Ação e doses dos inseticidas lufenuron e lambdacialotrina no controle de spodoptera frugiperda (J. e. Smith, 1797) (Lepidoptera: noctuidae)
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Data
2009-12-04
Autores
Silva, Rosemery Ferraz da [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Visando obter informações que possam contribuir para o melhor entendimento da eficácia de controle da lagarta do cartucho do milho, empregando defensivos agrícolas com diferentes mecanismos de ação, em diferentes doses, desenvolveu-se o presente trabalho procurando verificar o período de ação e o local de deposição na folha de milho, dos inseticidas lufenuron e lambdacialotrina, aplicados em pulverização com barra montada. Semeou-se uma área de 5.700 m2 com milho (Zea mays) do cultivar AL 25, na Fazenda Piloto do Departamento de Ciências Agrárias da Universidade de Taubaté. A pulverização dos defensivos agrícolas foi realizada aos 30 dias após a emergência das plantas, utilizando um trator com uma barra de pulverização de 12 m e pontas do tipo XR 8001 e XR 80015. O trator se deslocou a velocidade de 4 km/h numa parte da área e a 6 km/h na outra parte, de tal maneira que as subáreas receberam diferentes doses dos inseticidas, de acordo com a ponta utilizada e a velocidade de deslocamento do trator, obtendo-se 9 tratamentos. Após a pulverização dos inseticidas no campo, foi coletada a antepenúltima folha lançada de 10 plantas ao acaso em cada subárea, com 1, 5, 10 e 15 dias após a pulverização e levadas ao laboratório para a avaliação do número de lagartas sobreviventes. Ao chegar no laboratório, as folhas foram divididas em três regiões distintas: proximal, mediana e distal, em relação ao caule. Em seguida foi retirada a nervura central para evitar que se enrolassem. Partes das folhas foram colocadas em placas de “Petri” juntamente com 5 lagartas de 3º instar. As avaliações relativas à sobrevivência larval de S. frugiperda em todos os tratamentos, inclusive no tratamento testemunha, foram realizadas 24, 48, 72, 120 e 168 horas após a inoculação das lagartas. Cada época de coleta de folhas no campo foi considerada como um experimento...
Looking for better understanding the efficacy to control armyworm in maize crops using insecticides in different dosages and mode of action, this research aimed to verify the period of action and the correct area of deposition of the insecticides lambdacialothrin and lufenuron in spraying, through a set up bar. An area of 5,700 m2 was seeded with AL 25 maize (Zea mays) cultivar at the experimental farm from the Ciências Agrárias Department of Taubaté University. The insecticide sprayings were carried out 30 days after plants emergence, using a tractor coupled to a spraying with a bar of 12m length and tips XR 8001 and XR 80015. The tractor speed was 4.0 Km/h in the first half of the area and 6.0 Km/h in the second half and this way, both half areas received different insecticides dosages according to the speed established and the tip used, completing 9 treatments. In the field, 1, 5, 10 and 15 days after insecticide spraying, the leaf before the last of 10 plants were randomly collected from both areas and led to laboratory to evaluate the number of live armyworms. At the laboratory, the leaves were split up in 3 regions: the base region, middle region and top region in relation of maize stem. Afterward, the main vein was removed from each part to avoid dehydration. These little pieces of leaves were placed into a “Petri” dish with 5 larvae form 3rd instar. The surviving larvae of S. frugiperda in all treatments were determined 24, 48, 72, 120 and 168 hours after larvae inoculation. Each data from leaves collection in the field were considered a separate experiment. The obtained data were transformed in square root of (x + 0.5) and analyzed their variance... (Complete abstract click electronic access below)
Looking for better understanding the efficacy to control armyworm in maize crops using insecticides in different dosages and mode of action, this research aimed to verify the period of action and the correct area of deposition of the insecticides lambdacialothrin and lufenuron in spraying, through a set up bar. An area of 5,700 m2 was seeded with AL 25 maize (Zea mays) cultivar at the experimental farm from the Ciências Agrárias Department of Taubaté University. The insecticide sprayings were carried out 30 days after plants emergence, using a tractor coupled to a spraying with a bar of 12m length and tips XR 8001 and XR 80015. The tractor speed was 4.0 Km/h in the first half of the area and 6.0 Km/h in the second half and this way, both half areas received different insecticides dosages according to the speed established and the tip used, completing 9 treatments. In the field, 1, 5, 10 and 15 days after insecticide spraying, the leaf before the last of 10 plants were randomly collected from both areas and led to laboratory to evaluate the number of live armyworms. At the laboratory, the leaves were split up in 3 regions: the base region, middle region and top region in relation of maize stem. Afterward, the main vein was removed from each part to avoid dehydration. These little pieces of leaves were placed into a “Petri” dish with 5 larvae form 3rd instar. The surviving larvae of S. frugiperda in all treatments were determined 24, 48, 72, 120 and 168 hours after larvae inoculation. Each data from leaves collection in the field were considered a separate experiment. The obtained data were transformed in square root of (x + 0.5) and analyzed their variance... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Pragas agricolas, Inseticidas, Milho, Tecnologia de aplicação, Chemical control, Action period, Corn armyworm, Spray deposition
Como citar
SILVA, Rosemery Ferraz da. Ação e doses dos inseticidas lufenuron e lambdacialotrina no controle de spodoptera frugiperda (J. e. Smith, 1797) (Lepidoptera: noctuidae). 2009. iv, 50 f. Tese (doutorado) - Universidade Estadual Paulista, Faculdade de Ciências Agronômicas de Botucatu, 2009.