Pesquisa Agropecuária Brasileira
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/9886
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Resultados da Pesquisa
Item Leaf miner incidence in coffee plants under different drip irrigation regimes and planting densities(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 2012-02) Assis, Gleice Aparecida; Assis, Franscinely Aparecida; Scalco, Myriane Stella; Parolin, Francisco José Toloza; Fidelis, Iraci; Moraes, Jair Campos; Guimarães, Rubens JoséThe objective of this work was to evaluate the effect of different drip irrigation regimes and planting densities on the incidence of the leaf miner, Leucoptera coffeella, in arabica coffee plants for one year. The experiment was carried out in 2008, in a complete randomized block design, in a split‐plot in time arrangement, with four replicates. The treatments consisted of four drip irrigation regimes – soil water balance, irrigations at 20 and 60 kPa soil tensions, and a nonirrigated treatment –, which were distributed at three plant densities: 2,500, 5,000, and 10,000 plants per hectare. The evaluations were made on a monthly basis between January and December 2008. The highest pest occurrence period was from August to November, a season with low‐air relative humidity preceded by a drought period. Irrigated coffee plants showed an incidence of intact mines 2.2 times lower than that of nonirrigated plants. Irrigation and increasing of plant density contribute to the reduction of coffee leaf miner occurrence.Item High coffee population density to improve fertility of an oxisol(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 1999-03) Pavan, Marcos Antonio; Chaves, Júlia César Dias; Siqueira, Rubens; Androcioli Filho, Armando; Colozzi Filho, Arnaldo; Balota, Elcio LiborioThe objective of this work was to evaluate the effect of coffee (Coffea arabica L.) population densities on the chemical and microbiological properties of an Oxisol. The work was carried out on soil samples of 0-20 cm depth originated from an experimental site which had been used for coffee tree spacing studies during 15 years, in Paraná State, Brazil. Eight coffee tree populations were evaluated: 7143, 3571, 2381, 1786, 1429, 1190, 1020, and 893 trees/ha. Increasing plant population increased soil pH, exchangeable Ca, Mg, K, extractable P, organic carbon, moisture content and coffee root colonization by vesicular arbuscular mycorrhizal fungi, and decreased exchangeable Al and microbial biomass. Such results were attributed to better erosion control, improved plant residue management and nutrient cycling, and decreased leaching losses. Increasing coffee tree population per unit of area has shown to be an important reclamation recuperation strategy for improving fertility of the acid soils in Paraná, Brazil.Item Influência da densidade de plantio e sistema de podas na produção de café(Empresa Brasileira de Pesquisa Agropecuária - Embrapa, 1999-08) Toledo, Sérgio Vasco de; Barros, Inácio deDurante 19 anos, foi conduzido um experimento em Campinas, SP, que objetivou avaliar a influência da variedade, espaçamento, número de plantas na cova e sistema de condução da planta sobre a produção de café (Coffea arabica L.). As variedades Mundo Novo e Caturra foram estudadas com cinco densidades de plantio (1, 2, 3, 5 e 6 m 2 /cova) combinadas com uma ou duas plantas por cova e conduzidas sem podas, decotadas a 2 m de altura e recepadas em esquema predeterminado, tipo Beaumont & Fukunaga. Os resultados de 17 colheitas demonstraram que altas densidades de plantio apresentaram elevadas produções nas primeiras safras, com acentuado decréscimo após sete colheitas; a variedade Mundo Novo manteve o potencial produtivo, enquanto a Caturra diminuiu sensivelmente a produção ao longo dos anos; a adoção de um sistema de podas não influenciou na produção, e em alguns períodos foi prejudicial.