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        검색결과 176

        121.
        2017.04 구독 인증기관·개인회원 무료
        Thrips worms and root-knot nematodes occur in a variety of crops, and have shown a great deal of damage to farm income every year, and the damage is increasing every year. In order to solve these problems, a variety of biological materials are used in Korea to develop a control agent. However, there are very few products available that can satisfy the consumer's satisfactory control effect, efficacy, formulation stability and pesticide compatibility. In order to propose a biological control solution to these problems, this study was conducted to develop the optimal bioprocess technology and formulations suitable for the material by transferring the Aspergillus nigerF22 strain, which is effective for root-knot nematodes, at Chonnam National University. This study was conducted to investigate the efficacy of Aspergillus niger F22 20% suspension concentrate (Productname:NEMAFREE), which has excellent efficacy on root nematodes. The packing test result showed about 70-90% control effect. Soil fumigation and disinfection treatments after 4 days of planting were effective. In addition, we have developed a product to control the under powder pupa using Beauveria bassiana ERL836, an insect pathogenic microorganism, which has excellent control effect against resistant insect pupa. The main purpose of this study was to investigate the effect of insect pests on the under poor control of the pupa in the soil. In the pavement test, more than 70%(GR) formulation, which can be treated withch emical pesticides, and it is confirmed that synergy effect is in the control of Thrips worm.
        122.
        2016.04 구독 인증기관·개인회원 무료
        The banded greenhouse thrips, Hercinothrips femoralis (Reuter, 1891) (Thysanoptera: Thripidae: Panchaetothripinae), has been reported as a pest on many kinds of crops such as banana, sugar beet, eggplant, green pepper, and greenhouse ornamentals. Originally from the African continent, the species has expanded its distribution worldwide, including North and Central America, Europe, Asia, and Australia. In our country it was recorded for the first time by Woo in 1973, with six females from Jeju island, but after that there was no subsequent report about occurrence and damage until present. Recently, it was rediscovered in private homes, severely damaging to ornamental plants, angel’s trumpet (Brugmansia suaveolens) and ivy (Hedera helix) in Gyeonggi-do and Jeollabuk-do. For identification and future management of this exotic pest, representative morphological characteristics and already known biological informations are provided.
        123.
        2016.04 구독 인증기관·개인회원 무료
        Effectiveness of Beauveria bassiana ERL as entomopathogenic fungi against thrips pupae were evaluated on greenhouse cucumber(bumnong backdadagi), rose(Affinity) respectively. Control efficacy was calculated by the formula, (Dcontrol - Dtreatment)/Dcontrol x 100, where Dcontrol is the average density of thrips on the plots in which any pesticides and entomopathogenic fungi was not relesed and Dtreatment is the average density of thrips on the plots in which entomopathogenic fungi were released respectively. As a result, control efficacies of Beauveria bassiana ERL 10^7 cfu/g treatment against thrips on cucumber was 89.4~91.3%, respectively. In addition, control efficacy of Beauveria bassiana ERL 10^8 treatment against thrips on cucumber was 92.0~93.2%. Also, control efficacies of Beauveria bassiana ERL treatment against thrips on cucumber was 61.5-69.2%. Thus, even thrips control flow that occurs in the solanaceae vegetables thrips current period is officially Beauveria bassiana ERL 10 ^ 7 to effective treatment cfu / g, pepper and tomato cucumber and rose to occur will be effective. These results demonstrate the promise of entomopathogenic fungi, especially Beauveria bassiana ERL for management of thrips pupae. In addition to thrips control that is occurring in the solanaceae vegetables such as peppers and tomatoes will be effective.
        124.
        2016.04 구독 인증기관·개인회원 무료
        Western flower thrips, (Pergande) (Thysanoptera: Thripidae) have been recognized as serious pests worldwide. Commercially available chemical pesticides challenges against the resistance of the pest and safety to consumers. Herein we investigated the usability of soil-treatment of entomopathogenic Beauveria bassiana (Bb) ERL isolates in tomatoes. Bb-egfp was highly virulent to western flower thrips in laboratory conditions and colonized in soil, which provided a chance for western flower thrips larvae to contact the colonized fungal mass. In a glasshouse trial, Bb ERL836 and Bb ERL1578 granule (GR) were applied to soil surface and mixed well, and five females were infested to each pot of tomato 3 days after the application. The two treatments significantly reduced thrips population in tomatoes 20 and 40 days post applications, comparable to the control efficacy of clothianidin granule (GR) formulation. In the following field trial, the two ERL fungal treatments showed 69.2% and 61.5% of control efficacy, which were similar to that of clothianidin GR (76.9%). This work suggests that applied B. bassiana colonized in soil well and thrips larvae easily contacted the fungal mass, which possibly enabled the control strategy to be alternative way to the chemical control.
        125.
        2015.10 구독 인증기관·개인회원 무료
        Whiteflies (Hemiptera: Aleyrodidae) and thrips (Thysanoptera: Thripidae) are major pests on greenhouse crops including sweet pepper (Capsicum annuum L.) in South Korea. To manage this pest complex effectively, it is fundamental to understand population dynamics and spatial distributions of the pests. In this study, we conducted visual counting and used yellow sticky traps to monitor whitefly and thrips populations in sweet pepper greenhouse (6 × 28 m). The survey was conducted every two weeks over two months. A total of 84 traps were set up at 20cm from the plant top canopy and spaced 1m apart from each other. Leaves were selected randomly from the middle plant canopy for visual counting at the same sampling locations. The trap data indicate that the numbers of whiteflies and thrips increased from 5.50 ± 0.34 to 168.51 ± 14.95 and from 52.40 ± 1.67 to 158.42 ± 7.44 (mean ± SE) per trap, respectively, over the two-month observation period. In general, the spatial distributions of these pests aggregated near the greenhouse entrance with significant positive correlation between the densities of the two species (r = 0.74, P = 0.02). However, the results of visual counting were completely different; either species was rarely found on leaves, even when the trap catches were relatively high at the same locations. That is, there was no correlation between visual counting and sticky trap data sets. The current study will serve as a fundamental step to develop reliable and effective management programs for greenhouse sweet pepper.
        126.
        2015.04 구독 인증기관·개인회원 무료
        Western flower thrips (WFT), Franklinella occidentalis, is a major pest of ornamentals. Mycotized millet grains with entomopathogenic fungi applied to soil of potted marigold plants was tested to target pupating thrips. Two experimental fungal isolates, (Beauveria bassiana [ARS7060] and Metarhizium anisopliae [ERL1171]), were compared with the registered B.bassiana strain GHA and untreated controls in greenhouse caged trials. Mycotized millet grains were mixed into the upper surface of the potting soil in pots of flowering ‘Hero Yellow’ marigolds (4 g/pot). One week after application five mated WFT females were released onto each plant (four plants per cage). At 8 wks post-infestation, the mean total number of thrips per plant was 81 and 90% less in the ERL1171 and ARS 7060 treatments, respectively, than in the controls. The mean numbers of thrips per plant for the control and GHA treatments were not significantly different. Plant damage was 60% less on plants treated with the experimental fungi than the control and GHA treatments. At 10 wks post-application, 75-90% of WFT collected from the treatments were infected with the experimental isolates. These results demonstrate that soil applications of entomopathogenic fungi can reduce WFT populations significantly and prevent damage.
        127.
        2015.04 구독 인증기관·개인회원 무료
        Damages of medicinal crops by thrips and identification of thrips species were investigated on major medicinal crops, Platycodon grandiflorum, Schizandra chinensis, Codonopsis lanceolata, Lycium chinense, Bupleurum falcatum, Ledebouriella seseloides, Angelica gigas, Glycyrrhiza uralensis, Liriope platyphylla, Atractyloides sp., in Suwon, Eumseong, Jecheon, Pyeongchang, Chyungyang 2012. Thrips and their damages were found at all of the medicinal crops investigated, mostly occurring at early growing stages of each medicinal crop and causing apical meristem region withered, thereby inhibiting the growth of plants. As a result, Frankliniella intonsa, Thrips tabaci, and Megalurothrips distalis have been identified as dominant species on medicinal crops in open field, whereas Frankliniella occidentalis was restricted to Lycium chinense in which protected cultivation. Occurrence of thrips species on medicinal crops seems to be affected by host specificity and environmental factors such as cultivation types.
        128.
        2015.04 구독 인증기관·개인회원 무료
        This study was aimed at assessing the fumigant toxicity to adult Thrips palmi and Orius strigicollis of basil (Ocimum basilicum) essential oil compounds and structurally related compounds using vapour-phase toxicity bioassays. Results were compared with those for dichlorvos. Against adult T. palmi, linalool (LD50, 0.0055 mg cm–3) was the most toxic fumigant and was 15.2–fold more effective than dichlorvos (0.0837 mg cm–3). Strong fumigant toxicity was also observed in pulegone (0.0095 mg cm–3), (±)-camphor (0.0097 mg cm–3) and 1,8-cineole (0.0167 mg cm–3). Moderate toxicity was produced by camphene, 3-carene, (–)-menthone, (+)-α-pinene, (+)-β-pinene, α-terpineol and (–)-α-thujone (0.0215–0.0388 mg cm–3). Against adult O. strigicollis, dichlorvos (LD50, 9.0 ×10–10 mg cm–3) was the most toxic fumigant, whereas the LD50 values of these compounds ranged from 0.0127 to >0.23 mg cm–3. Based upon selective toxicity ratio (STR, O. strigicollis LD50/T. palmi LD50), the compounds described (STR, 0.7–>10.7) are more selective than dichlorvos (STR, 10.8×10–9 mg cm–3). Basil oil compounds described merit further study as potential insecticides for control of T. palmi in greenhouses because of their generally lower toxicity to O. strigicollis and their greater activity as a fumigant than dichlorvos.
        129.
        2015.04 구독 인증기관·개인회원 무료
        Thc climate change has the potential to significantly modify the actual distribution of insect pest with unknown consequences on agricultural systems and management strategies. In this study, Thrips palmi Karny was selected to predict distribution under climate change. T. palmi was introduced and first recorded in 1993 in Korea, and has become a serious pest of vegetable and ornamental crops. The MaxEnt was applied to T. palmi to predict its potential geographic distribution in Korea and Japan under the RCP 8.5 climate changing scenario. The MaxEnt software package is one of the most popular tools for species distribution and environmental niche modeling. The habitat prediction model of T. palmi in Korea was validated by the distribution of T. palmi in Japan. Based on the MaxEnt modeling, T. palmi would expand their potential distribution to whole Korean peninsula except the alpine region in Gangwon-do and Yanggang-do and Hamgyeongbuk-do in 2070s. Therefore, the monitoring system and management strategy for T. palmi should be reconsidered and re-evaluated.
        130.
        2015.04 구독 인증기관·개인회원 무료
        Yellow sticky traps are a key component of IPM programs for several greenhouse and vegetable pests. Yellow sticky traps have been used intensively for early detection, identification of hotspots as well as for estimating relative abundance and dispersals of adult insects occurring either in greenhouses or fields. In addition, the traps have the potential of suppressing adult populations alone or in combination with other control strategies such as biological and chemical controls. In spite of the fact that the traps have been widely used with several advantages for growers such as low cost and low training demands, the understanding of insect flight and dispersal behaviors based on sticky traps have been limited. Since the trap catches are highly associated with flight behaviors of insects, the catch data should be carefully interpreted and analyzed in conjunction with the flight behaviors of target insects to develop ecologically sound IPM programs. Thus, a control decision-making based on mean trap catches without knowledge in the flight behaviors may produce biased or wrong conclusion. In this study, flight and migration behaviors of insect pests such as thrips, whiteflies and leafminers are studied based on sticky trap catch data obtained from greenhouses and fields. Also I summarize the knowledge gaps that need to be addressed to develop yellow sticky traps into a more effective decision-making tool for pest management.
        131.
        2014.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        경기도 화성지역에서 시설재배 무화과를 대상으로 총채벌레의 발생현황과 피해특성을 조사하였다. 황색끈끈이트랩 및 피해과실에서 발생하는 총채벌레를 동정한 결과 파총채벌레(Thrips tabaci Lindeman), 꽃노랑총채벌레(Frankliniella occidentalis Pergande), 대만총채벌레(Frankliniella intonsa Trybom) 등 3종의 발생이 확인되었다. 이들 3종 중 파총채벌레의 밀도가 가장 높았으며, 다음은 꽃노랑총채벌레, 대만총채벌레 순으로 나타났다. 총채벌레에 의해 피해를 받은 과실은 비대생장과 착색이 정상적으로 이루어지지 않았고 표면이 거칠고 코르크화 되었다. 실체현미경 을 이용하여 피해 받은 과실의 내부를 조사한 결과 피해부위에 회색곰팡이가 발생하였고, 총채벌레의 사체 및 탈피각이 관찰되었다. 무화과 주 수 확기에 총채벌레에 의한 과실의 피해율은 7월이 18.2%로 가장 피해가 많이 나타났으며, 이후에는 8월(9.7%), 9월(2.9%), 10월(1.3%) 순으로 나타났다.
        4,000원
        132.
        2014.04 구독 인증기관·개인회원 무료
        Studies have reported differential attractiveness of yellow, white or blue sticky cards to greenhouse pests, especially to Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) and Trialeurodes vaporariorum Westwood (Homoptera: Alyerodidae). The main aim of this study was to determine whether yellow or blue sticky card offers a better option in monitoring or mass trapping these sympatric greenhouse pests. Laboratory study that included a multiple choice and no-choice tests to observe the attractiveness of blue, yellow, white or green sticky card to F. occidentalis and T. vaporariorum was conducted. Also, a glasshouse study was conducted to determine better composite attractiveness of yellow or blue sticky card. F. occidentalis showed higher preference to blue and yellow sticky cards in laboratory study and blue captured the highest number of F. occidentalis in glasshouse followed by the yellow. However, while the blue sticky card captured few T. vaporariorum, the yellow sticky card captured the highest number of T. vaporariorum in both laboratory and glasshouse tests. Since yellow sticky card received composite affinity of both F. occidentalis and T. vaporariorum, placement of yellow sticky card for the greenhouse pests, rather than blue or yellow targeted to individual species, is recommended for economical and optimal monitoring and/or mass trapping success of the tested greenhouse pests.
        133.
        2014.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        꽃노랑총채벌레는 꽃을 선호하며 국화의 주요해충이다. olfactometer를 이용하여 국화가 꽃노랑총채벌레를 유인하는 트랩식물로서 효용가치가 있는지를 조사하였다. 유리온실에 심겨져 있던 스텐다드국화의 화색별 꽃노랑총채벌레의 밀도를 타락법을 이용하여 조사한 결과, 개화시기의 경우에는 핑크색, 흰색, 노랑색의 꽃에서 각각 18.4, 56.6, 52.6 마리였고, 잎에서는 7.8, 16.6, 15.4 마리가 채집되었다. 꽃봉오리 형성시기의 경우에는 꽃봉오리에서 15.2, 45.8, 41.6 마리, 잎에서는2, 8.8, 3.4 마리였다. Y-tube olfactometer 시험에서 선호하는 쪽으로 향하는 꽃노랑 총채벌레의 수는 노랑색에 대하여 빨강색, 보라색, 흰색 꽃의 후각반응을 조사한 결과, 분명한 차이가 없었다. 4-way olfactometer 시험의 경우, 냄새와 동일한 시각자극이 주어졌을 때 꽃노랑총채벌레의 빈도수는 빨강색(1.3), 보라색(3.7)흰색(2.0) 보다 노랑색(10.7)을 선호하였고, 후각적 자극이 교란된 시각적 반응에서도 빨강색 (3.3), 보라색 (1.3), 흰색 (3.0) 보다 노랑색 (10.0)을 선호하였다. 노랑색의 시각적 자극만 제외하고 다른 꽃의 시각적인 자극과 동일한 후각적 자극을 주었을 경우에는 빨강색 (4.7), 보라색 (4.7), 노랑색 (2.0) 보다 흰색(8.3)을 선호하였다. 꽃노랑총 채벌레는 꽃이 개화하기 전에는 꽃의 후각적인 자극에 먼저 반응하여 꽃봉우리로 이동하고 개화되었을 때에는 꽃의 색깔에 더 잘 반응하여 노랑색꽃을 선호하는 것으로 보아 후각적인 자극보다는 시각적인 자극에 더 잘 반응하였다.
        4,000원
        134.
        2013.12 구독 인증기관 무료, 개인회원 유료
        Yellow tea thrip (Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) is anthophilous pests of many crops worldwide including five flavor berry. And the mealy bug (Pseudaulacaspis cockerelli (Cooley) (Hemiptera: Diaspididae)) is one of the hardest pests to control. Its body is covered with white waxy threads, which often make a chemical pest control useless. Five flavor berry (Schisandra chinensis Baill) is used in traditional Chinese medicine. So, the development of biological control against the major pest on five flavor berry is of great interest. In this work, a treatment of Chrysoperla nipponensis (Okamoto) was applied to five flavor berry fields infested by P. cockerelli and a treatment of Amblyseius swirskii Athias-Henriot was applied to two types of five flavor berry fields infested by S. dorsalis. Even though our tests found significant differences between the two culturing method(sod culture, nonwoven type mulching), the treatment of biological control agents decreased or a little increased the fruit damage, which was comparable to the chemical insecticide treatment. In the sod culture experiment, thrip population was significantly low and increased at a lower rate than in the nonwoven type mulching. It may be suggested from these results that A. swirskii and C. nipponensis as IPM program and sod culture could be incorporated into the integrated pest management system on five flavor berry.
        4,000원
        135.
        2013.10 구독 인증기관·개인회원 무료
        Cold tolerance of the palm thrips, Thrips palmi Karny, was investigated to predict its survival in field during winter. Supercooling temperatures of T. palmi ranged from -26.4 to -18.4°C. However, exposure to subzero temperatures (from -5°C to -15°C) gave significant mortality to all developmental stages of T. palmi. Thus, T. palmi was determined to be a freeze-susceptible and suffered with cold injury. A brief pre-exposure to a low temperature (4°C) for 7 h significantly increase the cold tolerance of all stages of T. palmi with respect to survival at -10°C and supercooling capacity. A pre-exposure of T. palmi at 4°C significantly increased the survival rate on all developmental stages at -10°C. The rapid cold hardiness (RCH) was dependent on the duration of the pre-exposure period at 4°C in adult stage. Cryoprotectant analysis using an HPLC showed that the pre-exposure treatment increased the adult to synthesize glycerol, trehalose, mannitol, and mannose, at which trehalose represented the highest content. This study suggests that all stages of T. palmi are able to become cold-hardy by RCH, in which several polyols may play crucial roles as cryoprotectant.
        136.
        2013.10 구독 인증기관·개인회원 무료
        Thrips palmi Karny was introduced and first recorded in 1993 in Korea. This species has become a serious pest of vegetable and ornamental crops. CLIMEX simulation was applied to T. palmi to predict the potential geographic distribution in Korea under the Representative Concentration Pathway (RCP) 8.5 climate change scenario. In the CLIMEX simulation, ecoclimatic index (EI) was calculated, and compared in each simulated year and each simulated location. The map comparisons showed a good agreement between simulated and present distributions of T. palmi, indicating that the CLIMEX model was well explained and appropriate for prediction of future distributions of this species in Korea. In near future, until a year of 2020, all the western and eastern parts of Korea showed favorable to marginal suitability for T. palmi populations in fields. After the year of 2040, the potential distributions are shifted from no persistent to favorable for establishment and persistence from coastal to interior of the Korean peninsula except a north-eastern interior region which is the northernmost part of high mountains (Baekdu-Daegan) area in South Korea. Based on simulation results, T. palmi would overcome its weather restriction in near future under a severe climate change scenario, thus, pest management measures and strategies should be re-constructed in Korea, with further studies including interspecific competition and understanding ecosystem change due to climate change.
        137.
        2012.10 구독 인증기관·개인회원 무료
        Frankliniella occidentalis Pergande and F. intonsa Trybom (Thysanoptera: Thripidae) are polyphagous insect pests on numerous crops. These two species reduce the crop production in two ways: by sucking sap from the plant parts and by serving as vectors for tospoviruses. In this study, we tried to confirm the previous observation of F. intonsa dominance on certain crops during recent years. Thrips populations were examined on greenhouse strawberry by installing circular yellow sticky cards with black background and on field pepper by destructive sampling of pepper flowers during season of 2012 in Songcheon, Andong. Eighty two to 92% and 3-5% of thrips collected from the both crops were F. intonsa and F. occidentalis respectively. Frankliniella. intonsa was 4-8 times more abundant than F. occidentalis in sticky cards and on pepper flowers. In conclusion, asymmetrical dominance of F. intonsa was found both in strawberry and pepper plant as we found in past on those crops. Underlying reasons such as interspecific competition and climate change were discussed.
        138.
        2012.10 구독 인증기관·개인회원 무료
        In the case of one standard-mum polyvinyl house, the density of F. occidentalis reached its peak in early June and decreased after the chemical control, which was carried out periodically. In the case of another standard-mum polyvinyl house, the density of F. occidentalis increased continuously in spite of the periodical chemical control after planting. In both polyvinyl houses, the density of F. occidentalis began to increase mid-May. The numbers of F. occidentalis collected on a tray with wet paper by heating the flowers of pink, white, and yellow Chrysanthemum standard mums were 18.4, 56.6, and 52.6 after flowering, but in the case of the leaves, the numbers were 7.8, 16.6, and 15.4. Also, the numbers of F. occidentalis collected on a tray with wet paper by heating the buds of pink, white, and yellow Chrysanthemum standard mums were 15.2, 45.8, and 41.6, but in the case of the leaves, the numbers were 2, 8.8 and 3.4. In the Y-tube olfactometer test, the frequency of F. occidentalis’ visits to one side arm of the Y-tube olfactometer was higher in the odor cue of the white flower than of the yellow, red, and violet flowers, but in the other combinations without white flowers, the frequency was higher in the odor cue of the violet and red flowers than of the yellow flowers. In the case of the four-choice olfactometer test, in the same visual cues as the odor cues of the pot mum flowers, the frequency of F. occidentalis was higher in the yellow flower than in the other flowers (white, red, and violet) in all the observation times (10, 15, and 20 minutes). In the case of the visual cues with disturbed odor cues, F. occidentalis preferred the yellow color to the other colors in all the observation times (10, 20, and 40 minutes). F. occidentalis preferred the white color to the other colors when the same odor cues as the flower color were provided, but the odor cue of the yellow flower was provided only without the color cue.
        139.
        2012.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
         ,  , Silver-grey or dark brown scaring, or dark brown discolored damages caused by the yellow tea thrip, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) have occurred on citrus fruits cultivated in the open field in east-south area orchards of Jeju Island since 2007. The weekly population of yellow tea thrips adults caught with a yellow sticky trap increased gradually from early May and peaked in late August, 2009. In 2010 and 2011, the most population was in early October. The yellow tea thrips of some species usually dominated from July in open citrus fields, and seven generations, at least, had occurred from May to late October 2009 by a yellow sticky trap survey. In 2009, S. dorsalis larva were observed from July and with peaks from late August to mid September and early October on citrus fruits. The damage symptoms appeared in the mid September. In 2011, the population peaks were in early July and late September, and the symptoms increased continually from mid July to late October. The symptoms were silver-scars or initial dark discolorations and then gradually changed to dark-brown discolorations or dark-brown scars. The percent of damaged fruits were 0.9%, 0.4%, 0.8% and 2.7% in 2008, 2009, 2010 and 2011, respectively, by survey in 64 typical orchards in Jeju Island. We are the first to report symptoms of the yellow tea thrip (Scirtothrips dotsalis) on citrus fruits.
        4,000원
        140.
        2011.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
         ,  , This study was conducted to develop economic injury level (EIL) of onion thrips, Thrips tabaci, on welsh onion (Allium fistulosum L. var) in the early transplanting stage. The changes of welsh onion biomass, yield loss, and T. tabaci density were investigated according to the inoculation periods of T. tabaci. In the early transplanting stage of welsh onion, the yield loss (%) increased with increasing inoculation periods: 17.0, 53.3, 38.4, and 80.8% yield loss in 5, 10, 15, and 20 d inoculation periods, respectively. The relationship between Cumulative Insect Days (CID) of T. tabaci and yield loss (%) of welsh onion was well described by a nonlinear logistic equation. Using the estimated equation, EIL of T. tabaci on welsh onion was estimated to 30 CID per plant based on the yield loss 12% (an empirical gain threshold 5% + marketable rate 93% of welsh onion). ET was calculated to 24 CID, which corresponds to 80% of EIL. Until a more defined EIL-model is developed, the present results should be useful for T. tabaci management in early growth stage of welsh onion. The effect of T. tabaci attack on the yield of welsh onion in late growing season (120 days after transplanting) was also examined. The yield of welsh onion increased at a low population density of T. tabaci and decreased at higher densities, showing a typical over-compensatory response.
        4,000원
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