• Title/Summary/Keyword: knot

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Allium tuberosum, a New Host of Root-knot Nematode, Meloidogyne Incognita in Korea (부추의 뿌리혹선충 피해 보고)

  • Kim, Dong-Geun;Lee, Joong-Hwan
    • Research in Plant Disease
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    • v.14 no.1
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    • pp.76-78
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    • 2008
  • During the investigation of Allium decline in Pohang, Korea, root-knot nematode was found from root of Allium tuberosum Roth. It was identified as Meloidogyne incognita and was first reported from Allium tuberosum. Allium decline was associated with root-knot nematode, root mite and Fusarium sp. but root-knot nematode appeared to be the main cause of Allium decline.

Efficacy of Different Seed Kernels against Root Knot Nematode Meloidogyne incognita in Mulberry

  • Chowdary, N.B.;Mukherjee, Sanchayita
    • International Journal of Industrial Entomology and Biomaterials
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    • v.6 no.2
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    • pp.133-138
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    • 2003
  • Five seed kernel namely, Neem (Azadirachta indica A. Juss.), Pongamia (Pongamia glabra L. Pierre), Tamarind (Tamarindus indica L.), Mahua (Madhuca indica Gmel.) and Shikakai (Acacia cancinna De.) were tested against hatching of eggs and larval mortality of Meloidogyne incognita causing root knot disease in mulberry along with Furadan (Carbofuran) and Bionema (a bioformulation developed from Verticillium chlamydosporium) for comparison. Results revealed that highest hush-up of hatching was observed in Neem (77.40%) and Pongamia (75.99%) seed kernel extracts at 100% concentration over the check. Similarly, highest larval mortality was observed in Neem and Pongamia by 76.00% and 74.50%, respectively at 100% concentration after 72 hrs of exposure period. Pot culture studies revealed that pre-application of seed kernel powders (20 days before inoculation of nematode) found to be more effective in controlling the root knot disease than post application. In pre application of seed kernel powders, maximum reduction of root knots was observed in case of Neem seed kernel powder (54.85%) followed by Pongamia (51.9%). Similar trend was also observed in reduction of egg masses/plant and nematode population /250 cc soil. Rest of the seed kernel extracts was found to be less effective in suppression of hatching, enhancing the larval mortality and controlling the root knot disease. However, application of Furadan and Bionema tested for the comparison were found to be more effective than seed kernel powders. The generated information seems to be useful in developing an ecofriendly integrated approach for the control of root knot nematode disease in mulberry.

Occurrence of the Root-Knot Nematode species in Vegetable Crops in Souss Region of Morocco

  • Janati, Soukaina;Houari, Abdellah;Wifaya, Ahmed;Essarioui, Adil;Mimouni, Abdelaziz;Hormatallah, Abderrahim;Sbaghi, Mohamed;Dababat, Abdelfattah A.;Mokrini, Fouad
    • The Plant Pathology Journal
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    • v.34 no.4
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    • pp.308-315
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    • 2018
  • Root-knot nematodes 'Meloidogyne spp' are the most destructive group of plant parasitic nematodes causeing serious losses in vegetables crops and this damages worsened when crops grown under greenhouses conditions. In this sutdy, the distribution and characterization of root-knot nematode species collected from the Souss region of Morocco where vegetables crops intensively cultivated were determined by using both morphological and molecular tools. Out of the 110 samples collected from different greenhouses 91 (81.7%) were found to be infested with root-knot nematodes. Thirty-seven populations of root-knot nematodes were morphologically identified based on perineal patterns as well as molecularlly using species-specific primers. The obtained results indicated that Meloidogyne javanica and M. incognita were identified in 86.4% and 13.5% of the total populations, respectively. The lowest incidence of root-knot nematodes (64%) was found in Toussous, whereas the highest frequencies of 100% and 90% were detected in Taddart and Biogra, respectively. As the majority of the samples have been infested with Meloidogyne species; this indicates that there is an urgent need to provide farmers with a proper control strategy.

Mechanical Properties and Comparisons of Cerclage Wires of Various Diameters in Different Knot Methods

  • Jang, Aram;Kim, Jieyoo;Park, Ji-Hun;Yoon, Eunchae;Lee, Dongbin;Lee, Jae-Hoon
    • Journal of Veterinary Clinics
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    • v.39 no.4
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    • pp.149-155
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    • 2022
  • The aim of this study was to compare the mechanical properties of 0.6 and 0.8 mm cerclage wires with the 1.0 mm cerclage wire in the twist, single-loop, double-loop, double-wrap, and loop/twist knot methods. Six stainless steel cerclage wires of various diameters in different knot methods were tied round a customized jig mounted on a load testing machine. The initial tension, initial stiffness, and yield load were evaluated. The failure mode of each cerclage was observed. For each wire size, the double-loop, double-wrap, and loop/twist knots showed significantly greater initial stiffness, and yield load than those seen with twist and single-loop knots. The single-loop knot showed the least initial stiffness regardless of the diameter. As the cerclage wire diameter increased, the cerclage tended to show significantly greater initial stiffness, and yield load. Failure modes varied depending on the knot configurations. Single-loop knots of smaller-diameter wires less than 1 mm had similar or lower initial tension, initial stiffness, and yield load than a twist knot. Owing to the variance in mechanical properties, the clinical application of the knot type should depend on the diameter of the cerclage wire.

A Study on a Traditional Knot Represented in the Remains - Focusing on the Remains of the Folklore Museum of On Yang - (유물에 표현된 전통매듭에 대한 연구 - 온양민속박물관을 중심으로 -)

  • Im, Sang-Im;Im, Yong-Ju
    • Korean Journal of Human Ecology
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    • v.10 no.2
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    • pp.189-203
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    • 2001
  • The pulpous of this study is to investigated the kind and feature of the knots used in four categories, "living, clothing, ceremony, and decoration", after analysing and examining 42 knot remains of the folklore museum of On yang. The method were by old books and various kind's related books, history of knots and kind of knots investigated and analyze relics were actual proof investigation of real things and supplementary materials were photos, drawings, and museum's explanation used. The results are as is following ; First, a knot is twisted by two threads, formed in the process of twisting, become in equal shape, and made in symmetry. Second, In knot's names, there are sangkang, karakge, ankyongchip, jamjary, kukhwa, bol, byongary, memi, kkondiki, kong, yonbong which are easily seen in nature. Third, a knot was used in as living things in the era of the three Kingdoms, as a decoration such as Buddhism goods in Koryo. In the era of Cho sun, Because of the development of knot's kind and the variety of service, it was the target of restriction as a luxury. Fourth, as a result of investigating museum's relics, a knot was smaller than the chief object because that is a decoration. Fifth, there are 8 kinds for living and clothing which are simple knots "doramaetup, karakgemaetup, and sangtchokmaetup". Sixth, the complex knots such as kukhwamaetup, byongarymaetup, and 3bolkamkae emaetup are used on pangchang, chokja, nambawi, and chobawi. Seventh, there are 10 kinds for ceremony, the simple knots are twisted and the complex knots such as kukhwamaetp, maehwamaetup, nabimaetup, and sasaekgupoki are used. Eighth, there are 14 kinds for decoration, the simple knots such as doraemaetup, kakagemaetup, santchokmaetup, and ankyongchipmaetup and the applied knots such as kukhwamaetup, byongarymaemaetup, changkumaetup, nabimaetup, and seokssima etup are used. There are 42 knot remains in the folklore museum of On yang. Of them, there are 33 kinds in the present, 17 used. that is because only several knots have been used. Finally, to forget the knot's way, we will set up a plan to keep with it.

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A Study on the Estimation for the Compressive Strength of Member According to the Knot Types (옹이 형태별 소재의 압축강도 예측에 관한 연구)

  • Kim, Gwang-Chul
    • Journal of the Korean Wood Science and Technology
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    • v.38 no.3
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    • pp.170-177
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    • 2010
  • Finite element numerical analysis was conducted with using the knot data which has a strong influence on the prediction of capacity for the structural wood member. Wood is a orthotropic property unlike other structural materials, so orthotropic property was applied. Knot was modelled as a cylinder shape, cone shape, and cubic shape. Compressive test was carried out to investigate the failure types and to calculate ultimate strengths for the wood members. Numerical model which can reflect the member size, number of knot, location of knot, size of knot was created and analyzed. By the numerical analysis using the ultimate compressive strength, numerical stress distribution types of each specimen was compared to real failure types for the test specimen. Cylinder shape modelling might be most reasonable, according to the necessary time for the analysis, the difficulty of element meshing, and the similarity of stress transfer around knot. Moreover, according to the stress and deformation distribution for the numerical analysis, failures or cracks of real specimen were developed in the vicinity of stress concentrated section and most transformed section. Based on the those results, numerical analysis could be utilized as a useful method to analyze the performance of bending member and tensile member, if only orthotropic property and knot modelling were properly applied.

Resistance of Pepper Cultivars to Two Species of Root-knot Nematodes (2종 뿌리혹선충에 대한 고추의 품종별 저항성)

  • 김동근;이재국
    • Korean journal of applied entomology
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    • v.40 no.2
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    • pp.143-147
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    • 2001
  • Nineteen pepper (Capsicum annuum L.) cultivars were screened for the resistance to two common species of root-knot nematodes, Meloidogyne incognita and M. arenaria. The tested pepper cultivars showed different degrees of resistance to M. incognita but all were resistant to M. arenaria. The cultivars cv. Gonggongchil, Green No. 500 Pimento, Dahonggeon, Manitta, Shinbaram, Perfecto, and Hanmaeum were resistant to the both species of root-knot nematodes. Therefore, seven selected resistant pepper cultivars are recommended as resistant rotation crops in greenhouses where root-knot nematodes are problematic.

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Finite Element Analysis of Membrane for LNG Storage Tank (액화천연가스 저장탱크용 멤브레인의 유한요소해석)

  • 김영규;윤인수;홍성호;전인기
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.18 no.10
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    • pp.2797-2804
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    • 1994
  • This paper analyzes the behaviors of corrugated membrane under the cryogenic liquid pressure and thermal loading using the FEM analysis program MARC. The FEM calculations were carried out on the basis of measured data of Technigaz membrane. It is very important to know the concentration levels and distributions of stress in the corrugated membrane. A quarter of the membrane sheet in place of the whole membrane was simulated because of its geometric symmetricity. The calculated results of the concentrated stress showed that the maximum stress occurs at the knot parts and at the root corner radius of the corrugations. The FEM calculated results indicated that the ring knot membrane which was developed in this study showed uniformly distributed stress and the lowest stress levels in the cross knot area in comparison with other two membranes. These results are very important to optimize the shape and improve the safety of membrane structure.

Incidence, and Identification of Three Root-Knot Nematode species Occurring in the Medicinal Herbs (약용식물의 뿌리혹선충 발생과 분류동정)

  • Park, So-Deuk;Kahn, Zakaullah;Kim, Jae-Cheol;Choi, Boo-Sull;Kim, Tak
    • Korean Journal Plant Pathology
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    • v.14 no.6
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    • pp.603-605
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    • 1998
  • Soil and root samples were collected form the rhizoshpere of 11 different medicinal plants to determine the incidence, density and identification of root-knot nematode species associated with medicinal herbs. About 55% of medicinal herbs examined was found to be infested with root-knot nematodes. As a result of infection casued by three root-knot nematodes, M. hapla recorded 43.3% in medicinal herba whereas M. incognita and M. arenaria showed 7.9% and 3.7%, repectively. Forsythia koreana, Hemerocalis fulva, Hibuscus mutabilis and Petasites japonicus were the most severely infested herbs whereas Acanthopanax sessilflorus was least infested. Population of the second stage younger plants. Meloidogyne hapla, M. incognita and M. arenaria were the species associated with the medicinal herbs. The most abundant nematode observed in medicinal herbs was M. hapla and followed by M. incognita and M. arenaria. M. arenaria was observed firstly on Ficus carica, one of medicinal plant.

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Offshore stow net modeling and analysis of behavior using numerical methods (수치해석을 이용한 근해안강망 어구 모델링과 거동분석)

  • JANG, Yong-Suk;LEE, Chun-Woo;CHOI, Kyu-Suk
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.57 no.4
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    • pp.283-291
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    • 2021
  • The Korean stow net is a fishing method that utilizes the changing direction of the net entrance with the tidal current. This study attempted to obtain basic data from the recent offshore stow net fisheries to improve the gear by analyzing the dynamic behavior of the nets affected by current speed and direction using computer simulations. A numerical calculation was performed at a current speed of 0.5 knot between 2.5 knot at each 0.5 knot. The time taken for the gear opening was the longest from 0.5 knot at 1,500 seconds and the shortest from 2.5 knot at 450 seconds in the simulations. In all cases, the net width and tension at net deployment gradually decreased as the current speed decreased. However, the net height tended to increase inversely proportional to the current speed. During the net rotation, the net height was maintained at all cases. The net width and tension fluctuated, but the regularity was very low. In this study, the calculated simulation data showed that the opening efficiency decreased proportional to the current speed. The opening efficiency is related to the catching efficiency; therefore, it is necessary to improve the gear to enhance its opening efficiency.