Current Issue 2018. Vol.37, Iss.2

Orginal Articles

• The Selection of Proper Resource and Change of Salinity in Helianthus tuberosus L. Cultivated in Saemangeum Reclaimed Tidal Land

  Yang-Yeol Oh, Jung-Tae Lee, Ha-Cheol Hong, Jae-Hyun Kim, Woo-Duck Seo, Sun Kim, Jin-Hee Ryu, Su-Hwan Lee, Young-Joo Kim / Korean Journal of Environmental Agriculture / 2018 / v.37, no.2, 73-78

  https://doi.org/10.5338/KJEA.2018.37.2.11

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Soil salinity of reclaimed tidal land in Korea is highly important factor. High salinity is harmful to crop productivity. Jerusalem artichoke (Helianthus tuberosus L.) is known to be salt-tolerant and has high adaptability to diverse pedo-climatic conditions. The objective of this study was to assess the changes of soil properties and crop productivity according to salt concentration in the reclaimed tidal lands.

  METHODS AND RESULTS:

  Experimental sites were selected at Saemangeum (35°46’N, 126°37’E) reclaimed tidal land, and their dominant soil series were Munpo (coarse loamy, mixed, non-acid, mesic, typic Fluvaquents). H. tuberosus L were collected from 12 locations across Korea. Tubers were planted at 75×25 cm with EC 2 to 7 dS m^-1. Soil samples were periodically collected from both 0~20 cm and 20~40 cm depths of each site. Soil salinity and soil moisture contents were varied depending on weather conditions. Soil electrical conductivity varied from 1.0 to 5.9 dS m^-1, and soil moisture contents varied from 9.2 to 28.7%. The white-colored tubers of H. tuberosus L. collected from `Yeongwol-gun’exhibited the highest height (207 cm), followed by the white-colored tubers of H. tuberosus L. collected from‘Iksan-si’(202 cm). The white-colored tubers of H. tuberosus L. collected from ‘GyeongJu-si’showed the highest yield (549 kg/10a). The purple-colored tubers of H. tuberosus L. collected from ‘Yeongwol-gun’showed the highest yield (615 kg/10a).

  CONCLUSION:

  Our results indicate that the plant height and tuber yield did not appear to be correlated. Considering yield and inulin content, the GyeongJu-si seemed to be suitable as the white-colored tubers of H. tuberosus L. and the Yeongwol-gun seemed to be suitable as the purple-colored tubers of H. tuberosus L. in the reclaimed tidal lands. However, it is necessary to consider the relationship between the inulin content and the yield.

• Effects of Various Light Sources on the Carotenoid and Glucosinolate Contents in Chinese Cabbage (Brassica rapa L. ssp. pekinensis)

  Ho-Young Sung, Lee-Kyeong Jo, Jin-Hyuk Chun, Hyun-Nyung Woo, Sun-Ju Kim / Korean Journal of Environmental Agriculture / 2018 / v.37, no.2, 79-86

  https://doi.org/10.5338/KJEA.2018.37.2.13

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Chinese cabbage biosynthesizes various phytochemicals including carotenoids and glucosinolates. Environmental stress has a major effect on the growth and yields of vegetables, and can significantly affect nutritionally important phytochemicals. Phytochemicals of plants are influenced by light, temperature, carbon dioxide, and growing conditions. The aim of this study was to investigate the effect of various light sources on carotenoid and glucosinolate contents in Chinese cabbage.

  METHODS AND RESULTS:

  [Experiment I] Set the control (field control, FC) on the ground. Using acrylic sunlight, experiments were set up transparency box (field transparency, FT), red box (field red, FR) and blue box (field blue, FB). [Experiment II] Set the control (chamber control, CC) in the greenhouse. Using plant growth chamber with artificial light, experiments were set up LED red (chamber red, CR), LED blue (chamber blue, CB), LED mixed red+blue (chamber red+blue, CRB) and fluorescent (chamber fluorescent, CF). After plant growth, Chinese cabbage was harvested at 110 days after sowing (DAS). The status of plants growth (leaf length, width, fresh weight etc.) was immediately investigated. Carotenoid and GSL contents were analyzed by HPLC. [Experiment Ⅰ] Results documented that the ranges of total carotenoid contents were 25.39 ~ 58.80 mg/kg dry wt for lutein, 0.84~ 4.22 mg/kg dry wt for zeaxanthin, and 3.85~18.71 mg/kg dry wt for β-carotene. Lutein was the highest for the content and the largest for the variation as well. [Experiment II] Results documented that the ranges of total carotenoid contents were 24.66~137.96 for lutein, 2.51~20.65 for zeaxanthin, and 8.40~49.80 mg/kg dry wt for β-carotene. The total carotenoid contents of CR (156.62) and CB (115.90) were 1.6~2.3 times larger than the other treatments, and β-carotene content was about twice as high as that of the other treatments on the CR (38.74 mg/kg dry wt.). [Experiment I] Total GSL content was the highest in FT (19.76) that was higher 1.7 times than the lowest treatment (11.39 μmol/g dry wt.). [Experiment II] The total content of GSL was highest in CRB (4.19) and lowest in CF (2.88 μmol / g dry wt.). In the CRB, total GSL contents (4.19 μmol/g dry wt.) was the highest.

  CONCLUSION:

  Total and individual carotenoid and GSL contents in Chinese cabbage show significant differences under different light sources. Red and blue lights contribute to significant carotenoids expression and antioxidant activity for nutrition and health benefits. These results concluded that the introduction of varying lights affected the synthesis of important nutrient compounds in Chinese cabbage. It is predicted that the application of good light source enhances the accumulation of functional compounds.

• Growth Control of Upper Part in ‘Fuji’/M.9 Apple Tree Canopy by Cutting Time of Trunk and Plant Growth Regulators

  Dong-Hoon Sagong, Jae-Wang Lee, Tae-Myung Yoon / Korean Journal of Environmental Agriculture / 2018 / v.37, no.2, 87-96

  https://doi.org/10.5338/KJEA.2018.37.2.15

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  The vigorous shoot growth in upper part of apple tree canopy leads to poor fruit quality and flower bud formation in lower part of canopy. So, this study was conducted to develop the proper control method about the shoot growth in upper part of apple tree canopy.

  METHODS AND RESULTS:

  Trunks of 'Fuji'/M9 apple trees were cut (back pruned) to 2.5 m in tree height on 11 February (dormant) or 12 April (full bloom). Naphthalene acetic acid (NAA) was applied at 2.0% to cut surface when trunk was pruned. Prohexadione-calcium (Pro-Ca) was sprayed at 250 mg/L above 2.0 m in tree height at 23 April (petal fall). The NAA or Pro-Ca application after trunk was pruned at dormant (TR-2 and TR-3) significantly reduced shoot growth in upper part of canopy compared with the control (tree was only pruned at dormant, TR-1), but the percent of shoots showing the secondary growth of TR-3 was higher over 2 times than that of TR-2. The reduction of shoot growth in upper part of canopy by TR-2 and TR-3 increased the fruit red color from the lower part in the treating year and blooming of the lower part in the following year.

  CONCLUSION:

  Applying 2.0% NAA to cut surface of pruned apple trunk at dormant was the most effective way for stabilization of the tree vigor in upper part of the canopy in a high density apple orchard.

• Residue Dissipation Patterns of Neonicotinoid Acetamiprid and Thiamethoxam in Swiss Chard for the Harvest Periods under Greenhouse Conditions

  Hee-Ra Chang, Jung-Sun You, Jung-Ah Do / Korean Journal of Environmental Agriculture / 2018 / v.37, no.2, 97-103

  https://doi.org/10.5338/KJEA.2018.37.2.17

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Dissipation of acetamiprid and thiamethoxam in greenhouse grown chard samples was evaluated at 5 intervals including the pre-harvest interval after application. This study was conducted to determine the residue levels, the biological half-lives and dissipation rate of acetamiprid and thiamethoxam in chard under controlled conditions.

  METHODS AND RESULTS:

  Acetamiprid and thiamethoxam were applied in accordance with good agricultural practices for chard. Chard samples were collected at 0, 1, 2, 3, 5, 7, 10 and 14 days after application. Quantitaion was performed by HPLC-DAD system with C18 column. Limit of quantification (LOQ) of acetamiprid and thiamethoxam were both 0.02 mg/kg for chard. The recovery of acetamiprid and thiamethoxam were 77.8~107.5% and 94.3~108.6% at two concentration levels. The half-lives of pesticide dissipation in chard for two fields were 11.9 and 8.2 days for acetamiprid and 3.6 and 3.3 days for thiamethoxam respectively. The dissipation rate of acetamiprid and thiamethoxam were estimated according to the statistics method with a 95% confidence.

  CONCLUSION:

  Dissipation of acetamiprid and thiamethoxam in chard were determined under greenhouse. The concentration of acetamiprid and thiamethoxam in chards at 0 days after application were below specified by Korean MRL. Dissipation rate constant will be useful to set the pre-harvest residue limit for public health and consumer protection.

• Simultaneous Pesticide Analysis Method for Bifenox, Ethalfluralin, Metolachlor, Oxyfluorfen, Pretilachlor, Thenylchlor and Trifluralin Residues in Agricultural Commodities Using GC-ECD/MS

  Kyung Geun Ahn, Gi Ppeum Kim, Young Sun Hwang, In Kyu Kang, Young Deuk Lee, Myoung Gun Choung / Korean Journal of Environmental Agriculture / 2018 / v.37, no.2, 104-116

  https://doi.org/10.5338/KJEA.2018.37.2.12

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  This experiment was conducted to establish a simultaneous analysis method for 7 kinds of herbicides in 3 different classes having similar physicochemical property as diphenyl ether(bifenox and oxyfluorfen), dinitroaniline (ethalfluralin and trifluralin), and chloroacetamide (metolachlor, pretilachlor, and thenylchlor) in crops using GC-ECD/MS.

  METHODS AND RESULTS:

  All the 7 pesticide residues were extracted with acetone from representative samples of five raw products which comprised apple, green pepper, Kimchi cabbage, hulled rice and soybean. The extract was diluted with saline water and directly partitioned into n-hexane/dichloromethane(80/20, v/v) to remove polar co-extractives in the aqueous phase. For the hulled rice and soybean samples, n-hexane/acetonitrile partition was additionally employed to remove non-polar lipids. The extract was finally purified by optimized Florisil column chromatography. The analytes were separated and quantitated by GLC with ECD using a DB-1 capillary column. Accuracy and precision of the proposed method was validated by the recovery experiment on every crop samples fortified with bifenox, ethalfluralin, metolachlor, oxyfluorfen, pretilachlor, thenylchlor, and trifluralin at 3 concentration levels per crop in each triplication.

  CONCLUSION:

  Mean recoveries of the 7 pesticide residues ranged from 75.7 to 114.8% in five representative agricultural commodities. The coefficients of variation were all less than 10%, irrespective of sample types and fortification levels. Limit of quantitation (LOQ) of the analytes were 0.004 (etahlfluralin and trifluralin), 0.008 (metolachlor and pretilachlor), 0.006 (thenylchlor), 0.002 (oxyfluorfen), and 0.02 (bifenox) mg/kg as verified by the recovery experiment. A confirmatory technique using GC/MS with selected-ion monitoring was also provided to clearly identify the suspected residues. Therefore, this analytical method was reproducible and sensitive enough to determine the residues of bifenox, ethalfluralin, metolachlor, oxyfluorfen, pretilachlor, thenylchlor, and trifluralin in agricultural commodities.

• Determination of Oxycarboxin Residues in Agricultural Commodities Using HPLC-UVD/MS

  Myoung-Gun Choung / Korean Journal of Environmental Agriculture / 2018 / v.37, no.2, 117-124

  https://doi.org/10.5338/KJEA.2018.37.2.14

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Oxycarboxin(5,6-dihydro-2-methyl-N-phenyl-1,4-oxathiin-3-carboxamide-4,4-dioxide) as oxanthiin is a systemic fungicide commonly used for control of various pathogens in agronomic and horticultural crops. In an effort to develop an analytical method to trace the fungicide, a method using HPLC equipped with UVD/MS was studied.

  METHODS AND RESULTS:

  Oxycarboxin was extracted with acetone from hulled rice, soybean, Kimchi cabbage, green pepper, and apple samples. The extract was diluted with saline water, followed by liquid-liquid extraction with methylene chloride. Florisil column chromatography was employed for the purification of the extracts. Oxycarboxin was determined on a Zorbax SB-AQ C₁₈ column by HPLC with UVD. Accuracy of the proposed method was validated by the recovery tests from crop samples fortified with oxycarboxin at 3 levels per crop.

  CONCLUSION:

  Mean recoveries ranged from 78.3% to 96.1% in five representative agricultural commodities. The coefficients of variation were less than 10%, and limit of quantitation of oxycarboxin was 0.04 mg/kg. A confirmatory technique using LC/MS with selected-ion monitoring was also provided to clearly identify the suspected residue. The method was reproducible and sensitive to determine the residue of oxycarboxin in agricultural commodities.

• Screening of Plant Extracts and Identification of their Insecticidal Metabolites against Myzus persicae

  Si young Yang, Da jung Lim, Yeo Hee Kim, In Seon Kim / Korean Journal of Environmental Agriculture / 2018 / v.37, no.2, 125-134

  https://doi.org/10.5338/KJEA.2018.37.2.19

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Green peach aphid (Myzus persicae) is an insect pest that significantly affects crop production. A number of pesticides have been used for aphid control, but their concerns on insect resistance and food safety have required alternative methods for pest management. In an effort to find for an alternative approach to aphid control, we screened plants extracts and examined their potentiality as insecticidal bio-resources.

  METHODS AND RESULTS:

  Two hundred and ninety eight plant extracts were examined for insecticidal activity against the aphid, and the best candidate among them was chosen for further study. The extracts from Cinnamomum camphora was determined to be the best candidate exhibiting insecticidal activity more than 60% at a level of 1,000 ㎍/mL. GC/MS analyses detected camphor, borneol, 4-terpineol, α-terpineol and caryophyllene oxide as major compositions from the extracts obtained by hydrodistillation. Caryophyllene oxide exhibited the highest insecticidal activity with a LC₅₀ value of 237 ㎍/mL. Camphor lowered significantly the LC₅₀ value of caryophyllene oxide and increased largely its concentration in aphid, suggesting that camphor played a role in enhancing the insecticidal activity of caryophyllene oxide.

  CONCLUSION:

  This study suggested that camphor and caryophyllene oxide may be used as an insecticidal bio-resource for insect control against green peach aphid.

• Intestine Bacterial Microbiota of Asian Hornet (Vespa Velutina Nigrithorax) and Honey Bee

  Euyeon Kim, Jeongwon Seo, So Hee Yang, In-Seon Kim, Yeonjong Koo / Korean Journal of Environmental Agriculture / 2018 / v.37, no.2, 135-140

  https://doi.org/10.5338/KJEA.2018.37.2.18

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  The Asian hornet (Vespa velutina nigrithorax), a wasp species, has attacked honey bee populations and affected the beekeeping industry in Korea over the past 15 years. However, little research has been done with this invasive species. In this study, we investigated the intestine bacterial microbiota of Asian hornets and honey bees to design an attractive trap for Asian hornets.

  METHODS AND RESULTS:

  Genomic DNAs isolated from the intestine microorganisms of Asian hornets and honey bees were utilized to amplify bacterial 16S rDNA for the comparative sequence analysis. The next generation sequencing analysis identified that the orders Flavobacteriales as the most abundant intestinal microorganisms in Asian hornets, showing a clear difference compared to honey bees in which Aeromonadales are dominant. We also report five newly identified 16S rDNA sequences of Asian hornet intestinal bacteria. According to the sequence blast search, these five bacteria belong to the genera Thalassomonas, Caedobacter, Vampirovibrio, Alkaliphilus and Calothrix.

  CONCLUSION:

  While Asian hornets and honey bees show similar intestine bacterial diversity, the relative ratio of bacterial populations is different. providing useful information to design pest control agents specifically targeting Asian hornets.

• Evaluation on Heavy Metal Contents in Agricultural Soils around Industrial Complexes in Korea

  Sun-Gang Yun, Mi-Jin Chae, Yoo-Hak Kim, Myung-Suk Kong, Ha-il Jung, Suk-Cheol Kim, Myoung-Suk Kim, Seong-Jin Park, Chang-Hoon Lee, Jae-E Yang, Sung-Chul Kim, Gi-In Kim, Gwon-Rae Kim, Goo-Bok Jung / Korean Journal of Environmental Agriculture / 2018 / v.37, no.2, 141-145

  https://doi.org/10.5338/KJEA.2018.37.2.16

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Agricultural soils are vulnerable from contamination of heavy metal derived from industrial waste. Monitoring on heavy metals on agricultural soils around industrial complexes and evaluation on distributional state on the concentrations of heavy metals in soil have been carried out for problem assessment on soil condition.

  METHODS AND RESULTS:

  Soil samples of 1,200, were collected from sixty site of industrial complexes located Gyounggi, Chungbuk, Cheonbuk, and Gyoungnam provinces. Total concentration of Cu, Pb, Zn, Ni, and As were analyzed. Heavy metal concentrations in most soil samples were below warning criteria, except 1 site of Pb, Ni, and As, separately. The comparison of mean values of heavy metal concentrations between soils around industrial complexes and paddy soils, showed similar levels of heavy metals, except Pb. The concentrations of lots of heavy metals were distributed between from warning criteria to one fifth level of warning criteria. However, in the case of Cu and Pb, more than 30% were distributed below one twenties level of warning criteria. These results were very similar with the distribution state of heavy metals in upland soils. The concentrations of heavy metals in surface soil and subsoil were similar among the heavy metals in soils around industrial complexes.

  CONCLUSION:

  The concentrations of heavy metals in soils around industrial complexes were distributed close to warning criteria. Long term and continous monitoring and evaluation on heavy metals in agricultural soils are required for food safety and sustainable soil management.

• Selenite Reduction to Elemental Selenium by Citrobacter Strain SE4-1 Isolated from a Stream Sediment

  Ji-Hoon Lee, Ahyeon Cho, Hyeri Lee / Korean Journal of Environmental Agriculture / 2018 / v.37, no.2, 146-149

  https://doi.org/10.5338/KJEA.2018.37.2.20

  Abstract Full-Text PDF

  Abstract

  

  BACKGROUND:

  Selenium is an essential element for all life forms but can be toxic above certain narrow levels. Prevalent forms of selenium in oxic environment are selenium oxyanions such as selenite and selenate, which may be contaminants in soils and water bodies. Bacterial reduction of more mobile selenium species (selenite or selenate) to less mobile elemental selenium may suggest a benign solution for alleviating toxicity and bioavailability of the selenium species.

  METHODS AND RESULTS:

  A facultative anaerobic bacterium, Citrobacter strain SE4-1 was isolated from the contaminated stream sediments and found to effectively reduce selenite to elemental selenium. Aqueous phase of selenite was analyzed by inductively couple plasma spectroscopy and the precipitated sphere-shaped elemental selenium was observed by transmission electron microscopy.

  CONCLUSION:

  The bacterial strain SE4-1 isolated in this study suggests a potential role in biogeochemical cycle of selenium by the selenite reduction in the stream environment, and potentials for biotechnological applications to reduceselenium concentrations in selenium-contaminated systems such as wastewater, soil, and groundwater.