• Horticultural Science & Technology
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• v.33 no.1
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• pp.47-54
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• 2015

This research was conducted to investigate the changes in moisture retention capacities of expanded rice-hull (ERH)-based root media and their influences on the growth of mother and daughter plants in vegetative propagation of 'Seolhyang' strawberry. The proportion of water at the container capacity of ERH medium was in the range of 20 to 23%. This range was lower than the 60 to 66% of strawberry-specialized medium, the 30 to 34% of soil mother material (SMM) and the 30 to 35% of loamy sand. The moisture content of ERH was reduced to 10 to 12% at 8 hours after irrigation, and there were large variations among replications of ERH medium. Among four kinds of root media formulated to contain ERH, the medium of ERH + coir dust (CD) (55 + 45%, v/v) had 26.5 and 32.5% water contents at 20 and 40 days after irrigation to daughter plants, respectively. The m edia o f ERH + sandy loam (S L) and E RH + S MM showed similar trends i n moisture r etention. The pH and EC i n the all root media tested were in the range of 6.7 to 7.1 and 0.03 to $0.08dS{\cdot}m^{-1}$, respectively. The pHs and ECs measured at 20 and 40 days after irrigation were not significantly different in each root medium. Among the root media formulated to contain ERH, the growth of daughter plants was the highest in the treatment of ERH + SL (55 + 45%, v/v). As the blending rate of coir dust was elevated in the ERH + CD media, moisture retention capacity increased gradually, but the growth of daughter plants became worse even though the medium showed higher moisture retention capacity than other root media tested. The growth of roots and aboveground tissues of daughter plants deteriorated in the root media formulated by blending ERH + perlite (PE) at various ratios. The results of this research suggest the optimum formulations of root media and management of moisture content in raising of strawberry daughter plants when ERH is a component of root media.

• Journal of Bio-Environment Control
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• v.31 no.4
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• pp.497-503
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• 2022

This study was conducted to investigate the horticultural media + decomposed granite + reused rock wool in the following mixing ratio: Control = 100:0, M1 = 80:0:20, M2 = 60:30:10, M3 = 40:30:30, M4 = 30:40:30, M5 = 0:50:50 (reused rockwool : decomposed granite : horticultural media) and develop the physicochemical properties and the growth of 'Sulhyang' strawberry runner plant. In the physical aspect of the horticultural media, statistical differences were recognized that the bulk density and particle density were lower in the control and M1. But the bulk density and particle density were high in the M3, M4, and M5, because it had high mixing ratio between recycled rock wool and decomposed granite. EAW and WBC showed a similar tendency. The air porosity and total porosity were higher in control and M1 than M3, M4, M5. Exchangeable cation (K⁺, Ca²⁺, Na⁺, Mg²⁺) and base replacement capacity (CEC) were higher in control and M1, than M2, M3, M4, and M5. As a result of the cultivation of 'Sulhyang' runner plant, the plant length was long in M2, 32.1 cm and smaller than M5 to 28.4 cm. However, if the crown diameter, which is the growth indicator of the runner plant, all 6 treatments were formed 11.23 mm-12.03 mm, which is considered to be suitable for the growth of the runner plant. There wasn't a statistical difference between the weight and dry weight of the root. As a result, the growth difference of the seedlings by the horticulture media was similar. Therefore, considering the physical properties of the horticultural media, it was judged that the air porosity and total porosity would be improved when the recycled rock wool and the decomposed granite were properly mixed rather than the use of the horticultural media as a single medium, which would be advantageous for irrigation management.

• Journal of Bio-Environment Control
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• v.32 no.4
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• pp.405-415
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• 2023

This study was conducted to investigate optimal conditions for cutting propagation of the strawberry cultivar "Sulhyang" through the collection methods of cuttings (runners tips), leaf number of cuttings, and cutting time. Cuttings were collected from the mother plant in the nursery bed (MP) and plants after fruit harvest (HP); the leaf number of cuttings was 0, 1, and 2, and the cutting time was at one-week intervals from June 4 to July 9. The survival rates for MP and HP cuttings were notably high, reaching 99.5% and 98.7%, respectively, but no significant difference was found. The number of roots were higher in MP cuttings, and there was no significant difference in crown and leaf growth. The fruit yields were 419.2 and 428.4 g, for MP and HP cuttings, respectively. The survival rates according to leaf number of cuttings were 98.1% and 98.3% for 1 and 2 remaining leaves, respectively, and remarkably lower at 25.3% for no remaining leaves. The root numbers were 26.0 and 26.3 for 1 and 2 remaining leaves, respectively, compared with 23.5 for no remaining leaves, with no significant differences in crown and leaf growth. The fruit yields were 424.4 and 421.5 g for 1 and 2 remaining leaves, respectively, and 396.7 g for no remaining leaves. The survival rates according to cutting time was over 97.2% in all cutting time without any difference in each treatment. The root, shoot, and crown of the nursery plant before planting showed the best growth in the cuttings on June 4 and 11, resulting in the highest fruit yields of 433.3 and 426.4 g, respectively, with the lowest yields at 384.5 g for cutting time on July 9. Both MP and HP materials proved suitable for strawberry cuttings. The optimal leaf number for cuttings was at least 1, and the optimal cutting time in Gyeongnam area was evaluated as around June 4-11.

• Journal of Bio-Environment Control
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• v.33 no.1
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• pp.12-21
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• 2024

The aim of this research was to investigate the effect of gibberellin on improving seedling growth characteristics and enhancing strawberry quality in cutting propagation. Cuttings of the cultivar 'Seolhyang' were treated with GA₃ for 30 and 60 minutes at concentrations of 50, 100, and 150 mg·L^-1, with distilled water used for dipping as the control. Evaluation of seedling growth showed a positive correlation between the duration of gibberellin dipping and growth characteristics such as leaf number and SPAD value. Plant height, petiole length, leaf length and width, and leaf area varied significantly based on the interaction between dipping time and concentration. Crown diameter exhibited differences depending on the dipping time, with cuttings producing superior seedlings having a diameter of 8.0 mm or more for all treatments except the 30-minute, 100 mg·L^-1 treatment. The T/R ratio was significantly lower in the 30-minute, 50 mg·L^-1 treatment, indicating the highest plant vigor. Quantum yield was lower at a concentration of 150 mg·L^-1, showing a decreasing trend with increasing gibberellin concentration. Nonphotochemical quenching was significantly smaller in the 30-minute, 150 mg·L^-1 treatment, indicating an effective reduction of stress in the cuttings. Antioxidant content was highest in the 30-minute, 50 mg·L^-1 treatment and the 60-minute, 150 mg·L^-1 treatment. Moreover, the results of post-transplanting growth assessment showed no negative effect of gibberellin on flowering induction. Therefore, it was confirmed that gibberellin treatment during the cutting propagation of 'Seolhyang' strawberries had a positive effect on the production of high-quality seedlings. Dipping the cuttings in 50 mg·L^-1 gibberellin for 30 minutes is considered to be the most suitable method for improving growth and quality compared to the control.

• 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.

• Korean Journal of Rural Living Science
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• v.8 no.1
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• pp.7-13
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• 1997

In this study we examined the greenhouse worker's work load to test the efficiency of the developed vehicles (hand operated vehicle (HV), simple battery-powered autonomous vehicle (AV)). The subject of this study were healthy adult females who had experience in growing crops. We measured workers' heart rate, blood Pressure. rectal temperature, mean skin temperature, oxygen consumption and blood lactate level as a physiological index of work load. The results of this study are as follows : The test group using experimental vehicle showed the lower heart rate (mean$\pm$S.D. for HV, AV respectively 74$\pm$5, 75$\pm$3 beats/min, p＜0.01) than the control group (84$\pm$8beat/min) not using experimental vehicle and the lower systolic blood Pressure (HV, AV respectively 109$\pm$8, 109$\pm$9 mmHg, p＜0.01) than the control group (121$\pm$11 mmHg), and lower rectal temperature(HV, AV respectively 37.0$\pm$0.1, 36.8$\pm$0.2$^{\circ}C$, p＜0.01) than the control group (37.0$\pm$0.2$^{\circ}C$), and the less oxygen consumption (HV, AV respectively 2.13$\pm$0.09, 1.66$\pm$0.52$m\ell$/kg/min, p＜0.01) than the control group(2.43$\pm$0.12$m\ell$/kg/min), and the lower blood lactate level (HV, AV respectively 2.03$\pm$1.00, 1.66$\pm$0.52mmol, p＜0.01) than the control group (2.43$\pm$0.12mmol). Judging from these results, these experimental vehicles for greenhouse workers can be confirmed as a useful tool. It is suggested that these vehicles would alleviate the peasant's syndrome including muscle fatigue and musculoskeletal disease usually caused by working in an uncomfortable posture.

• Journal of Environmental Science International
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• v.24 no.2
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• pp.197-205
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• 2015

This study was performed to identify the effect of fertilizer application and planting method on growth and yield of 'Seolhyang' strawberry during seedling raising. According to the concentration of fertilizer applied, the height of daughter plants was the highest at an EC of $0.8dS{\cdot}m^{-1}$. Leaf number and crown diameter were greatest at an EC of $0.6-0.8dS{\cdot}m^{-1}$. In the first measurement, root number was highest in non-fertilizer application, while root weight was heaviest in non-fertilizer application and EC $0.4dS{\cdot}m^{-1}$. The higher the concentration of fertilizer applied as culture media, the lower the growth rate. Thirty days after planting on the main field, plant height and number of new leaf were highest at an EC of $0.8dS{\cdot}m^{-1}$. However, no significant difference was found in leaf length and width and chlorophyll content according to fertilizer application. Marketable yield of 25 g or higher was greatest in EC $0.6dS{\cdot}m^{-1}$. In contrast, no significance was found in total marketable yield at an EC of $0.4-0.8dS{\cdot}m^{-1}$. Aconsistent pattern was exhibited in the growth of 1-5 harvesting flower clusters according to planting method. The length of leaf and flower cluster was short and chlorophyll content was low, when bed soil was removed 100% in harvesting of the first flower cluster. In all treatment, leaf length was shortened until harvesting of the second and third flower cluster, but rapidly lengthened in harvesting of the third and fourth flower clusters. Moreover, the length of flower cluster had a increasing tendency from harvesting of the third flower cluster. However, chlorophyll content was reduced continuously until harvesting of the fifth flower cluster, and was lowest in harvesting of the fourth flower cluster without removal of bed soil. Total yield was greatest in treatment of crown removal in bed soil between November and May. Late marketable yield between March and May was highest in treatment of 100% bed soil removal, followed by treatment of crown removal. Marketable yield of 25 g or higher was greatest in treatment of crown removal between December and February, while greatest in treatment of 100% bed soil removal between March and May.

• Research in Plant Disease
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• v.17 no.3
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• pp.295-301
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• 2011

The effect of various fungicides on anthracnose of strawberry, caused by Colletotrichum gloeosporioides, was determined in vitro, and in greenhouse and field trials. The $EC_{50}$ values of benomyl were clearly different between two sensitive and resistant groups of isolates. Iminoctadine tris had lower $EC_{50}$ values than mancozeb and propineb as protective fungicides and the response of mancozeb, propineb and azoxystrobin was variable depending on the isolate. In the greenhouse, pre- and post- inoculation fungicide applications significantly reduced disease compared to the non-treated control. Propineb, mancozeb and azoxystrobin were effective in controlling the disease when applied prior to inoculation. Metconazole and prochloraz-Mn treatments as ergosterol biosynthesis-inhibiting fungicides had the lowest incidence of anthracnose. In the nursery field trials in 2009 and 2010, the reduced fungicide spray program provided similar levels of disease control compared to the calendar-based applications with captan. A reduced spray program based on efficacious fungicides such as prochloraz-Mn will be useful for strawberry growers and provide more options for controlling anthracnose in Korea.

• Research in Plant Disease
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• v.21 no.4
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• pp.273-279
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• 2015

Major diseases and insect pests in nursery season of strawberry were anthracnose, powdery mildew, Fusarium wilt, two-spotted spider mite, and aphids. Environmental-friendly and chemical application schedules can improve diseases and insect pests control with relatively fewer organic and chemical materials inputs compared with spray programs when it's occurred. Field experiments were performed in 2012 to 2013 according to calendar-based spray programs with environmental-friendly spray calendar (EFSC) and conventional chemical spray calendar (CSC) for controlling diseases and insect pests of strawberry plants cv, Seolhyang during the two nursery seasons. EFSC did reduce the incidence of diseases and insect pests as compared to the non-treated control. Incidence of anthracnose and powdery mildew by EFSC and CSC was similar in 2012 and 2013 seasons. In addition, occurrence of two-spotted spider mite in EFSC in 2013 was similar to those of CSC and was shown highly in early and mid-June both 2012 and 2013 seasons. Occurrence of aphid in EFSC was shown highly in early and mid-June both 2012 and 2013 seasons. These results suggest that EFSC program may be effective for controlling strawberry diseases and insect pests by using environmental-friendly organic materials.

• The Korean Journal of Pesticide Science
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• v.20 no.1
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• pp.35-40
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• 2016

Recently, bacterial angular leaf spot disease, caused by Xanthomonas fragariae, causes severe damage in strawberry production and its' export to other countries, since the pathogen has been classified as an A2 quarantine pathogen. Typical the Angular Leaf Spot (ALS) disease represent that water-soaked angular spots symptoms, bacteria ooze exudate under relatively high humidity condition and later the spot become reddish brown on the leaf surface. The pathogen disseminated by irrigation water, infected mother plant and farmer's hand. In this study, we reported that rubbing inoculation method showed more effective in the pathogen dissemination than infiltration with needles, regardless the strawberry cultivars. Additionally, Dichloroisocyanurate (NaDCC) treatment in commercial strawberry fields provided reliable efficiency to reduce the bacterial angular leaf spot disease incidency and severity.