• Korean journal of applied entomology
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• v.48 no.2
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• pp.165-170
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• 2009

This study was conducted to investigate specific stages and distribution of overwintering nymphs of green rice leafhopper, Nephotettix cincticeps by measuring head capsule width. The nymphal head capsule width of the 1st instar to the 5th instar was 0.381, 0.502, 0.673, 0.979 and 1.128 mm, respectively. lts coefficient variation was 5.3, 4.0, 3.0, 4.5 and 5.3%, respectively. Growth ratio of each instar was not significantly different among 2nd to 4th instars as 1.31 to 1.34, but for the 5th instar it decreased as 1.28. The logarithm of the nymphal head capsule width was regressed as a function of the stage number of insects, resulting in LogY = 1.4627 + 0.1192X ($r^2= 0.9993$). Also fitness to the Dyar's law for the nymphal head capsule width of each instar was 98% or over and the Dyar's constant (K) was 1.316. The occurrence of N. cincticeps was maximum at the end of January with 195 individuals/0.25 $m^2$. The most abundant instar in the overwintering N. cincticeps population was 4th instar accounting for over 90%. Population of the 5th instar began to increase from mid-March, and adults began to occur in early April.

• Korean journal of applied entomology
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• v.21 no.4 s.53
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• pp.216-221
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• 1982

This experiment was conducted in Jeonnam to investigate the effects of fertilizer amounts at two application levels on disease severity of bacterial leaf blight, yield and qualify of rice grains using nineteen rice cultivars. Incidence of bacterial leaf blight was more severe in the field with higher amount of fertilizer application. Disease severity was also different depending upon maturity of rice cultivars of early maturing group, however, the flag, second and third leaves were diseased in rice cultivars of medium late maturing group. Such differences were more obvious in the field with higher amount of fertilizer application than in the field with ordinary fertilizer application. Rice cultivars such as Taebaegbyeo, Hangangchalbyeo, Baegunchalbyeo, Palgwangbyeo and Milyang 42 were resistant whereas rice cultivars such as Milyang 30, Geumgangbyeo, Nagdongbyeo and Jinjubyeo were susceptible to bacterial leaf blight in both treatments. However, fertilization rate and percentage of ripeness were decreased resulting in heavy loss of yield. The rate of green-kerneled rice was increased resulting in poor qualify.

• Korean journal of applied entomology
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• v.23 no.4 s.61
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• pp.237-241
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• 1984

The trichogrammatidae ego parasite of the green rice leafhopper (GRLH), paracentrobia andoi, were investigated to know their parasitic activities after overwintering in the paddy banks and fallow fields, their seasonal variation and per cent parasitism in the paddy fields of Gyeongnam provincial O.R.D. at Jinju from 1982 to 1984. The parasitic activities of Paracentrobia andoi after overwintering in the Paddy banks in early Masch were high and tended to decrease remarkably since early April by moving to the fallow fields. The parasitic rate of paracentrobia andoi on GRLH was $21\%$ between late April and early May. the peak of egg laying period of GRLH. The per cent parasitism of the wasps in fallow fields was an average of $0\%$ in Gyeochang and Namji and $9.6-29.2\%$ in Namhae, Kimhae and Jinju. The parasitic activites of Paracentrobia andoi had three peakrs in paddy field, however, the highest peak was ovserved between mid- August and early October. The per cent egg parasitism of Paracentrobia andoi was an average of $16.5\%$ on second generation of Nepotettix cinctireps and $36.7\%$ on third generation of the leafhopper.

• Mycobiology
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• v.51 no.5
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• pp.273-280
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• 2023

The nucleolus is the largest, membrane-less organelle within the nucleus of eukaryotic cell that plays a critical role in rRNA transcription and assembly of ribosomes. Recently, the nucleolus has been shown to be implicated in an array of processes including the formation of signal recognition particles and response to cellular stress. Such diverse functions of nucleolus are mediated by nucleolar proteins. In this study, we characterized a gene coding a putative protein containing a nucleolar localization sequence (NoLS) in the rice blast fungus, Magnaporthe oryzae. Phylogenetic and domain analysis suggested that the protein is orthologous to Rrp8 in Saccharomyces cerevisiae. MoRRP8-GFP (translational fusion of MoRRP8 with green fluorescence protein) co-localizes with a nucleolar marker protein, MoNOP1 fused to red fluorescence protein (RFP), indicating that MoRRP8 is a nucleolar protein. Deletion of the MoRRP8 gene caused a reduction in vegetative growth and impinged largely on asexual sporulation. Although the asexual spores of DMorrp8 were morphologically indistinguishable from those of wild-type, they showed delay in germination and reduction in appressorium formation. Our pathogenicity assay revealed that the MoRRP8 is required for full virulence and growth within host plants. Taken together, these results suggest that nucleolar processes mediated by MoRRP8 is pivotal for fungal development and pathogenesis.

• Korean journal of applied entomology
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• v.16 no.4 s.33
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• pp.217-220
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• 1977

During 1976 the effects of carbofuran placement in the root zone of the rice plants, the varieties Palkweng and Yushin, were evaluated for control of common rice pests in the paddy field at the Honam Crops Experiment Station. The methods of insecticide placement included the use of capsule formulation and liquid injection by the root-zone liquid insecticide injector designed at the International Rice Research Institute. The single ro~t-zone application of carbofuran at 2 days after transplanting was compared with two and fcur broadcast applications of carbofuran and diazinon. Capsules were the most. effective in controlling the striped rice borer (Chilo suppressalis), small brown plant-hopper (Laodelphax striatellus), green rice leafhopper (Nephotettix cincticeps) and stripe virus disease which is transmitted by the small brown planthopper. However, one injector application of carbofuran was equal or better the broadcast applications. Their control effectiveness were more significant on Palkweng susceptible to common rice pests than on Yushin resistant to the stripe virus disease.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.5
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• pp.394-406
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• 2004

A split-plot designed experiment including four rice varieties and 10 nitrogen levels was conducted in 2003 at the Experimental Farm of Seoul National University, Suwon, Korea. Before heading, hyperspectral canopy reflectance (300-1100nm with 1.55nm step) and nine crop variables such as shoot fresh weight (SFW), leaf area index, leaf dry weight, shoot dry weight, leaf N concentration, shoot N concentration, leaf N density, shoot N density and N nutrition index were measured at 54 and 72 days after transplanting. Grain yield, total number of spikelets, number of filled spikelets and 1000-grain weight were measured at harvest. 14,635 narrow-band NDVIs as combinations of reflectances at wavelength ${\lambda}l\;and\;{\lambda}2$ were correlated to the nine crop variables. One NDVI with the highest correlation coefficient with a given crop variable was selected as the NDVI of the best fit for this crop variable. As expected, models to predict crop variables before heading using the NDVI of the best fit had higher $r^2$ (>10\%)$ than those using common broad- band NDVI red or NDVI green. The models with the narrow-band NDVI of the best fit overcame broad- band NDVI saturation at high LAI values as frequently reported. Models using NDVIs of the best fit at booting showed higher predictive capacity for yield and yield component than models using crop variables.

• Journal of the Korean Applied Science and Technology
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• v.2 no.1
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• pp.45-55
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• 1985

The present study was designed to investigate the effects of dietary fiber sources and levels on serum lipids in rats fed a hypercholesterol diet containing 0.5% cholesterol. Male Sprague-Dawley rats weighing 52.7 ${\pm}$ 7.27g were devided into sevel groups by completely randomized block design and fed various dietary fibers which were prepared from Rice bran, Siraegi (The dried green parts of a radish) and Bracken Fern at a level of 5% and 10% respectively. The results obtained in this study are summarized as follows: 1. Body weight gains were not significantly different among the groups and food intake was significantly higher in rats fed a diet of Siraegi 10% than those fed the control diet. 2. Fecal wet weights were significantly increased in all experimental groups. 3. Levels of serum total cholesterol in all experimental groups were significantly lower than that of the control group except the level in the R 10(Rice bran 10%) group. 4. Free Cholesterol levels in the serum were increased in all experimental groups, especially the levels in the R 10 (Rice bran 10%) and S 10 (Siraegi 10%) groups were significantly higher than that of the control group. 5. Ester Cholesterol levels in the serum were significantly lower in rats fed the experimental diets than those fed the control diet. 6. There was a tendency of higher serum HDL-Cholesterol levels in R5 (Rice bran 5%), R10 (Rice bran 10%) and B5(Bracken 5%) groups compared to the control group however no significant differences were found between the control group and all the experimental groups except in the case of the S5 (Siraegi 5%) group. 7. LDL, VLDL-Cholesterol levels in the serum sere significantly reduced in the S5 (Siraegi 5%), B5 (Bracken 5%) and B10 (Bracken 10%) groups. 8. The HDL-C./Total-C. Ratio was increased in all experimental group especially the Ratios in the S5 and B5 groups were significantly higher than that of the control group.

• Magazine of the Korean Society of Agricultural Engineers
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• v.17 no.1
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• pp.3677-3684
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• 1975

A newly devised dryer with heated air for the farm products, especially suited for high water content materials such as red pepper, Beer ground, each Vegetables, and Low water content materials such as Rough rice was tested for its thermal efficiency and drying mechanism, and the optimum conditions for each sample were established. In order to improve the present rural situation of drying farm products which entirely dependent upon natural solar radiation, a study upon an economic multi-parpose dryer was conducted. A series of drying tests were run first with red pepper which is one of the important cash crop in Korean farm. And successive series of tests were also run with such proaucts as garlic, sweet potatoes, green onion, radish, Beer ground and Rough rice. The results from the above experiment in drying system with heat dryer can be summarized as follows. 1. Drying duration could be shortened by the tempering effect in high water content crop such as red pepper and beer ground. 2. The color changes occured in around 20% water content in red pepper. The degree of color change was heavily affected by high temperature and short drying duration. 3. The drying condition of red pepper was most favourable at the temperature of 85$^{\circ}C$ in early stage and 80$^{\circ}C$ in middle stage and 75$^{\circ}C$ at the final stage, and with the air rate of 0.81㎥/sec and with sample amount of 200kg. 4. The drying condition of Rough rice(I.R.667) was most favourable at the templature of 40$^{\circ}C$ in early stage and 35$^{\circ}C$ in middle stage and final stage and with the air rate of 0.2㎥/sec and with sample amount of 75kg. 5. In order to prevent the color change of red pepper and to assure high efficiency in drying mechanism, it was necessary to lower the temperature as the time passes in drying process. 6. For vege tables, the drying rate were short in early stage and there was also tempering effect. However, for garlics, Constant drying rates through the early and final stages were observed and there were no tempering effects. 7. The drying condition or capability were as follows; Sample drying temp($^{\circ}C$) amount of material(kg) drying time(hr) Red pepper 85 200 9 Garlic 85 150 7 Sweet potato 85 200 6 Green Onion 85 200 4 Carrot 85 200 4 Radish 90 250 4 Rough rice(I.R.667) 35 75 4 Beer ground 90 320 3 Considering the above result of experiments, if this kind of dryers were distributed Korean farm and the optimun process were practiced in rural area, it would certainly help them improving the qualites of their product preventing their undue losses, and thus assuring an increase of Korean farm income and promotion of their living standards.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.18 no.7
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• pp.819-827
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• 2007

A numerical algorithm for estimating precise backscattering coefficients of rice fields is proposed and its accuracy is verified in this paper. After a bunch of rice plants above water surface is modeled with a bunch of randomly oriented lossy dielectric bodies above an impedance surface and the equivalent volume currents of the lossy dielectrics are computed using the moment method. Then, the scattered fields of a rice field with many bunches are computed with a Monte Carlo method, and consequently the backscattering coefficient of the rice field is computed for various incidence angles and polarizations. Finally, the backscattering coefficient of a rice field is measured at 1.85 GHz using an R-band scatterometer system, and these experimental data are used to verify the numerical algorithm proposed in this paper. It is found that the numerical computation results agree well with the measurement data.

• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.473-479
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• 1998

Identification of rice species was attempted by three side (top, side and front) images of brown rice. Nine parameters of each image were area, aspect ratio, maximum diameter, minimum diameter, perimeter, roundness and red (R), green (G) and blue (B) pixel values of an image. Forty rice samples consisted of 19 species used for the study and total 27 image characteristics for a kernel were measured. For calibration and confirmation, 105 and 20 brown rice kernels per each sample were used respectively. For best identification of rice species, 24 image characteristics were selected for discriminant analysis. Average percentages for correct identification of rice species were 84.75% and 84.93% for calibration and confirmation data set, respectively. The highest and lowest percentage for correct identification were 99.05% for Nongan and 50.63% for Hwaseung respectively in calibration data. The confirmation data showed that the correct identification of Nongan or Paalgong was 100%, while that of Hwaseung was 47.62%. The result of the study showed that three side (top, side and front) image of brown rice was not suitable for identification of rice species suggesting that additional techniques are required for better discrimination of rice species.