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        검색결과 262

        221.
        2008.05 구독 인증기관·개인회원 무료
        This study was conducted to investigate the regional difference in the degree of resistance development of the spirodiclofen 36% WP, an acaricide of tetronic acid class, against two-spotted spider mite, Tetranychus urticae occurred in apple orchard. Two-spotted spider mite was collected from every three regions in the Chungbuk and Gyeongbuk. To compare with the degree of resistance development, this pest was focused on the ovicidal activity (when treated acaricide). The managed orchard in Sancheok-myeon, Myeongseo-ri, Chungju was controlled by several different acaricides from 2001 to 2007, and spirodiclofen WP was used for the last six years. In case of managed orchard, LC50 of spirodiclofen WP was 14.0 ppm, it showed 1.6 fold (resistance ratio) that was estimated as considerably low level resistance ratio comparing to the those of susceptible strain showed in 8.7 ppm. LC50 of spirodiclofen WP against etoxazole-resistant two-spotted spider mite, gained from Chungbuk National University, was investigated in 7.5 ppm. This observation indicates that spirodiclofen WP did not occurred in cross resistance with etoxazole SC. At other regions in Chungju, the resistance ratio against spirodiclofen WP showed as 1.0 and 1.4 fold, respectively. In Gyeongbuk, one region of Yecheon and two regions of Yeongju, it showed as 0.7, 0.8 and 0.9 fold, respectively.
        222.
        2008.05 구독 인증기관·개인회원 무료
        We examined the adulticidal activity of 34 plant essential oils when they were sprayed on female Culex pipiens pallens adults. At concentrations of 1000 ppm, four oils, namely, cardamon, coriander, rosemary, and sandalwood, had adulticidal activities ranging from 67.8% to 98%. Sandalwood oil had the highest adulticidal activity with an LC50 value of 445ppm. Gas chromatographic (GC) and GC-mass spectrometric analyses revealed that the major constituents of cardamon were 1,8-cineole, α-terpinolene and α-terpinene; those of coriander were γ-terpinene, camphor, linalool and geranyl acetate; those of rosemary were β-pinene, 1,8-cineol, camphor and linalool; and those of sandalwood were α-santalol (69.4%) and β-santalol (15.3%). Both of the major components of sandalwood had the highest adulticidal activity of all the monoterpenes tested. When inhibitors of enzymes known to promote insecticide resistance were mixed with each of the four essential oils, a synergistic effect was only observed when sandalwood was mixed with 100 ppm PBO, which enhanced the adulticidal activity of 500 ppm sandalwood from 41% to 90%.
        223.
        2008.05 구독 인증기관·개인회원 무료
        This study was performed to investigate the change of probing and feeding behavior of Q type of B. tabaci according to the decrease of residual effect of two insecticide, emamectin and pyridaben, using EPG technique. Examined the residual activity during 20 days, pyridaben is showed longer than emamectin benzoate. When treated two insecticides onto tomato leaves with the recommended concentration through 20 days, EPG waveforms of Q type of B. tabaci was recorded during three hours compare with the characteristic patterns of feeding behavior between two insecticides such as duration of first probing time, total duration of non-probing phase, total duration of probing phase and total duration of phloem phase. Recorded result from the change in total duration of probing activity to react the two insecticides, pyridaben was showed higher the time of probing activity, however, total duration of phloem phase was appeared low activity. Total duration of phloem phase with passage of days did not show until seven days, however, and gradually increased in emamectin benzoate after 10 days. In conclusion, residual effect between two insecticides was showed more rapidly decreased in emamectin benzoate, however, feeding behavior of Q type of B. tabaci was increased.
        224.
        2008.05 구독 인증기관·개인회원 무료
        This study was conducted to investigate the numerical measurements of chestnut weevil, Curculio sikkimensis, reared in the lab and outdoor field from 2003 to 2006. Numerical measurements were calculated for the sex ratios, fresh weight, body length and width, head width, proboscis length, and antennal length. The female adult was bigger than male in fresh weight, body length and width, head width, proboscis, and antennal length. The size of egg was showed 0.8±0.03mm (n=20). Larval instars was measured 98 mg in body weight, 10.65 and 3.99 mm in body length and width, 1.70 mm in head width. Pupal size was also measured as 7.01±0.65mm in female, 6.53±0.48mm in male. The larva of C. sikkimensis overwintered through 3 years and the size of body weight, body length, and body width were decreased.
        225.
        2008.05 구독 인증기관·개인회원 무료
        This study was conducted to investigate the numerical measurements of chestnut weevil, Curculio sikkimensis, reared in the lab and outdoor field from 2003 to 2006. Numerical measurements were calculated for the sex ratios, fresh weight, body length and width, head width, proboscis length, and antennal length. The female adult was bigger than male in fresh weight, body length and width, head width, proboscis, and antennal length. The size of egg was showed 0.8±0.03mm (n=20). Larval instars was measured 98 mg in body weight, 10.65 and 3.99 mm in body length and width, 1.70 mm in head width. Pupal size was also measured as 7.01±0.65mm in female, 6.53±0.48mm in male. The larva of C. sikkimensis overwintered through 3 years and the size of body weight, body length, and body width were decreased.
        226.
        2008.05 구독 인증기관·개인회원 무료
        As a major component of cuticle wax, cuticular hydrocarbon plays key roles as a chemical cue among inter- and intra-species in some beetles like as pheromone and alleolochemicals in addition to the physical function. In this study, cuticular hydrocarbon was analyzed and compared with three species of beetles adult, Monochamus alternatus, M. saltuarius belong to the Monochamus sp., and belong to the same class, Moechophyta diphysis, a typical vector of pine wilt disease. The composition of cuticular hydrocarbon of three species of beetles adult did not show the difference between male and female in intra-species, however, showed the difference in inter-species. They also differed from carbon numbers in inter species as 25-32 in M. saltuarius, 25-35 in M. alternatus, and 23-31 in M. diphysis. Major constituent of M. saltuarius was analyzed as n-C25, 2 or 4 MeC26, 9-C25:1, n-C27, 4-MeC28, n-C29, (9,x)-,and/or (11,x)-diMeC29; those of M. alternatus were n-C25, n-C27, 4-MeC28, n-C29, (9,x)-, and/or (11,x)-diMeC29, 9-C29:1, n-C29, (9,x)-,and/or (11,x)-diMeC29; and those of M. diphysis were n-C25, n-C26, n-C27, 3-MeC27,9-C29:1, 11-MeC29. The contents of n-alkanes were as follows: M. saltuarius ≒ M. alternatus > M. diphysis. The contents of monomethylalkanes were as follows: M. diphysis > M. saltuarius ≒ M. alternatus. The contents of dimethylalkanes were as follows: M. saltuarius ≒ M. alternatus > M. diphysis. And the content of olefine in female were analyzed as follows: M. saltuarius > M. alternatus ≒ M. diphysis, and the male's contents were similar in three kinds of beetles.
        227.
        2008.05 구독 인증기관·개인회원 무료
        This study was performed to investigate the feeding behavior of Bemisia tabaci B- and Q-biotypes using EPG technique against seven tomato and eight red pepper commercial varieties. EPG waveforms was recorded during three hours compare with the characteristic patterns of feeding behaviors between two biotypes such as total duration of non-probing times, the time taken until stylet activities changed after reaction, number of probes, and total duration of phloem phase. In comparing the effect of the varieties between the two biotypes, biotype Q showed the feeding behavior against all pepper varieties in the total duration of phloem feeding. Daeshin variety has the longest feeding time. However in total duration of phloem feeding, biotype B was observed in hanyeoreumbigarim and Daeshin varieties, but feeding time was very short. Biotype B was longer in total duration of non-probing, and showed lower number of probes, and total duration of probing phase. However, biotype Q was shorter time in total duration of non-probing phase than biotype B, but showed more aggressive probing and stylet pathway pattern. These results suggest that biotype Q are more preferred the pepper host than biotype B. However, tomato varieties between the two biotypes did not show the difference.
        228.
        2008.05 구독 인증기관·개인회원 무료
        Root-knot nematodes, Meloidogyne spp., are the most important plant-parasitic nematodes, causing severe crop yield loss with an estimated 1000 billion dollars a year worldwide. The nematodes also cause disease complexes with other microbial pathogens, damaging plants more severely than each of the pathogens alone or their sum does and making control efficiencies weakened or nullified in disease complexes. In our study, the synergistic effect of the root-knot nematode Meloidogyne incognita was confirmed in the fusarium wilt of tomato caused by Fusarium oxysporum f. sp. lycopersici, which showed greatly increased wilt symptoms in combined inoculations. Use of antifungal and nematicidal plant growth-promoting rhizobacteria (PGPR) were considered for controlling the disease complex because of its causal agents. Among forty PGPR strains tested, P. polymyxa G508, G462 and P. lentimorbus G158 showed strong antifungal and nematicidal activities against F. oxysporum f. sp. lycopersici and M. incognita second stage juveniles (J2), respectively. The Cultures of these bacterial strains inhibited the nematode egg hatching completely even at 1% diluted concentration. In pot experiments, treatment of the Paenibacillus strains reduced wilt severity of tomato with the control efficacy of about 90% ~ 98%. Their treatment also reduced gall formation by 64% - 88% compared to the untreated control. P. lentimorbus GBR158, which well established on seeds and hypocotyls at high population levels, reduced the disease complex greatly with the control value of about 98% when the tomato seeds were treated with the bacterial strain. Plant growth was also stimulated by the seed treatment of the bacterial strain. Scanning electron microscopy revealed alteration and distortion of hyphal cell walls of F. oxysporum and lysis of M. incognita egg shell by the bacterial treatment, showing direct antifungal and nematicidal action mechanisms. No extensive giant cell formation was observed near nematode in the tomato roots treated with the bacteria, indicating a systemic action mechanism. All of these results suggest that the Paenibacillus strains, especially G158 may have a high potential to be developed as biological agents for controlling the root-knot nematode and the disease complex.
        230.
        2005.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        6,300원
        231.
        2005.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of the present study is to investigate what the memory representation of L2 text is like based on the Causal Network Model. In order to do that, 8 stories were read in English by Korean students and recalled in Korean. Their recall was analysed in terms of the number of causal connections each sentence has as specified in the model. And then it was compared with the results of Kim (2001) where Korean students read and recalled the same stories in Korean. The overall amount of recall was not different between L1 and L2 texts, but the pattern of recall showed differences in terms of the causal structure proposed by Causal Network Model. While the recall of L1 text was nicely accounted for by the number of causal connections specified in the model, the recall of individual goal statements in L2 text did not reflect the causal structure. Interesting was the finding that the more important goal among the two goal statements was recalled better for L2 than for L1 text.
        5,400원
        236.
        2003.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        6,100원
        237.
        2003.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        6,700원
        238.
        2003.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 액상유기성 슬러지로부터 용존 유기물을 회수하기 위한 막결합형 발효 시스템의 여과특성의 검토에 초점을 두었다. 0.1 μmsim5 μm 범위에서 6종류의 막공경을 대상으로 한 슬러지 발효액의 정밀여과 특성으로 막공경이 작을수록 전체저항이 큰 값을 나타내었고 케?층의 형성에 의한 저항이 전체저항의 68~88%를 차지하여 막투과유속의 저하는 주로 입자간의 물리화학적 상호작용에 의한 막표면에의 강한 입자침전에 기인함을 알 수 있었다. 발효액의 고형물 농도가 증가함에 따라 막투과유속은 감소하였으나 일정이상의 고형물 농도에서는 비례관계를 보이지 않았다. 막면유속이 증가할수록 그리고 5.0~6.0의 pH범위에서 높은 막투과유속이 얻어졌고 에너지 효율측면에서는 가능한 낮은 압력에서 여과하는 것이 유리한 것으로 나타났다. 0.1μm과 0.2μm의 막공경에서는 100%의 미생물 제거율을 보였다 액상 유기성 슬러지로부터 용존 유기물을 효율적으로 회수하기 위한 최적 막공경은 제안된 기준의 관점에서 볼 때 1μm 정도라 판단되어진다.
        4,000원
        240.
        2003.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        6,900원
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