• Korean journal of applied entomology
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• v.46 no.3
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• pp.409-414
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• 2007

Economic injury levels and economic thresholds were estimated for the american serpentine leafminer (Liriomyza trifolii) on greenhouse eggplant. Liriomyza trifolii density was increased until the late June and decreased after the July in innoculation on may 17. Growth of an aerial plants and fruits were not different in treatment respectively. But total number of fruits and yields were decreased on higher inoculation density. Whereas the rate of yield loss was increased. The rates of damaged leaf by L. trifolii were increased on higher inoculation density and the peak was 65%. The number of commodity fruits and the rates of commodity fruit were become lower than non-treatment (72.2%). The rates of damaged leaf area were 5.3, 11.7, 19.7, 25.7% on inoculation densities and the rates of yield loss were 0.6, 4.8, 9.8, 14.7%, respectively. There existed close correlation between rate of yield loss and inoculation density (Y = 0.76779X + 0.298354, $R^2\;=\;0.9599$). Considerated of the results, the economic injury levels of L. trifolii on eggplant greenhouse was 6.1 adults per 4 plant and the economic thresholds was 4.9 adults per 4 plant.

• Journal of Bio-Environment Control
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• v.10 no.1
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• pp.36-41
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• 2001

This experiment was carried out to investigate temperature distribution in the double layer plastic greenhouse and chilling injury to watermelons grown during a cold season. Temperatures on eastern and western sides were about 6.2% and 14.7%, respectively, lower than that of central section in a south-north oriented greenhouse. Daily mean temperature in the northern part was about 1-2$^{\circ}C$ higher than that in the southern part of the greenhouse. In terms of vertical temperature distribution inside the greenhouse, temperature at ground surface was approximately 1$^{\circ}C$ lower during the day and 0.5$^{\circ}C$ higher during the night than that in the upper part, 2m from the ground surface. Leaf mould medium kept higher ground temperatures as compared to sandy soil, red clay soil, and in the northern and southern sides as compared to the central part of the greenhouse. A symptom of chilling injury on leaves was upward curling, followed by chlorosis and necrosis. A severe symptom of chilling injury to plants was the breakdown of vascular bundles. Root growth was more susceptible than stem or leaf growth to low temperatures. At 3$0^{\circ}C$, main and lateral roots grew vigorously, while lateral root growth was inhibited at 22$^{\circ}C$ and root growth was stopped at 14$^{\circ}C$ and 6$^{\circ}C$. Small and puffy fruits with dark green surface were produced at low temperatures. In cold season cultivation of watermelons, it is suggested that plants be transplanted in the central part and train to sides of the greenhouse in order to reduced chilling injuries.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.4
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• pp.206-212
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• 2009

We investigated the patterns of freeze injury in dormant 'Changhowon Hwangdo' peach fruit by observing the extent of browning and germination of the branches that were treated with freezing temperature sets simulating the process of natural freezing incidences in orchards. Under the treatment of freezing temperature of $-15^{\circ}C$, the browning ratios were 15% for flower bud and less than 3% for both leaf bud and cambium. Under the $-20^{\circ}C$ treatment, the browning ratios were 40% for both flower and leaf buds and 1% for cambium. The browning ratios were 86%, 68% and 40% respectively for flower bud, leaf bud, and cambium under the $-25^{\circ}C$ treatment. All the samples showed 100% browning ratio under the $-30^{\circ}C$ treatment. The budburst ratios of leaf buds were 85%, 66%, 32%, and 0% under the -15, -20, -25 and $-30^{\circ}C$ treatments, respectively. The branches of peach fruit treated with the same freezing temperature showed different responses depending on the sampling date. In January the browning ratio was low and the budburst ratio was high whereas in February the opposite was the case, showing vulnerability of peach trees to low temperature after endo-dormancy release.

• Herbal Formula Science
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• v.27 no.3
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• pp.199-211
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• 2019

Objectives : Present study investigated the hepatoprotective effects of various combinations of lemon balm and dandelion (LD) leaf extract on carbon tetrachloride ($CCl_4$)-induced acute liver injury. Methods : Mice were orally treated with 200 mg/kg of LD extracts [1:1, 1:2, 1:4, 1:6, 1:8, 2:1, 4:1, 6:1, or 8:1 (weight : weight)] for 7 days, and then intraperitoneally injected with $CCl_4$ (0.5 mL/kg). Silymarin (100 mg/kg) was used as reference drug. Body weight gain, relative liver weight, serum biochemistry, histopathologic analyses, and hepatic antioxidant system were examined to elucidate the fittest combination ratio of LD extract. Results : All varying combinations of LD extract significantly increased body weight gain and decreased relative liver weight by $CCl_4$. In addition, LD extract reduced serum aspartate aminotransferase and alanine aminotransferase. Histopathological analyses indicated that LD extract significantly decreased histological activity index score, degenerated hepatocytes, and infiltrated inflammatory cells induced by $CCl_4$. Moreover, LD extract reduced lipid peroxidation, and attenuated the reduction of hepatic glutathione, superoxide dismutase, and catalase by $CCl_4$. Although there were no statistical differences in body weight gain between silymarin- and LD extract-treated groups, administration of 1:1, 2:1, and 4:1 combination of LD extract exhibited more favorable hepatoprotective effects than silymarin. Especially, 2:1 combination of LD extract showed the most potent hepatoprotective effects. Conclusion : Of various combinations of LD extract tested, present results suggest that 2:1 combination of LD extract would be a promising herbal formulation to protect liver from oxidative stress.

• Korean Journal of Medicinal Crop Science
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• v.14 no.2
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• pp.113-116
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• 2006

This study was carried out to investigate spectral irradiance characteristics of blue, yellow, and blue-black colored polyethylene (PE) shading net and the effect on growth characteristics and yield in ginseng seedling. The spectral irradiance $({\mu}mol/m^2/s/nm)$ showed the peak at 498 nm in both of blue and blue-black PE shading net, and 606 nm under yellow PE one. The intensity of blue light in blue shading was more strong than that of blue-black shading, control. Blue shading was increased by 17% and 23% in accumulated quantum for daytime, $0.5^{\circ}C and $0.2^{\circ}C$ in maximum temperature on June 2 than that of yellow and blue-black shading, respectively, but heat injury ratio of the former was lower than that of the latter. Chlorophyll content and stem length in blue shading were decreased more significantly than those of yellow and blue-black shading. The specific leaf weight was higher under blue and yellow shading than that of blue-black shading. Ginseng seedling harvested in blue shading was increased by $13{\sim}17%$ in the number of root, and $17{\sim}20%$ in root weight per $m^ 2 compared to yellow and blue-black shading owing to the increase of survived plant, and the decrease of specific leaf weight, heat injury ratio, and stem length.

• Journal of Korean Society for Atmospheric Environment
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• v.8 no.1
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• pp.13-19
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• 1992

This study was conducted to determine the efficacy of using uniconazole,[(E)-1-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazole-1-yl)-1-penten-3-ol)] as a phytoprotectant against $SO_2$ injury in snap been (Phaseolus vulgaris L. 'Strike'). Thirteen days prior to $SO_2$ fumigation, plants were given a 100 ml soil drench of uniconazole solution at concentrations of 0.02, 0.10, 0.25 and 0.50 mg/pot. All four uniconazole concentrations were significantly effective in providing protection against $SO_2$ exposure(3 h at 1.5 ppm), but uniconazole treatment above 0.02 mg/pot severely reduced stem elongation, leaf enlargement, flowering date and pod number and weight. Uniconazole treatment had little or no effect on stomatal conductance but reduced transpiration rate on a whole plant basis by nearly 40%. This may reflect an alteration in canopy structure by reducing stem elongation and leaf enlargement. Although uniconazole did not increase the activities of superoxide dismutase(SOD) and peroxidase(POD) in non-$SO_2$-fumigated plants, it significantly increased those enzyme activities in $SO_2$-fumigated plants. Chlorophyll concentration on the basis of unit area was increased 50-60% by uniconazole. However, the difference was not detected on the basis of dry weight. $SO_2$ increased variable chlorophyll fluorescence (Fv) 48% after 1.5 h of exposure in non-uniconazole treated plants but decreased Fv in the plants after 3 h of exposure. By appliing uniconazole, it was possible to maintain high Fv values in the latter group of plants. These results suggest that the phytoprotective effects of uniconazole are related to its growth-retarding properties as an anti-gibberellin as well as the increase of activites of free radical scavengers such as SOD and POD.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.1
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• pp.137-143
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• 1997

This study was carried out to investigate the effect of godulbaegi leaf extracts on detoxication of liver injury in $CCl_4$-treated rats. We divided normal group(5) and $CCl_4$-treated group and then $CCl_4$- treated group was divided into 6 groups; only $CCl_4$-treated group(CS), aqueous extract pretreated group (CSA), n-butanol extract pretreated group(CSB), Tween 80 pretreated group(CT), n-hexane extract pretreated group(CTH) and ethyl acetate extract pretreated group(CTE). The ratio of liver weight per body weight and the activity of GPT in hexane extract group(CTH) were lowest, similar to the results of S. Godulbaegi n-hexane extract(IS) groups intoxicated by $CCl_4$ had lower values of MDA than CS and CT which are control groups. Histological finding of liver tissue revealed less of necrosis in IS extracts groups than in control groups(CS, CT). From these results, IS extracts could predominently prevent hepat-otoxicity of rats. Especially, hexane extract was effective on the detoxication of liver injury among the other extracts.

• Korean Journal of Weed Science
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• v.32 no.1
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• pp.35-43
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• 2012

The objective of this research was to confirm the difference in physiological responses to environmental stresses such as chilling, high temperature, NaCl, and chemical stress (paraquat) in Protox inhibitor resistant-transgenic rice (MX, PX, and AP37) and its non-transgenic counterpart (WT). Transgenic and non-transgenic rice plants were exposed to a chilling temperature of $5^{\circ}C$ for 1 day or a high temperature of $45^{\circ}C$ for 4 days and allowed to recover at $25^{\circ}C$ for 6 days after the chilling treatment or 8 days after the high temperature treatment. Leaf injury, shoot fresh weight, porphyrin biosynthesis substances, and chlorophyll content were investigated in transgenic and non-transgenic rice at 6 days after 0.5% and 1% NaCl treatments or at 5 days after 0~300 ${\mu}M$ paraquat treatments. No significant difference in leaf injury and shoot fresh weight were observed between transgenic and non-transgenic rice during chilling and recovery. Plant height and shoot fresh weight were also similar between transgenic and non-transgenic rice during the high temperature and recovery period (0~5 days). However, plant height and shoot fresh weight in transgenic rice line MX and PX were lower than in non-transgenic rice at 6 days for recovery. Leaf injury, chlorophyll, and Mg-Proto IX ME contents had no significant difference between transgenic rice and non-transgenic rice after NaCl treatment, but Proto IX content for AP37 and shoot fresh weight for PX and AP37 in 0.5% NaCl treatment were significantly reduced compared with non-transgenic rice. There was no difference in leaf injury and shoot fresh weight when comparing transgenic rice and non-transgenic rice after paraquat treatment. Although transgenic rice and non-transgenic rice showed a little difference at a particular measurement period in certain environmental stresses, there was generally no difference in physiological responses between transgenic rice and non-transgenic rice.

• Korean Journal of Weed Science
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• v.30 no.3
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• pp.300-307
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• 2010

Greenhouse experiment was conducted to evaluate tolerance of six rice cultivars, three Indica${\times}$Japonica rice (long grain, cv. Dasanbyeo, Segejinmi and Hanareumbyeo) and three Japonica rice (short grain, Nampyung, Ilpumbyeo and Junamjosaeng) cultivars, to mesotrione+pretilachlor (MP) and bensulfuron-methyl+mesotrione+pretilachlor+pyriftalid (BMPP) in transplanting rice. Two herbicides were applied at 90 g and 180 g a.i. $ha^{-1}$ to three to four leaf stage rice at 5 and 15 days after transplanting, respectively. Related study was also conducted to compare $GR_{50}$ for Indica${\times}$Japonica and Japonica rice cultivars at different MP rates. Response to two herbicides varied with respect to rice cultivars and herbicide rates. All Indica${\times}$Japonica rice cultivars exhibited susceptible to both MP and BMPP as reflected by increased visual injury, shorter plant height and higher plant dry matter reduction when compared with nontreated rice cutlivars. The degree of foliar chlorosis by MP at 90 g a.i. $ha^{-1}$ was 5~6 at 7 days after treatment(DAT) but it was decreased to 3~6 at 14DAT. The degree of leaf chlorosis treated with 180 g a.i. $ha^{-1}$ MP was 6~7 at 7DAT and it was also decreased to 3~8 at 14 DAT. The plant hight of Indica${\times}$Japonica rices was inhibited by 18~43% at application of 90 g a.i. $ha^{-1}$ MP and 30~50% at 180 g a.i. $ha^{-1}$ MP. The dry matter reduction was greater than that of plant height inhibition, showing 46~73% at 90 g a.i. $ha^{-1}$ MP and 65~82% at 180 g a.i. $ha^{-1}$ MP. Similar leaf chlorosis injury and growth inhibition of rice cultivars was observed in the BMPP treatment. The injury and growth inhibition by MP and BMPP increased with increase in herbicide rate from 90 g a.i. $ha^{-1}$ to 180 g a.i. $ha^{-1}$. However, most of the Japonica cultivars are tolerant to MP and BMPP at both rates. There was no visible leaf chlorosis but plant height and dry matter production were slightly reduced at 180 g a.i. $ha^{-1}$. Based on $GR_{50}$ value determined in reduction of shoot dry weight for MP, the Indica${\times}$Japonica rice showed 12.9 fold lower compared with the Japonica rice. The result indicates that rice cultivars vary in tolerance to herbicides of MP and BMPP and Indica${\times}$Japonica rices were more susceptible than the Japonica rices to the MP and BMPP.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.22 no.2
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• pp.23-26
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• 1977

In order to test cold tolerance of rice plants 16 varieties were treated at day/night temperature of 10/5$^{\circ}C$ at the 2nd, 4th, and 6th leaf stages. Indica$\times$japonica varieties were more sensitive to low temperature than a japonica variety. Among indica$\times$japonica varieties, "Tongil", "Suweon ＃251", and "Suweon ＃277" were less sensitive to low temperature compared to other indica$\times$japonica varieties tested. The 4th leaf stage was more sensitive to low temperature than 2nd and 6th leaf stages. than 2nd and 6th leaf stages.