• Korean Journal of Agricultural and Forest Meteorology
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• v.18 no.4
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• pp.179-187
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• 2016

This study was conducted to determine the impact of elevated temperature and $CO_2$ concentration based on climate change scenario on growth and fruit quality of pepper (Capsicum annuum L. cv. Muhanjilju) with SPAR (Soil Plant Atmosphere Research) chamber. The intraday temperatures of climate normal years fixed by $20.8^{\circ}C$ during the growing season (May 1~October 30) of climatic normal years (1971~2000) in Andong region. There were treated with 4 groups such like a control group (ambient temperature and 400ppm $CO_2$), an elevated $CO_2$ group (ambient temperature and 800ppm $CO_2$), an elevated temperature group (ambient temperature+$6^{\circ}C$ and 400ppm $CO_2$) and an elevated temperature/$CO_2$ group (ambient temperature+$6^{\circ}C$ and 800ppm $CO_2$). Compared with the control, plant height, branch number and leaf number increased under the elevated temperature and elevated temperature/$CO_2$ group. However, leaf area and chlorophyll content showed a tendency of decreasing in the elevated temperature group and elevated temperature/$CO_2$ group. The number of flower and bud were decreased in the elevated temperature and elevated temperature/$CO_2$ group (mean temperature at $26.8^{\circ}C$) during the growth period. The total number and the weight of fruits were decreased in the elevated temperature group and elevated temperature/$CO_2$ group more than the control group. While the weight, length and diameter of fruit decreased more than those of control as the temperature and $CO_2$ concentration increased gradually. This result suggests that the fruit yield could be decreased under the elevated temperature/$CO_2$ ($6^{\circ}C$ higher than atmospheric temperature/2-fold higher than atmospheric $CO_2$ concentration), whereas the percentage of ripen fruits after 100 days of planting was increased, and showed earlier harvest time than the control.

• International Journal of Industrial Entomology and Biomaterials
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• v.22 no.2
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• pp.29-37
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• 2011

Commercially managed bees are available for pollination services and are used in large commercial fields, small gardens, or enclosures such as greenhouses and screen houses. This paper describes the current status and agricultural utilization of commercially managed bumblebees as well as bumblebee rearing techniques in Korea. We surveyed the use rate and number of bumblebees for the pollination of 10 major horticultural crops and fruit trees in Korea; in 2009, the use rates were approximately 7.9% and 2.8%, respectively. The use number of bumblebees as pollinators was more than 64,345 colonies, which included 51,400 colonies for 10 major horticultural crops and 12,945 colonies for 10 major fruit trees in 2009. The value of bumblebees as pollinators in 2009 in Korea was estimated at more than 5,100,000,000 won. We also describe feeding, rearing room conditions, colony initiation, mating and diapause breaks to establish year-round mass rearing techniques of the bumblebee Bombus ignitus.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.769-782
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• 2020

Interest in fruit and vegetables has increased due to changes in consumer consumption patterns, socioeconomic status, and family structure. This study determined the factors influencing the demand for fruit and vegetables (strawberries, paprika, tomatoes and cherry tomatoes) using a panel of Rural Development Administration household-level purchases from 2010 to 2018 and compared the ability to the prediction performance. An artificial neural network model was constructed, linking household characteristics with final food expenditure. Comparing the analysis results of the artificial neural network with the results of the panel model showed that the artificial neural network accurately predicted the pattern of the consumer panel data rather than the fixed effect model. In addition, the prediction for strawberries was found to be heavily affected by the number of families, retail places and income, while the prediction for paprika was largely affected by income, age and retail conditions. In the case of the prediction for tomatoes, they were greatly affected by age, income and place of purchase, and the prediction for cherry tomatoes was found to be affected by age, number of families and retail conditions. Therefore, a more accurate analysis of the consumer consumption pattern was possible through the artificial neural network model, which could be used as basic data for decision making.

• Journal of Korean Academy of Rural Health Nursing
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• v.18 no.1
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• pp.11-18
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• 2023

Purpose: This study is to compare adolescents' health behaviors by city size and to propose regionally tailored health promotion. Methods: We analyzed the data from the 17th Youth Health Risk Behavior Online Survey, national widly performed in 2021. Multi-sample descriptive and linear regression analysis was performed by city size. Results: The frequency of fruit consumption in the last week was 2.88 in the rural area, which is lower than 2.98 and 3.05 in other cities (F=10.98, p<.001). The number of high-intensity physical activity days in the last week (7 days) was 2.90 days in the rural area, higher than 2.74 and 2.73 days in other cities (F=3.36, p=.038). The number of days smoking cigarettes in the last 30 days was 3.23 days in the rural area, higher than 3.08 and 3.02 days in other cities (F=3.41, p=.035). BMI was 22.01 in the rural area, which was higher than 21.57 and 21.61 in other cities (F=4.19, p=.015). Conclusion: School health offices in the rural area districts need to operate to manage lack of fruit intake, smoking, and weight management programs in association with local healthcare institutions.

• Journal of Bio-Environment Control
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• v.30 no.3
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• pp.237-243
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• 2021

The objective of this study was to evaluate the effect of stem number on plant growth, fruit quality, and yield of sweet peppers grown in greenhouses under supplemental lighting in winter. The seedlings were transplanted at 3.2 plants·m^-2 on October 26, 2020, and started supplemental lighting with 32 high pressure sodium lamps for 16-hour photoperiod from December 1, 2020 to May 25, 2021. Stems were differently trained with 2 and 3 numbers after branching nodes were developed. In the final harvest, the plant height was significantly shorter in the 3 stem-plants than in the 2 stem-plants. The number of nodes per stem and the leaves per plant were increased in the 3 stem-plants than in the 2 stem-plants, while the leaf area was less affected. There were no significant differences in the dry mass of leaves, stems, and immature fruits between the 2 and 3 stem-plants. The fruit fresh weight and fruit dry weight in the 3 stem-plants were decreased by 17% and 12% at 156 days after transplanting (DAT), and by 17% and 15% at 198 DAT compared to those in the 2 stem-plants, respectively. The marketable fruit rates were 93.6% and 95.4% in the 2 and 3 stem-plants, respectively. The total fruit yield in the 3 stem-plants was increased by 30.2% as compared to that in the 2 stem-plants. We concluded that the 3-stem-training cultivation positively affected the total fruit yield by sustaining adaptive vegetative growth of the plants. This result will help producers make useful decisions for increasing productivity of sweet peppers in greenhouses.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.454-462
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• 2014

This study was carried out to determine the effect of tree height on light transmission, spray penetration, tree growth performance, fruit quality attributes, and labor productivity in the slender-spindle system of 'Hongro'/M.9 apple trees. With increasing tree height, the light penetration into the internal parts of the canopy decreased, especially in the lower canopy. Leaf area index (LAI) increased with increasing tree height, thereby leading to a reduction in the extent of spray penetration into the interior of the canopy. With increasing tree height, shoot growth was more vigorous but produced slender shoots in the upper canopy compared to the lower canopy. Although the soluble solid content and coloration of fruit decreased, there was no difference in fruit firmness and acidity. In addition, the number of final fruit set increased, although the production of large fruit (> 305 g) decreased. The increase in tree height also significantly increased the labor required for practices such as thinning of flowers and fruits, pruning, and harvesting. Nevertheless, this problem of increased in labor input in taller trees would was eased by use of a mechanical lift. Utilizing a lift for thinning the flowers of trees 4.5 m in height saved 14.6 min per tree, compared to the use of ladder. Therefore, it is highly considerable that in order to enhance light transmission and fruit coloration, light conditions should be improved in the internal tree canopy of slender-spindle systems.

• Horticultural Science & Technology
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• v.31 no.6
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• pp.798-806
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• 2013

Precise, fast, and cost-effective identification of crop cultivars is essential for plant breeder's rights. Traditional methods for identification of persimmon cultivars are based on the evaluation of sets of morphological characteristics. However, it is difficult to distinguish closely related cultivars using only morphological traits. This study was conducted to develop DNA markers for identification of the 32 persimmon cultivars in Korea and Japan. A total of 309 randomly amplified polymorphic DNA (RAPD) markers were identified using 40 different random primers. Various number of polymorphic bands ranged from 4 (OPP-08) to 14 (UBC159) were detected with an average of 7.7. Resulting 57 RAPD fragments were selected, and their sequences were determined for developing sequence characterized amplified region (SCAR) markers. As a result, 15 of 57 RAPD fragments were successfully converted to SCAR markers. Single polymorphic bands of the same size as or smaller than the RAPD fragments were amplified depending on SCAR markers. Among these markers, a combination of eight SCAR markers (PS225_200, PSN05_420, PSF13_523, PSN11_540, PS372_567, PS485_569, PSP08_635, and PS631_735) provided sufficient polymorphisms to identify 32 persimmon cultivars. These newly developed markers will be a fast and reliable tool to identify persimmon cultivars.

• Korean Journal of Food Science and Technology
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• v.7 no.4
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• pp.194-199
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• 1975

The physiological and chemical investigations to explain the after-ripening processes in got green pepper fruit were carried out by treating the fruit with ethephon either alone or with phenylalanine. The studied metabolic changes in fruit during after-ripening period was carbon dioxide and oxygen concentration in interior of the pepper fruit, total carotenoid, ${\beta}-carotene$, total sugar, and free reducing sugar in pepper fruit. These metabolic changes were explained inrelation to the color enhancement judged by the color score to explain the after-ripening processes. Ethephon treatment at 500 ppm significantly accelerated color enhancement as compared to the control and further ethephon treatment increased the number by 20 percent which was not possible in control during same after-ripening period. The oxygen concentration in interior of the pepper fruit during after-ripening period was increased in control when the color score (color enhancement) increased rapidly. However, with ethephon treatment, the oxygen concentration was decreased when the color score increased. Although total and free reducing sugar content were decreased during the after-ripening period total carotenoid and ${\beta}-carotene$ content was increased by 50 and 200 percent, respectively, over control. Also the capsaicin contents was increased by 20 percent by ethephon treatment over control. Although phenylalanine treatment did not affect the capsaicin content, capsaicin content tended to be increased by phenylalanine treatment when treated with ethephon. Acknowledgements: This work was supported by funds from Korean Traders Scholarship Foundation.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.306-311
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• 2008

Proper tree vigor and crop load were determined for 'Fuji'/M.9 apple trees in high density planting system from 2001 to 2003. Leaf/fruit ratio was highly correlated to mean fruit weight (y=1.715x+205.02, $R^2=0.66^{**}$) and yield (y=-35.l56x+5963.7, $R^2=0.44^{**}$). In addition, there was a significant correlation between the number of leaves per tree and mean fruit weight. However, crop load did not affect tree growth, soluble solids content of fruit, and Hunter a value. To harvest the fruits heavier than 300 g without biennial bearing, it was appropriate to crop 55 to 64 fruits in a tree with 55 leaves per fruit of adult tree. The good indices for proper tree vigor could be 20 to 25 cm of mean shoot length and above 95% of shoot termination rate. Moreover, no secondary growth and 20 to 30% of spur formation could be the indices for highly productive tree vigor.

• Applied Microscopy
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• v.44 no.2
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• pp.41-46
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• 2014

In this study, the vegetative and reproductive morphology and anatomy of two Hawaiian endemic Portulaca species were examined. Specifically, P. molokiniensis and P. sclerocarpa were compared to closely related species in the genus. The comparisons were both qualitative and quantitative, using characteristics of leaves, stems, roots, and fruits. Tissue organizations of vegetative and reproductive parts of the plants were assessed using microtechnique procedures, statistical analysis, and scanning electron microscopy. The most notable features of these two species were (1) the size and frequency of stomata in P. molokiniensis, and (2) the large number of sclerenchymatous cell layers in the thickest fruit walls of P. sclerocarpa. These findings may imply that stomata development in P. molokiniensis and thick fruit wall development in P. sclerocarpa are evolved features of survival. In particular, the development of thickened walls in indehiscent fruits likely has evolutionary implications of ecological tolerance for better adaptation.