• Korean Journal of Agricultural Science
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• v.50 no.3
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• pp.407-413
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• 2023

This experiment was carried out to breed a medium maturing variety of Italian ryegrass (Lolium multiflorum Lam.) in Grassland and Forage Crops Division, National Institute of Animal Science, Rural Development Administration (RDA), Cheonan from 2019 to 2020. An Italian ryegrass variety, IR 604 is a tetraploid variety with green in leaf color and has half-erect growth habit in late autumn and erect growth habit in early spring, IR 604 was on May 17 in heading date as a medium maturing variety. Also, IR 604 was longer by 11 cm in flag leaf length and longer by 1.3 cm in plant height than those of the control variety, Kowinner, respectively. IR 604 was also thicker by 1.0 mm in stem thickness and strong in winter hardness. Dry matter (DM) yield (11,036 kg/ha) of IR 604 was 16.6% higher than that of Kowinner. Total digestible nutrient (TDN), crude protein (CP) and relative feed value (RFV) of IR 604 were 60.4, 13.8% and 100.6 which are 1.4, 3.3%, 7.7 higher than those of Kowinner, respectively. Acid detergent fiber (ADF) and neutral detergent fiber (NDF) of IR 604 were 35.5 and 56.7% which are 1.3 and 3.6% lower than those of Kowinner, respectively.

• Korean Journal of Organic Agriculture
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• v.21 no.4
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• pp.669-684
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• 2013

This study was investigated to evaluate the effects of biodiversity and pest insect occurrence by soil surface management methods such as green manure crop, grass planting and clean-tilled crops on persimmon orchards. Green manure crop pests was investigated 7 species including Hypera postica, Laodephax striatellus, Megoura crassicauda, Aphis craccivora, Nephotettix cincticeps, Liriomyza sp., black spot and the most dangerous pest was H. postica but it did not damaged persimmon tree. Amount of pests and natural enemies dwelling soil covering plant was not difference between organic farming (hairy vetch planting) and conventional farming (natural weed). Homona magnanima occurred three times a year but it rarely damaged leaf of persimmon. Total adult moth catched by pheromone trap was 1,261 organic farm, 1,003 conventional farm and 621 clean-tilled farm. Grapholita molesta occurred four times a year but it also rarely damaged twig of persimmon. Number of collected invertebrate species and individuals on soil sample was follow as : 838 individuals of 22 species at organic farm, 421 individuals of 17 species at conventional farm and 381 individuals of 15 species at clean-tilled farm. The richness index was lined up by organic farm 3.12> conventional farm 2.65> clean-tilled farm 2.36.

• Korean Journal of Soil Science and Fertilizer
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• v.38 no.5
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• pp.269-273
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• 2005

A field experiment was conducted to evaluate the effect of slow-release fertilizer on the yield and quality of the third-harvest tea leaves. The yield of the third harvested tea leaves was decreased to 5.8-14.4% in slow-release fertilizer block, except to the N $50kg\;10a^{-1}$ ($316kg\;10a^{-1}$), compared to traditional urea treatment ($313kg\;10a^{-1}$). Nitrogen uptake and nitrogen uptake efficiency of slow-release fertilizer was reduced as nitrogen application level increased. The contents of chemical components related to the tea quality such as total-nitrogen, total amino acid, chlorophyll and theanine were somewhat lower in the slow-release fertilizer treatments, except to the treatment of N $50kg\;10a^{-1}$, than those in the traditional urea application, but those of tannin, caffeine and vitamin C were not different among the treatments. In scoring test, apparence and quality of green tea of the slow-release fertility treatments were not different, except to the N $40kg\;10a^{-1}$ treatment, compared to those in the treatment of urea. In conclusion, slow-release fertilizer and conventional urea treatments showed not different in both yield and quality of green tea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.350-357
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• 2021

In the present study, the seed color of 200 common bean genetic resources was analyzed and located on the HTML color chart to classify these resources according to color characteristics. This classification method predicts the components of seed and may serve as a new method for efficiently using secured genetic resources. The imagary data of common bean exhibiting various seed colors were expressed using the HTML color chart. According to the proposed classification method, the seed color was distributed in seven categories: yellow-green, yellow, brown, red, white, gray, and indigo. In addition, the distribution of each seed color was according to its concentration. The distribution by concentration was the highest for red, whereas the distribution of gray and yellow-green was not concentration-dependent. As the dominant pigments based on color distribution, chlorophylls in yellow-green; carotenoids in yellow; and anthocyanins in brown, red, white, gray, and indigo significantly affected seed color. When expressed objectively, seed colors can be applied to the systematic management, breeding, and cultivation of genetic resources and can be useful for marketing or developing products of desired colors. This method can also be applied to other crops.

• Korean Journal of Environmental Biology
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• v.17 no.4
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• pp.529-541
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• 1999

In order to elucidate characteristics of water quality, investigation of monthly dynamics of environmental factors and algal populations at major four stations of the mid and lower part in Taechong Reservoir was performed from June 1998 to June 1999. Water temperature, DO and pH were ranged 5.3~27.7$^{\circ}C$, 6.2~13.8 mgO$_2$/1 and 6.4~9.5, respectively. Those were varying as the season changes. Among inorganic nitrogen nutrients, NH$_4$was ranged from 5.5% to 7.2% of NO$_3$and NO$_3$was almost same through the seasons except summer in which it was low. SRP and SRSi were increased in summer when the blue-green algae became dominant. Those were decreased as the cell density of diatom increased when the water temperature dropped. Therefore SRSi was considered to be another important nutrient factor contributing to the increment of biomass of freshwater algae as well as SRP. Average chi-$\alpha$ concentration ranged from s to 12 $\mu$g/1 and in the lower part or the reservoir, the lowest was found. Moreover, there were remarkable increment in summer when TN/TP ratio were decreasing from relationships between TN/TP ratio and chi-$\alpha$ concentration. Annual mean ratio of TN/TP ratio was relatively high as the value was 110, which was relatively high, and it showed that P is the dominant factor in the algal growth. The dynamics of phytoplankton were simply dominated by a few species seasonally. In summer, blue -green algae such as Anabaena, Microcystis and Oscillatoria were dominant and algal bloom of blue -green began from early summer, sustained to late autumn. The average standing crops of A. spiroides v. crassa, M. aeruginosa and O. limosa were ranged 0.3~2.0$\times$10$^4$cells/ml, 6.4$\times$10$^2$~1.0$\times$10$^4$cells/ml and 4.6$\times$10$^3$~1.6$\times$10$^4$cells/ml, respectively. In winter, diatom Stephanodiscus was considered to be an important species whose average standing crops of Stephunodiscus was 4.9$\times$10$^2$cells/ml from November to April of the next year and the highest was 1.3$\times$10$^3$cells/ml in January.

• Korean Journal of Soil Science and Fertilizer
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• v.42 no.5
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• pp.371-378
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• 2009

This study was carried out to investigate the improvement effect of soil fertility by incorporation of GMC(green manure crops) at rice cropping after cultivation GMC such as the barley for alternative rye in paddy field over the past two years(2006~2007). Plots, which consisted of incorporation time of GMC as rye; heading stage, barley; heading stage, heading stage of rye and 10days after heading stage were divided by amount of applied rates; standard fertilizer fertilization, diagnosis fertilization and non-fertilization. we investigated change of soil physico-chemical properties, degree of decomposition on GMC in soil, growth and yield potential. The obtained results were summarized as follows. The fresh weight of GMC at incorporation time on heading stage of rye, heading stage and 10days after heading stage of barley were $2,715,\;2,352,\;2,867kg\;10a^{-1}$ respectively. Content of total nitrogen at three incorporation times was 1.31, 1.46, 1.38% and the C/N ratio were 33.4, 28.7, and 34.6, respectively. Some soil physical properties, such as soil hardness and bulk density tended to decrease with incorporation of GMC, while surface soil depth and porosity were increased. Some soil chemical properties, such as content of exchangeable cations and cation exchangeable capasity(CEC) were increased with incorporation of GMC compared with before experiment. Rice yields was increased 3~9% in diagnosis application plots on application of barley compared with control($559kg\;10a^{-1}$) and incorporation of barley caused to improve perfect kernel ratio 73.6~78.7% in appearance characteristics of brown rice compared with cotrol(73.0%). It was found that incorporation with 10days after heading stage of barley was more effective to reduce chemical nitrogen fertilizer and to improve soil fertility.

• Research in Plant Disease
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• v.18 no.4
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• pp.277-289
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• 2012

The total number of requests and associated specimens for the diagnosis of virus infection were 573 and 2,992, respectively, on crops from agricultural places of farmers, Agricultural extension services and so forth for 5 years from 2007. The total number of virus tests was 13,325. The number of species of viruses infected on the submitted crops was 21 in 2007, 15 in 2008, 23 in 2009, 21 in 2010 and 17 in 2011. The newly recorded viruses were Tobacco leaf curl virus (TbLCV) in 2007, Tomato yellow leaf curl virus (TYLCV) in 2008, Impatience necrotic spot virus (INSV) and Radish mosaic virus (RaMV) in 2009, and Beet western yellows virus (BWYV) in 2010. Forty virus species including Alfalfa mosaic virus were detected over 5 years. The ten most frequently detected virus species were Cucumber mosaic virus (CMV), Tomato spotted wilt virus (TSWV), Tomato leaf curl virus (TYLCV), Cucumber green mottle mosaic virus (CGMMV), Broad bean wilt virus 2 (BBWV2), Zucchini yellow mosaic virus (ZYMV), Melon necrotic spot virus (MNSV), Pepper mild mottle virus (PMMoV), Watermelon mosaic virus (WMV) and Pepper mottle virus (PepMoV). The types of crops submitted from agricultural places were 51 in total and the ten most frequently submitted crops were red pepper, tomato, paprika, watermelon, melon, rice, cucumber, corn, radish and gourd. The total request rate for the top 10 crops and top 20 crops was 81.6% and 94.2%, respectively. Eight pepper infecting virus species included CMV, and the average infection rate was 24.6% for CMV, 18.9% for PMMoV and 14.7% for TSWV. Seven kinds of double infection were detected in pepper including BBWV2+CMV at 14.7% on average, and four types of triple infection including BBWV2+CMV+PepMoV at 0.9% on average. Six virus species detected on tomato including TYLCV, and the average infection rate was 50.6% for TYLCV, 14.5% for TSWV and 10.9% for Tobacco leaf curl virus (TbLCV). The mixed infection of CMV+TSWV on tomato was 3.9% on average and of Tomato mosaic virus (ToMV)+TYLCV was 0.4% on average. Five viruses detected on watermelon included MNSV and the average infection rate was 37.0% for MNSV, 20.4% for CGMMV, 18.1% for ZYMV and 17.8% for WMV. The mixed infection rate on watermelon was CMV+MNSV and WMV+ZYMV having an average infection rate of 0.7% and 5.0%, respectively. The average infection rates on melon were 77.6% for MNSV, 5.6% for CMV and 3.3% for WMV. Mixed infections of CMV+MNSV occurred on melon with an average infection rate of 13.5%.

• Korean Journal of Organic Agriculture
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• v.22 no.3
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• pp.503-519
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• 2014

This study was conducted to investigate ginger growth and its nutrient uptake depending on changes of soil properties as affected by applications of green manure crop and/or charcoal in continuous cropping system. The green manure crops applied were barley and hairy vetch, and charcoal was additionally treated in selected plots as a soil conditioner. Experimental plots were prepared as Plot 1 (control), Plot 2 (barley of 8kg $10a^{-1}$), Plot 3 (hairy vetch of 12kg $10a^{-1}$), Plot 4 (charcoal of 1,000kg $10a^{-1}$ and barley 8kg $10a^{-1}$), and Plot 5 (charcoal of 1,000kg $10a^{-1}$ and hairy vetch of 12kg $10a^{-1}$) with two different soil conditions (high clay content, HCC and low clay content, LCC). When comparing selected chemical properties of soils before and after cultivating ginger plant, soil pH decreased from 6.9~8.1 to 6.8~7.6, and electrical conductivity (EC) also declined from $0.45{\sim}1.25dSm^{-1}$ to $0.30{\sim}0.61dSm^{-1}$. However, the content of soil organic matter (SOM) and total nitrogen (T-N) increased. Thus, the soil chemical properties were improved with the applications of green manures and charcoal. Also, macro- and micro-nutrient contents of ginger plants in the different plots were various between normal and diseased plants grown in soils with HCC and LCC. In particular, the concentration of manganese (Mn) was 3~4 folds higher in the diseased plant than in the normal plants. Ginger growth status and yield was relatively improved with the applications of green manures and charcoal as comparing with control plot. Especially in the Plot 4 with LCC, the ginger plant was not infected by root-rot disease.

• Journal of Environmental Impact Assessment
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• v.17 no.5
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• pp.311-320
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• 2008

Reusing livestock manure have various advantages in securing soil organic resources, and since the costs needed for converting them into liquefied fertilizers are relatively moderate compared to normal treatment, such methods are necessary. In this study, the Recycling Capacity Assessment of Gyeonggi-do was carried out by comparing between the fertilizer demands for specific crops based on the cultivation areas and the amount of fertilizer resources that are generated from livestock manure. From this assessment, the possibility of obtaining resources by converting livestock manure into fertilizers were evaluated. The amount generated of Livestock Manure in Gyeonggi-do were evaluated by applying the emission units to the number of livestock manure. And from the amount generated of Livestock Manure, the amount of fertilizer produced from Livestock Manure were calculated by using the fertilizer a component rate. When considering the amount of fertilizer produced from Livestock Manure based on the type of livestock, N 6,626 ton/year, $P_2O_5$ 1,824 ton/year, $K_2O$ 4,480 ton/year were produced from milk cow manure, while N 5,247 ton/year, $P_2O_5$ 2,772 ton/year, $K_2O$ 2,879 ton/year, were produced from beef cattle manure. N 14,924 ton/year, $P_2O_5$ 7,205 ton/year, $K_2O$ 6,750 ton/year were produced from pigs and N 12,651 ton/year, $P_2O_5$ 4,458 ton/year, $K_2O$ 5,542 ton/year were produced by chickens. So the total amount of fertilizers that can be obtained from livestock manure were 3,668 ton/year Nitrogen, 16,259 ton/year phosphate and 19,651 ton/year kalium. And the total fertilizer demands in Gyeonggi-do were Nitrogen 27,200 ton/year, Phosphate 8,853 ton/year, and kalium 13,211 ton/year respectively. Nitrogen which had higher demands than production quantities were considered as limitation factors in crop growth. So the Recycling Capacity Assessment was carried out mainly based on Nitrogen. Since the Nitrogen quantities that can be provided by recycling livestock manure were 3,532 ton/year lesser than the Nitrogen demands, it is estimated that it would be desirable to convert livestock manure into resources. But in order to properly convert the entire livestock manure into organic resources, the seasonal situation that effects the nitrogen demands of crops along with the regional effects due to the industrial structures should be seriously analyzed. In addition, a system that can effectively produce and manage fertilizer should be established.

• The Korean Journal of Pesticide Science
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• v.19 no.3
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• pp.264-271
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• 2015

Stink bugs do damage on various crops including upland crops and tree fruits. Especially, yellow-brown stink bug (Halyomorpha halys ($St{\aa}l$)) and brown-winged green (Plautia stali) are severely damaged on apple orchard. Using seven insecticides - dinotefuran WP, etofenprox WP, chlorpyrifos WP, cabaryl WP, chlothianidin SC, flonicamid WG, and bifenthrin WG - registered on apple, contact and residual toxicities were tested on both male and female of P. stali and H. halys that preferred apple fruit. Contact toxicity of dinotefuran WP was excellent on male P. stali 48 hours after treatment (HAT) with 96.7% and significant on male Halyomorpha halys 48 HAT with 74.5% but the others had low effect. Contact toxicity on these stink bugs were higher in male than female. All insecticides except flonicamid, residual effects were all effective on both male and female of P. stali, while chlorpyrifos and bifenthrin were showed higher residual toxicity on both male and female of H. halys in laboratory condition. Two insecticides, chlorpyrifos and bifenthrin, were selected for the field test. Bifenthrin have a high residual effect on P. stali until 5 days after treatment, but have a low residual toxicity on H. halys in the field test. Chlorpyrifos showed higher residual toxicity in the laboratory, however, showed low residual efficacy on two species stink bug onto the field.