• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 167
  • 38
  • 10
  • 4
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 235
  • 235
  • 170
  • 124
  • 117
  • 85
  • 81
  • 63
  • 46
  • 46
  • 40
  • 38
  • 30
  • 28
  • 23
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

Métodos metaheurísticos aplicados a um modelo de planejamento de culturas /

Oliveira, Cíntia Pimentel de. January 2013 (has links)
Orientador: Helenice de Oliveira Florentino Silva / Banca: Daniela Renata Cantane / Banca: Antonio Álvaro de Assis Moura / Resumo: No contexto atual de sustentabilidade, formas alternativas à utilização de produtos que podem levar o planeta a uma crise ambiental estão sendo fortemente estudadas. Na agricultura, uma preocupação brasileira 'e com a redução do consumo de agrotóxicos, já que o país é um dos maiores consumidores mundiais do produto. Neste sentido, o planejamento das atividades agrícolas é uma ação preventiva que pode colaborar com a redução da proliferação de pragas entre as culturas plantadas em lotes e, consequentemente, a redução no consumo de produtos químicos. Ele visa determinar a melhor forma de ocupação de áreas de plantio de modo que a disposição das culturas e/ou variedades em talhões favoreça o controle eficiente de pragas. Neste trabalho é proposto um modelo de otimização 0-1 para minimizar a probabilidade de proliferação de pragas entre as culturas plantadas, respeitando restrições de demanda, ocupação de lotes, período de cultivo das culturas e tempo de planejamento. Nesta modelagem, considera-se uma área de plantio genérica, com lotes irregulares e culturas já plantadas em fazendas vizinhas. Para resolução do modelo foram utilizadas as estratégias Metaheurísticas Algoritmo Genético (AG), Simulated Annealing (SA) e a abordagem híbrida Algoritmo Genético com Simulated Annealing (AG+SA) para obtenção de boas estimativas para o planejamento otimizado das atividades agrícolas. Aplicações práticas a duas instâncias distintas foram realizadas e as melhores soluções factíveis encontradas pelos algoritmos são apresentadas, bem como comparação e discussão dos resultados e desempenho computacional dos métodos. Os resultados computacionais indicam que os algoritmos metaheurísticos propostos encontraram soluções factíveis de boa qualidade em um tempo computacional reduzido, e em especial, as estratégias híbridas demonstraram ser excelentes ferramentas para auxilio no planejamento de plantio / Abstract: In the sustainability context we are living nowadays, alternative forms to the utilization of products that can lead the Earth to an environmental crisis have been strongly studied. In agriculture, the Brazilian concern is about the reduction of pesticide consumption, once the country is one of the world's major consumers of it. In this sense, the planning of the agricultural activity is a preventive action that can contribute to reduce the proliferation of pests among crops planted in lots and, consequently, decrease the excessive consumption of such chemicals. This approach aims to determine the best way to use the planting areas arranging the crops and/or varieties in support to an efficient pests control. The research's objective is to propose an optimization model 0-1 in order to minimize the likelihood of pests proliferation among planted crops, considering constraints demand, lots occupation, crops growing period and planning time. In this model, it is considered a generic planting area with irregular lots and already planted crops in neighboring farms. In the model's solutions, Genetic Algorithm and Simulated Annealing Metaheuristics strategies were used, as well as a Genetic Algorithm jointly with Simulated Annealing hybrid approach in order to obtain good estimates for the optimized planning of agricultural activities. A practical application for the two instances was performed and the best feasible solutions found by the algorithms are presented as well as a comparison and discussion of the results and performance of computational methods. The computational results indicate that the metaheuristic algorithms found feasible solutions with good quality in a reduced computational time, and in particular, the proposed hybrid strategies have proven to be excellent tools to help planning the planting / Mestre
72

Fatores e mecanismos que influenciam a resistência em soja a Anticarsia gemmatalis Hübner e Spodoptera frugiperda (J. E. Smith) /

Souza, Bruno Henrique Sardinha de. January 2014 (has links)
Orientador: Arlindo Leal Boiça Júnior / Coorientador: Michael Joseph Stout / Banca: José Djair Vendramim / Banca: Valter Arthur / Banca: Francisco Jorge Cividanes / Banca: Ricardo Antonio Polanczyk / Resumo: A lagarta-da-soja Anticarsia gemmatalis Hübner e a lagarta-militar Spodoptera frugiperda (J. E. Smith) são duas das principais pragas desfolhadoras da cultura da soja. Entre os métodos disponíveis para seu controle destaca-se o uso de genótipos que apresentam moderada e alta resistência a insetos. No entanto, diversos fatores, inerentes à planta ou ao inseto, podem influenciar a expressão da resistência nas plantas. Desse modo, esse trabalho teve o objetivo de avaliar possíveis fatores que possam influenciar a expressão da resistência em soja, testando-se as hipóteses de que flavonoides, nutrientes, enzimas oxidativas, compostos fenólicos, proteínas e inibidores de proteinase possam ser alguns dos mecanismos responsáveis pela resistência à lagarta-da-soja e lagarta-militar. Três experimentos foram realizados a fim de elucidar essas questões. O primeiro experimento avaliou a influência dos seguintes fatores na expressão de antixenose nos genótipos resistente IAC 100 e suscetível BRSGO 8360 a ambas as espécies de insetos em testes de preferência alimentar com e sem chance de escolha: uma lagarta versus duas lagartas por disco foliar; uso de lagartas sem interrução de alimentação versus com suspensão de alimentação por três horas antes do ensaio; disco foliar versus folíolo inteiro; parte superior versus parte inferior da planta; e estádio vegetativo versus estádio reprodutivo. O segundo experimento avaliou a influência da parte superior versus inferior da planta e de plantas em estádio vegetativo versus plantas em estádio reprodutivo na expressão de antibiose a A. gemmatalis e S. frugiperda nos genótipos resistente PI 227687 e suscetível IGRA RA 626 RR. Além disso, foram avaliadas as concentrações de nutrientes e flavonoides como possíveis mecanismos responsáveis pela resistência em soja. Os macronutrientes quantificados nas folhas dos genótipos de soja provenientes dos respectivos tratamentos ... / Abstract: The velvetbean caterpillar Anticarsia gemmatalis Hübner and the fall armyworm Spodoptera frugiperda (J. E. Smith) are two of the major defoliating pests of soybeans. Among the methods available for their control, the use of genotypes possessing moderate and high resistance stands out. However, numerous factors, inherent to the plant or to the insect, may influence the expression of resistance in plants. Thus, this work aimed to evaluate potential factors influencing the expression of resistance in soybeans, and we tested the hypotheses that flavonoids, nutrients, oxidative enzymes, phenolics, proteins, and proteinase inhibitors may be some of the mechanisms responsible for resistance to the velvetbean caterpillar and fall armyworm. Three experiments were performed in order to elucidate these issues. The first experiment evaluated the influence of the following factors on the expression of antixenosis in the resistant genotype IAC 100 and susceptible genotype BRSGO 8360 to both insects in free-choice and no-choice feeding assays: one larva versus two larvae per leaf disc; use of non-starved larvae versus larvae starved for three hours prior to the assay; leaf disc versus entire leaflet; upper part versus lower part of plants; vegetative growth stage versus reproductive stage. The second experiment assessed the influence of the upper part versus lower part of the plant, and plants at vegetative growth stage versus reproductive stage on the expression of antibiosis to A. gemmatalis and S. frugiperda in the resistant genotype PI 227687 and susceptible genotype IGRA RA 626 RR. In addition, the concentration of nutrients and flavonoids were evaluated as potentital mechanisms responsible for resistance in soybeans. The macronutrientes quantified in the leaves of the soybean genotypes from the respective treatments were N, P, K, Ca, Mg, and S; the quantified micronutrients were B, Cu, Fe, Mn, and Zn; among the flavonoids, we quantified ... / Doutor
73

Ocorrência e dinâmica populacional de insetos-pragas e predadores associados às culturas de nabo forrageiro e milho em sistemas de plantio direto, em Chapadão do Sul, MS /

Braga, Isa Marcela da Silva. January 2013 (has links)
Orientador: Francisco Jorge Cividanes / Coorientador: Terezinha Monteiro dos Santos Cividanes / Banca: César Freire Carvalho / Banca: Guilherme Duarte Rossi / Resumo: O conhecimento da dinâmica populacional de insetos e inimigos-naturais em grandes áreas de cultivos é fundamental para a implementação de um programa de Manejo Integrado de Pragas. A ocorrência de populações destes insetos em altas densidades populacionais no início de cultivo de grandes culturas deve-se principalmente à sua manutenção na área em outras plantas hospedeiras ou plantas invasoras, que servem como abrigo e fonte de alimentação, permitindo que os mesmos se estabeleçam e permaneçam na área na cultura subsequente, formando o fenômeno chamado de "Ponte Verde". O presente trabalho teve como objetivos avaliar a ocorrência de espécies de insetos-pragas e inimigos naturais na cultura do nabo forrageiro, semeada como cultura de cobertura de solo e na cultura do milho em sucessão, em um sistema de plantio direto. O experimento foi instalado em Chapadão do Sul, MS, no ano agrícola de 2012/2013, sendo semeado nabo forrageiro na estressafra e milho na safra verão. As avaliações foram realizadas semanalmente, em 10 pontos, amostrando-se cinco plantas por ponto, totalizando 50 plantas por semana em ambas as culturas. Em razão da dinâmica dos insetos nas duas culturas estudadas no presente trabalho, os mesmos foram agrupados de acordo com o seu modo de alimentação ou ataque e relevância para cada uma, sendo assim, agrupados em: grupo das pragas desfolhadoras, grupo de insetos sugadores, grupo de insetos secundários e grupo de insetos predadores nas duas culturas. Os resultados evidenciaram que a cultura do nabo forrageiro é um importante hospedeiro de pragas primárias e secundárias que ocorrem em outras culturas, de modo que a sua colheita ou incorporação como adubação verde ao solo, deve ser realizada com antecedência ao plantio de milho ou soja em rotação de cultura, para não formar uma "Ponte Verde" / Abstract: The knowledge of the population dynamics of insects and natural enemies - in large areas of crops is critical to the implementation of a program of Integrated Pest Management. The occurrence of populations of these insects at high population densities in early cultivation of major crops is mainly due to its maintenance in the area on other host plants or weeds that serve as shelter and power supply, allowing them to settle and remain in the area in subsequent culture, forming the phenomenon called " Green Bridge". This study aimed to evaluate the occurrence of species of insect pests and natural enemies in the culture of turnip sown as cover crop and soil in corn in succession, in a no-till system. The experiment was installed in Chapadão Sul, MS, in the agricultural year 2012/2013, and sowed turnip in offseason and summer maize crop. Evaluations were performed weekly in 10 points, sampling up to five plants per point, totaling 50 plants per week in both culture. Given the dynamics of insects in the two cultures studied in this work, they were grouped according to their feeding mode or attack and relevant to each, so grouped as: group of defoliating pests, group of sucking insects, group of insects and secondary group of predatory insects in the two cultures. The results showed that the culture of the turnip is an important host of primary and secondary pests that occur in other culture, so that your harvest or incorporation as green manure to the soil, should be performed prior to planting corn or soybean crop rotation, not to form a "Green Bridge" / Mestre
74

Estratégias para controle de Enneothrips flavens Moulton, 1941 (Thysanoptera : Thripidae) e Stegasta Bosqueella (Chambers, 1875) (Lepidoptera: Gelechiidae) em amendoim /

Souza, Tamiris Marion de. January 2019 (has links)
Orientador: Antonio Carlos Busoli / Coorientador: Marcos Doniseti Michelotto / Resumo: O objetivo deste trabalho foi avaliar diferentes estratégias para o controle de Enneothrips flavens e Stegasta bosqueella no campo em dois anos consecutivos e semi-campo no ano de 2017/2018. No ano de 2016/2017, utilizou-se o delineamento experimental de blocos completos casualizados (DBC) em esquema fatorial 3 x 4, com quatro repetições, sendo o primeiro fator as três cultivares (Runner IAC 886, IAC 503 e IAC Top Verde) e segunda fator correspondente aos quatro tratamentos (1. testemunha; 2. aplicação de silício via foliar; 3. nível de controle (NC); 4. inseticida). Observou-se que o tratamento controle foi o que apresentou maior percentual de infestação, as notas mais altas de sintomas visuais das lesões e uma produtividade média de 3.500 kg ha-1. O tratamento com silício via foliar se comportou de forma semelhante ao tratamento controle, não diferindo desse tratamento. O tratamento NC foi o que apresentou melhor controle e produtividade, além de reduzir o número de aplicações na cultura e, o tratamento de pulverização de inseticidas pode controlar as duas pragas, apresentar notas de sintomas visuais de lesões menores, mas com uma produtividade inferior ao tratamento. O Runner IAC 886 mostrou-se mais suscetível a pragas e com baixa resposta aos tratamentos, apresentando produtividade relativamente menor. A cultivar IAC 503 apresentou percentuais de infestações e notas de sintomas intermediários e com produtividade acima de 3.500 kg ha-1. A cultivar IAC Top Verde apresentou ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The objective of this work was to evaluate different strategies for the control of Enneothrips flavens and Stegasta bosqueella in the field in two consecutive years and semi-field in the year 2017/2018. In the year 2016/2017, a randomized complete block design (DBC) was used in a 3 x 4 factorial scheme, with four replications, the first factor being the three cultivars (Runner IAC 886, IAC 503 and IAC Top Verde) and second factor corresponding to the four treatments (1. Witness; 2. Application of silicon via foliar; 3. Control Level (NC); 4. Insecticide). It was observed that the control treatment was the one that presented the most percentages of infestation, the highest notes of visual symptoms of injuries, and a mean productivity of 3,500 kg ha-1 . The silicon treatment via foliar behaved similar to the control treatment, not differing from this treatment. The NC treatment was the one that presented better control and productivity, besides reducing the number of applications in the crop and, the treatment of spray of insecticides can control the two pests, present notes of visual symptoms of minor injuries, but with a productivity inferior to treatment. Runner IAC 886 showed to be more susceptible to pests and with low response to treatments, presenting relatively lower productivity. The cultivar IAC 503 presented percentages of infestations and intermediate symptoms notes and with a productivity above 3,500 kg ha-1 . The cultivar IAC Top Verde showed percentages of high i... (Complete abstract click electronic access below) / Mestre
75

AppleMgr, a prototype decision aid for apple pest management

Haley, Sue 09 March 1990 (has links)
Computer decision aids can help integrate and apply diverse sources of information and expertise to problems of integrated pest management (IPM) in agriculture and forestry. AppleMgr combines a rule-based expert system with databases and spreadsheets in a prototype decision aid intended to be expanded and modified for use by extension workers in the Northwest U.S. The program requires an IBMcompatible microcomputer with hard disk. AppleMgr concentrates on the two most important insect pests on apple in the Northwest--codling moth, Cydia, pomonella (L.), and San Jose scale, Quadraspidiotus perniciosus Comstock, and on phytophagous mites, whose control largely depends on predators. The primary goal of AppleMgr is to demonstrate an improved process of decision making in apple IPM. AppleMgr is composed of modules for diagnosis of pest injury, identification of pest and natural enemy specimens, and management. The first two modules arrive at conclusions through backward-chaining inference from user observations. The management module uses backward chaining supplemented with external calculation programs to find the net benefit of a pesticide application. A method is included to predict yield and fruit size from crop samples. Cullage from codling moth and San Jose scale, mite effect on fruit size, probability of biological mite control and pesticide efficacy are predicted from researchers' data and estimates. Selected relative beneficial and adverse side effects of pesticides are presented in spreadsheets. An analysis of packing house records for apple crops from eight orchards at three yields using 1987 and 1988 prices and packing charges showed that net crop value varied by up to $8000 per acre. The variability in crop value and the importance of adverse side effects of pesticides suggest that the commonly-used "action thresholds" for treatment are seriously inadequate. AppleMgr may point the way toward more dynamic and realistic methods of IPM decision making. / Graduation date: 1990
76

Converging air jets in orchard spraying : influence on deposition, air velocities and forces on trees /

Svensson, Sven Axel. January 2001 (has links)
Thesis (Ph. D.)--Swedish University of Agricultural Sciences, 2001. / Includes bibliographical references.
77

Ecological studies on Myzus persicae (Sulz.) and Lipaphis erysimi (Kalt.) (Homoptera: Aphididae) on cruciferous crops in Hong Kong

Lee, Hay-yue, Lawrence, 李熙瑜 January 1977 (has links)
published_or_final_version / Zoology / Doctoral / Doctor of Philosophy
78

Rodent damage control in commercial forestry in the Natal Midlands, South Africa.

Taylor, Stuart. January 1996 (has links)
Rodents cause damage in commercial forests by gnawing at the bark of the trees. It is currently estimated that rodent damage in commercial forestry costs the industry R50 million per annum. The species of rodents which cause the damage are not known, neither is the reason behind this behaviour. Through stomach analysis it has been established that 3 species are involved Otomys irroratus, Rhabdomys pumilio and Mastomys natalensis, however this behaviour is confined to the winter. Chemical analysis of the bark reveals that the percentage concentration of nitrogen varies seasonally. The period of high concentration correlates with periods when the natural food of the rodents is restricted and when bark gnawing is most prevalent. In the past the industry's response to the damage has been to treat the areas with rodenticides. Using standard CMR methods, the two commercially-licensed rodenticides and raptor perches were tested to examine their efficacy as rodent control strategies. It was found that at a lower application of I block of rodenticide every third tree there is little difference in the effectiveness of the rodenticide brands and there is also little reduction in the abundance of the rodents. At a higher application rate of I block per tree, the abundance of rodents is reduced but termination of the treatment results in the rodent numbers quickly recovering, indeed they surpassed their original population numbers within 4 months. Apart from the environmental dangers of applying such concentrations of poison, this is clearly an uneconomic solution. My results indicate that at first planting, the sites should be provisioned with raptor perches at a density of 16 ha⁻². Contrary to accepted policy the perches do not require cross pieces, which add to the expense and offer no advantage in raptor residency time. In areas of very high rodent abundance the provisioning of tree collars provide physical protection to the trees. An additional benefit of the collars is that the collars cause a beneficial microclimate around the tree which enhances its growth rate. When the tree is around 2 years old it should be pruned to a height of I ffi, the slash being left in the inter-row. Results show that trees treated in such a way experience no further attack and the rodents browse on the prunings. As the cost of the perches is reduced and the cost of pruning is non-recurring the recommendations provide an economical and environmentally sympathetic alternative to rodenticide application. / Thesis (M.Sc.)-University of Natal, Pietermaritzburg, 1996.
79

Taxonomic studies of laelapid mites (Acari: Mesostigmata: Laelapidae) and their use in combination with entomopathogenic nematodes (Rhabditida: Steinernematidae, Heterorhabditidae) to control Frankliniella occidentalis (Thysanoptera: Thripidae)

Moreira, Grazielle Furtado [UNESP] 23 April 2014 (has links) (PDF)
Made available in DSpace on 2015-03-03T11:52:37Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-04-23Bitstream added on 2015-03-03T12:06:21Z : No. of bitstreams: 1 000807233_20150423.pdf: 130707 bytes, checksum: d1216633a769f5eba4ecf88e8223de6a (MD5) Bitstreams deleted on 2015-04-23T11:39:25Z: 000807233_20150423.pdf,Bitstream added on 2015-04-23T11:39:57Z : No. of bitstreams: 1 000807233.pdf: 3171399 bytes, checksum: 12fcf4cc4f2fcf5fbdcdccd0a49cbe2e (MD5) / A família Laelapidae Berlese (Mesostigmata: Dermanyssoidea) é cosmopolita e ocupa uma diversidade de habitats, onde seus hábitos podem variar de espécies de vida-livre a espécies associadas a artrópodes, mamíferos e pássaros. Algumas espécies dessa família, bem como os nematoides entomopatogênicos (NEP) têm demonstrado bom potencial como agentes de controle biológico. Frankliniella occidentalis (Pergande), uma das espécies mais importantes de tripes-praga, causa danos a várias plantas cultivadas, atuando como praga ou vetor de patógenos. Os objetivos desse estudo foram a preparação de um catálogo taxonômico para lelapídeos de vida-livre e associados a artrópodes, o estudo taxonômico de espécies de Laelapidae coletados no Brasil, a preparação de uma chave para gêneros de Laelapidae de vida livre e associados a artrópodes até o momento conhecidos da América do Sul, e avaliar os efeitos de diferentes espécies de lelapídeos e NEP como agentes de controle de F. occidentalis. Um total de 828 espécies pertencentes a 41 gêneros são relatados no catálogo. Nove espécies novas foram descritas e uma chave para gêneros de ocorrência na América do Sul de Laelapidae foi elaborada. Em testes de laboratório, Cosmolaelaps jaboticabalensis Moreira, Klompen & Moraes e Stratiolaelaps scimitus (Womersley) predaram aproximadamente 2,5 e 3,9 pré-pupa/pupa de F. occidentalis e ovipositaram aproximadamente 2,2 e 1,4 ovos por dia, respectivamente. Heterorhabditis amazonensis GL Andaló, Nguyen & Moino Jr. foi o nematoide mais virulento, causando a mortalidade de aproximadamente 87,5% das pre-pupas/pupas oferecidas. Nenhum dos predadores avaliados mostrou preferência por este nematoide como presa e nenhum dos NEP avaliados interferiram na sobrevivência dos predadores. Para C. jaboticabalensis, a fase imatura (ovo-adulto) foi completada em 12,3 ± 5; 6,6 ± 0,6 e 7,1 ± 0,6 em F. occidentalis, Protorhabditis sp. ... / The cosmopolitan Dermanyssoidea mite family Laelapidae Berlese occupies a diversity of habitats, where their habits vary from free-living to arthropod, mammal and bird associates. Some species of this family as well the entomopathogenic nematodes (EPN) have shown good potential as biological control agents. Frankliniella occidentalis (Pergande), one of the most important thrips pests, causes major damage to several cultivated plants, acting as pest or vector of pathogens. The aims of the study reported in this document were the preparation of a taxonomic catalog of the free-living and arthropod associated laelapid mites, the taxonomic study of the laelapid species collected in Brazil, the preparation of a key for the South American free-living and arthropod associated genera, and evaluations of the effect of different laelapid and EPN species as control agents of F. occidentalis. A total of 828 species of 41 genera are reported in the catalog. Nine new species were described and a key for the separation of genera reported in South America genus was prepared. In laboratory tests, Cosmolaelaps jaboticabalensis Moreira, Klompen and Moraes and Stratiolaelaps scimitus (Womersley) preyed upon about 2.5 and 3.9 pre-pupae/pupae of F. occidentalis and laid about 2.2 and 1.4 eggs per day, respectively. Heterorhabditis amazonensis GL Andaló, Nguyen and Moino Jr. was the most virulent nematode, producing mortality of about 87.5% of exposed pre-pupae/pupae. None of the evaluated predators showed preference for that nematode as prey and none of the evaluated nematodes interfered in the survivorship of the predators. For C. jaboticabalensis, total immature development (egg-adult) was completed in 12.3 ± 5, 6.6 ± 0.6 and 7.1 ± 0.6 on F. occidentalis, Protorhabditis sp. and T. putrescentiae, respectively. Fecundity and intrinsic rate of increase were higher on Protorhabditis sp. (71.6 ± 9.1 eggs/female; 0.28 female/female/day) than ...
80

Suscetibilidade de Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) a entomopatógenos

Agostini, Lucas Trevisoli [UNESP] 22 July 2014 (has links) (PDF)
Made available in DSpace on 2015-03-03T11:52:42Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-07-22Bitstream added on 2015-03-03T12:07:10Z : No. of bitstreams: 1 000807109.pdf: 457835 bytes, checksum: c8b102f16b86a5f3ecea8c8ee3c9df40 (MD5) / A pesquisa objetivou analisar a suscetibilidade de duas populações distintas de Helicoverpa armigera a produtos comerciais à base de Bacillus thuringiensis (Bt) e isolados de Beauveria bassiana, Metarhizium anisopliae e Metarhizium rileyi. As populações foram coletadas em lavouras de soja nos municípios de Rio Verde (GO) e Luís Eduardo Magalhães (BA) e criadas em laboratório até a décima geração antes do início dos bioensaios. Os formulados utilizados foram Dipel® PM (B. thuringiensis var kurstaki), Xentari® WG (B. thuringiensis var. aizawai) e Agree® WG (B. thuringiensis var. aizawai GC91 transconjugado com B. thuringiensis var. kurstaki), com a aplicação de 50 ?L da suspensão do produto biológico, na concentração de 107 esporos viáveis/mL, sobre a superfície da dieta acondicionada em recipientes esféricos de plástico (2 cm de diâmetro x 3 cm de altura). Em cada recipiente foi inserida uma lagarta, de cada instar larval, em um total de 100 lagartas por tratamento distribuídas em 10 repetições. As avaliações referentes à mortalidade foram efetuadas a cada 24 horas, até o sétimo dia após a aplicação dos tratamentos. Os fungos B. bassiana e M. anisopliae foram obtidos a partir dos produtos comerciais biológicos Boveril® PM e Metarril® PM, respectivamente, enquanto que M. rileyi foi isolado de cadáveres de H. armigera, sendo padronizados na concentração de 108 conídios viáveis/mL. Como unidade experimental foram utilizados recipientes de plástico (2 cm de diâmetro x 3 cm de altura), com dieta artificial na qual uma alíquota de 50 ?L do fungo foi misturada ou aplicada na superfície. Em cada recipiente foi inserida uma lagarta de primeiro instar, com menos de 24 h de vida, totalizando 100 lagartas por tratamento distribuídas em 10 repetições. A mortalidade foi avaliada a cada 24 h, até o décimo dia após a aplicação dos tratamentos. Lagartas de primeiro instar de H. armigera, de ambas ... / The research aimed to assess the suscetibility of two distinct Brazilian populations of Helicoverpa armigera to commercial Bacillus thuringiensis insecticides and isolates of Beauveria bassiana, Metarhizium anisopliae and Metarhizium rileyi.The pest populations were collected in soybean fields located in Rio Verde (GO) and Luís Eduardo Magalhães (BA), taken to laboratory and reared until the tenth generation on artificial diet, to be used in the experiment.The bioassays were performed using spherical plastic receptacles (2-cm diameter x 3- cm height) containing artificial diet until complete the half volume. The formulated products used were Dipel® WP (B. thuringiensis var kurstaki), Xentari® WG (B. thuringiensis var. aizawai) and Agree® WG (B. thuringiensis var. aizawai GC91 with B. thuringiensis var. kurstaki), spraying 50 ?L of biological product solution at 107 viable spores/mL, on the surface of the diet. One caterpillar was inserted in each receptacle, related with larval instar, totaling 100 caterpillars per treatment and each group containing 10 caterpillars were considered a replication. Mortality were assessed each 24h, until the seventh day after the beginning of the bioassay. To perform the bioassays with entomopathogenic fungi, B. bassiana and M. anisopliae were obtained from the bio-insecticides Boveril® WP and Metarril® WP, respectively and M. rileyi was isolated from H. armigera cadavers at concentration of 108 viable conidia/mL. The bioassays were performed using spherical plastic receptacles (2-cmdiameter x 3-cm height) containing artificial diet until complete the half volume. After this step, a solution of 50 ?L containing the entomopathogenic fungi was sprayed on the diet surface. One caterpillar was inserted in each receptacle, with less than 24 h after hatch, totaling 100 caterpillars per treatment. Each group containing 10 caterpillars were considered a replication. Mortality were assessed each 24h, until ...

Page generated in 0.0593 seconds