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De Souza Silva-Camacho D.,Federal Rural University of Rio de Janeiro | Gomes R.D.S.,Federal Rural University of Rio de Janeiro | Santos J.N.S.,Instituto Federal Do Norte Of Minas Gerais Ifnmg | Araujo F.G.,Federal Rural University of Rio de Janeiro
Journal of the Marine Biological Association of the United Kingdom | Year: 2016

We examined the benthic fauna in four areas along a mangrove tidal channel in south-eastern Brazil, between October 2008 and August 2009. The tested hypothesis is that the most abundant groups avoid competition as they occupy different types of substrata and that the longitudinal distance from the sea also affects the occurrence of benthic fauna along the channel. We also examined the prop root epibiont fauna to describe this different community. Polychaeta was the dominant group in the sediment whereas Isopoda and Tanaidacea were the dominant groups on the prop roots. We found a tendency for higher infauna species richness and diversity in the innermost channel area during the summer. Higher abundance of epibiont fauna was also found in summer with tidal movements allowing the colonization of the prop roots of the mangrove forest by some taxa. The polychaetes Ceratocephale sp. and Laeonereis acuta had indication of habitat partitioning, with the first occurring mainly in very fine sand sediment whereas the latter preferred medium sand sediment. The microcrustaceans Chelorchestia darwini and Tanaidacea sp. 1 occurred in high abundance colonizing the prop roots. Exosphaeroma sp. was found in high abundance in infauna and epibiont fauna. The tested hypothesis of spatial partitioning of the mangrove channel by the benthic fauna was confirmed with the most abundant species occupying the substrata with different grain fractions and prop roots in different stations. Copyright © Marine Biological Association of the United Kingdom 2016 Source


Grossi M.C.,Instituto Federal Do Norte Of Minas Gerais Ifnmg | Justino F.,Federal University of Vicosa | Rodrigues R.A.,Federal University of Goais | Andrade C.L.T.,Embrapa Milho e Sorgo
Bragantia | Year: 2015

Based on sensitivity analyses the effect of changing in climate on sorghum has been investigated. This has been achieved by conducting crop modeling experiments carried out with weather observations and output of global climate models. As can be anticipated results demonstrated that the sorghum yield is more sensitive to rainfall, solar radiation and CO2 concentration. However, the increase in CO2 concentration has a positive effect on yield in years that the crop is submitted to water stress. This effect is extremely reduced under well watered conditions and therefore is subject to the climate inter-annual variability. Accumulated solar radiation along the sorghum cycle below 1900 MJ m–2 has also been shown to reduce the yield. Compared to other weather variables the sorghum yield is less sensitive to changes in relative humidity. In this sense, changes in stomatal closure and therefore photosyntesis is not highly dependent on water vapor pressure. These finds can be applied for both climate observations and global models output. © 2015, Instituto Agronomico. All rights reserved. Source


Santos J.N.S.,Instituto Federal Do Norte Of Minas Gerais Ifnmg | Gomes R.D.S.,Federal Rural University of Rio de Janeiro | Vasconcellos R.M.,Instituto Federal Of Educacao | Silva D.D.S.,Instituto Federal Do Norte Of Minas Gerais Ifnmg | Araujo F.G.,Federal Rural University of Rio de Janeiro
Journal of the Marine Biological Association of the United Kingdom | Year: 2014

We examined the benthic macroinfauna at three strata during two seasons (winter and summer) on two sandy beaches (dissipative and reflective) in south-eastern Brazil. The hypothesis raised is that effects of morphodynamics and zonation determine the structure of macroinfauna, with dissipative beaches having comparatively higher species richness and density than the reflective beaches. Flamengo beach (dissipative) had higher species richness but lower density compared to Grumari beach (reflective). A high dissimilarity in assemblage structure (91.75%) was detected between the two beaches. Zonation in the occurrence of macroinfauna was detected for the two beaches in the two examined seasons. At Grumari beach, Emerita brasiliensis occurred mainly in stratum 1 (intertidal swept zone) while Saccocirus sp. occurred in stratum 2 (infralittoral at 0.5 m depth), whereas at Flamengo beach E. brasiliensis and Enoploides sp. had the highest density in stratum 1 (intertidal swept zone) whereas Scolelepis goodbodyi and Donax uncinata dominated in stratum 3 (infralittoral at 1.0 m depth). Scolelepis goodbodyi, Dispio uncinata, Enoploides sp., Nematoda and Trileptium sp. were associated with higher a Dean parameter and content of organic matter at Flamengo beach. In contrast, Hastula sp., Donax sp., Pisionidens indica, Hemipodus californiensis, Saccocirus sp. and Phyllodocidae were associated with the higher wave period and grain size of Grumari beach. The hypothesis that macroinfauna structure differs between the beaches and strata was confirmed, with the dissipative beaches having comparatively higher richness but lower density than the reflective beaches. Copyright © Marine Biological Association of the United Kingdom 2014. Source


Batista C.H.,Instituto Federal Do Norte Of Minas Gerais Ifnmg | de Aquino L.A.,Federal University of Vicosa | Silva H.R.F.,IFNMG | dos Santos Junior V.C.,IFNMG | Pacheco D.D.,IFNMG
Bioscience Journal | Year: 2011

This paper objective was to evaluate P levels in irrigated crops or rainfed in productivity and P uptake by cotton plant. The experiment was conducted at the Instituto Federal do Norte de Minas (IFNMG), Campus Januária. The treatments consisted of three P rates (0, 50 and 120 kg ha-1 of P2O5) and three cropping systems (Sprinkler, Dripping and Rainfed). It was adopted the randomized block design in factorial design with three replications. At 80 days after emergence (DAE), leaves, stems, and reproductive structures were collected. Each organ was dried, crushed, and P content determined. P content of each organ was calculated. The macro and micronutrients levels in the fifth fully expanded leaf from the apex to the base (leaf index) were determined. The P and S contents were higher in irrigated plants by dripping. The P and Mg highest values were obtained with 120 kg ha-1 de P2O5. The irrigated plants had higher P content in shoots compared to those under rainfed. Regardless of the method, irrigation and the highest P rates increased the quantity of reproductive structures, the quantity of the bolls per plant, and seed cotton productivity. Source


Silva H.R.F.,Instituto Federal Do Norte Of Minas Gerais Ifnmg | de Aquino L.A.,Federal University of Vicosa | Batista C.H.,Instituto Federal Do Norte Of Minas Gerais Ifnmg
Bioscience Journal | Year: 2011

The residual nutrients of a crop can be significant for the productivity of other crops in succession. The objective was to evaluate the residual effect of phosphate fertilization on productivity and nutrient content in the index leaf of cultivated sunflower in succession to cotton. The experiment was installed in Quartzanic Neossoil. We adopted the randomized block design in factorial scheme with three replications. The treatments consisted of P doses (60 and 120 kg ha -1 of P 2O 5) x split four ways PS, P1, P2, and P3 (100/0, 80/20, 60/40, 40/60% of the applied dose at sowing and at 35 DAE in coverage respectively) and a treatment without P application. Phosphate fertilizer was applied to grown cotton before sunflower. We evaluated the number of days for R1, R5, and R6 stages, the number of leaves, and plant height in R1 and R5, the mass of a thousand seeds, the nutrient content in the index leaf, and sunflower productivity. The application of 60 kg ha -1 dose of P 2O 5 in cotton has allowed the productivity achievement of 2232 kg ha -1 in sunflower crop in succession. The greater portion of P dose application for covering the cotton plant (P3 = 60%) resulted in higher productivity of sunflower in succession, as well as in higher foliar content of P and Ca. N, P, K, Ca, Mg, S, B, and Mn sunflower foliar content were positively influenced by phosphorus application on cotton grown previously. Source

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