• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.304-304
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• 2017

In semi-arid countries such as Namibia, the flooding unexpectedly happens in a rainy season, causing losses in the yield of upland-adapted cereal crop. In flooding conditions, rice roots sequentially form aerenchyma and a barrier to radial oxygen loss (ROL), and oxygen is released into the rhizosphere near the root tips. Iijima et al. (2016) and Awala et al. (2016) reported that close mixed-planting with rice can mitigate the flood stress of co-growing upland-adapted cereal crop by modifying their rhizosphere microenvironments via the oxygen released from the rice roots. Moreover, by using the model system of hydroponic culture, it was confirmed that oxygen from rice roots was transferred to co-growing upland-adapted cereal crop in close mixed planting system (Kawato et al., 2016). However, it is not sure whether the ability of oxygen release varies among rice cultivars, because Kawato et al. (2016) used only one japonica cultivar, Nipponbare (Oryza sativa). The objective of this study was to compare the ability of oxygen release in rhizosphere among rice cultivars. The experiment was conducted in a climate chamber in Kindai University. We used 10 rice cultivars from three different rice species (O. sativa (var. japonica (2), var. indica (3)), Oryza glaberrima Steud. (2) and their interspecific progenies (3)) to compare the ability of oxygen release from the roots. According to the method by Kawato et al. (2016), the dissolved oxygen concentration of phase I (with shoot) and phase II (without shoot) were measured by a fiber optic oxygen-sensing probe. The oxygen released from rice roots was calculated from the difference of the measurements between phase I and phase II. The result in this study indicated that all of the rice cultivars released oxygen from their roots, and the amount of released oxygen was significantly correlated with the above-ground biomass (r = 0.710). The ability of oxygen release (the amount of the oxygen release per fresh root weight) of indica cultivars (O. sativa) tended to be higher as compared with the other cultivars. On the other hand, that of African rice (O. glaberrima) and the interspecific progenies tended to be lower. These results suggested that the ability of oxygen release widely varies among rice cultivars, and some of indica cultivars (O. sativa) may be suitable for close mixed-planting to mitigate flood stress of upland-adapted cereal crop.

• Korean Journal of Environmental Agriculture
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• v.21 no.2
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• pp.122-129
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• 2002

The removal rate of heavy metals from the wastewater, the accumulation and translocation of heavy metals in plants after transplanting, and the responses of water celery growth with different wastewater treatments were investigated to determine the potential ability of green-remediation with hydroponic culture of water celery. The removal rate and translocation of Cd, Cu, Ni and Pb from different wastewater to plants were compared with cultivation periods after transplanting. The removal rate of heavy metals from wastewater was different with each treatment but increased with growing periods of water celery plants. The removal rate of Cd, Cu, Ni and Pb in Artificial solution, Artificial solution+EDTA, Munmark industrical wastewater, Jungsun minewater is ranged from 22 to 73%, from 28 to 100%, from 13 to 92% and from 41 to 100% at 6 days after transplanting, respectively. The translocations of Cd, Cu, Ni and Pb from roots to shoots in Artificial solution, Artificial solution+EDTA, Munmark industrical wastewater, Jungsun minewater are ranged from 14 to 28%. 8 to 30%. from 28 to 45% and from 2 to 15% at 12 days after transplanting, respectively. In plant growth responses, it appears to be inhibited the plant growth over all treatments excepts for Munmark industrial wastewater in these glowing periods. Therefore the water celery might play a useful role in phytoremediation to clean up wastewater contaminated with Cd, Cu, Ni or Pb.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.5
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• pp.619-628
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• 1995

Crude aqueous extracts from dried leaves, stems, roots, and flowers from both field grown and greenhouse grown alfalfa plants inhibited alfalfa seed germination and seedling growth. The degree of inhibition was greater in the field grown plant extracts. Flowers extract of field grown plant most inhibited alfalfa germination and seedling growth. In the concentration study, the highest concentration of extract (9.0%, w/v) significantly inhibited total alfalfa seed germination by 50% as compared to control. In partitioning study using pot hydroponic culture of plant biomass into leaves, stems, root, LAR products of LWR and SLA exhibited significant variation among four species. This result support that the inhibitory effect of autotoxic substances presenting in alfalfa tissue may be possible interference with the patitioning of biomass into leaf component relative to the total biomass produced by the alfalfa plant. Toxicity of extract was not reduced by adding activated charcoal, Dowex-50W, amberlite to the extract. Toxic substances existing in most plant tissues but mainly above ground foliage are water soluble and stable and may persist in old alfalfa fields. Thus, it is recommended to remove as much as possible of the above growth parts, especially vegetative stage, before one tries to re-establish alfalfa in former field of alfalfa.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.1
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• pp.7-15
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• 1993

Nitrogenous and non structural carbohydrate compounds in the remaining tissues of 10 weeks old alfalfa (Medicago sativa L.) grown in hydroponic culture, were analysed during 24 days of regrowth following shoot removal. The dry weights of the remaining organs were not significantly changed for 10 days following shoot removal. Compared with uncut plants, defoliation drastically depressed root growth, in particular that of taproot. During 6 days of regrowth, nitrogen contents in all remaning organs significantly decreased. Nitrogen loss in this period was pronounced in root system. Nitrogen contents in each organ after 24 days of regrowth in defoliated plant were recovered completely or exceeded initial level. Amino acid-N was the most readily available form of nitrogen while protein-N was the largest storage pool. The tap root contained about 51.0% and 33.4%, respectively, of the total starch and total ethanol-soluble sugar contents. The starch content of tap roots initially exceeded 40.7 mg. plant$^{-1}$ (day 0), and then declined to the minimum level on day 14. This result clearly showed that the tap root is the major storage site for metabolizable nitrogen (protein-N and amino acid-N) and carbohydrate(starch), and that the degradation of these researves occur much actively in the early period of regrowth.

• Korean Journal of Medicinal Crop Science
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• v.25 no.3
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• pp.175-182
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• 2017

Background: Ginseng is a perennial crop grown for more than four years in the same place. Therefore, it is highly affected by the soil environment, especially nutrients in the soil. The present study was carried out to investigate to the influence of boron and iron concentrations on the physiological status, growth, and mineral uptake of ginseng to obtain the basic information for diagnosing a physiological disorder in ginseng plants. Methods and Results: The boron and iron concentrations were controlled at 3, 30, 150, 300 and 2, 20, 100, $200mg/{\ell}$, respectively. When treated with $150mg/{\ell}$ of boron, the ginseng plants showed yellowing or necrosis symptoms at the edge or end of their leaves. Compared with the $3mg/{\ell}$ treatment, the root weight decreased by 13 and 24% in the 150 and $300mg/{\ell}$ treatments, respectively. When treated with $20mg/{\ell}$ of iron, the ginseng plants showed yellowing between the veins of the leaves followed by the formation of brown spots. The root weight gradually decreased with increasing iron concentration. Approximately 55% decrease in root weight was observed upon treatment with $200mg/{\ell}$ of iron. Conclusions: The boron toxicity occurs in the leaves of ginseng at the boron concentration of approximately 1,900 mg/kg or more. The iron toxicity occurs at the iron concentration of approximately 120 mg/kg for leaves and 270 mg/kg for roots.

• 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.28 no.3
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• pp.343-352
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• 2010

In order to understand the plant responses to salt stress (0, 50, and 100 mM NaCl), Chinese cabbage seedlings grown up to two leaf stages by hydroponic culture were used. Fresh and dry weight, chlorophyll (Chl), antioxidant materials, polyamine content, antioxidant enzyme activities, and inorganic ion level were evaluated. Fresh and dry weights of Chinese cabbage increased with the increase in salinity while the optimal growth occurred at 50 mM NaCl. The Chl a, total Chl, carotenoid content, and Chl a/b ratio increased by the 6 days after treatment with 100 mM NaCI; however, the Chl b content decreased. Glutathione increased in the root of Chinese cabbage for 6 days. Dehydroascorbate increased remarkably by day 6 caused by the salt stress in both leaf and the root. While ascorbate peroxidase increased, the activity of catalase and glutathione reductase decreased gradually in the first leaf for 6 days. The $Na^+$ content increased by 12.5-fold in the 3 days after treatment with 100 mM NaCI in the shoot, whereas the $Ca^{2+}$, $K^+$, and $Mg^{2+}$ content measured in the same treatment decreased by 43 to 57%. Spermidine content decreased as salinity increased, but spermine content increased. The growth promotion, glutathione and ascorbic acid content in Chinese cabbage were increased by low salt stress, and shortening of the cultivation period for growth increase of Chinese cabbage is expected.

• Journal of Animal Environmental Science
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• v.16 no.1
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• pp.51-60
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• 2010

This experiment was conducted to investigate the effects of concentrated pig slurry separated from membrane filter and by environment-friendly agro-materials mixtures on growth of lettuce in hydroponics. The swine waste treatment system having a ultra filtration and a reverse osmosis process was designed in this study. Filtration of pig slurry was necessary to prevent the hose clogging in hydroponics. Primary separation using ultra filter was followed by concentration by RO (Reverse Osmosis). The concentrated pig slurry (CS) was mixed by five different environment-friendly agro-materials mixtures. The chemical nutrient solution was the solution of National Horticulture Research Station for the growth of lettuce. The concentration of nutrient solution in hydroponics was adjusted a range of 1.5 mS/cm in EC. The concentrated pig slurry was low in phosphorus(P), suspended solid and heavy matal, but rich in potassium (K). The concentrated slurry was lowest in the growth characteristics of leaf lettuce. And also SPAD value in leaf was reduced in plot treated with concentrated slurry. But the growth of lettuce in the mixtures plot (CS+BM+AA, CS+BM+AA+SW) in hydroponics was significantly high compared to concentrated slurry. The fresh yield of lettuce was 78, 84% that of nutrient solution as 131.9, 142.2g in plot of CS+BM+AA and CS+BM+AA+SW, respectively. Our studies have shown that it is possible to produce organic culture using concentrated slurry and environment-friendly agro-materials mixture, although growth is slower than when using a conventional inorganic hydroponic solution.

• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.158-165
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• 2019

The effects of microbubbles on glucosinolate accumulation and growth of watercress (Nasturtium officinale R. Br.) were investigated. Watercress plant at the 4th mature leaf stage (2 weeks old) were exposed to microbubbles or non-microbubbles generated in an Otsuka-house nutrient solution for 3 weeks in a controlled environment culture room. Stem length of the watercress grown under the microbubbles was 41% shorter than that of the non-microbubbles, showing significantly different. However, shoot fresh and dry weights, root length, leaf length, leaf width, SPAD, and quentum yield of the watercress were not significantly different between treatments. Glucoiberin, glucobrassicin, gluconapin, gluconasturtiin of the watercress grown under microbubbles, excepted for 4-methoxyglucobrassicin, were significantly higher than those of the watercress grown in non-microbubbles. In addition, watercress grown under microbubbles for 3 weeks contained 85% (${\mu}mol/g$ DW) and 65% (${\mu}mol/plant$) more total glucosinolate, respectively. Results indicated that microbubbles generated in a deep flow technique hydroponics system could increase the accumulation of glucosinolate without growth reduction.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.29 no.1
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• pp.35-41
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• 2023

The purpose of this study was to examine the effect of each storage temperature condition of 5, 10, 15 and 20℃ to maintain the freshness of mini paprika (Capsicum annuum cv. New Raon Red) in corrugated box. Changes in general appearance, fresh weight loss, firmness, SSC (solid sugar content), and Hue angle were investigated. Furthermore, storage at temperatures ranging from 5℃ to 15℃ for 14 days resulted in maintaining freshness for 35 days. Paprika stored at 20℃ showed significantly higher loss of fresh weight and firmness than that of other storage temperatures. Furthermore, paprika stored at 5℃ and 10℃ showed a lesser decrease in hue angle than that at 15℃ and 20℃. However, the SSC of mini paprika was not significantly affected by storage temperature. These results suggest that corrugated box packaging in combination with low storage temperatures (5~10℃) could be effective in prolonging the shelf life of mini paprika. Therefore, the results represented that the low temperature storage in combination with cardboard box treatment could be effective in prolonging the shelf life of fresh paprika.