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Andrade W.E.B.,Centro Estadual Of Pesquisa E Desenvolvimento Da Pecuaria Of Leite Cepdpl | Guimaraes P.T.G.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Faquin V.,Federal University of Lavras | Guimaraes R.J.,Federal University of Lavras
Coffee Science | Year: 2014

The objective of this work was to evaluate different arrangements of population (distances between rows × distances between plants in the row) in the productivity in the coffee plants (Coffea arabica) in North-West Fluminense. The variety was Catuai Vermelho IAC 144, the experimental design was a randomized complete block, with four replicates, in splitplot. Four distances between rows (1,0, 1,5, 2,0 e 2,5 m) were used in the plot and four distances between plants in the row (0,25, 0,50, 0,75 e 1,00 m) in the subplot. The test was evaluated in the period 2004 - 2011 (eight outputs) by analyzing the cumulative production in bags of coffee per hectare benefited by means of the production biennia. The results were submitted to analysis individual variance and differences between means were compared by F test at 5% probability, to study through regression. It was observed that the reduction in the distance between the rows and between the plants in the row resulted in increased production eight samples evaluated; that more productive combinations for the same population of plants per hectare occurred when it was used shortest distance between plants and that the same plant but in different arrangements do not provide the same production. Source

Carvalho L.M.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Bueno V.H.P.,Federal University of Lavras | Castane C.,IRTA Entomology
Journal of Applied Entomology | Year: 2011

Orius species are important biological control agents of thrips in protected crops. Rearing conditions in mass production facilities may affect their performance in the crop when searching for the target prey. The aim of this study was to evaluate and compare the search behaviour and orientation towards prey of two Orius species, O.laevigatus (Fieber) and O. insidiosus (Say) that have been reared in the laboratory under different conditions, with wild (field-collected) individuals. Adult predator females were placed in a Y-tube olfactometer and offered a choice between the odours released by plants of different species (cotton, common bean, sweet pepper and cucumber), which were either non-infested or infested with Frankliniella occidentalis (Pergande) adults.O. laevigatus and O. insidiosus responded to odours from thrips-infested plants and these responses were influenced by the origin of the colonies. A larger percentage of laboratory-reared O. laevigatus females (42%) did not made a choice between thrips-infested or clean plants, compared with wild individuals (17%). Of those females that did respond to plant odours, a smaller percentage of laboratory-reared O. laevigatus females (34%) responded to the odours from thrips-infested plants compared with wild insects (76%). No significant differences were found inO.insidiosus females that did not make a choice between thrips-infested or clean plants (14% for wild vs. 17% for lab individuals). Also, no significant differences were found between O. insidiosus females that selected thrips-infested plants at the corresponding proportion of wild (75%) and laboratory-reared (70%) individuals. We propose that the olfactometer test could be a complementary evaluation aspect to the already developed quality criteria for performance of mass-reared Orius predators. © 2010 Blackwell Verlag, GmbH. Source

Reis T.H.P.,Federal University of Lavras | Neto A.E.F.,Federal University of Lavras | Guimaraes P.T.G.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Guerra A.F.,Embrapa Cerrados | De Oliveira C.H.C.,Federal University of Lavras
Pesquisa Agropecuaria Brasileira | Year: 2013

The objective of this work was to evaluate, in the rainy and dry seasons, the nutritional status and foliar fractions of P in coffee plants, according to phosphate fertilization, and to determine their relation with coffee yield. The cultivar Rubi MG-1192 of Arabic coffee was used under central-pivot, with high density (7,143 plants per ha) on Rhodic Hapludox, in the Cerrados' region. From 2002 to 2010, the following annual doses of P were used: 0, 50, 100, 200, and 400 kg ha-1 P2O5. Foliar samples were taken after harvest, in July (dry season), and before grain filling stage, in December (rainy season). Foliar P contents were evaluated in 2009 and 2010, and the coffee yield, from 2008 to 2011. Coffee yield responded linearly to doses up to 400 kg ha-1 of P2O5. In high yielding conditions, with high P supply, foliar ranges of P are probably different from the ones reported in literature. The reserve of inorganic phosphorus in coffee leaves increases in plants with improved P supply, which ensures greater metabolic activity of plants during periods of drought stress and enables higher productivity. Source

Silva V.A.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Morais D.L.B.,Biojan MG Agroindustrial Ltda. | Kakida J.,Biojan MG Agroindustrial Ltda. | Ferreira E.A.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Silva V.F.,Instituto Federal Of Educacao
Pesquisa Agropecuaria Brasileira | Year: 2012

The objective of this work was to evaluate the possibility of reduction in the production cycle of physic nut (Jatropha curcas) by the use of different formation or production pruning. One experiment for each kind of pruning was carried out in the semiarid region of Minas Gerais state, Brazil, with five treatments each. Treatments were related to primary branch pruning heights, and to pruning or elimination of secondary branches. With the formation pruning, it was possible to reduce the harvest period from 120 to 48 days, but always with significant losses in plant yield in the first cycle. Production pruning can concentrate harvest in 90 days and, in some cases, improve plant yield. Source

Vieira R.F.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Paula T.J.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Pires A.A.,Instituto Federal Of Educacao Ciencia E Tecnologia Do Espirito Santo | Carneiro J.E.S.,Federal University of Vicosa | da Rocha G.S.,Federal University of Vicosa
Agronomy Journal | Year: 2011

Molybdenum (Mo) reserve in large seeds can complement Mo uptake by plants from soil, but the content of Mo in common bean (Phaseolus vulgaris L.) seed for this purpose is unknown. We hypothesized that 3.639 ± 0.751 μg Mo seed -1 would be sufficient to complement Mo uptake by irrigated common bean plants from a Mo-poor soil. Th ree field experiments were performed in a clayey Ultisol naturally infested by native strains of Rhizobium in Zona da Mata, Minas Gerais, Brazil. Treatments were arranged as 4 × 2 factorial combination of Mo contents in seeds [small (0.007 ± 0.007 or 0.248 ± 0.057 μg Mo seed -1) or large (3.639 ± 0.751 or 6.961 ± 1.844 μg Mo seed -1)] and Mo spraying treatments (90 g ha -1 or unsprayed) with six replications. Phosphorus, N (25 kg ha -1), and K were applied together in the furrow during planting time. No topdressing N was applied. Final plant population and seed yield were evaluated in two experiments. Molybdenum contents in the seeds did not aff ect plant population. On average, unsprayed plants from seeds with small Mo contents yielded 1785 kg ha -1, while those from seeds with large Mo content yielded 2109 kg ha -1. Foliar application of Mo increased plant N status, plant growth, and yield in plants originated from seeds with small Mo content, but not in plants grown from seeds with large Mo content. We conclude that 3.639 ± 0.751 μg Mo seed -1 sufficiently complement the Mo uptake by common bean plants from soil. © 2011 by the American Society of Agronomy. Source

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