• Proceedings of the Korean Society of Food Hygiene and Safety Conference
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• 2001.10a
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• pp.120-122
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• 2001

This study was carried out to monitor suspected endocrine disrupting pesticides and industrial organic chemicals among circulated agricultural products in the north area of Seoul in 2001. Procymidone, vinclozolin, endosulfan, chlorothalonil, chloropyrifos and pendimetaline (pesticides) and butylated hydroxytoluene(industrial organic chemicals) were certified by GC-MS. Detected 6 pesticides were remained mostly in the green vegetables, spices and wild plants with $3\%$ detected. Butylated hydroxytoluene(industrial organic chemicals) used for green house cover stuffs was contained mostly in the green vegetables, spices and wild plants not in the fruits and cereals with $43\%$ detected. In the same agricultural products containing butylated hydroxy toluene showed same detection tendency with remaining endocrine disrupting pesticides.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.56 no.2
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• pp.167-176
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• 2011

Brown planthopper (BPH) is a serious insect pest of rice crop throughout rice growing countries, and yield loss due to its infection can be up to 60%. This study aimed to evaluate efficiency of molecular markers for screening BPH resistance accessions among 86 aromatic rice germplasm Eighty-six accessions of aromatic rice germplasm included two accessions of Tongil type (bred in Korea), 28 accessions of japonica type and 56 accessions of indica type. We applied eight STS markers (pBPH9, pBPH19, pBPH20, pBPH21, AJ09-b, RG457L, RG457B, and 7312.T4A) which were linked to four of BPH resistance genes, Bph1, Bph13(t), Bph10, and Bph18(t) respectively. One japonica type accession, 415XIr352, and six indica type accessions possessed one or four positive bands when tested with four STS markers linked to Bph1 gene. One indica type aromatic rice, Basmati9-93, showed the target bands linked to the Bph10 gene. The other accessions did not show same fragments as the respective resistant lines. Bph13(t) is the most widely introduced resistance gene and only one accession showed positive bands implying that this accession might harbor Bph10 and Bph18(t) genes. Three aromatic accessions, Domsiah, Khao Dawk Mali 105 and 415XIr352 showed gene pyramiding of Bph1 and Bph13(t). Two indica aromatic rice, Ds 20 and Basmati 9-93, possessed at least two BPH resistance genes, Bph1, Bph18(t) and Bph13(t), Bph18(t), respectively. These results indicates that aromatic rice germplasm have narrow diversities of BPR resistance genes.

• Korean Journal of Environmental Biology
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• v.41 no.2
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• pp.126-137
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• 2023

Paddy fields provide important habitats for biodiversity conservation within the agricultural ecosystem. Their importance is gradually increasing as their ecological value is better understood. Benthic macroinvertebrates dominate paddy fields. They play an essential role in maintaining the biodiversity of paddy ecosystems. This study aimed to analyze characteristics of benthic macroinvertebrate communities and main environmental factors affecting the distribution of golden apple snails (Pomacea canaliculata). Results showed that the diversity index (H') of the benthic macroinvertebrate community was the highest at the Sangju site (St. 12) but the lowest at the Sancheong site (St. 18). Total Dissolved Solids (TDS), salinity, and Electrical Conductivity (EC) values were the highest in Gimhae and Yeongam based on Canonical Correspondence Analysis (CCA). Numbers of P. canaliculata (m-2) were relatively low in Gunsan and Iksan where water temperatures were high. Therefore, changes in geographical characteristics and environmental factors might affect the distribution of P. canaliculata and characteristics of benthic macroinvertebrate communities. Results of this study can be used as primary data for biodiversity conservation and ecosystem service evaluation in agroecosystems.

• The Korean Journal of Mycology
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• v.50 no.2
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• pp.93-102
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• 2022

A new cultivar of oak mushroom Lentinula edodes 'Jadam' was bred from monokaryotic strains of 'Hwadam-18' and 'GMLE36295-22'. The optimum temperature for mycelial growth of 'Jadam' on potato dextrose agar was 22-25℃. Total cultivation period of the new cultivar, from inoculation to its first harvest, was 122-124 days, shorter to that of the control cultivar 'Hwadam'. Total yield of 'Jadam' was 623.8 g per 3 kg substrate, and is higher than that of 'Hwadam' (455.2 g). In the fruiting body of the new cultivar, the stipe was shorter and thinner than those of 'Hwadam'. A farmhouse field test showed that the period of mycelial growth and browning was shorter than that of control cultivar 'L808'. The total yield for 2 flush was 543.3 g for 'Jadam'. It was similar to the 585.3 g of the control cultivar. Therefore, the new cultivar 'Jadam' could be a substitute for 'L808' in the field of farms.

• The Plant Pathology Journal
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• v.31 no.3
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• pp.259-268
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• 2015

This study investigated the chemical characteristics and microbial population during incubation of four kinds of aerated compost teas based on oriental medicinal herbs compost, vermicompost, rice straw compost, and mixtures of three composts (MOVR). It aimed to determine the effects of the aerated compost tea (ACT) based on MOVR on the growth promotion of red leaf lettuce, soybean and sweet corn. Findings showed that the pH level and EC of the compost tea slightly increased based on the incubation time except for rice straw compost tea. All compost teas except for oriental medicinal herbs and rice straw compost tea contained more ${NO^-}_3-N$ than ${NH^+}_4-N$. Plate counts of bacteria and fungi were significantly higher than the initial compost in ACT. Microbial communities of all ACT were predominantly bacteria. The dominant bacterial genera were analyzed as Bacillus (63.0%), Ochrobactrum (13.0%), Spingomonas (6.0%) and uncultured bacterium (4.0%) by 16S rDNA analysis. The effect of four concentrations, 0.1%, 0.2%, 0.4% and 0.8% MOVR on the growth of red leaf lettuce, soybean and sweet corn was also studied in the greenhouse. The red leaf lettuce with 0.4% MOVR had the most effective concentration on growth parameters in foliage part. However, 0.8% MOVR significantly promoted the growth of root and shoot of both soybean and sweet corn. The soybean treated with higher MOVR concentration was more effective in increasing the root nodule formation by 7.25 times than in the lower MOVR concentrations Results indicated that ACT could be used as liquid nutrient fertilizer with active microorganisms for culture of variable crops under organic farming condition.

• Korean Journal of Weed Science
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• v.30 no.2
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• pp.164-170
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• 2010

In organic agriculture, cover crops are used for weed control. Cover crops inhibited weed germination or growth by allelopathy or shading effects. In this study, we used rye as cover crop to control weed in organic soybean field. The main treatment was rye using method such as living mulch, incorporating and mowing. Sub-treatment was rye planting density and soybean planting density. One month after soybean sowing, weed emergency and growth had been highly suppressed by rye in all treatments. Living mulch treatment was the best effective way to control the weed about 92%, and mowing treatment was the second about 75% compare to control. The weed control efficiency between rye planting densities was similar during one month. Soybean planting density treatment was same result as rye planting density. As a result of this experiment, we recommend rye as living mulch in one row planting.

• Journal of Wetlands Research
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• v.25 no.4
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• pp.237-247
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• 2023

Paddy fields not only provide a variety of ecosystem services but also serve as crucial habitats for biodiversity conservation. Recently, their ecological value and significance have been increasingly emphasized. Therefore, this study aimed to investigate the characteristics of soil seed banks and analyze their correlation with soil environmental factors in Conventional Paddy field (CP) and Organic Paddy field (OP) with different farming practices. Our results revealed that the vegetation in CP was simple, resulting in low plant diversity in the soil seed banks. On the other hand, the vegetation in OP was relatively diverse, leading to higher plant diversity in the soil seed banks. Additionally, distinct differences in soil environmental characteristics were observed between OP (K, Ca, Mg, Na, Fe, Mn, B↓) and CP (K, Ca, Mg, Na, Fe, Mn, B↑). These results suggest that variations in agricultural practices for rice cultivation have influenced the structure and diversity of vegetation and soil seed banks. Furthermore, these agricultural practices have had both direct and indirect effects on soil environmental factors. Our findings can serve as fundamental data for evaluating biodiversity conservation in agricultural ecosystems, ecosystem restoration, and ecological value assessment.

• Korean Journal of Organic Agriculture
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• v.23 no.3
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• pp.423-453
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• 2015

This study started with two questions. The first question is 'Why does organic agriculture want to be linked with cooperative?' The second is 'What is the characteristics of the mutual relationship between organic agriculture and cooperative?', especially in Wonju. Up to now, there have been various kinds of discussion about cooperation between organic agricultural campaign and cooperative in Wonju. But there are few concrete data showing what role cooperative plays in the cyclical process of production-distribution-consumption of organic agriculture. Thus, we conducted a survey applying the Delphi technique to the 35 organic agricultural specialists active in Wonju. First, small-scale family farm producers established a social economic cooperative network in around 2003 to perform 'the activities of innovators' through forming an organization. Producers moved from the stage in which they were supported one-sidedly by consumers to the stage where they could 'lead' cooperation. Each farm organization built a vertical integration, and horizontal cooperative systems with other farm organizations. But, practical cooperative activities have remained in the doldrums. They tend to show trends deviating from the principles of organic agriculture and cooperative. Second, the relationship between producers and consumers in Wonju can be described as 'producer-consumer cooperative type'. In Wonju, the producers' organization is not a sub-contractor which simply deliver organic agricultural products to producers' cooperative, but is an equal subject which creates its own value chain. The cooperative (cooperative organization) leads distribution and consumption of organic agricultural products and mutual communication. But, the closeness between producers and consumers has got loosened. And, it is problematic that the proportion of local food consumption in Wonju is very low. There is a very strong tendency to ride the central distribution system of producers' cooperative coalition. Consequently, it is necessary for producers' cooperatives in Wonju to run a local food distribution system based on the 'cooperative system among cooperatives'.

• Agricultural and Biosystems Engineering
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• v.6 no.1
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• pp.15-21
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• 2005

This study was conducted to develop a nondestructive grouping system for soil organic matter using visible (VIS) and near infrared (NIR) spectroscopic method. The artificial light was irradiated on the cut soil surface at 15 to 20 cm depths to reduce the errors of light at open field. The reflectance energy from the cut soil surface was measured to group the soil organic matter using VIS/NIR light sensor with narrow band pass filter. From reflectance spectra of soil samples, the sensitive wavelengths for measuring the soil organic matter were selected and compared to previous research results. The grouping system for soil organic matter consisted of light sensor with band pass filter measuring the reflectance energy of the cut soil surface, global positing system (GPS), analog-to-digital (AD) converter, computer and operating software. The regression models to predict the soil organic matter were developed and evaluated. From field test, the accuracies of the developed light sensor system were 81.3% for five-stage grouping of the soil organic matters and 91.0% for three-stages grouping of the soil organic matters, respectively. It could be possible to support the decision making for variable rate applications with the developed grouping system for soil organic matter in precision agriculture.

• Research in Plant Disease
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• v.21 no.4
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• pp.297-308
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• 2015

In order to control seed-borne diseases, we obtained extracts from commercial fermented food products of Kimchi, Gochujang, Doenjang, Ganjang and Makgeolli and their suppressive effects against seed-borne diseases were studied. In addition, the suppressive effects of bacterial strains isolated from the fermented foods were screened in vitro and in vivo. Among fifty food extracts, twenty food-extracts suppressed more than 92% incidence of seedling rots in vitro and seven food extracts increased 58.3-66.8% of healthy seedling in the greenhouse. Among 218 isolates from the fermented foods, 29 isolates showing high antifungal activity against seven seed-borne fungal pathogens were selected. Among 29 isolates, 13 isolates significantly reduced seedling rot and increased healthy seedlings. Sixteen isolates with high antifungal activity and suppressive effect against sesame seedling rots were identified by 16S rRNA sequencing. Fourteen of sixteen isolates were identified as Bacillus spp. and the other two isolates from Makgeolli were identified as Saccharomyces cerevisiae. It was confirmed that B. amyloliquifaciens was majority in the effective bacterial population of Korean fermented foods. In addition, when the bioformulations of the two selected effective microorganisms, B. amyloliquifacien Gcj2-1 and B. amyloliquifacien Gcj3-1, were prepared in powder forms using bentonite, kaolin, talc and zeolite, talc- and kaolin-bioformulation showed high control efficacy against sesame seed-borne disease, followed by zeolite-bioformulation. Meanwhile control efficacy of each bentonite-bioformulation of B. amyloliquifacien Gcj2-1 and B. amyloliquifacien Gcj3-1 was lower than that of bacterial suspension of them. It was found that the selected effective microorganisms from Korean fermented foods were effective for controlling seed-borne diseases of sesame in vitro and in the greenhouse. We think that Korean fermented food extracts and useful microorganisms isolated from the extract can be used as bio-control agents for suppressing sesame seed-borne diseases based on above described results.