• Korean Journal of Environment and Ecology
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• 제32권1호
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• pp.30-38
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• 2018

The purpose of this paper is to provide reference data about propagation, restoration, and preparation of policy of endangered Sarcandra glabra (Thunb.) Nakai by investigating growth response and variation of ecological niche breadth according to moisture and nutrient under the condition of elevated $CO_2$ concentration and elevated temperature. We divided the investigation into the controlled group and treated group (elevated $CO_2$ concentration and elevated temperature) and then varied the moisture and nutrient treatment for testing. The results showed that the ecological niche breadth was wide at moisture and nutrient gradients of 0.899 and 0.844, respectively, under control. Also, the ecological niche breadth regarding the moisture and nutrient gradients under treatment simulating global warming was wider as 6.60% and 2.09%, respectively. Therefore, moisture and nutrient will not be the restriction factors concerning the growth of Sarcandra glabra under continued global warming. However, it will be advisable to specify the nutrient content condition in the soil to be 10% for population restoration when growing Sarcandra glabra in the green house which is not affected by external environment since the studies of rearing reaction reported that Sarcandra glabra prefer 10% of nutrient content than 0-5%. Furthermore, it is necessary to protect evergreen broad-leaved forest where is the natural habitat of Sarcandra glabra that has relatively high nutrient content.

• Korean journal of applied entomology
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• 제14권3호
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• pp.147-153
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• 1975

During 1973 a field experiment was carried out to evaluate effectiveness of the root zone application of insecticides in medical gelatin capsules for control of several rice insect pests and dwarf virus disease. At three days after transplanting the capsules were pushed by hand about 2.5cm into the soil, near roots of Tongil rice plants. At the given day intervals number of leaf-and plant-hoppers on the hills were recorded by direct count, and dead hearts and white heads by stem borers and dwarf virus infected hills were observed in the experiment plots. Finally grain yields were measured. The percentages of dead hearts and white heads in all the plots were too low for evaluating the effectiveness of insecticides against the striped rice borers. Carbofuran of the insecticides tested was relatively effective against green rice leafhopper (Nephotettixcincticeps) and small brown planthopper (Laodelphax striatellus), although small number of insects on the hills were recorded. Relatively small number of white-backed planthopper (Sogatella furcifera) was occured in the BPMC and Diazinon treated plots. BPMC and Carbofuran were highly effective against the brown planthopper (Nilaparvata lugens) to 80 days after treatment. Incidence of dwarf virus disease was least in the plots of Carbofuran treatment. The highest grain yield was recorded in the plots treated with Carbofuran, and it seemed to be related with good protection from the dwarf virus disease and leaf-and plant-hoppers.

• Korean Journal of Plant Resources
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• 제25권1호
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• pp.132-141
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• 2012

This study was carried out to test seed germination responses to temperatures and pre-treatments in Hippophae rhamnoides, which has many abilities in antioxidant activity, soil improvement and erosion control. H. rhamnoides seeds were placed at 10, 15, 20, 25, 30 and $35^{\circ}C$ under light condition. As the results, germination percentage (GP) was the highest at 15 and $20^{\circ}C$, and mean germination time (MGT), germination rate (GR) and germination value (GV) were the highest at $25^{\circ}C$. Quadratic and linear regression model were used to determine the cardinal temperatures such as base ($T_b$), maximum ($T_m$) and optimum ($T_o$) temperature for germination. In quadratic regression model using PG, $T_b$, $T_m$ and $T_o$ was estimated as 0.6, 36.4 and $18.5^{\circ}C$, respectively, and temperature range for germination was $35.8^{\circ}C$. In linear regression model using GR, $T_b$, $T_m$ and $T_o$ was estimated as 8.3, 35.4 and $25.3^{\circ}C$, respectively, and temperature range for germination was $27.2^{\circ}C$. Germination properties were investigated after H. rhamnoides seeds were treated by prechilling (1, 2, 4, 6 and 8 weeks), stratification (2, 4, 6 and 8 weeks), solid matrix priming (seed : carrier : water = 5 : 1 : 7, 8, 9 and 10), osmo-priming (-0.25, -0.5, -1.0 and -1.5 MPa) and calcium chloride ($CaCl_2$) -priming (100, 200, 300 and 400 mM). The highest GP was observed in $CaCl_2$ 300 and 400 mM treatments, and MGT was the shortest in stratification 6 and 8 weeks treatments. GR and GV were the highest and GP was the second highest when seeds were prechilled for 1 and 2 weeks. Consequently, prechilling 1 or 2 weeks treatment was considered as the appropriate method when we contemplate qualitative and quantitative effects in seedling production.

• Journal of Bio-Environment Control
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• 제17권4호
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• pp.288-292
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• 2008

This study was conducted to identify the effects of irrigation amount to produce high quality melon fruit in fertigation culture. Irrigation amount of during fruit harvesting period was doubled at the low irrigation point ($(-45{\sim}50\;kPa$) treatment as 115 mm as than that of the high irrigation point ($-20{\sim}25\;kPa$) treatment. The plant growth rates such as stem length, leaf weight and plant height were a little diminished at the low irrigation point ($-45{\sim}50\;kPa$) than those of the other treatments. Internode length was however not affected by irrigation amount. Fruit weight was lighter at the low irrigation point ($-45{\sim}50\;kPa$) than that of at the high irrigation point and fruit height was shorter, but fruit diameter was not affected by irrigation amount. Fruit soluble solid was $0.9^{\circ}Bx$ higher at the low irrigation point ($-45{\sim}50\;kPa$) than at the high irrigation point ($-20{\sim}25\;kPa$) and net index was higher. Total marketable yield was highest by 3,937 kg/10a at the high irrigation point ($-20{\sim}25\;kPa$), but the excellent marketable yield was highest by 2,531 kg/10a at the low irrigation point ($-45{\sim}50\;kPa$). Inorganic contents of the soil N, K, Ca and Mg were not affected by irrigation amount. It was therefore thought that optimum irrigation point to produce high quality melon fruit by fertigation culture was $-45{\sim}50\;kPa$ at ripening stage.

• Journal of Bio-Environment Control
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• 제21권4호
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• pp.322-326
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• 2012

Recently, researches related to plant factory system has been activated and production of Ssam-vegetables using artificial lighting has been increasing. In South Korea, Ssam-vegetables are very popular and the consumption is increasing every year. Because leaf vegetables cultivated under hydroponic systems are more preferable rather than those cultivated by soil culture in Korea, the plant factory system would be more effective in production of Ssam-vegetables. Therefore, this study was carried out in order to analyze the yield and vitamin C contents in red mustard (Brassica juncea L.) and pak-choi (Brassica campestris var. chinensis), which are used a lot for the Ssam-vegetables in South Korea, as influenced by different concentrations of the nutrient solution in a plant factory system. As a results, there was no significant differences in the plant height among the treatment of EC in the nutrient solution, but for red mustard plants, the number of leaves tended to decrease in the treatment with higher EC. Leaf area of pak-choi plants was significantly increased in the higher EC, while the fresh weight had a tendency to increase along with increasing EC in the nutrient solution for both crops. The photosynthetic rates did not show a distinct tendency by EC levels for red mustard plants, but for pak-choi plants, it tended to be higher at the high EC. The contents of ascorbic acid in leaves were higher with decreasing EC concentration in the nutrient solution for red mustard plants, while the content was the highest at EC $2.0dS{\cdot}m^{-1}$ for pak-choi plants. In summary, considering the marketable yields and vitamin C at different nutrient concentrations in a plant factory, the optimal concentration for red mustard and pak-choi plants was thought to be EC $2.0{\sim}2.5dS{\cdot}m^{-1}$.

• KOREAN JOURNAL OF CROP SCIENCE
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• 제55권2호
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• pp.144-150
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• 2010

The agricultural techniques of environmental friendly using the green manure crops have been required recently more to have the safety agricultural products and to reduce the use of fertilizers and agricultural chemicals. The utilization of green manure crops related closely to cropping system would be very important. The purposes of this study are both to investigate the effects of green manure crops of hairy vetch, legume, and rye, gramineae, and to compare the effects between them in rice cultivation. The hairy vetch and rye were treated as green manure crops into paddy soil at 10 days before the rice transplanting. The plant height was increased gradually from the maximum tillering to the heading growth stage, showing that it was the highest with treatment of conventional cultivation in 2007 and the highest with hairy vetch in 2008. The number of tillers was higher with treatment of hairy vetch and hairy vetch+rye than those with the conventional cultivation. Dry weight was also higher with hairy vetch than that with the conventional, while it was lower clearly in rye than those in hairy vetch and conventional. According to the high tilller number and spikelet number per panicle out of the yield components relatively, the yield of rough rice was increased to about 6% and 8% in 2007 and 2008, respectively, comparing with the yield in the conventional cultivation. Based on these results, the hairy vetch would be a good green manure crop in rice cultivation.

• Horticultural Science & Technology
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• 제29권1호
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• pp.16-22
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• 2011

In developing soil wetting agent using polyoxyethylene nonylphenyl ether (PNE) and polyoxyethylene castor oil (1:1; v/v), the effect of application rates on changes in concentration of PNE, initial wetting of peatmoss + perlite (7:3) medium, and growth of hot pepper (Capsicum annuum L. 'Knockwang') plug seedlings were investigated. The elevation of application rates of wetting agent increased the amount of water retained by the root media. The treatment of 2.5 $mL{\cdot}L^{-1}$ showed similar water retention to + control ($AquaGro^L$ 3.0 $mL{\cdot}L^{-1}$). Most of the liquid wetting agent (LWA) incorporated during the medium formulation leached out in the first and second irrigation, then it decreased gradually until 10 times in irrigation. In investigation of the influence of LWA on position of water infiltrating into root media, the vertical water movements in treatments of 0.5, 1.0, and 1.5 $mL{\cdot}L^{-1}$ were much faster than those in 0.0 $mL{\cdot}L^{-1}$ (-control), but relative speed of water movement decreased by the elevation in application rate of LWA to 2.0 or 2.5 $mL{\cdot}L^{-1}$. The evaporative water loss of root media that to contained various rate of LWA and irrigated to reach container capacity was the fastest in -control among the treatments and it delayed as the application rate of LWA was elevated. The plant height of 22.2 cm in 0.5 $mL{\cdot}L^{-1}$ and stem diameter of 3.26 mm in 1.0 $mL{\cdot}L^{-1}$ were the highest among the treatments tested. The treatment of 1.0 $mL{\cdot}L^{-1}$ also had the heaviest fresh and dry weights such among treatments tested as 3.08 g and 0.861 g per plant, respectively. The elevated application rate over than 1.5 $mL{\cdot}L^{-1}$ resulted in decreased seedling growth. The results mentioned above indicate that optimum application rate of LWA is 1.0 $mL{\cdot}L^{-1}$.

• Journal of Mushroom
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• 제19권3호
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• pp.166-175
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• 2021

In this study, monokaryons of "Heukari" (Pleurotus ostreatus) and "Hosan" (Pleurotus pulmonarius) were separated to remove the cell wall, and a cross-species protoplast fusion was developed through chemical treatment with polyethylene glycol. The protoplast-fused PF160306 and PF160313 strains have a culture period of 10 and 2 days shorter than that of the "Heuktari" and "Hosan" cultivars, respectively. Furthermore, the growth of the strains was faster than that of the existing cultivars. The yield was 135.9 g per bottle, which was approximately 8% higher than that of the commercially available "Hosan" cultivar; however, it was not statistically significant. A growth survey was conducted after treatment at five temperatures (15, 18, 21, 23, and 25℃). The growth of the strains accelerated with the increase in temperature. However, at 21℃, the yellow color of pileus was the brightest. Band pattern, assessed using URP Primer 7, was similar to that of the "Hosan" cultivar. The DPPH radical scavenging capacity and polyphenol content were 62.5% and 43.5 mg/mL, respectively, for "Sunjung" and 65.7% and 49.9 mg/mL, respectively, for PF160313. Furthermore, the antihypertensive activities of the "Sunjung" cultivar and PF160313 were similarly high at 74% and 75%, respectively. In conclusion, cross-species hybridization via the protoplast fusion technique can be used for obtaining primary data for mushroom breeding to develop new varieties. In addition, the protoplast fusion technique might aid in expanding the market for yellow mushrooms.

• Journal of Bio-Environment Control
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• 제28권2호
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• pp.110-116
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• 2019

This study was conducted to determine the effects of a pre-planting fertilizers with various $NH_4{^+}:NO_3{^-}$ ratios in a coir dust:peatmoss:perlite (3.5:3.5:3.0, v/v/v) medium on the growth of hot pepper (Capsicum annuum L. cv. Nokkwang) plug seedling. Nitrogen levels were fixed to $300mg{\cdot}L^{-1}$ and the $NH_4{^+}:NO_3{^-}$ ratios were varied to 0:100, 27:73, 50:50, 73:27, and 100:0. The 50-cell trays were filled with treatment media containing pre-plant fertilizers, then seeds were sown. After seeds were germinated, the trays were moved to greenhouse and seedlings were feed with 13-2-13 and 20-9-20 fertilizers, alternatively. The changes in pH and EC were measured every week and soil solution for nutrient concentrations were analyzed in week 0, 3, and 7. The measurements of seedling growths as well as analysis of tissue nutrient contents were also conducted in week 7. The varied $NH_4{^+}:NO_3{^-}$ ratios did not influence on the pHs of root media after incorporation of pre-planting fertilizers, but the ECs were heightened as proportion of $NH_4{^+}$ to $NO_3{^-}$ were elevated. During the raising of seedlings, the pHs rose over time in the treatments of 0:100 and 27:73 ($NH_4{^+}:NO_3{^-}$). The concentrations of all macro-elements in root media decreased gradually as seedlings grew in all treatments. The seedling growths 7 weeks after seed sowing were the highest in the treatments of 27:73 and 50:50 ($NH_4{^+}:NO_3{^-}$) and those became worse in the treatments of higher $NH_4{^+}$ ratios than 73%. In terms of inorganic element contents based on the dry weight of above ground tissue, the treatment of 0:100 showed the lowest content of Ca, Mg, Na, Cu, Mn, and Zn. Based on the results, it is desired that $NH_4{^+}$ ratio in pre-planting fertilization is maintained to be 50% or less for the raising of hot pepper plug seedlings.

• Economic and Environmental Geology
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• 제55권6호
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• pp.727-736
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• 2022

Ice wedges are subsurface ice mass structures that formed mainly by freezing precipitation with airborne dust and surrounding soil particles flowed through the active layer into the cracks growing by repeating thermal contractions in the deeper permafrost layer over time. These ice masses characteristically contain high concentrations of solutes and solids. Because of their unique properties and distribution, the possibility of harnessing ice wedges as an alternative archive for reconstructing paleoclimate and paleoenvironment has been recently suggested despite limited studies. It is imperative to preserve the physicochemical properties of the ice wedge (e.g., solute concentration, mineral particles) without any potential alteration to use it as a proxy for reconstructing the paleo-information. Thawing the ice wedge samples is prerequisite for the assessment of their physicochemical properties, during which the paleo-information could be unintentionally altered by any methodological artifact. This study examined the effect of thawing conditions and procedures on the physicochemical properties of solutes and solid particles in ice wedge samples collected from Cyuie, East Siberia. Four different thawing conditions with varying temperatures (4 and 23℃) and oxygen exposures (oxic and anoxic) for the ice wedge sample treatment were examined. Ice wedge samples thawed at 4℃ under anoxic conditions, wherein biological activity and oxidation were kept to a minimum, were set as the standard thawing conditions to which the effects of temperature and oxygen were compared. The results indicate that temperature and oxygen exposure have negligible effects on the physicochemical characteristics of the solid particles. However, the chemical features of the solution (e.g., pH, electric conductivity, alkalinity, and concentration of major cations and trace elements) at 4℃ under oxic conditions were considerably altered, compared to those measured under the standard thawing conditions. This study shows that the thawing condition of ice wedge samples can affect their chemical features and thereby the geochemical information therein for the reconstruction of the paleoclimate and/or paleoenvironment.