• Journal of Bio-Environment Control
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• v.33 no.1
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• pp.71-78
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• 2024

Among the various environmental conditions necessary for growing crops, light is closely related to the anthesis. This study aimed to determine the optimal photoperiod affecting floral differentiation in an edible flower, marigold, to efficiently cultivate the crops in a closed-type plant factory. The experiment was conducted with photoperiods of 4, 8, 12, and 16 hours. French marigold (Tagetes patula L.) 'Durango Red' seeds were sown in polyurethane sponges, and the photoperiod treatments were applied immediately. The extent of floral differentiation was examined at 2-3 day intervals, defined as the visible appearance of flower buds at least 2 mm in size. The growth parameters such as shoot fresh weight and dry weight, height, and leaf area were measured. The optimal photoperiod was determined based on the days when the floral differentiation had occurred in 50% of the total plants. In the 4-hour treatment, proper growth and flower buds did not appear. From the 8-hour treatment, the plant grew normally, and floral differentiation occurred, however, the 8-hour treatment showed the slowest floral differentiation compared to the 12 hours treatments or more. The 12- and 16-hour treatments didn't show significant differences in floral differentiation. While the 16-hour treatment exhibited the highest results in all growth parameters, it was not significantly different from the 12-hour treatment except for shoot dry weight and leaf area. According to the results, 8 hours of photoperiod induced floral differentiation. However, more time was required for flower bud formation, and plant growth was significantly lower compared to photoperiods of 12 hours or more. Considering the energy consumption and its growth, the optimal photoperiod for marigold was 12 hours.

• Korean Journal of Agricultural Science
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• v.4 no.1
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• pp.26-33
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• 1977

We have studied the responce of nitrogen on the newly bred varieties, Yusin and Milyang #23, and the effects of defoliation at maturing stage on the rate of ripened grains under different nitrogen levels. The results obtained are summarized as follows : 1. Milyang #23 as well as Tongil was found to be highly nitrogen responsive variety and showed good grain maturing percentage. The number of grain per unit area affected the total yield under the high levels of nitrogen application. The variety, Yusin, was less responsive to nitrogen and had also less leaf area than other varieties under the high level of nitrogen application. Yusin also seemed to have low maturing percentage due to unbalanced ratio between photosynthetic area and size of storage. 2. The low internodes and leaf blade of Yusin and Milyang #15 were grown too much under high levels of nitrogen and these caused more lodging and less light penetration in pant canopy. 3. The effects of defoliation at maturing stage on yield was high under the high levels of nitrogen application, especially when defoliation was done early stage of maturing. The effects of defoliation appeared to be greates in Tongil than in Milyang #15.

• Journal of the Korean GEO-environmental Society
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• v.14 no.9
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• pp.31-37
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• 2013

In this study installation diameter, interval, area replacement ratio and ground hardness of applicable ground in C.G.S method should be mastered through surrounding ground by conducting modeling. Optimum artificial neural network was selected through the study of the parameter of artificial neural network and prediction model was developed by the relationship with numerical analysis and artificial neural network. As this result, C.G.S pile settlement and ground settlement were found to be equal in terms of diameter, interval, area replacement ratio and ground hardness, presented in a single curve, which means that the behavior pattern of applied ground in C.G.S method was presented as some form, and based on such a result, learning the artificial neural network for 3D behavior was found to be possible. As the study results of artificial neural network internal factor, when using the number of neural in hidden layer 10, momentum constant 0.2 and learning rate 0.2, relationship between input and output was expressed properly. As a result of evaluating the ground behavior of C.G.S method which was applied to using such optimum structure of artificial neural network model, is that determination coefficient in case of C.G.S pile settlement was 0.8737, in case of ground settlement was 0.7339 and in case of ground heaving was 0.7212, sufficient reliability was known.

• Journal of agriculture & life science
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• v.50 no.2
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• pp.73-82
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• 2016

Best drought tolerance index was determined through statistics analysis and growth appearance of drought tolerant plants was determined by cultivation in pot and sloping land. For determination of best drought tolerant indicators, RD(Resistant dry days), LD(Leaf area), UTR(Unit transpiration), RWC(Relative water content), RWL(Relative water loss), LA(Leaf area), SN(Stoma unmber) and SA(Stoma area) were carried out by correlation and PCA analysis. RWL and UTR were affected on plant drought tolerance according to comparison among six indices for resistant dry days. The PCs axes separated SA, LA, RD and RWC and SN. UTR was negatively correlated with SA, RWL were also negatively correlated with RWC and SN. RWL and UTR were proved best selection indicator for the selection of drought tolerant species. Ulmus parvifolia, Bidens bipinnata, Patrinia villosa, Kummerowia striata, Arundinella hirta, Artemisia gmelini etc. were selected drought tolerant plants. Shoot growth appearance of drought resistant plants was differed pot and sloping land. Shoot growth and leaf number was no significant differences between the pot and sloping land. However, root growth of drought tolerant plants was all the difference between two cultivation. T/R ratio of drought tolerant plants was also found a big difference. T/R ratio of drought tolerant plants in sloping land was lower than that of pot. These results will be served efficiently plant breeding.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.202-208
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• 2020

The objective of this study was to select the right species among Agastache in the family Lamiaceae as the result of growth analysis and functional substance analysis. Among 22 species of Agastache, five species (Agastache cana, Agastache foeniculum, Agastache rugosa 'Spike Blue', Agastache rugosa 'Spike Snow', Agastache rupestris) were selected by referring to United States Department of Agriculture (USDA)'s plant hardiness zone area and Korea's one based on USDAs. These plants were cultured at 24 ± 1℃ and 18 ± 1℃ (day and night temperatures, respectively) and 65 ~ 75% relative humidity in a hydroponic culture system for 4 weeks. In terms of growth analysis experiment, stem length, root length, leaf width, leaf area, leaf number, SPAD value, and fresh and dry weights of shoots and roots were measured. The results showed that A. rugosa SS and A. rugosa SB have a higher overall balance value than other species. When compared functional substance value (rosmarinic acid, tilianin, and acacetin) of five species, A. rugosa SS and A. rugosa SB are significantly higher than other species in Agastache. It seems to be directly proportional to the growth analysis results. When considering the growth and functional substance part comprehensively, A. rugosa SS and A. rugosa SB are the most optimal high-value species among Agastache.

• Horticultural Science & Technology
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• v.30 no.2
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• pp.201-207
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• 2012

This study was conducted to investigate the effect of supporting material and ionic strength of the MS medium on growth of strawberry plantlets cultured in vitro for the rapid mass production. Explants of $Fragaria$ $ananassa$ 'Houkouwase' in vitro were planted in the agar or Tosilee (commercial plug medium) medium as the supporting material and supplied with 1/4 MS, 1/2 MS or basal (as the control) MS medium in an autotrophic micropropagation. Plant height and root length were significantly greater when they were cultured in 1/2 MS medium as compared to those grown in the agar medium. Also, shoot fresh and dry weights, and leaf area in the 1/2 MS medium were greater than in 1/4 MS or basal MS medium. When plantlets were cultured in Tosilee medium and fed with the basal MS medium, plant height, root length, shoot fresh and dry weights, root fresh and dry weights, and leaf area were promoted and greater than those in plantlets cultured in the agar medium.

• Journal of Bio-Environment Control
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• v.12 no.1
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• pp.22-25
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• 2003

Seedlings of ‘Nokgwang’ and ‘Kwari’ green pepper were cultured in 32-cell plug trays in TK$_2$ medium to find out optimal concentrations of phosphate. Seedling growth of both ‘Nokgwang’ and ‘Kwari’ cultivars was affected by phosphate strength. Applying P fertilizer to the plug system caused a marked increase in plant height and leaf area at 1.0 phosphate strength. On the other hand, total dry weight increased with increasing phosphate strength. Higher chlorophyll content was observed in ‘Nokgwang’ than ‘Kwari’ in all treatments. Phosphate strength greater than 0.5 gave similar chlorophyll content. Photosynthetic rate was higher for plants fertilized with 1.0 strength for ‘Nokgwang’ and 0.5 strength for ‘Kwari’than the other treatments. Higher concentrations of phosphate reduced photosynthesis in both cultivars. With ‘Nokgwang’increasing concentration of phosphate up to 1.0 strength resulted in increase in stomatal conductance and transpiration rate.

• Journal of Bio-Environment Control
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• v.12 no.1
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• pp.26-29
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• 2003

Experiments were conducted to estimate optimal potassium strength in the nutrient solution for ‘Nokgwang’and‘Kwari’green pepper seedlings cultured in small plug-cell trays. Plant height, stem diameter, and leaf area increased with increasing K concentration, with greater effect on ‘Kwari’ than ‘Nokgwang’. Total dry weight increased by increasing potassium strength.‘Kwari’had heavier dry weight than ‘Nokgwang’Chlorophyll content differed by cultivars and potassium strength. The highest chlorophyll content was obtained at 2.0 strength potassium in‘Nokgwang’, but not in‘Kwari’Net photosynthesis was greater in plants fertilized with 1.5 strength potassium for‘Nokgwang’and 2.0 strength potassium for ‘Kwari’than the other treatments.

• Journal of The Korean Society of Grassland and Forage Science
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• v.8 no.3
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• pp.110-116
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• 1988

The response of forage yield was studied with various growth indices to develop yield model and to determine optimum cutting time in three cultivars of orchardgrass 1. Number of tiller per plant was the highest at 3rd cutting stage. But, it was decreased rapidly at 4th cutting stage. Leaf Area Index (LAI) was the highest at 3rd cutting stage. LA1 was increased slowly during 15 days to 20 days after cutting and thereafter increased rapidly. 2. In dry matter yield over cutting stages, 1st cutting and 3rd cutting stages were higher yield than others. Change of dry matter yield was similar to that of LA1 in all cutting stages. 3. Leaf Elongation Rate (LER) and Specific Leaf Weight (SLW) were reached to maximum at 20 to 25 days and 25 to 30 days after cutting, respectively, 4. Dry matter yield was highly correlated with LA1 (r=0.905)and with CGR (r=0.962) over three cultivars. Also, LA1 was significantly with LER. The best-fit yield model was obtained in multiple regression equation which included both dependent variables of LA1 and CGR. 5. Optimum cutting times which were determined by the relationships between D.M. yield and LAI, and between D.M. yield and CGR, were ranged from 32 days t o 36 days depend on each cutting stages.

• Asian Journal of Turfgrass Science
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• v.6 no.2
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• pp.73-81
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• 1992

This study was designed to estimate on the interaction of the first productivity, light condition and to examine the ecophysiological 'characteristics of Zoysia japonica. Artificial community of Zoysia japonica was analyzed effect of matter production and growth construction under various shading condition. The results summarized this experiment were as follows ; 1. The relative growth rate(RGR) in all experimental plots was high during the growth stage of 20 days after transplanting and then tend to decrease. RGR value in severe shading or short day condition was remarkably decreased from the early growth stage. 2. The net assimilation rate(NAR) was high during the early growth stage after transplanting. and then decreased the growth proceeded. NAR value in the severe shading or short day condition plots was low. 3. The increasing rate of leaf ared ratio(LAR) was high during the early growth stage after transplanting in the control plot and 30% shading plot, but it appeared to be high 40 days after transplanting in the 50% and 70% shading plot. LAR was appeared to be negative correlation against RGR and NAR. 4. The crop growth rate(CGR) in each experimental plot was increased until 50 days after transplanting, and then decreased. After that time, the maximum CGR value appeared in the control plot(1.56g /g, 10days), 60days after transplanting. CGR had positive correlation with LAI. The optimum LAI in the control, 30%, 50%, and 70% shading plots was appeared as 2.10, 1.75, 1.25, and 0.90.