999 resultados para Broca-da-cana


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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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Diatraea saccharalis Fabr. (Lepidoptera: Crambidae) is a major sugarcane pest in Brazil. The management of infested areas is based on the release of Cotesia flavipes (Cameron) (Hymenoptera: Braconidae), a parasitoid of D. saccharalis larvae, but there are doubts about the effectiveness of C. flavipes, primarily regarding its rate of dispersal in sugarcane fields. Thus, the objective of this study was to evaluate the dispersal of C. flavipes in a sugarcane field and suggest a release method that provides higher parasitoid efficiency. The study was carried out in four areas of approximately 1 ha, in which stalk pieces containing 20 D. saccharalis larvae were distributed in a rectangular grid, and 12,000 C. flavipes adults were released at four points, that were 50 m apart and 25 m from the field border. Three days later, the D. saccharalis larvae were recovered and kept in the laboratory until they reached pupal stage or C. flavipes emergence. Parasitism varied from 13.2% to 42.8%. The random distribution of parasitized larvae was found in one assay. In three areas, the parasitized larvae showed an aggregated distribution, with a range of 15 to 25 m. Since the parasite's success is directly linked to parasitoid dispersion, it would be interesting to move the release points to 30 m from each other because the dispersal may happen in a 15 m radius.

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Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

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Pós-graduação em Agronomia (Produção Vegetal) - FCAV

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Com o uso de variedades adaptadas e o manejo do solo pós-colheita da soqueira de cana-de-açúcar em sistema de colheita mecanizada, poderá ser afetada a incidência de pragas e a produtividade do canavial. Assim, desenvolveu-se o presente trabalho com o objetivo de se avaliar a influência da palhada de dezoito variedades de cana-de-açúcar submetidas a diferentes sistemas de manejo de colheita mecânica, sem queima, na produtividade agrícola e na incidência de broca-comum e cigarrinha-das-raízes na cultura de cana-de-açúcar. Os tratamentos foram constituídos pela presença da palha sem trituração/sem cultivo (PST/SC); palha sem trituração/com cultivo com escarificador (PST/CC); palha triturada/com cultivo com escarificador (PT/CC). O rendimento de colmos na cana-soca é favorecido pelo manejo, com cultivo, da palhada da planta crua, colhida mecanicamente, sem alteração na incidência de broca-comum e da cigarrinha das raízes. A variedade SP87-365 de cana-de-açúcar é opção viável e rentável, em qualquer sistema de manejo da cana crua, com adaptação à colheita mecânica e às condições edafoclimáticas da região de Ribeirão Preto, SP. A incidência de broca-comum e da cigarrinha das raízes pode ser bastante reduzida com a utilização das variedades SP88-817 e SP76-112 de cana-de-açúcar, em qualquer sistema de manejo da palhada da cana crua colhida mecanicamente e minimizada na colheita mecânica da cana crua, seguida de trituração da palhada e cultivo com escarificador na entrelinha.

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The objective of this study was to evaluate the reaction of ten sugarcane cultivars to Diatraea saccharalis under field conditions, using a randomized block design with treatments in factorial 2x10 with six replications. The first factor was represented by two levels of infestation (infested and not infested) by borer and the second one, by the ten sugarcane varieties (IAC87-3396, IAC91-1099, IACSP93-3046, IACSP94-2101, IACSP94-2094, IACSP94-4004, IACSP95-5000, IACSP96-3060, IACSP96-2042 and SP91-1115). The experiment was evaluated in two crop cycles: plant crop and first ratoon. All cultivars were attacked by the borer, being IACSP94-4004, IACSP96-2042 and SP91-1115 the most damaged cultivars with the highest infestation index. During the plant crop, plots infested by the borer presented higher fiber content than the ones not infested. During the first ratoon, non infested plants produced 10% less and presented lower purity and higher content of reducing sugars than the non-infested plants.

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The objective of this work was to evaluate the effect of nitrogen-fertigation on the damage caused by the borer-rot complex to the productivity and quality of fertigated sugarcane. The experiment was carried out in field, using a randomized complete block design, with four replicates and five N doses (0, 50 100, 150, and 200 kg ha-1) applied through drip irrigation. The following variables were determined: number of holes caused by Diatraea saccharalis (Lepidoptera: Crambidae); number of internodes infected with red rot; incidence percentage of red rot; stalk productivity; and sugar content. In laboratory, the attractiveness and the consumption of culm fragments by fourth instar caterpillars, in trials with or without choice, were evaluated. Nitrogen fertigation increased the incidence of D. saccharalis and red rot. The number of holes produced by the larvae was correlated with the occurrence of red rot. Sugar percentage reduced with the increase in the number of red rot affected internodes. Nitrogen doses did not affect the attractiveness of sugarcane culm fragments; however, higher N doses increased the consumption of these fragments by D. saccharalis caterpillars. Despite the damages to quality, nitrogen fertilization expressively enhanced the productivity of stalks and sugar.

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Aiming qualitative improvements in the mass rearing of Cotesia flavipes (Cameron, 1891) (Hymenoptera: Braconidae) in laboratory, tests were conducted with adults feed before parasitism on Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae) larvae, using 14 artificial diets based on sucrose, brewer yeast and honey. The design was completely randomized with 15 treatments and five replications. The biological parameters evaluated in F1 and F2 generations were: number of adults emerged; sex ratio; adult emergence percentage; weight of pupae mass; and male and female longevity. The highest average of emerged adults were 85 in diet with sucrose 5% for F1 generation, and 91 in diet with sucrose 5% + yeast brewer 2,5% for F2; the smaller average of adult emergency were 63.60 in diet with honey 5% + yeast brewer 2.5 % for F1 generation and 66.80 in diet with honey 5% for F2. Diets that produced more females were honey 5% + yeast brewer 2.5%, showing the sex ratio of 0.82 for F1 generation, and sucrose 10% + 2.5% yeast brewer 2.5% (0.75) for F2, while sucrose 10% + yeast brewer 2.5% (0.60 for F1) and honey 2.5% (0.59) provided fewer females for F2 generation. The highest percentage of adult emergence were 93.90% with the diet containing sucrose 2.5% + yeast brewer 2.5%) and 93.89 % with honey 5% + yeast brewer 2.5%, and the lowest 81.71% (honey 5% + yeast brewer 2.5%) for F1 and 78.96 % (honey 5%) to F1 and F2, respectively. The diet with Mel 2.5% produced greater weight of pupae mass. The adult longevity did not differ significantly for all diets in F1 and F2 generations. Diets containing 5% or 10% of sucrose or honey provide, in general, improve the qualitative development of C. flavipes in mass rearing.

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A broca do pedúnculo floral do coqueiro, Homalinotus coriaceus (Gyllenhal), é uma praga limitante à produção de coco no Brasil, provocando a queda das flores e dos frutos imaturos. Sua biologia é pouco conhecida o que tem dificultado a seu manejo adequado no campo. Dessa forma, foi realizado o estudo da biologia desse inseto no Laboratório de Entomologia da Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA) Tabuleiros Costeiros - CPATC, em Aracaju, SE, à temperatura de 25 ± 2°C, umidade relativa de 70% e fotofase de 12h. Para alimentação e oviposição dos adultos coletados no campo foram utilizados toletes de cana-de-açúcar como substrato, nos quais as fêmeas colocaram ovos individualizados, cujo período de incubação variou de seis a 14 dias. As larvas foram criadas no mesocarpo de coco, desenvolvendo-se em 144 dias em média, passando por cinco a sete ínstares. O período pupal médio foi de 31 dias. A longevidade do adulto variou de 303 a 695 dias para fêmeas e de 246 a 635 dias para machos, sendo o ciclo de ovo a adulto de 181,9 dias para fêmeas e 188,5 para machos. Foram observadas diferenças morfológicas nas pupas e nos adultos, que podem ser utilizadas para separação dos sexos. Ao contrário dos machos, as fêmeas apresentam, na fase de pupa, duas estruturas arredondadas e elevadas situadas na face ventral e final do abdome e, na fase adulta, o penúltimo tergito abdominal projeta-se sobre o último.

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Pós-graduação em Agronomia (Proteção de Plantas) - FCA

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The sugar cane plantation expands its borders each year, throughout the national territory. Thus, increases the amount of biomass that will to be exploited by man in sugar and alcohol produce and also by other organisms, which will have food in abundance. The growth of mechanized harvesting, with the consequent decrease in burning of straw and the expansion of the sucroalcooleiro sector are causing changes into entomofauna in certain areas or regions of sugar cane plantation. One of the new threats to the sugar cane plantations in southcentral region, causing uncertainty and concern to farmers, is the giant worm, Telchin licus, known in Brazil since 1927, in the Northeast of Brazil, is considered a major pest of cane sugar. In 2007 it was first recorded in the state of São Paulo, which accounts for 60% of the country's crops. Whereas until then there is not much information about their management and control, the aim of this review is to gather information on the basis for its control within the context of Integrated Pest Management of cane sugar.