• The Korean Journal of Pesticide Science
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• v.13 no.1
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• pp.28-38
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• 2009

An extrapolation of residue data of seven commonly used pesticides namely bifenthrin, chlorothalonil, cypermethrin, diazinon, fenvalerate, phenthoate and procymidone on a total of 22 minor crops has been carried out in an experimental field trial. The pesticides were applied to 11 leafy-, 5 root- and 6 stem-crops grown in the experimental green-house and the crops and plants were randomly collected at 1, 3, 5, 7 days after application. The average recoveries of applied pesticides were ranged from 72.0 to 117.0% in leafy crops, from 81.3 to 105.0% in stem crops and from 70.1 to 108.1% in the root-crops. Limits of detection (LODs) were 0.005-0.1 mg/kg in the leafy crops and 0.001-0.005 mg/kg in both the stem & root crops. Based on the results of residual dissipation pattern and their morphology, all crops were classified into high and low residual groups. The results showed that it might be possible to extrapolate residual data of stem-crops to root-crops within the same group. Crops that have currently no registered pesticide for use, would be possible to use the pesticides which are already been registered for the similar crops.

• Asian-Australasian Journal of Animal Sciences
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• v.28 no.2
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• pp.280-289
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• 2015

Anaerobic digestion is an efficient and renewable energy technology that can produce biogas from a variety of biomasses such as animal manure, food waste and plant residues. In developing countries this technology is widely used for the production of biogas using local biomasses, but there is little information about the value of these biomasses for energy production. This study was therefore carried out with the objective of estimating the biogas production potential of typical Vietnamese biomasses such as animal manure, slaughterhouse waste and plant residues, and developing a model that relates methane ($CH_4$) production to the chemical characteristics of the biomass. The biochemical methane potential (BMP) and biomass characteristics were measured. Results showed that piglet manure produced the highest $CH_4$ yield of 443 normal litter (NL) $CH_4kg^{-1}$ volatile solids (VS) compared to 222 from cows, 177 from sows, 172 from rabbits, 169 from goats and 153 from buffaloes. Methane production from duckweed (Spirodela polyrrhiza) was higher than from lawn grass and water spinach at 340, 220, and 110.6 NL $CH_4kg^{-1}$ VS, respectively. The BMP experiment also demonstrated that the $CH_4$ production was inhibited with chicken manure, slaughterhouse waste, cassava residue and shoe-making waste. Statistical analysis showed that lipid and lignin are the most significant predictors of BMP. The model was developed from knowledge that the BMP was related to biomass content of lipid, lignin and protein from manure and plant residues as a percentage of VS with coefficient of determination (R-square) at 0.95.This model was applied to calculate the $CH_4$ yield for a household with 17 fattening pigs in the highlands and lowlands of northern Vietnam.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.spc1
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• pp.77-84
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• 2005

Three new rice farming systems, i.e. (1) straw-mulched no-till rice cropping system(SMNTRCS), (2)straw-mulched no-till rice-vetch cropping system (SMNTRWCS), (3)conventional rice-barley cropping system(CRVCS) have been established and compared with (4)conventional rice cropping system(CRCS). Grain appearance of brown rice of Korean native rice cultivars in SMNTRCS and SMNTRVCS were better than those in CRBCS and CRCS. Grain appearance of milled rice in SMNTRCS was better than those of other cropping systems. Korean native rice cultivars showed more white belly and broken rice than those of recommended rice cultivars. Mg and K contents of Korean native rice cultivars were the highest in SMNTRVCS. Protein contents of all the cultivars tested were the highest in SMNTRCS. Protein contents of Korean native cultivars were higher than those of recommended cultivars. Amylose contents of the cultivars tested were from 16 to 22 percent, while those of Aedal and Jenmjo were significantly higher than those of the other cultivars. Alkali digestibility values(ADV) of milled rice grain, tested in $1.2\%$ potassium hydroxide for 23 h at $30^{\circ}C$, showed varietal differences and the cultivars grown in CRBCS were the highest and the lowest in CRCS.

• Korean Journal of Weed Science
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• v.14 no.1
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• pp.34-41
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• 1994

To better understand the allelopathic effect of sorghum(Sorghum vulgare L.), the inhibitory activities of water extracts of the stem, leaf and root, and of residues of the stem to major crops and weeds associated with them were evaluated. The allelopathic activity of sorghum plants was species specific, and depended on source and concentration. Germination, and shoot and root length of all test species were inhibited by the different concentrations of the stem extract. Among the crop species, radish showed the most inhibition, followed by wheat and rice. Maize was the least sensitive species. Of the weed species, Ipomoea triloba was most inhibited, followed by Echinochloa colona and Rottboellia cochinchinensis. The water extracts of leaves, stems, and roots significantly inhibited germination and seedling growth in E. colona and radish. The stem extract gave the greatest inhibitory effect on E. colona while all three extracts produced similar response in radish. In the greenhouse trial, sorghum stem residue placed on the soil surface as mulch significantly inhibited seedling growth in E. colona and radish, but not that in rice.

• Korean Journal of Environmental Agriculture
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• v.16 no.3
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• pp.255-258
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• 1997

In order to determine the removal efficiency of pesticide residues on apples by ultrasonic cleaner, apples(Fuji var.) were artificially treated by dipping in water solution of fenitrothion EC, chlorpyrifos EC and phenthoate EC. The treated apples were washed by the ultrasonic cleaner with water, 30% ethanol solution or 0.2% detergent solution, respectively. The removal efficiency of fenitrothion, chlorpyrifos and phent-hoate by ultrasonicated washing in water for 0.5min. was 39.2%, 32.0% and 50.4%, respectively, but there was a tendency to decrease the removal efficiency of the pesticide residues as the duration of ultrasonicated washing period is increased. The maximum removal efficiency of the pesticide residues washed in the detergent solution was observed by ultrasonicated washing the samples for 5min. and it was recorded as 33.5% ; fenitrothion, 30.1% ; chlorpyrifos and 48.3% ; phenthoate, respectively. However it's appeared that the longer the ultrasonicated washing period in 30% ethanol solution the more pesticides from the apples were removed and the maximum removal efficiency of the pesticides was recorded as 66.2%(fenitrothion ; washed for 15min.), 41.7%(chlorpyrifos ; washed for 10min.), 74.2%(phenthoate ; washed for 10min.).

• The Korean Journal of Pesticide Science
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• v.9 no.4
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• pp.330-337
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• 2005

This study was investigated to elucidate the pesticide mobility in three different soil textures(Heongseong sandy loam; Chuncheon, loam; Taeback, silty clay loam) and four different gravel contents(0, 20, 40, 60%) of Taebaek soil using soil column. Carbofuran, which ranks the highest water solubility among 7 pesticides(carbendazim, carbofuran, chlorpyrifos, cypermethrin, dimethomorph, diniconazole and endosulfan) was defected over 87% in leachate samples within all soil types from early sampling time. Amount of 5 residual pesticides excluding carbendazim and carbofuran were ordered silty clay loam > loam > sandy loam, indicating pesticide residues are related to percentage of clay contents in soils. Comparing the amount of residual pesticides in soil column(upper, middle and lower layer), 6 pesticides apart from carbofuran were found in the range of $50{\sim}92%$ on the upper layer of silty clay loam and loam. Mobility of pesticides either in soil or leachate samples is dependant on water solubility of pesticide and clay content of soil. The results obtained from four different gravel contents of Tacback soil were similar to the results of three different soil textures. Also it was found that more the gravel contents, faster the flow velocity of leachate water. These results possibly provide an idea to select proper pesticides and to reduce soil and water contamination at alpine and sloped-land.

• Korean Journal of Environmental Agriculture
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• v.42 no.2
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• pp.139-151
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• 2023

Sulfonylurea herbicides are widely used in agriculture because they have a long residual period and high selectivity. An analytical method was developed using QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) technique for simultaneous determination of sulfonylurea herbicide residues in agricultural products by liquid chromatography tandem mass spectrometry and for establishment MRL (Maximum Residue Limit) of those herbicides in Korea. Extraction was performed using acetonitrile containing 0.1% formic acid with MgSO₄ (anhydrous magnesium sulfate) and NaCl (sodium chloride) and the extract was cleaned up using MgSO₄ and C₁₈ (octadecyl). The matrix-matched calibration curves were composed of 7 concentration levels from 0.001 to 0.25 mg/kg and their coefficients of determination (R²) exceeded 0.99. The recoveries of three spiking levels (LOQ, 10LOQ, 50LOQ, n=5) were in the range of 71.7-114.9% with relative standard deviations of less than 20.0% for all the five agriculture products. All validation values met criteria of the European Union SANTE/11312/2021 guidelines and Food and Drug Safety Evaluation guidelines. Therefore, the proposed analytical method was accurate, effective, and sensitive for sulfonylurea herbicide residues determination in agricultural commodities.

• Journal of Korean Society for Atmospheric Environment
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• v.31 no.1
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• pp.63-71
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• 2015

The gaseous and particulate emissions from agricultural crop residues burning were investigated. The test residues included white soybean stem, pepper stem, apple branch, peach branch, pear branch, grape branch, sesame stem, perilla stem, and barley stem. Particulate emissions were dominated by fine particles (< $0.1{\mu}m$ in size). The highest $PM_{2.5}$ Emission factors were from barley stems (35.2 g/kg), and the lowest from pepper stems (7.9 g/kg). Emission factors for CO, NO, and VOCs were 146~305 g/kg, 4.94~15.02 g/kg, 27.4~353.3 g/kg, respectively. Benzene played an important role in VOCs emissions from biomass burning.

• Mycobiology
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• v.43 no.1
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• pp.14-23
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• 2015

The influences of temperature and nutritional conditions on the mycelium growth of oyster mushroom Pleurotus ostreatus (PO) and Pleurotus cystidiosus (PC) were investigated in laboratory experiment during the summer season of 2014. The results of the experiment indicated that potato dextrose agar (PDA) and yam dextrose agar (YDA) were the most suitable media for the mycelium growth of oyster mushroom PO while four media (PDA, YDA, sweet potato dextrose agar, and malt extract agar medium) were not significantly different in supporting mycelium growth of oyster mushroom PC. The optimal temperature for mycelium growth of both oyster mushroom species was obtained at $28^{\circ}C$. Mycelium growth of oyster mushroom PO was improved by carbon sources such as glucose, molasses, and at 1~5% sucrose concentration, mycelium colony diameter of mushroom PO was achieved the highest value. Whereas glucose, dextrose, and sucrose as carbon sources gave the good mycelium growth of oyster mushroom PC, and at 1~3% sucrose concentration, mycelium colony diameter of PC was achieved the maximum value. Ammonium chloride concentrations at 0.03~0.09% and 0.03~0.05% also gave the greatest values in mycelium colony diameter of mushroom PO and PC. Brown rice was found to be the most favourable for mycelium growth of two oyster mushroom species. In addition, sugarcane residue, acasia sawdust and corn cob were selected as favourable lignocellulosic substrate sources for mycelium growth of both oyster mushrooms.

• Current Research on Agriculture and Life Sciences
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• v.32 no.2
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• pp.67-73
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• 2014

Mulberry fruits were semi-dried using hot air ($60-100^{\circ}C$) or cool air ($20-40^{\circ}C$), and the effects of the drying temperature and processing time on the quality of the final dried mulberry fruits were investigated. Response surface methodology was employed to establish a statistical model and predict the conditions resulting in minimal loss of the total phenolic content (TPC) and ascorbic acid. Thus, using overlapped contour plots, the optimal conditions for producing semi-dried mulberry fruits, which reduced the moisture residue to 45% and minimized the nutrient losses of TPC and ascorbic acid, were determined for the hot-air process ($60.7^{\circ}C$ for 5.4 h) and cool-air process ($34.8^{\circ}C$ for 23.3 h). Plus, a higher drying temperature was found to lead to a faster loss of moisture and ascorbic acid, while the TPC was significantly decreased in the cool-air dried mulberry fruits due to the higher activity of polyphenol oxidase between 30 and $40^{\circ}C$.