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Mendonca E.S.,Federal University of Espirito Santo | De Lima P.C.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Guimaraes G.P.,Federal University of Espirito Santo | Moura W.M.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Andrade F.V.,Federal University of Espirito Santo
Revista Brasileira de Ciencia do Solo | Year: 2017

Green manures are an alternative for substituting or supplementing mineral nitrogen fertilizers. The aim of this study was to quantify biological N fixation (BNF) and the N contribution derived from BNF (N-BNF) to N levels in leaves of coffee intercropped with legumes grown on four family farms located in the mountainous region of the Atlantic Forest Biome in the state of Minas Gerais, Brazil. The following green manures were evaluated: pinto peanuts (Arachis pintoi), calopo (Calopogonium mucunoides), crotalaria (Crotalaria spectabilis), Brazilian stylo (Stylosanthes guianensis), pigeon pea (Cajanus cajan), lablab beans (Dolichos lablab), and velvet beans (Stizolobium deeringianum), and spontaneous plants. The experimental design was randomized blocks with a 4 × 8 factorial arrangement (four agricultural properties and eight green manures), and four replications. One hundred grams of fresh matter of each green manure plant were dried in an oven to obtain the dry matter. We then performed chemical and biochemical characterizations and determined the levels of 15N and 14N, which were used to quantify BNF through the 15N (δ15N) natural abundance technique. The legumes C. mucunoides, S. guianensis, C. cajan, and D. lablab had the highest rates of BNF, at 46.1, 45.9, 44.4, and 42.9%, respectively. C. cajan was the legume that contributed the largest amount of N (44.42 kg ha-1) via BNF.C. cajan, C. spectabilis, and C. mucunoides transferred 55.8, 48.8, and 48.1%, respectively, of the N from biological fixation to the coffee plants. The use of legumes intercropped with coffee plants is important in supplying N, as well as in transferring N derived from BNF to nutrition of the coffee plants. © 2017, Revista Brasileira de Ciencia do Solo. All rights reserved.


Vieira R.F.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Paula Junior T.J.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Teixeira H.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Carneiro J.E.D.S.,Federal University of Viçosa
Plant Disease | Year: 2010

White mold of common bean (Phaseolus vulgaris), caused by Sclerotinia sclerotiorum, is a major yield-limiting disease during the fall-winter season in Brazil. This study was conducted to evaluate the efficacy of decreasing within-row densities for an indeterminate growth habit (type IIIa) cultivar, keeping constant the between-row spacing of 0.5 m, to manage the disease. A modification of within-row plant distributions was also attempted in order to reduce white mold intensity. The study was conducted with sprinkler irrigation in two growing seasons (2000 and 2001) in Viçosa, State of Minas Gerais, Brazil, in an area naturally infested with sclerotia. In 2000, treatments were arranged as 3 × 2 × 2 factorial combination of within-row densities (15, 7.5, or 5 plants/m), within-row plant distributions (single and equidistant plants or equidistant groups of three plants), and fluazinam treatments (with or without). In 2001, 16, 12, 8, or 4 plants/m were combined with fluazinam treatments. Fluazinam was applied at both flowering onset and 10 or 13 days later. Average incidence was 92.6% in 2000 and 77.8% in 2001; severity index was 69.8% in 2000 and 40.2% in 2001; and yield was 1,656 kg/ha in 2000 and 2,542 kg/ha in 2001. White mold decreased and yield increased as within-row densities were reduced, regardless of fluazinam treatments. A distribution of equidistant groups of three plants was ineffective in reducing disease. The use of 4 equidistant plants/m in infested irrigated areas was an effective strategy in white mold management. © 2010 The American Phytopathological Society.


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 Viçosa | da Rocha G.S.,Federal University of Viçosa
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.


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.


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.


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.


Guedes J.M.,Federal University of Lavras | Vilela D.J.M.,Federal University of Lavras | Rezende J.C.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Silva F.L.,Empresa de Pesquisa Agropecuaria de Minas Gerais | And 2 more authors.
Bragantia | Year: 2013

This study aimed to identify the genetic divergence among coffee trees of the Maragogipe group in the active germplasm coffee bank in Patrocínio, Minas Gerais, Brazil, using multivariate analyzes. In the study, 27 morpho-agronomical descriptors were assessed. Mahalanobis generalized distance was applied to quantify the genetic divergence among genotypes. The following methods were used: Tocher clustering, Unweighted Pair-Group Method Using Arithmetic Averages (UPGMA) hierarchical clustering and the canonical variables analysis. The cluster analysis by Tocher method and the UPGMA separated the accessions into three and six groups, respectively. The analysis of the relative contribution of each characteristic to the genetic dissimilarity highlighted the intensity of curling leaf, inflorescence number per leaf axil and average yield as those that contributed most to the achievement of genetic divergence. It was observed that the first three canonical variables explained more than 90% of the total variance contained in the set of the analyzed characteristics. The combination between MG0167 and MG0170 accessions is the most promising for a possible crossing for immediate use in breeding programs.


da Silva J.T.A.,Empresa de Pesquisa Agropecuaria de Minas Gerais | da Silva I.P.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Simao F.R.,Empresa de Pesquisa Agropecuaria de Minas Gerais
Pesquisa Agropecuaria Brasileira | Year: 2016

The objective of this work was to estimate nitrogen and potassium rates, in order to obtain maximum technical and economic efficiency and the critical levels of these two nutrients on leaves of irrigated 'Tahiti' lime tree, grown in a Typic Quartzipsamment soil in five crop seasons. A randomized complete block design was carried out with four replicates, in a 4x5 factorial arrangement, with four N rates (0, 25, 50, and 100 kg ha-1) and five K2O rates (0, 25, 50, 100, and 200 kg ha-1). The estimated rates to achieve the maximum technical efficiency were 90, 99, 69, 66, and 100 kg ha-1 N, and for the maximum economic efficiency, 85, 95, 67, 64, and 93 kg ha-1 N, for the first, second, third, fourth, and fifth crop seasons, respectively. The rates of K2O to obtain the maximum technical efficiency were 126, 116, 101, 98, and 95 kg ha-1, and for maximum economic efficiency, 112, 105, 94, 90, and 88 kg ha-1 K2O, respectively, for the first, second, third, fourth, and fifth crops. The average, estimated critical levels for leaf contents are 25 g kg-1 N and 22 g kg-1 K, in five crop seasons.


da Silva J.T.A.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Pereira R.D.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Rodrigues M.G.V.,Empresa de Pesquisa Agropecuaria de Minas Gerais
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2012

The objective of this study was to verify appropiate N sources (ammonium sulfate, ammonium nitrate, calcium nitrate and urea) for banana and to determine the application rate for maximum physical and economic efficiency. The experiments were conducted in northern semiarid region of Minas Gerais in Red Latosol and Red-Yellow Latosol. The experimental design was in randomized blocks with 20 treatments and four repetitions. The treatments were arranged in (4 × 5) factorial, being four N sources (ammonium sulfate, ammonium nitrate, calcium nitrate and urea) and five N rates (0, 100, 200, 400 and 800 kg ha-1 year-1). The N increased production in the 1st cycle of banana grown in the Red-Yellow Latosol, where N rates for maximum physical efficiency were 521, 471, 410, 424 kg ha-1 and to achieve maximum economic efficiency were 105, 204, 260 and 5 kg ha-1 for ammonium sulfate, ammonium nitrate, urea and calcium nitrate, respectively, with urea being the most efficient source of nitrogen. In the 2nd and 3rd cycles N reduced production. In the Red Latosol, no effects of N on the variables of plant growth and production were observed in the 1st and 2nd cycles of banana.


da Silva J.T.A.,Empresa de Pesquisa Agropecuaria de Minas Gerais | Simao F.R.,Empresa de Pesquisa Agropecuaria de Minas Gerais
Pesquisa Agropecuaria Brasileira | Year: 2015

The objective of this work was to estimate the K dose necessary to obtain the maximum physical efficiency of production and the critical foliar level of the nutrient, as well as to verify the relationship of soil application of K with the nutritional balance and the incidence of Panama disease (Fusarium oxysporum) in 'Prata Anã' (AAB) banana. The experiment was conducted during four production cycles in the semiarid region of the state of Minas Gerais, Brazil, in a clayey Oxisol, with 69 mg dm-3 available K. Treatments were distributed in a randomized complete block design in a 4×4 factorial arrangement, with four K rates (0, 250, 500, and 1,000 kg ha-1 K2O per year), four production cycles and six replicates. Soil application of K did not influence banana production in the first cycle. The mean rate of K2O to achieve maximum physical efficiency of production of 'Prata Anã' in the second, third, and fourth cycles was 880 kg ha-1. The mean values of leaf concentrations of N, K, Ca, and Mg were similar between the production cycles. The mean critical foliar level of K, estimated in the three production cycles, was 28.9 g kg-1. Fertilization with K increases the production and the tolerance of 'Prata Anã' banana to the Panama disease, in soil with average content of K.

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