• 한국토양동물학회지
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• 제1권2호
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• pp.81-88
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• 1996

Entomopathogenic nematodes, Steinernema carpocapsae, was able to invade and kill the several lepidopteran pests including the beet armyworm, Spodeptera exigua Hubner, which was the most effective target host. The beet armyworms treated with the effective nematode concentrations were died within 48 hrs. The lethal effect of the nematode was varied among the developmental stages of the host. The fifth instar larvae of the beet armyworm was more vulnerable to the nematode than the third instar larvae. Pupae was, however, refractory to the nematode. All three bioessays (topical application, filter paper test, and soil treatment) showed the positive correlation between the number of the treated nematodes and the mortality of the host. Topical application was the most effective and fast-acting method so that it gave the lethal effect 2 days earlier than did filter paper test at the same number of the treated nematodes. Soil treatment required higher number of the nematodes to get the effective lethality than did filter paper test. The fifth instar larvae of the beet armyworm expressed the specific hemolymph proteins of 5 to 10 kDa in response to nematode infection.

• The Plant Pathology Journal
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• 제32권4호
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• pp.329-339
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• 2016

The short-term effects of low-level contamination by heavy metals (As, Cd, Cu, and Pb) on the soil health were examined by analyzing soil nematode community in soils planted with tomatoes. For this, the soils were irrigated with five metal concentrations ([1, 1/4, $1/4^2$, $1/4^3$, and 0] ${\times}$ maximum concentrations [MC] detected in irrigation waters near abandoned mine sites) for 18 weeks. Heavy metal concentrations were significantly increased in soils irrigated with MC of heavy metals, among which As and Cu exceeded the maximum heavy metal residue contents of soil approved in Korea. In no heavy metal treatment controls, nematode abundances for all trophic groups (except omnivorous-predatory nematodes [OP]) and colonizer-persister (cp) values (except cp-4-5) were significantly increased, and all maturity indices (except maturity index [MI] of plant-parasitic nematodes) and structure index (SI) were significantly decreased, suggesting the soil environments might have been disturbed during 18 weeks of tomato growth. There were no concentration-dependent significant decreases in richness, abundance, or MI for most heavy metals; however, their significant decreases occurred in abundance and richness of OP and cp-4, MI2-5 (excluding cp-1) and SI, indicating disturbed soil ecosystems, at the higher concentrations (MC and MC/4) of Pb that had the most significant negative correlation coefficients for heavy metal concentrations and nematode community among the heavy metals. Therefore, the short-term effects of low-level heavy metal contamination on soil health can be analyzed by nematode community structures before the appearance of plant damages caused by the abiotic agents, heavy metals.

• 한국환경농학회지
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• 제29권3호
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• pp.282-286
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• 2010

잘게 부순 유채씨를 토양에 처리하여 토양중의 선충을 친환경적으로 방제하고 오이의 수량을 높이고자 2007년부터 2009년까지 3년간 시험한 결과 토양에 유채종실의 시용량이 많을수록 처리 후 50일에 토양 중 cyanate의 량이 많은 것을 볼 수 있었는데 유채 200 kg/10a을 시용한 토양 중 thiocyanate의 량은 30 mg/kg, 400 kg/10a을 시용한 토양은 40 mg/kg 으로 조사되었다. 토양선충 밀도는 관행의 경우 토양 300 g당 463 마리로 피해유발 수준인 150마리보다 보다 훨씬 높은 밀도로 가시적인 피해가 나타났으나 유채를 처리한 모든 시험구 토양의 경우 토양 300 g당 13~17마리로 뿌리혹 선충의 피해는 나타나지 않았다. 수량은 유채 시 용량이 많을수록 6~15% 증수하는 경향이나 선충 피해 예방과 경제성을 고려할 때 10a당 200 kg를 시용하는 것이 좋을 것으로 사료되었다.

• 대한수의학회지
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• 제22권2호
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• pp.253-258
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• 1982

The frequent finding of soil contamination by dogs' feces are remarkable, and such soil contamination may be public health problem. Of 608 samples, 30(4.9%) were positive for nematode ova. Ten paint 3% of sail samples from parks and 7.9% from footpaths were found to contain nematode eggs. Of the helminth eggs detected, eggs of Toxocara spp. were the most commonly encountered, and mostly from the soil of footpaths. No eggs were recovered from the soil of school yards; the level of soil contamination was low in public play areas. Egg recovery rate of the soil to dogs' feces collected from footpaths was approximately 1:5. And the larvae demonstrated from the soil in the present study were nematode larvae, mainly recovered from parks.

• The Plant Pathology Journal
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• 제33권1호
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• pp.66-74
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• 2017

This study was conducted to examine infectivity (penetration and gall and egg-mass formations) of the root-knot nematodes, Meloidogyne incognita and M. hapla, on carrots grown in soil conditions of 5 different soil textures consisting of bed-soil (b) and sand (s) mixtures (b-s mixtures) at the ratios of 10:0, 7:3, 5:5, 3:7, and 0:10. For M. incognita, the nematode penetration rates in b-s of 0:10 (100% sand) were significantly higher than in the other b-s mixtures, more greatly at 2 and 5 days after inoculation than at 10 DAI, while no significant differences in the penetration rates were mostly shown for M. hapla at the above DAI. However, for both nematodes, gall and egg-mass formations were remarkably increased in the b-s mixture of 0:10, compared to the other b-s mixtures, which is coincided with the general aspects of severe nematode infestations in sandy soils. This suggests the increased gall and egg-mass formations of M. incognita should be derived from the increased penetration rates in the sandy soil conditions, which provide a sufficient aeration due to coarse soil nature for the nematodes, leading to their mobility increased for the enhanced root penetration. For M. hapla, it is suggested that the sandy soil conditions affect positively on the healthy plant growth with little accumulation of the inhibitory materials and sufficient aeration, enhancing the nematode growth and feeding activities. All of these aspects provide information reliable for the development screening techniques efficient for the evaluation of the nematode resistance in the breeding programs.

• The Plant Pathology Journal
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• 제17권3호
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• pp.159-163
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• 2001

Influence of soil temperature [accumulated degree-day for the base temperature $5^{\circ}$($\textrm{DD}_5$)] on the development of Meloidogyne arenaria were studied in a winter grown oriental melon greenhouse in Seongju, Korea. Egg masses were first observed on roots at the accumulation of 565 $\textrm{DD}_5$(40 days after transplanting), suggesting that the nematode has completed the first generation in 40 days. Second-stage juveniles (J2) densities were lowest at 863 $\textrm{DD}_5$ in April, first increased at 1,334 $\textrm{DD}_5$ in May, peaked at 2,951 $\textrm{DD}_5$ in July, and decliner thereafter. Development of egg masses and J2 density in soil revealed that M. arenaria could develop in 7-8 generations in a year in the greenhouse. Degree-day monitoring, therefore, could aid to predict nematode development in soil and can be valuable tool a to develop root-knot nematode control strategies.

• 한국식물병리학회지
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• 제11권1호
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• pp.39-46
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• 1995

Ditylenchus destructor isolated from diseased ginseng roots was cultured on ginseng calli, fungal mycelium (Fusarium solani), carrot discs and radish sprouts. Effects of temperature, organic material and flooding on the nematode population changes were examined. D. destructor multiplied readily on the culture media except radish sprout medium, and was cultured best on the fungal culture at 2$0^{\circ}C$. Feeding of the fungal hypha and radish root hairs, molting and mating in the fungal culture medium were observed. Addition of organic materials (perilla, sesame, soybean and ginseng leaves) in soil significantly increased Aphelenchus avenae and saprophytic nematode populations, while D. destructor populations changed little and the nematode population growths were limited by the organic amendments (except sesame leaves). The nematode populations in soil including D. destructor were decreased by flooding. The results indicate that D. destructor may survive but not multiply readily in soil without host plants and that it can be effectively controlled by flooding.

• 식물병연구
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• 제26권2호
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• pp.72-78
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• 2020

클로버씨스트선충은 국내 고랭지배추 재배지에서 가장 문제되고 있는 식물기생선충 중 하나이다. 본 연구는 새로 개발한 훈증성 약제 처리기의 성능을 시험하기 위하여 고랭지배추 문제 클로버씨스트선충을 대상으로 훈증성 약제 2종(dimethyl disulfide [DMDS], metam sodium [MNa])의 살선충 활성을 검정하였다. 훈증성 약제의 방제 효과는 약제 처리 4주 후 처리구별 토양으로부터 씨스트를 채집하여 클로버씨스트선충 알 부화율을 조사하였고, 씨스트 내부의 알을 배추에 접종하여 얻은 암컷 증식 수를 조사하여 평가했다. DMDS (39 l/10 a)는 클로버씨스트선충 알 부화율과 암컷 증식 수를 각각 99.0% 이상 억제하였으나, MNa (29 l/10 a)는 알 부화율은 78.3-99.4%, 암컷 증식 수는 34.7-49.3% 정도 억제하였다. 훈증성 약제 2종의 처리 깊이에 따른 클로버씨스트선충 알 부화율과 암컷 증식수는 통계적으로 유의미한 차이를 보이지 않았다. 본 연구에서 개발된 토양 소독기를 이용하여 DMDS를 토양 처리하면 클로버씨스트선충 방제 효과가 있을 것으로 보인다.

• The Plant Pathology Journal
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• 제37권6호
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• pp.596-606
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• 2021

Soil-borne diseases are the major problems in mono cropping. A mixture (designated LTM-m) composed of agricultural wastes and a beneficial microorganism Streptomyces saraceticus SS31 was used as soil amendments to evaluate its efficacy for managing Rhizoctonia solani and root knot nematode (Meloidogyne incognita). In vitro antagonistic assays revealed that SS31 spore suspensions and culture broths effectively suppressed the growth of R. solani, reduced nematode egg hatching, and increased juvenile mortality. Assays using two Petri dishes revealed that LTM-m produced volatile compounds to inhibit the growth of R. solani and cause mortality to the root knot nematode eggs and juveniles. Pot and greenhouse tests showed that application of 0.08% LTM-m could achieve a great reduction of both diseases and significantly increase plant fresh weight. Greenhouse trials revealed that application of LTM-m could change soil properties, including soil pH value, electric conductivity, and soil organic matter. Our results indicate that application of LTM-m bio-organic amendments could effectively manage soil-borne pathogens.

• The Plant Pathology Journal
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• 제27권3호
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• pp.266-271
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• 2011

Physicochemical characteristics and heavy metal content of soils located along the drainage way of an abandoned mine at Busan, Korea ($35^{\circ}31'N$, $129^{\circ}22'E$) (contaminated soil; CS) and uncontaminated soils (50-70 m apart from the drainage way) (NS) were examined. Growth of tomato plants (Solanum lycopersicom cv. Rutgers) in CS and NS, development of the root-knot nematode (Meloidogyne incognita) as root-knot gall formation on tomato plants, and non-parasitic nematode populations in soil were also examined. Growth of tomato plants, root-knot gall formation, and non-parasitic nematode populations were significantly reduced in CS with higher As content, lower pH, higher electrical conductivity (EC), and lower available phosphate (av. $P_2O_5$) than in NS. None of the other physicochemical characters examined differed significantly between CS and NS (low and no significance) and were above or below the critical levels detrimental to plant growth and nematode development, suggesting that As may be the primary hazardous heavy metal in CS. The toxicity of As might be enhanced at low pH in CS because exchangeable forms of some heavy metals increase with the decrease of soil pH. The heavy metals, especially As, may have contributed to increasing EC and decreasing av. $P_2O_5$. Therefore, the effects of mine drainage contamination from the abandoned mine were derived primarily from contamination by heavy metals such as As. These may have been enhanced in toxicity (solubility) by the lowered pH, increased soil salinity (EC) and decreased av. $P_2O_5$. Our results suggest synergistic adverse effects on the plant and the nematode by decreasing osmotic potential and nutrient availability.