• The Korean Journal of Mycology
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• v.51 no.4
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• pp.277-286
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• 2023

Tan spot, caused by Pyrenophora tritici-repentis, is a major foliar disease in wheat worldwide. In April 2021, tan spot symptoms were observed in a commercial wheat field in Suncheon, Jeonnam Province, Korea, with over 5% of the wheat leaves exhibiting symptoms. These symptoms included oval-shaped tan necrosis surrounded by a bright halo. The three representative isolates exhibited irregular mycelial growth on V8-potato dextrose agar and produced pseudothecia. Based on the concatenated sequence datasets of four multi-genes, including the internal transcribed spacer, large subunit ribosomal RNA, glyceraldehyde-3-phosphate dehydrogenase, and RNA polymerase II second-largest subunit genes, phylogenetic analysis revealed that these three isolates clustered in the same clade as P. tritici-repentis. Results of pathogenicity test indicated that the initial symptoms appeared 5 days post-inoculation (dpi), with typical tan spot symptoms developing at 7 dpi. The pathogen was successfully re-isolated from the symptomatic tissues, thus fulfilling Koch's postulates. Furthermore, we selected three fungicides that effectively inhibited the mycelial growth of P. tritici-repentis by more than 90% in vitro. To the best of our knowledge, this is the first report of tan spot disease in wheat in Korea.

• Korean Journal of Agricultural and Forest Meteorology
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• v.8 no.3
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• pp.169-173
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• 2006

This study used loess from the source region of Asian dust (a desert area in China) to analyze the effects of Asian dust on fruiting and fruit quality in Korean fruit trees. Asian dust and loess from the source region were highly alkaline compared to average Korean field soil. Organic material contents of Asian dust were about three times as high as that of the average field soil. Loess was dusted onto the stigma of apple, pear, and peach trees. fruiting, seed number, fruit quality and pollen tube elongation were investigated. Pollination and fertilization were not influenced while pollen tube elongation was slightly influenced. Consequently, fruiting, seed number and fruit quality were not affected by the dusting treatment.

• Korean Journal of Agricultural Science
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• v.7 no.1
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• pp.52-58
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• 1980

This study was conducted to detect copper which is considered in the soils of orchards, since copper fungicide has been applied to fruit trees. Soil samples taken from the fields of the chief producing districts of apple (Chungju, Yesan, Daegu), pear (Yangju, Bucheon, Seonghwan) and citrus (Seogypo in Jeju island) were analysed by an atomic absorption spectrophotometer. The results obtained were summarized as follows ; 1. In orchards of apple, the amount of copper of soils from Yesan, Chungju and Daegu were ranged 2.6-171.3ppm, 2.2-136.1ppm and 14.3-134.6ppm, respectively. Very little copper was detected from the soils in the field which has been cultivated for less than 20 years. About 100ppm and 130-170ppm of copper were detected in the field which has been cultivated for 30 years and for 50-60 years, respectively. Most of the copper was detected in the surface layer of soils (0-10cm), while very low content of copper was detected in the deeper layer of soils (10-20cm). 2. In orchards of pear, 20-30ppm of copper was detected from the surface of soils in the field which has been cultivated for more than 30 years and the highest level of copper, 36.8ppm, was detected from Yangju area. The amount of copper of soils from Yangju, Seonghwan and Bucheon were ranged 3.6-36.8ppm, 9.7-19.4ppm and 3.6-24.7ppm, respectively. 3. In orchards of citrus of Jeju island, only trace amount and 23-38ppm of copper were detected in the fields cultivated for 15 years and 20-30 years, respectively. The highest level of copper, 57ppm, was detected from the surface layer of soils in the field which has been cultivated for 35 years, but in most of the soil samples tested, only the natural background level of copper, about 20ppm, was detected. 4. The levels of copper residue in all the soil samples tested were lower than the tolerance level (125ppm of copper which is extracted in 0.1N-HCl solution), except those of copperr residue, 130-170ppm, that were detected from the orchards of apple which have been under cultivation for 50-60 years. Hence no problem for the farming could be speculated with the present concentration of copper analysed.

• Korean Journal of Environmental Agriculture
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• v.35 no.3
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• pp.159-165
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• 2016

BACKGROUND: Carbonized biomass is increasingly used as a tool of soil carbon sequestration. The objective of this study was to evaluate soil carbon storage to application of carbonized biomass derived from pear tree pruning.METHODS AND RESULTS: The carbonized biomass was a mobile pyrolyzer with field scale, which a reactor was operated about 400~500℃ for 5 hours. The treatments were consisted of a control without input of carbonized biomass and two levels of carbonized biomass inputs as 6.06 Mg/ha, C-1 and 12.12 Mg/ha, C-2. It was shown that the soil carbon pools were 49.3 Mg/ha for C-1, 57.8 Mg/ha for C-2 and 40.1 Mg/ha for the control after experimental periods. The contents of accumulated soil carbon pool were significantly (P < 0.001) increased with enhancing the carbonized biomass input amount. The slopes (1.496) of the regression equations are suggested that carbon storage from the soil was increased about 0.1496 Mg/ha with every 100 kg/ha of carbonized biomass input amount.CONCLUSION: Our results suggest that application of carbonized biomass would be increased the soil carbon contents due to a highly stable C-matrix of carbonized biomass. More long-term studies are needed to be proved how long does carbon stay in orchard soils.

• The Korean Journal of Pesticide Science
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• v.16 no.4
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• pp.395-400
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• 2012

In order to survey the actual pesticide usage, this survey was carried out on the growers of 3 plant groups, fruit vegetables, fruits and rice field, from 2009 to 2011. 390 farmers were selected from main production areas to investigate their pesticide application during the growing seasons. Input amounts per area of domestic fruit vegetables was surveyed as 11.6 kg a.i./ha for red pepper of field culture, 2.0 kg a.i./ha for red pepper of greenhouse, 2.3 kg a.i./ha for strawberry, 2.2 kg a.i./ha for watermelon, 4.8 kg a.i./ha for cucumber, 1.5 kg a.i./ha for oriental melon and 2.1 kg a.i./ha for tomato, respectively. Input amounts per area on fruits and on rice field were surveyed as 11.7 kg a.i./ha for apple, 12.5 kg a.i./ha for pear, 7.7 kg a.i./ha for peach, 4.5 kg a.i./ha for grape, 40.0 kg a.i./ha for citrus 5.4 kg a.i./ha for persimmon, and 3.46 kg a.i./ha for rice, respectively. As a result of the actual pesticide usage survey, The safety guideline for pesticide use is generally kept well by all farmers of fruits vegetables, fruits and rice.

• Journal of Integrative Natural Science
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• v.12 no.4
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• pp.133-141
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• 2019

Mesenchymal stem cells (MSCs) are known to differentiate into multiple lineages, making neurogenic differentiation an important target in the clinical field. In the present study, we induced the neurogenic differentiation of cells using histone deacetylase (HDAC) inhibitors and studied their mechanisms for further differentiation in vitro. We treated cells with the HDAC inhibitors, MS-275 and NaB; and found that the cells had neuron-like features such as distinct bipolar or multipolar morphologies with branched processes. The mRNA expressions encoding for NEFL, MAP2, TUJ1, OLIG2, and SYT was significantly increased following HDAC inhibitors treatment compared to without HDAC inhibitors; high protein levels of MAP2 and Tuj1 were detected by immunofluorescence staining. We examined the mechanisms of differentiation and found that the Wnt signaling pathway and downstream mitogen-activate protein kinase were involved in neurogenic differentiation of MSCs. Importantly, Wnt4, Wnt5a/b, and Wnt11 protein levels were highly increased after treatment with NaB; signals were activated through the regulation of Dvl2 and Dvl3. Interestingly, NaB treatment increased the levels of JNK and upregulated JNK phosphorylation. After MS-275 treatment, Wnt protein levels were decreased and GSK-3β was phosphorylated. In this cell, HDAC inhibitors controlled the non-canonical Wnt expression by activating JNK phosphorylation and the canonical Wnt signaling by targeting GSK-3β.

• Journal of Bio-Environment Control
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• v.23 no.3
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• pp.256-261
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• 2014

This study was carried out to determine the effect of the artificial pollination on fruit set, seed formation and fruit quality in kiwifruit and to confirm the effective pollination time for optimal fruit set in the shelter greenhouse cultivation. Also, the effect of artificial pollination practice by the pollen diluent solution was tested. By artificial pollination, fruit set, seed formation, and fruit quality was improved both in the open field condition and in the shelter greenhouse cultivation. In order to find the effective pollination period (EPP), artificial pollination was carried out every day until 7 days after full bloom. Number of seeds and fruit set rate and fruit growth of kiwifruit were no significantly different until 4 days after full bloom (DAFB), but, those of kiwifruit from 5 DAFB significantly decreased. Consequently, the effective pollination period of kiwifruit in the shelter greenhouse was 4 days after full bloom. Also, artificial pollination by the pollen diluent solution was showed the similar fruit set and fruit quality compare to that by lycopodium powder. Accordingly, artificial pollination by the pollen diluent solution should be very effective practice for labor saving in kiwifruit cultivation.

• The Korea Journal of Herbology
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• v.30 no.1
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• pp.43-49
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• 2015

Objectives : In this study, the anti-stress effects of ethanolic extract of Opuntiaficus-indica (OF70E) were investigated. Methods : To determine the effects of OF70E on physical stress, changes in whole-body cortisol level or behavior were monitored in zebrafish. After treatment with 0.9% saline or OF70E for 6 min, all fish underwent net handling stress (NHS), which induced physical stress. And then, we conducted open field test (OFT) or sacrificed fish for collecting body fluid from whole-body. We used the cortisol enzyme-linked immunoassay kit to measure the amount of cortisol in each zebrafish sample. Results : In result, compared with normal group which were not treated by NHS, whole-body cortisol levels were significantly increased in stressed-control group. Compared with control group, pretreatment with OF70E at concentrations of 25, 50 and 100 mg/L for 6min significantly inhibited the increase of whole-body cortisol levels induced by NHS(p<0.05). To anti-stress effects of OF70E on behavior, we conducted OFT after the induction of NHS following pretreatment of OF70E. As results of OFT, compared with unstressed-normal group, distance moved was significantly decreased by induction of NHS in stressed-control group (p<0.05). OF70E-pretreatment blocked decreases of distance moved increased by NHS (p<0.05). And meandering movement, immobility and turn angle were significantly increased by NHS in stressed-control group compared with unstressed-normal group (p<0.05). OF70E-pretreatment prevented the increases of meandering movement immobility and turn angle by NHS (p<0.05). Conclusions : In conclusion these results suggest that OF70E-pretreatment may prevent stress responses.

• Journal of the Korea Organic Resources Recycling Association
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• v.26 no.2
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• pp.11-18
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• 2018

Biochar is a carbon-rich solid product obtained by the pyrolysis of biomass. It has been suggested to mitigate climate change through increased carbon storage and reduction of greenhouse gas emission. The objective of this study was to evaluate carbon dioxide ($CO_2$) and nitrous oxide ($N_2O$) emissions from soil after various biochars addition. The biochars were produced by pyrolysing pear branch, rice hull and bean straw at $400{\sim}500^{\circ}C$. The treatments were consisted of a control without input of biochar and three type biochars input as 5.0 Mg/ha. Emissions of $CO_2$ and $N_2O$ from upland soil were determined using closed chamber for 8 weeks at $25^{\circ}C$ of incubation temperature. It was shown that the cumulative $CO_2$ were 207.1 to $255.2g\;CO_2/m^2$ for biochar input treatments and $258.6g\;CO_2/m^2$ for the control after experimental periods. The cumulative $CO_2$ emission was slightly decreased in biochar input treatment compared to the control. It was appeared that cumulative $N_2O$ emissions were $2,890.6mg\;N_2O/m^2$ for control, 379.7 to $525.2mg\;N_2O/m^2$ for biochar input treatment at the end of experiment. All biochar treatments were found to significantly reduce $N_2O$ emission by 82~87%. Consequently the biochar from byproducts such as pear branch, rice hull and bean straw could suppress the soil $N_2O$ emission. The results from the study imply that biochar can be utilized to reduce greenhouse gas emission from the upland field.

• Weed & Turfgrass Science
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• v.6 no.1
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• pp.21-27
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• 2017

This study was investigated in order to occurrence of weed flora in orchard (apple, grape, peach, pear etc.) fields and to the establishment of weed control basic data in these weeds. And this study was survey on 2015. As a result of the study on orchard weeds, there were total of 492 weeds including 63 families. Among all the weeds, 159 species were annual, 97 species were winter annual and 236 were perennial. Each fruit tree patterns of occurrence weeds, 306 species 50 families in apple orchard, 304 species 50 families in pear orchard, 286 species 50 families in grape orchard, and 288 species 48 families in peach orchard. Dominance was the highest with Digitaria ciliaris followed by Artemisia princeps, Stellaria aquatica, Commelina communis, Acalypha australis etc. in order. And exotics weeds occurred 127 species. Trifolium repens was the highest in importance analysis and the followings were in order of Conyza canadensis, Chenopodium album, Taraxacum offcinale, Rumex crispus etc. Changes in weed vegetation in orchard during 30 years, did not very many changed. In 1990, D. ciliaris, Persicaria hydropiper, Portulaca loeracea were dominant. In 2003, D. ciliaris was the most abundant species, followed by A. australis, A. princeps species. And in 2015, also D. ciliaris was the most dominant, followed by A. princeps, S. aquatica.