• Journal of Ecology and Environment
• /
• v.38 no.3
• /
• pp.353-360
• /
• 2015

A survey of weed occurrence was conducted to identify problematic weed species in a horticultural crop field to get basic information for effective weed control. Surveys of weed species occurring in horticultural crop fields (garlic, onion, red pepper and Chinese cabbage) were conducted in Chungnam province of Korea from April to October in 2014. A total of 516 sites of the 17 regions were identified as having 114 weed species belonging to 32 families. The most dominant weed species in the horticultural crop fields were Chenopodium album var. centrorubrum (8.83%), followed by Digitaria ciliaris (5.71%), Conyza canadensis (5.46%) and Capsella bursa-pastoris (4.67%). Specifically, as a result of this study, the occurrence of 35 species of exotic weeds, such as Chenopodium album and Taraxacum officinale, were confirmed. Almost 68% of the investigation sites was determined under dominance value 1 (range of cover < 10; numerous individuals) by Braun-Branquet cover-abundance scale, indicating a proper weed control in horticultural crop field. As a result of scientific and technological advances, an improved cultivation method is changing the weed occurrence in agricultural land. Additional research needs to be undertaken for the development of weed control methods through such periodic monitoring of occurrence of weeds.

• The Plant Pathology Journal
• /
• v.35 no.6
• /
• pp.585-597
• /
• 2019

A disease forecast model for Marssonina blotch of apple was developed based on field observations on airborne spore catches, weather conditions, and disease incidence in 2013 and 2015. The model consisted of the airborne spore model (ASM) and the daily infection rate model (IRM). It was found that more than 80% of airborne spore catches for the experiment period was made during the spore liberation period (SLP), which is the period of days of a rain event plus the following 2 days. Of 13 rain-related weather variables, number of rainy days with rainfall ≥ 0.5 mm per day (L_day), maximum hourly rainfall (P_max) and average daily maximum wind speed (W_avg) during a rain event were most appropriate in describing variations in airborne spore catches during SLP (S_i) in 2013. The ASM, Ŝ_i = 30.280+5.860×L_day×P_max-2.123×L_day×P_max×W_avg was statistically significant and capable of predicting the amount of airborne spore catches during SLP in 2015. Assuming that airborne conidia liberated during SLP cause leaf infections resulting in symptom appearance after 21 days of incubation period, there was highly significant correlation between the estimated amount of airborne spore catches (Ŝ_i) and the daily infection rate (R_i). The IRM, ${\hat{R}}_i$ = 0.039+0.041×Ŝ_i, was statistically significant but was not able to predict the daily infection rate in 2015. No weather variables showed statistical significance in explaining variations of the daily infection rate in 2013.

• The Plant Pathology Journal
• /
• v.34 no.3
• /
• pp.191-198
• /
• 2018

Fast and accurate diagnosis is needed to eradicate and manage economically important and invasive diseases like fire blight. Loop-mediated isothermal amplification (LAMP) is known as the best on-site diagnostic, because it is fast, highly specific to a target, and less sensitive to inhibitors in samples. In this study, LAMP assay that gives more consistent results for on-site diagnosis of fire blight than the previous developed LAMP assays was developed. Primers for new LAMP assay (named as DS-LAMP) were designed from a histidine-tRNA ligase gene (EAMY_RS32025) of E. amylovora CFBP1430 genome. The DS-LAMP amplified DNA (positive detection) only from genomic DNA of E. amylovora strains, not from either E. pyrifoliae (causing black shoot blight) or from Pseudomonas syringae pv. syringae (causing shoot blight on apple trees). The detection limit of DS-LAMP was 10 cells per LAMP reaction, equivalent to $10^4$ cells per ml of the sample extract. DS-LAMP successfully diagnosed the pathogens on four fire-blight infected apple and pear orchards. In addition, it could distinguish black shoot blight from fire blight. The $B{\ddot{u}}hlmann$-LAMP, developed previously for on-site diagnosis of fire blight, did not give consistent results for specificity to E. amylovora and on-site diagnosis; it gave positive reactions to three strains of E. pyrifoliae and two strains of P. syringae pv. syringae. It also, gave positive reactions to some healthy sample extracts. DS-LAMP, developed in this study, would give more accurate on-site diagnosis of fire blight, especially in the Republic of Korea, where fire blight and black shoot blight coexist.

• Proceedings of the Korean Society of Organic Agriculture Conference
• /
• 2009.12a
• /
• pp.279-280
• /
• 2009

우리나라는 1990년대 후반부터 유기농업에 대한 관심이 높아지기 시작해 유기농산물 생산이 매년 증가추세를 보이고 있다. 유기농업의 관심증대는 유기농업에 사용되는 자재에도 영향을 미치게 되었으며, 친환경농업육성법 제7조에 따른 별표1에 유기농산물 생산을 위해 사용이 허용된 자재 119종을 명시하였다. 또한 이를 원료로 한 친환경유기농자재에 대해 농촌진흥청에서 고시한 '친환경유기농자재 목록공시기준 및 품질규격'에 따라 제품을 평가하여 친환경유기농자재목록에 등재하게 되어있다. 본 연구는 우리나라 친환경유기농자재 등록을 위한 안전성 평가 항목을 유럽에서 적용하고 있는 유기 농자재 목록공시를 위하여 요구되는 FiBL(스위스 국제유기농업연구소)의 평가 항목과 미국 OMRI(미국 유기농자재 평가원)의 평가 항목을 비교하여 도입이 가능한 항목을 검토, 제안하기 위해 수행하였다. 조사 결과는 친환경유기농자재 평가항목의 국 내외 기준 평가와 친환경유기농자재 평가의 국제 규격 부합도 평가, 두 가지로 구분되며, 친환경유기농자재 평가항목의 국 내외 기준 평가 결과 선진국의 평가 항목에 비해 평가항목들이 세분화되어 있지 않고 검토과정이 서면으로 이뤄지기 때문에 전문가들의 평가에도 한계가 있었다. 따라서 OMRI 및 FiBL의 평가항목 중 국내에 도입 가능한 항목을 수집하여 평가항목 개선방안(표 1)을 제시하였다. 국제 규격 부합도 평가 결과 친환경유기농자재 관련 법규 및 규정의 분산으로 인해 생산자 및 수요자가 자재 등록 및 사용에 어려움이 따르고 있고, 미국 OMRI의 경우 자재를 자체적으로 분석하여 검토하는 절차에 반해 우리나라의 경우 전문기관과 전문 인력의 부족으로 평가결과에 대해 수요자의 신뢰도가 낮아지고 있다. 환경위해성 및 독성에 대한 안전성 강화를 위해 전문기관과의 협의 및 심의 체계 확립이 필요하며 올바른 관리를 위한 자재 종류별 최소한의 담당 전문가 배치가 필요하다.

• Toxicological Research
• /
• v.28 no.3
• /
• pp.179-185
• /
• 2012

Paecilomyces sinclairiis (PS) is known as a functional food or human health supplement. However concerns have been raised about its kidney toxicity. This study was performed to investigate the kidney toxicity of PS by 13 week-oral administration to rats. Blood urea nitrogen (BUN), serum creatinine, and kidney damage biomarkers including beta-2-microglobulin (${\beta}2m$), glutathione S-transferase alpha (GST-${\alpha}$), kidney injury molecule 1 (KIM-1), tissue inhibitor of matrix metalloproteinase 1 (TIMP-1), vascular endothelial growth factor (VEGF), calbindin, clusterin, cystatin C, neutrophil gelatinase-associated lipocalin (NGAL) and osteopontin were measured during or after the treatment of PS. BUN, creatinine and kidney damage biomarkers in serum were not changed by PS. However, kidney cell karyomegaly and tubular hypertrophy were observed dose-dependently with higher severity in males. KIM-1, TIMP-1 and osteopontin in kidney and urine were increased dose dependently in male or at the highest dose in female rats. Increased urinary osteopontin by PS was not recovered at 2 weeks of post-exposure in both genders. Cystatin C in kidney was decreased at all treatment groups but inversely increased in urine. The changes in kidney damage biomarkers were more remarkable in male than female rats. These data indicate that the PS may provoke renal cell damage and glomerular filtration dysfunction in rats with histopathological lesions and change of kidney damage biomarkers in kidney or urine. Kidney and urinary KIM-1 and cystatin C were the most marked indicators, while kidney weight, BUN and creatinine and kidney damage biomarkers in serum were not influenced.

• Journal of Environmental Science International
• /
• v.27 no.12
• /
• pp.1241-1247
• /
• 2018

This study was conducted to evaluate resistance of 10 different cowpea cultivars which were introduced from the United States against two major root-knot nematodes, Meloidogyne arenaria and M. incognita, that affect greenhouse crop cultivation in Korea. The results showed that the resistance of the tested cultivars to the root-knot nematodes varied with the cultivar. Texas Cream 40 showed moderate resistance to M. arenaria whereas the other cultivars were susceptible. Purple Hull Pinkeye and Texas Pinkeye Purple Hull were found to be resistant to M. incognita, whereas Mississippi Silver showed moderate resistance and the other cultivars were susceptible. As the cultivars exhibit resistance to M. arenaria and M. incognita, such cultivars resistant to root-knot nematodes should be considered during the cultivation of cowpea as a green manure crop.

• Korean Journal of Environmental Agriculture
• /
• v.37 no.4
• /
• pp.324-332
• /
• 2018

BACKGROUND: Insects are ectothermic organisms in terrestrial ecosystems and play various roles such as controlling plant biomass and maintaining species diversity. Because insects are ectothermic, their physiological responses are very sensitive to environmental temperature which determines survival and distribution of insect population and that affects climate change. This study aimed to identification of genes contributing to fitness under high temperature. METHODS AND RESULTS: To identify genes contributing to fitness under high temperature, the transcriptomes of fat body in Plutella xyostella larva have been analyzed via next generation sequencing. From the fat body transcriptomes, structure-related proteins, heat shock proteins, antioxidant enzymes and detoxification proteins were identified. Genes encoding proteins such as structural proteins (cuticular proteins, chitin synthase and actin), stress-related protein (cytochrome P450), heat shock protein and antioxidant enzyme (catalase) were up-regulated at high temperature. In contrast expression of glutathione S transferase was down-regulated. CONCLUSION: Identifications of temperature-specific up- or down-regulated genes can be useful for detecting temperature adaptation and understanding physiological responses in insect pests.

• Korean Journal of Environmental Agriculture
• /
• v.40 no.1
• /
• pp.1-12
• /
• 2021

BACKGROUND: G protein-coupled receptors (GPCRs) are widely distributed in various organisms. Insect GPCRs shown as in vertebrate GPCRs are membrane receptors that coordinate or involve in various physiological processes such as learning/memory, development, locomotion, circadian rhythm, reproduction, etc. This study aimed to identify GPCRs expressed in fat body and compare the expression pattern of GPCRs in different temperature conditions. METHODS AND RESULTS: To identify GPCRs genes and compare their expression in different temperature conditions, total RNAs of fat body in Plutella xylostella larva were extracted and the transcriptomes have been analyzed via next generation sequencing method. From the fat body transcriptomes, genes that belong to GPCR Family A, B, and F were identified such as opsin, gonadotropin-releasing hormone receptor, neuropeptide F (NPF) receptor, muthuselah (Mth), diuretic hormone receptor, frizzled, etc. Under low temperature, expressions of GPCRs such as C-C chemokine receptor (CCR), opsin, prolactin-releasing peptide receptor, substance K receptor, Mth-like receptor, diuretic hormone receptor, frizzled and stan were higher than those at 25℃. They are involved in immunity, feeding, movement, odorant recognition, diuresis, and development. In contrast to the control (25℃), at high temperature GPCRs including CCR, gonadotropin-releasing hormone receptor, moody, NPF receptor, neuropeptide B1 receptor, frizzled and stan revealed higher expression whose biological functions are related to immunity, blood-brain barrier formation, feeding, learning, and reproduction. CONCLUSION: Transcriptome of fat body can provide understanding the pools of GPCRs. Identifications of fat body GPCRs may contribute to develop new targets for the control of insect pests.

• Journal of Drive and Control
• /
• v.17 no.4
• /
• pp.23-30
• /
• 2020

Driving on irregular and inclined roads using agricultural machinery such as spraying machines or trucks in orchards causes farmer casualties associated with the overturning of agricultural machinery. In addition, the harm to agricultural workers caused by the excessive inhalation of the scattered pesticide frequently occurs during pest control processes. To address these problems, we introduced precision agricultural technology that could selectively spray pesticides only where the fruit is present by recognizing the presence or shape of the fruit in the orchard. In this paper, a 16-channel LIDAR (VLP-16) made of Velodyne was used to identify the shape of fruit trees. Solenoid valves were attached to the end parts of 12 nozzles of the orchard spraying machine for on/off control. The smart spraying machine implemented in this way was mounted on a vehicle capable of autonomous travel and performed selective control depending upon the shape of the fruit trees while traveling in the orchards. This is expected to significantly reduce the amounts of pesticides used in orchards and production costs.

• Korean journal of applied entomology
• /
• v.60 no.2
• /
• pp.229-234
• /
• 2021

This study investigated spray patterns and coverage generated by three types of commercial nozzles for spraying pesticides with Unmanned Aerial Vehicles (UAVs) using a multi-copter. Flufenoxuron+metaflumizone SC and bifenthrin EC were sprayed. The falling particles of the spraying agent were measured using WSP (Water and oil Sensitive Paper) and the coverage was determined. The results showed that the uniformity of falling particles was different according to the difference in wind strength, and there was no difference for different formulations. The injection amount for each nozzle was found to be different from the official information provided by the manufacturers. These results could be used to establish guidelines for the control of UAVs and pesticide registration testing.