• Horticultural Science & Technology
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• v.32 no.5
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• pp.636-644
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• 2014

This experiment examined the effects of preharvest Ca-chitosan spraying and short-term post-harvest treatment with high $pCO_2$ on the shelf-life of 'Seolhyang' strawberry fruit. Fruit firmness decreased when harvested late in the season and was little affected by Ca-chitosan spray treatments. Short-term treatment with high $pCO_2$ after harvest, however, significantly increased fruit firmness regardless of preharvest treatment. The combined treatment of Ca-chitosan spray and high $pCO_2$ led to an additional increase in shelf-life through delay of skin disorder, fruit decay incidence and firmness loss during simulated marketing. The residual effects of both treatments, however, were reduced when fruit were harvested late in the season. Fruit firmness was more affected by high $pCO_2$ treatment whereas decay and visual quality were affected by preharvest spraying with Ca-chitosan. Although more research is required to determine the optimum concentration of calcium and chitosan, and the optimal spray interval, our results show that the combined treatment of preharvest Ca-chitosan spray and postharvest high $pCO_2$ is effective in improving strawberry fruit shelf-life by increasing firmness and delaying decay.

• Journal of Bio-Environment Control
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• v.29 no.3
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• pp.252-258
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• 2020

The aim of this study was to investigate the effects of timing of collecting date and concentration of IBA and NAA, in order to enhance initial activity and seedling quality of domestic strawberry. Strawberry cuttings were separately taken twice, in June 7 and in July 5, and IBA and NAA were treated with the concentrations of 0.025, 0.05 and 0.1% at cutting date, respectively. The seedlings were evaluated for the percentage of survival during 18 days at 6 times after tunnel cultivation. The NAA treatment was inappropriate for strawberry cutting due to the high rate of seedling mortality, regardless of the collecting date. The vitality of the seedlings was highest at IBA 0.1% in June collecting and at IBA 0.05% in July collecting. The seedlings from June collecting had a higher quantum yield at IBA 0.1% and the seedlings from July collecting at IBA 0.05%. Therefore, IBA could be more effectively applied than NAA to promote the vitality and quality with the appropriate concentration of 0.1% at June collecting and 0.05% at July collecting, respectively.

• Journal of agricultural medicine and community health
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• v.38 no.2
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• pp.71-84
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• 2013

Objectives: As suicide among the elderly population has been a critical issue in Korea, this study aimed to evaluate correlations of suicidal ideation with protective and risk factors among elderly who reside in a rural community. Methods: A total of 157 elders from Gyeongju city, who had attended senior centers in, were enrolled to answer questionnaires including the Geriatric Depression Scale Short Form-Korea and the Scale for Suicidal Ideation. Data were analyzed using SPSS 18.0K for Windows, and included t-test, Pearson correlation, and a three-step hierarchical multiple regression analyses. Results: Using the hierarchical regression analyses for predicting the elderly's suicidal ideation, male gender and social group variables were entered as predictors in the first step(adjusted $R^2$=0.107, P<0.05). Pain, ADLs, family support variables were not entered in the second step. Depression variable was the only predictor in the third step(adjusted $R^2$=0.384, P<0.001). Conclusions: Although this study confirmed the impact of depression on the suicidal ideation, elderly with risk factors including male gender and social isolation should receive a special attention from community health care professionals.

• Horticultural Science & Technology
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• v.33 no.5
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• pp.722-729
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• 2015

Powdery mildew (PM) caused by Podosphaera aphanis is a major disease that can result in significant yield losses in strawberry (Fragaria ${\times}$ ananassa Duchesne). For preventing PM, pesticides are usually applied in strawberry. In this study, molecular markers were developed to increase breeding efficiency of PM-resistance cultivars by marker-assisted selection (MAS). An $F_2$ population derived from a cross between PM-resistance 'Seolhyang' and PM-susceptibility 'Akihime' was evaluated for disease resistance to PM and RAPD (random amplification of polymorphic DNA)-BSA (bulked segregant analysis). Among 200 RAPD primers tested, OPE10 primer amplified a 311bp-band present in with 331bp. Sequence alignment performed for searching polymorphisms and six single nucleotide polymorphism (SNP) were found in amplified regions. To develop polymorphic marker for distinguishing between resistant and susceptible, RAPD was converted to cleaved amplified polymorphic sequence (CAPS) marker. Among restriction enzymes associated with six SNPs, Eae I (Y/GGCCR) was successfully digested to 231bp in susceptible. The results suggest that the selected CAPS marker could be used for increasing efficiency of selecting powdery mildew resistant strawberry in breeding system.

• Research in Community and Public Health Nursing
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• v.32 no.3
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• pp.368-381
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• 2021

Purpose: The obesity prevention and management program led by public health centers are important in the community. This study aims to identify the current status of obesity prevention and management programs at public health centers and perceptions regarding facilitators and barriers when implementing programs. Methods: This study used a concurrent mixed methods design. A survey was conducted to investigate the current status and infrastructure of the obesity prevention and management program at eighty-three public health centers nationwide. Nine program managers and six local residents with experience in the program were interviewed by using a semi-structured questionnaires. Results: Most of the infrastructure facilities for the program were inadequate, and insufficient budgets and lack of professional staff were identified as barriers. Facilitators included diversification of program delivery methods, operator competence, and visible outcomes and rewards. For the effectiveness of the program, it is vital to have adequate assistants, a sufficient budget, various promotional methods, and connections with various institutions in the community. On this basis, it is acknowledged that the public health center serves as a platform for preventing and managing obesity in the community. Conclusion: It is expected that infrastructure improvements in public health centers and the link with community resources are needed. In addition, there is an urgent need to set standards for obesity prevention and management programs implemented in public health centers to 'resolve regional disparities'.

• Journal of Bio-Environment Control
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• v.28 no.1
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• pp.55-65
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• 2019

The effects of stigma removal from floral organ and treatment of auxin on those regions were evaluated on the fruit growth and quality in strawberry (Fragaria ananassa Duch.). The removal of stigma reduced the fruit weight, fruit length, and fruit width, while fruit growth declined as the number of removed stigma increased. The removal of stigma also resulted in reduced fruit firmness, sugar content, and total anthocyanin content, and decreased value of Hunter a for red color and increased value of Hunter b for yellow. The number of seeds deceased as the regions of removed stigma increased. The treatment of auxin on the region of removed stigma improved fruit size, while it reduced fruit firmness, sugar content, and anthocyanin content. The delay in fruit ripening was observed from both stigma removal and auxin treatment. The incidence of malformed fruits increased as the regions with removed stigma increased. The treatment of auxin also promoted fruit malformation.

• Journal of Bio-Environment Control
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• v.28 no.4
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• pp.302-310
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• 2019

This study was conducted to investigate the effects of LEDs on the fruit qualities of two strawberry (Fragaria ${\times}$ ananassa Duch.) cultivars such as hardness, phytochemicals, and antioxidant activity using the strawberry fruits, which were harvested by 50% and 100% ripening levels of fruits grown under LEDs illuminated during 6 hours after sunset from November 2018 to January of the following year. In the hardness of strawberry fruit, when two strawberry cultivars were illuminated red LED light, in 50% ripening as well as 100% ripening fruit of both 'Daewang' and 'Seolhyang' cultivars were significantly higher compared to other treatments. Also, in the sugar content on 50% ripening fruit of two cultivars, the fruit of red LED light was significantly higher than in the other LEDs and control. On the other hand, in the acidity of 50% and 100% ripening levels of strawberry fruit, the fruit under control condition was higher in than that of LEDs. The phenolic compounds of strawberry fruit grown in control was much higher than that of strawberry treated with LEDs. However, the influence of LEDs on flavonoid and anthocyanin content of strawberry fruit did not affected. Changes in the phytochemicals contents of the strawberry tends to be affected depending on the maturity of fruit. Antioxidant activity such as DPPH and ABTS of were not different by maturity of fruit, and supplementation of LEDs during 6 hours at night. Therefore, we concluded that lighting of LEDs is effective for fruit quality in terms of sugar accumulation and fruit hardness.

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.1-7
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• 2022

Strawberry is a stand-out cultivating fruit in Korea. The optimum production of strawberry is highly dependent on growing environment. Smart farm technology, and automatic monitoring and control system maintain a favorable environment for strawberry growth in greenhouses, as well as play an important role to improve production. Moreover, physiological parameters of strawberry plant and it is surrounding environment may allow to give an idea on production of strawberry. Therefore, this study intends to build a machine learning model to predict strawberry's yield, cultivated in greenhouse. The environmental parameter like as temperature, humidity and CO₂ and physiological parameters such as length of leaves, number of flowers and fruits and chlorophyll content of 'Seolhyang' (widely growing strawberry cultivar in Korea) were collected from three strawberry greenhouses located in Sacheon of Gyeongsangnam-do during the period of 2019-2020. A predictive model, Lasso regression was designed and validated through 5-fold cross-validation. The current study found that performance of the Lasso regression model is good to predict the number of flowers and fruits, when the MAPE value are 0.511 and 0.488, respectively during the model validation. Overall, the present study demonstrates that using AI based regression model may be convenient for farms and agricultural companies to predict yield of crops with fewer input attributes.

• Journal of Bio-Environment Control
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• v.31 no.2
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• pp.98-103
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• 2022

Non-destructive estimation of leaf area is a more efficient and convenient method than leaf excision. Thus, several models predicting leaf area have been developed for various horticultural crops. However, there are limited studies on estimating the leaf area of strawberry plants. In this study, we predicted the leaf areas via nonlinear regression analysis using the leaf lengths and widths of three-compound leaves in five domestic strawberry cultivars ('Arihyang', 'Jukhyang', 'Keumsil', 'Maehyang', and 'Seollhyang'). The coefficient of determination (R²) between the actual and estimated leaf areas varied from 0.923 to 0.973. The R² value varied for each cultivar; thus, leaf area estimation models must be developed for each cultivar. The leaf areas of the three cultivars 'Jukhyang', 'Seolhyang', and 'Maehyang' could be non-destructively predicted using the model developed in this study, as they had R² values over 0.96. The cultivars 'Arihyang' and 'Geumsil' had slightly low R² values, 0.938 and 0.923, respectively. The leaf area estimation model for each cultivar was coded in Python and is provided in this manuscript. The estimation models developed in this study could be used extensively in other strawberry-related studies.

• Research in Plant Disease
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• v.28 no.2
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• pp.61-68
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• 2022

Powdery mildew and two-spotted spider mite are detrimental to strawberry plants and are controlled with traditional pesticides. To accommodate consumer demand, eco-friendly methods of pest control are required. Strawberries were cultivated (in soil and in a hydroponic system) for two years, and ultraviolet B (UV-B) irradiation was used as an alternative pest control during the harvesting season. Three varieties were grown (Seolhyang, Kingsberry, and Durihyang), and four UV-B lamp/mulch (black, green, and light reflection sheet [LRS]) combinations were used during harvesting: UV-B+black or green mulch, UV-B+black or green+LRS, no UV-B+black or green, and no UV-B+black or green+LRS. In all varieties, powdery mildew was 65% more controlled when UV-B irradiation was used. The adult two-spotted spider mite density was lowest in the UV-B lamp+black or green+LRS treatments. Therefore, UV-B irradiation during the strawberry harvesting season could effectively control powdery mildew and two-spotted spider mite with little side effect on the plants.