• Journal of Practical Agriculture & Fisheries Research
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• v.22 no.1
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• pp.27-33
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• 2020

To date, various kiwifruit cultivars have been developed and released. Asexual propagation by grafting onto seedlings rootstock have been widely utilized commercially in fruit trees including kiwifruit (Actinidia spp.). Most of commercial kiwifruit cultivars belong to A. chinensis and A. deliciosa. Recently, several cultivars were developed by interspecific hybridization with different species including A. arguta. There is a possibility for graft-incompatibility due to interspecific hybridization and therefore, we investigated graft-compatibility of newly released yellow-fleshed kiwifruit cultivars and a hybrid cultivar with various rootstocks of different species. The yellow-fleshed cultivars grafted onto same species, A. chinensis 'Kuimi', showed good shoot elongation, about 1 m in length 50 days after grafting. In contrast, the shoot elongation of the yellow-fleshed kiwifruit grafted onto different species was retarded. The shoot length of a hybrid cultivar (A. arguta × A. deliciosa) 'Skinny Green' grafted onto four different species was about 1 m in length, showing good graft compatibility with other species. Nevertheless, long term studies for graft compatibility of hybrid cultivars are still needed since graft-incompatibility between different species can occur several years later.

• Journal of Practical Agriculture & Fisheries Research
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• v.24 no.1
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• pp.5-13
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• 2022

Sunbigi tree(Vitex rotundifolia L.f.), which grows wild in the southern part of Korea and along the coast of the West Sea, has a lot of useful value in terms of resource utilization. Since ancient times, it has been used as folk medicine or herbal medicine in the private sector. Although the leaves and stems have a strong scent, the fruit also has a strong scent, so there are some studies on extracting essential oil from the fruit of Sunbigi tree and analyzing the ingredients, but there are few studies on the fragrance component by extracting hydrosol. The reason is that the fruits are hard and it is difficult to identify the active ingredients contained in the general extraction method. Therefore, in this study, the results of analyzing the components contained in the fragrance of hydrosol obtained by extracting hard fruits at high temperature by different extraction methods are as follows. 1. The extraction condition with the highest flavonoid content was 30.57 mg/g with ethanol, followed by hot water extract at 18.26 mg/g and water extract at 9.69 mg/g with the lowest. 2. As a result of distillation extraction from the fruit of Sunbigi tree, the fragrance of hydrosol is 3-Methyl-2-butenoic acid, cyclobutyl ester, Eucalyptol, L-alpha-Terpineol, 1H-Cycloprop[e]azulen-7-ol, decahydro-1 ,1,7-trimethyl-4-methylene-, [1ar-(1a.alpha.,4a.alpha.,7.beta.,7a.beta.,7b.alpha.)] were found to be many.

• Journal of Practical Agriculture & Fisheries Research
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• v.23 no.2
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• pp.5-14
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• 2021

It was investigated how the contents of four active ingredients, nodakenin, decursinol, decursin, and decursinol angerate, which are active ingredients of Angelica gigas Nakai, cause material changes depending on the type of bacteria. Fermentation experiments were conducted using 9 types of bacteria: 5 types of Bacillus EMD17, 9-3, HCD2, #8, 191 and 4 types of Lactobacillus KCTC 3320, WCP02, S65, P1201. 1. The contents of decursin and decursinol angerate, which are indicator substances, rapidly decreased after 2 days of fermentation by inoculating Bacillus bacteria in the extract of Angelica gigas Nakai. Even after 4 days of fermentation, the contents of decursin and decursinol angerate were the same as on the 2nd day. On the other hand, the content of nodakenin and decursinol increased after 4 days of fermentation. In addition, the content of decursin increased significantly after 6 days of fermentation. 2. Substance changes of nodakenin and decursinol after inoculation of Bacillus bacteria into the extract of Angelica gigas Nakai were almost non-existent regardless of the type of bacteria. The change in effective content of decursin and decursinol angerate was large in Bacillus EMD17 and 9-3. Changes in the contents of decursin and decursinol angerate were almost non-existent in Bacillus HCD2, #8, and 191 strains. 3. As a result of finding out the change in active ingredient after 8 days of fermentation using 4 types of Lactobacillus KCTC 3320, WCP02, S65, and P1201 extracts of Angelica gigas Nakai, there was almost no change in the contents of nodakenin and decursinol regardless of the type of bacteria. However, in the case of fermentation with Lactobacillus S65 and P1201, the contents of decursin and decursinol angerate were changed.

• Journal of Practical Agriculture & Fisheries Research
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• v.23 no.1
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• pp.5-12
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• 2021

In order to extract the essential oil contained in the Elsholtzia splendense Nakai, a fully-bloomed individual was collected and the living body was used for the experiment. Plants were divided into 0.7kg of flowers and 1.5kg of leaves + stems, and extracted by parts and used for scent pattern analysis, and extracted after adding 5kg of outpost for the analysis of essential oil components. Essential oil extraction was performed using the SDE method improved by Schultz et al. (1977), and the extraction time was limited to 1 hour after the material started boiling. The extracted essential oil component was analyzed for fragrance pattern analysis using an e-nose, and the results of analyzing the substance of the essential oil component by GC-MS are as follows. 1. As for the fragrance pattern analysis, in the case of essential oils extracted from flowers, the scent quality was the best at 10-20 minutes, and the scents extracted from stems and leaves were somewhat of poor scent quality, but the fragrance was good at 10-40 minutes. The intensity of scent was the strongest in 10-20 minutes, and the intensity of incense was high even in 30-40 minutes. The scent extracted from the stems and leaves was generally not strong, but appeared high in 10 to 20 minutes. 2. There were 40 kinds of essential oils contained in Elsholtzia splendense Nakai oil. Among them, Mequinol, Benzene, 1,2,3,4-tetramethyl, Elsholtziaketone, and Dehydroelsholtziaketone were identified.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.2
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• pp.77-84
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• 2022

This study aimed to evaluate the growth, yield, and grain quality characteristics of rice varieties that were subjected to water stress during the tillering stage. We also sought to identify whether water stress could be indicated via the plants' response to chlorophyll fluorescence. In this study, we induced water stress by intentionally cutting off water for 30 days, starting 15 days after transplanting the rice varieties to a greenhouse. We analyzed nine rice varieties, including Ilpum, which is the most frequently cultivated variety in Gyeongsangbuk-do, South Korea. The control group was planted in a paddy field where irrigation was entirely dependent on rainfall. Our results revealed that the heading stage of the nine studied varieties occurred approximately ten days earlier in the rain shelter than in the field. Moreover, the rice yield, head rice rate, and palatability score decreased by 18.6%, 17.1%, and 8.3%, respectively, while protein content increased by 20.2% compared with the control group. The Saenuri and Haimi varieties showed the lowest reduction in yield under the water stress conditions, while the Daebo and Samkwang varieties showed the highest reduction in yield. The chlorophyll fluorescence response after re-irrigation was measured between July 30^th and August 17^th. The ratio of variable fluorescence to maximum chlorophyll fluorescence (F_V/F_M) values failed to recover to their baseline values, resulting in either no change or a reduction in fluorescent response, even after re-irrigation of Daebo and Samkwang varieties. These results can be utilized as empirical data for drought-affected farms to select resistant varieties that can respond to spring drought in the southern plains of Gyeongsangbuk-do.

• Journal of Practical Agriculture & Fisheries Research
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• v.24 no.4
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• pp.30-34
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• 2022

This study was carried out to analyze the effect of changes in the light environment caused by the daylight disturbance on the productivity and quality of the standard cut flower rose cultivar 'Monet'. It was artificially shaded to obstruct the sunlight and the productivity and growing characteristics of roses according to the time of daylight disturbance were investigated. The number of cut flowers per unit area (3.3m²) of the cut flower rose 'Monet' was 40 stems in the control, while in the 4-hour, 8-hour, and 12-hour treatments, it was 32, 29, and 25, respectively. As the daylight disturbance time was increased, the number of cut flowers showed a tendency to decrease. In the case of cut flower characteristics related to the quality of cut roses, all characteristics such as flower width, flower height, petal length, and petal width, decreased by 10 to 20% in the 12-hour treatment compared to the control. In addition, growth characteristics such as peduncle length, peduncle thickness, and cut flower height, which determine the marketability of cut roses, also tended to decrease as the daylight disturbance time increased. On the other hand, the number of days to flowering increased by 14.0% from 24.3 to 27.7. The overall growth characteristics were contracted and flowering was delayed as the time of daylight disturbance increased. In the results of this study, as the daylight disturbance time increased, flower size, cut flower length, and fresh weight was decreased. This is due to the decrease in the total photosynthetic amount as the daily average photosynthetic photon flux density (PPFD) was decreased, resulting in a decrease in the quality of roses. It is judged that it is because they do not receive enough carbohydrates necessary for growth and development.

• Journal of Bio-Environment Control
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• v.31 no.3
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• pp.212-220
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• 2022

When it comes to single node leafy stem cuttings of rose (Rosa hybrida), environmental management such as air temperature, relative humidity, and light affect productivity. In order to investigate the effect of air temperature and relative humidity on the cutting success rate and rooted cuttings quality, a transparent airtight box was used to implement a closed system. We have also tried to find out the most effective photoperiod and the number of leaflets in closed system using artificial light (white LED, 104.0 µmol·m^-2·s^-1 photosynthetic photon flux density). The first experiment was conducted for a total of 6 weeks under 4 airtight period conditions. The number of roots and longest root length decreased as the airtight period increased. But there were no significant differences in the survival rate, shooting rate, and rooting rate according to airtight periods. In the second experiment the results indicated that survival and shooting rate were significantly affected by the photoperiod (0/24, 2/22, 4/20, 8/16, and 16/8 h), the number of leaflets (0, 2, and 4 leaflets) of the cuttings and their interaction. The survival rate was the highest in the 16-h day length and 4 leaflets. By considering survival rate and shooting rate with energy efficiency, the 8-h day length and 2 or 4 leaflets were judged to be the most effective.

• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.1
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• pp.125-143
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• 2018

The study consisted of a survey of the residential satisfaction level of the 3rd grade students and a survey of accessibility from farms for practical field training to public facilities. According to the geographical location of the farms on the map, the average distance to facilities related to convenience or safety and health that students complained was about 12km. And that to social and public facilities was about 4.4km. Students pointed out the convenience of using transportation, commercial and convenient facilities, and the safety of anti-crime security facilities as complaints during the practice session. Residential satisfaction levels in five realms, such as facility and structure, convenience, safety, comfort and sociality, were not all reached at the satisfaction level. In particular, the satisfaction level of female students was sub-normal in the safety and convenience realms. The average satisfaction levels reviewed by department were sub-normal for horse industry and floriculture departments. By residential patterns, satisfaction with sharing with the farmers was higher than with other patterns. And satisfaction level by housing structure was much lower in the assembly and container structures Since residential satisfaction level is determined by the inside and outside environment of the dwelling, college should provide students with accurate and vivid data using information communication technologies.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.2
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• pp.5-13
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• 2019

Orostachys species grow from anywhere in Korea. This variety, which lives in the harsh areas of the beach and mountains, is known to have as much change as it was isolated. It has been used as a medicine for a long time, and now the flower is beautiful and has been developed for horticulture. As a result of morphological characteristics and component analysis of three Orostachys species, the following results were obtained. 1. Orostachys species showed two types of leaves according to the growing environment. O. japonica (Maxim.) A. Berger and O. minuta (Kom.) A. Berger were lanceolate, and O. chongsunensis Y. N. Lee was obovate. 2. The leaves were all green. However, some of the O. japonica (Maxim.) A. Berger had white powder. Some of the O. minuta (Kom.) A. Berger was green with red spots on the back. O. chongsunensis Y. N. Lee showed strong gray before flowering but weak green when flowering. 3. The thorns of the leaves were O. japonica (Maxim.) A. Berger and O. minuta (Kom.), but O. chongsunensis Y. N. Lee was not. 4. Whether it was a leaf dot or not, there were dots in O. japonica (Maxim.) A. Berger and there were dots on the O. minuta (Kom.) and the O. chongsunensis Y. N. Lee. 5. The flowers were all white, and the stamens were red in O. japonica (Maxim.) A. Berger and O. minuta (Kom.) A. Berger and white in O. chongsunensis Y. N. Lee. 6. It was confirmed that the ingredients in Orostachys species contained kaempferol, quercetin, flavonoid etc., which have high antioxidant activity.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.2
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• pp.103-114
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• 2019

In this study we examined the preferences of college life factors for students at Korea National College of Agriculture and Fisheries(KNCAF). Analytical techniques of unstructured data used opinion mining and text mining techniques, and the results of text mining were visualized as word cloud. And those results were used for statistical analysis of the students' willingness to farm after graduation. The items of the favorable survey consisted of 10 items in 5 areas including university image, self-capacity, dormitory, education system, and future vision. After classifying the emotions of positive and negative in the collected questionnaire, a dictionary of positive and negative was created to evaluate the preference. The items of 'college image' at the time of university support, 'self after 10 years' after graduation, 'self-capacity' and 'present KNCAF' showed high positive emotion. On the other hand, positive emotion was low in the items of 'college dormitory', 'educational course', 'long-term field practice' and 'future of Korean agriculture'. In the cross-analysis of the difference in the will to farming according to gender, farming base, and entrance motivation, the will to farm according to gender and entrance motivation showed statistically significant results, but it was not significant in farming base. Also in binary logistic regression analysis on the will to farming, the statistically significant variable was found to be 'motivation for admission'