Navegando por Autor "Martins, Elem Fialho"
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Item Avaliação de doses de misturas de materiais orgânicos na produção de café em propriedades familiares das matas de Minas(Embrapa Café, 2015) Lima, Paulo César de; Moura, Waldênia de Melo; Almeida, Carlos Henrique da Silva; Martins, Elem Fialho; Silva, Paulo Roberto PereiraUma importante questão levantada por agricultores das Matas de Minas em prospecções de demandas realizadas pela EPAMIG, relaciona-se às práticas que envolvem a adubação em sistemas orgânicos e agroecológicos, que estão entre as principais dificuldades para o cultivo de café. O desafio é encontrar alternativas de baixo custo e garantir uma produção sustentável. A questão básica é a baixa fertilidade dos solos, causada pelas características naturais e pelo grau de degradação de algumas áreas. Também a baixa capacidade de aquisição de insumos e o limitado domínio sobre os processos de ciclagem de nutrientes nesses sistemas têm resultado em baixos níveis de “input”, evidenciando a necessidade de se traçar estratégias de adição de nutrientes para que os agroecossistemas sejam melhorados. Em função dessa demanda esse trabalho teve por objetivo avaliar doses de misturas de materiais orgânicos obtidas de materiais disponíveis em propriedades de base familiar ou de fácil aquisição com baixo custo como fontes de nutrientes para adubação de cafeeiros. Foram instalados quatro experimentos em propriedades familiares nos municípios de Araponga e Ervália. Por meio da experimentação participativa com os agricultores foram testadas quatro diferentes misturas de materiais orgânicos indicadas por eles, em doses correspondentes a 50, 150, 300 e 600 kg/ha de nitrogênio, em delineamento experimental em blocos casualizados com três repetições. Por meio dos dados de produtividades foram realizadas análises de regressão para produtividade em função de dose. Foram analisadas as composições químicas dos materiais empregados, de solos e de folhas dos cafeeiros. As produtividades médias obtidas pelas quatro misturas de materiais orgânicos variaram entre as colheitas de 2013 e 2014. No ano de 2013 variaram de 27 sacas de café beneficiadas por hectare na dose correspondente a 50 kg de N/ha a 44,6 sacas/ha na dose correspondente a 600 kg de N/ha. Nas colheitas de 2014 as variações foram de 18 a 30 sacas/h, respectivamente. Essa diferença poderia ser atribuída a um efeito de bienalidade e/ou a grande redução nas precipitações do período chuvoso 2013/14.Item Conservation biological control of coffee leaf miner: role of green lacewings and parasitoids(Universidade Federal de Viçosa, 2021-10-29) Martins, Elem Fialho; Venzon, Madelaine; Schmidt, Jason M.; Perez, André LageCoffee leaf miner, Leucoptera coffeella, is a key coffee pest in the Neotropics. The larvae feed on the parenchyma between surfaces of coffee leaves causing decrease of the photosynthesis rate leading to significant losses in yield and in the longevity of coffee plant. Several natural enemies are involved in coffee leaf mine biological control, such as wasps, ants, parasitoids and green lacewings. However, normally their populations are not enough to decrease or to maintain the coffee leaf mine populations below threshold levels in coffee monocultures, due to their dependence on resources, such as pollen and nectar, which are scarce in conventional systems. The association of plant species to coffee crops might represent an effective strategy through the provision of alternative food and refuge for natural enemies. I investigate here whether the diversification of Coffea arabica crops with Inga edulis “erva-baleeira”, Varronia curassavica “inga”, Senna macranthera “fedegoso” and non-crop plants favors the biological control of coffee leaf miner by its predators and parasitoids. These plants can provide resources such as nectar and pollen constantly, shelter and oviposition and mating sites for natural enemies with either extrafloral nectaries (I. edulis and S. macranthera) and/or inflorescences (V. curassavica). Firstly, we performed laboratory experiments to evaluate whether the immature stages of the green lacewing Ceraeochrysa cubana are able to prey on the immature stages of coffee leaf miner (Chapter I). Larvae of C. cubana successfully prey on eggs and pupae of coffee leaf miner, being the first report about green lacewing predation on the pest eggs. We also investigate whether V. curassavica provides selective resources to C. cubana without benefiting coffee leaf miner adults (Chapter II). Larvae of C. cubana survived longer in the presence of V. curassavica inflorescences, and decrease the population growth rate of the pest. In the field, we evaluated the visitors of the inserted plants and whether the strategic diversification with I. edulis, S. macranthera and V. curassavica added to non-crop areas under management of no pesticide use influence the abundance and richness of predatory green lacewings and wasps, increase the parasitism and control coffee leaf miner compared to conventional coffee systems (Chapter III). I found that ants are the most abundant visiting insects of I. edulis, S. macranthera and V. curassavica. In addition, I found that although there was no significant difference in the abundance of green lacewings and wasps between systems, parasitism rate was higher in the diversified. Despite that, there was no difference in the pest infestation comparing to conventional coffee systems in 2019 and 2021, but in 2020 it was higher in the diversified. However, CLM populations did not reach threshold in any system. Our study demonstrates through laboratory and field experiments that it is possible to improve the biological control of coffee leaf miner with safe strategies to environment and humans, in addition to maintaining biodiversity in coffee agroecosystems. Keywords: Leucoptera cofeella. Conservation biological control. Ceraeochrysa cubana, Varronia curassavicaItem Intercropping coffee with Varronia curassavica Jacq. affects arthropod biodiversity(Universidade Federal de Viçosa, 2023-07-28) Marques, Daniel Maciel; Venzon, Madelaine; Fonseca, Maira Christina Marques; Martins, Elem Fialho; Bernardes, Rodrigo Cupertino; Vilela, Emerson FerreiraCoffee is one of the most important commodities in Brazil, and the country is the largest producer of coffee berries in the world. The changes in the global perception of the importance of agricultural landscapes, climate change, contamination by pesticides and loss of biodiversity haves led to improve the research and the practices on more sustainable agroecosystem and food production. In this sense, companion crop plants can be powerful allies to promote sustainable agroecossystems, reducing the effects of climate changes and loss of biodiversity, as well as improving the natural pest control by offering plant resources needed by natural enemies, resulting in less crop damage by pests. The objective of this study was to evaluate the potential of Varronia curassavica as companion crop to improve pest control of coffee leafminer (CLM) and coffee berry borer (CBB) and to increase the biodiversity, especially parasitoids and predators, as well as studying its protection to coffee plants. The first experiment was carried out in a coffee farm in Paula Cândido, in the Atlantic Forest biome, and the second in Patrocínio, in the Cerrado biome, both in the state of Minas Gerais, Brazil. At Paula Cândido, we sampled coffee plants for CLM and CBB from January and May of 2023. Biodiversity was also evaluated by sampling arthropods on coffee trees using entomological net and by tray beating. The effect of distance on the protection of coffee plants against CLM provided by V. curassavica was evaluate on transects in a farm where V. currassavica was associated to coffee in Patrocinio. No differences in infestation levels in diversified and conventional plots were observed in Paula Cândido, which was low probably due to chemical inputs and the rainy season. The total number of natural enemies sampled was not significant different in both plots, but diversified plots showed significant higher abundance of predators of Geocoridae and Linyphiidae families and parasitoids of Tachinidae and Chalcididae families. The mean infestation rate of Leucoptera coffeella on the diversified system in Cerrado was low and no differences were observed on the infestation levels across the transect. These results show that Varronia curassavica can be a suitable plant to be used in agroecossystems