $200mg{\cdot}L^{-1}$ of BA, $GA_3$, or SA solution. The chemicals were sprayed two times on leaves of runner plants at an interval of two weeks. After 9 weeks the results showed that the application of all chemicals caused reduction of root length and chlorophyll (SPAD) content as compared to the control. The lowest chlorophyll (SPAD) content was recorded in plants treated with $GA_3$. However, the treatment of $200mg{\cdot}L^{-1}$ $GA_3$ promoted leaf area, leaf fresh weight, and plant fresh weight. The greatest flower induction (85%) and number of inflorescences (4.3 inflorescences per plant) were observed in the treatment of $200mg{\cdot}L^{-1}\;SA$, followed by $100mg{\cdot}L^{-1}\;SA$. Overall, results suggest that foliar application of $GA_3$ solution could accelerate plant growth, while foliar application of SA solution could induce hastened flowering. Further studies may be needed to find out the relationship between $GA_3$ and SA solutions treated in a combination, and the molecular mechanism involved in those responses observed.

• Horticultural Science & Technology
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• v.29 no.5
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• pp.488-493
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• 2011

Callus culture initiation of strawberry (Fragaria${\times}$ananassa Duch.) was investigated at different Murashige and Skoog (MS) medium strengths, types and concentrations of plant growth regulators, and incorporating a cold pretreatment period to determine the optimal nutritional and environmental conditions. No high quality callus was induced on MS media without auxin regardless of medium strength. When 6-benzylaminopurine (BA) was combined with indole acetic acid (IAA), naphthalene acetic acid (NAA), and 2,4-dichlorophenoxyacetic acid (2,4-D), high quality callus were highly induced compared to medium supplemented with auxin alone. When $0.5mg{\cdot}L^{-1}$ BA was combined with IAA, NAA, and 2,4-D, high quality callus induction was more effective than the medium supplemented with the other BA concentrations. The best combination of auxin and cytokinin for high quality callus induction was $1.0mg{\cdot}L^{-1}$ NAA and $0.5mg{\cdot}L^{-1}$ BA. Although the differences in callus induction were not significant, high quality callus induction at half strength MS medium was more effective than at full strength medium. When $30g{\cdot}L^{-1}$ sucrose was added to the half strength MS medium, the rate of high quality callus induction increased. The optimum cold pretreatment temperature and period for high quality callus induction were $4^{\circ}C$ and 72 h, respectively. Regeneration rate of high quality callus increased in MS medium supplemented with thidiazuron.

• Horticultural Science & Technology
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• v.34 no.4
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• pp.626-633
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• 2016

The objective of this study was to assess the effect of precooling and application of gaseous $ClO_2$ on the retention of freshness and quality of 'Maehyang' strawberry fruits intended for export. 'Maehyang' strawberry fruits (Fragaria ${\times}$ ananassa Duch.) were grown in commercial greenhouses and then harvested. Fruits of uniform and medium size at 60% ripeness were selected and assigned to one of four treatment groups: non-treatment (control), precooling only (PO), gaseous $ClO_2$ only (GCO) or precooling combined with gaseous $ClO_2$ (P + C). Weight loss was lowest in the PO treatment and greatest in the GCO treatment after export. Compared to the control and PO treatment groups, strawberry fruits in the GCO treatment group maintained high brightness and high chroma. Six days after shipping, fruits in the P + C treatment group had the highest soluble solids content, even as high as $10.05^{\circ}Brix$; the lowest value was observed in the PO treatment. The incidence rate of gray mold in strawberry fruits was 20% and 17% in the control and the PO treatment, respectively; in the GCO treatment, the incidence rate of gray mold amounted to 10%. No gray mold was observed in the P + C treatment group. These results indicate that gaseous $ClO_2$ treatment combined with precooling (P + C) was effective in maintaining the freshness of 'Maehyang' strawberry fruits intended for export from South Korea to Hong Kong.

• Horticultural Science & Technology
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• v.35 no.4
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• pp.439-445
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• 2017

Transplant production in a plant factory with artificial lighting provides several benefits; (1) rapid and uniform transplant production, (2) high production rate per unit area, and (3) production of disease free transplants production. To improve the growth of runner plants when strawberry transplants are produced in a plant factory, we conducted two experiments to investigate (1) the effect of different light intensity for stock and runner plants on the growth of runner plants, and (2) the effect of different container volume for runner plants on their growth. When the stock and runner plants were grown under nine different light conditions composed of three different light intensities (100, 200, and $400{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPF) for each stock and runner plants, increasing the light intensity for stock plants promoted the growth of runner plants, however, the growth of runner plants was not enhanced by increasing the light intensity for runner plants under same light intensity condition for stock plants. We also cultivated runner plants using plug trays with four different container volumes (21, 34, 73, and 150 mL) for 20 days after placing the stock plants, and found that using plug trays with lager container volume did not enhance the growth of runner plants. These results indicate that providing optimal condition for stock plants, rather than the runner plants, is more important for increasing the growth of the runner plants and that the efficiency of strawberry transplant production in a plant factory can be improved by decreasing light intensity or container volume for runner plants.

• Food Science and Preservation
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• v.17 no.1
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• pp.72-78
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• 2010

To develop a low-ethanol strawberry wine, the use of pectinase to improve the extraction yield of strawberry juice was investigated, and changes in physicochemical characteristics during ethanolic fermentation were assessed. The juice yield from strawberry fruit increased by 18.9% after Viscozyme L treatment (1,000 ppm, 30 min), compared with a control group, a greater increase than seen with other pectinases (17.5-18.7%). No significant quality differences were observed between control juice and juice prepared with enzyme treatment, indicating that neither physicochemical characteristics nor ethanol content during fermentation were affected by pectinase treatment. The major pigments of strawberry juice were cyanidin-3-glucoside and pelargonidin-3-glucoside, both of which are anthocyanins. The pigment level after enzyme treatment was slightly lower than that of the control group, at all fermentation times. We consider that the economics of strawberry wine manufacture may be increased by use of pectinase because juice level was increased, but no change in ethanol content or physicochemical characteristics was apparent.

• Korean Journal of Agricultural Science
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• v.9 no.2
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• pp.461-466
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• 1982

Lower and upper petiole segments of strawberry plants (Fragaria${\times}$ananassa) were cultured on Murashige and Skoog (MS) medium containing 2mg/liter Benzylamino purine (BA), 0.02mg/liter 2,4-dichlorophenoxyacetic acid (2,4-D), or their coinbination. Of the lower petiole segments, 55% or more were differentiated on the media containing $2mg/{\ell}\;BA$ or $2mg/{\ell}\;BA+0.02mg/{\ell}\;2,4-D$. There was no significant difference in results be tween these treatments. BA did not influence root formation. No shoots we re initiated from the upper petiole segments. Root formation was stimulated by the $0.02mg/{\ell}\;2,4-D$ medium, whereas it inhibited shoot formation. Upper petiole segments produced more roots than did lower petiole segments.

• Horticultural Science & Technology
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• v.31 no.2
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• pp.224-230
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• 2013

The objective of this study was to identify the content of phenolic and volatile organic compounds in edible and non-edible parts of 'Seolhyang' strawberry plants. We performed a comparative chemical analysis of the compounds found in roots, leaves, petioles, runners, and unripe and ripe fruits during vegetative propagation and reproductive growth. The contents of ellagic and gallic acids in the leaves of runner plants during vegetative propagation were $7.36{\pm}1.10$ and $5.07{\pm}3.66mg{\cdot}g^{-1}$ FW, respectively, and were higher than those in the other parts. The main volatile organic compound was identified as 3-hexen-1-ol, and it was mostly detected in leaves. The content of ellagic acid in leaves during reproductive growth was $12.96{\pm}2.30mg{\cdot}g^{-1}$ FW, while that in the other parts was below $6.00mg{\cdot}g^{-1}$ FW. The content of gallic acid in unripe fruits was $2.75{\pm}0.48mg{\cdot}g^{-1}$ FW and was higher than that in the other parts. Ripe fruits contained the lowest contents of ellagic and gallic acids but contained the most diverse volatile organic compounds, including sesquiterpenes, among the tested plant parts. The results indicate that non-edible parts (e.g., leaves and unripe fruits) of strawberry plants can be used as a raw material for antioxidant and anti-inflammatory agents, and edible parts (i.e., ripe fruits) can be available for making an essential oil.

• Korean Journal of Environmental Agriculture
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• v.33 no.4
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• pp.358-363
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• 2014

BACKGROUND: Many strawberry growers are utilizing daylength extension by using incandescent bulb or fluorescent lamp to break dormancy of strawberry induced by low temperature and short day conditions. Conventional incandescent bulb and fluorescent lamp consume a lot of electricity and have short longevity. Red light known for most efficient wavelength for daylength extension light of short-day plant and long-day plant. This study was conducted to verify the effects of red light to enhance growth and to increase production of strawberry (Fragaria ${\times}$ ananassa Duch. cvs. "Seolhyang") METHODS AND RESULTS: Three red light (660nm) of 0.70, 0.87, and $1.05{\mu}mol/m^2/s$ (PAR) and conventional incandescent bulb of 40 Lux were treated respectively under the pot experiment. All treatment irradiated from 18:00 to 24:00 for 6 hours. Red light treatment tend to increase leaf stem number, flower stem number, weight of flower stem, crown weight, root weight, and leaf area of strawberry then incandescent bulb treatment. In field experiment, red light of $0.7{\mu}mol/m^2/s$ (PAR) and conventional incandescent bulb of 40 Lux were irradiated respectively. Field experiment showed that the leaf number, leaf weight, and crown weight of strawberry increased than those of incandescent bulb control with red LED of $0.7{\mu}mol/m^2/s$ (PAR). Red LED treatment increased the fruit number over 15g than incandescent bulb. Furthermore, red LED treatment decreased fruit number below 15g of strawberry than incandescent bulb treatment. Therefore, We believed that red LED treatment increased marketable fruit number by increment of weight of each fruit. Consequently, marketable fruit number, fruit weight, and fruit production of strawberry were increased than those of incandescent bulb by 5 %, 2.9 %, and 8.5 % respectively, but not showed significantly differences. CONCLUSION: These results presumably due to directly enhanced photosynthesis of strawberry leaves and activated action of Pfr phytochrome form by red light. In conclusion, red LED of 660nm could be used for daylength extension light source to enhance production of strawberry.