Universidade Federal de Viçosa

About: Universidade Federal de Viçosa is a education organization based out in Viçosa, Brazil. It is known for research contribution in the topics: Population & Biology. The organization has 16012 authors who have published 26711 publications receiving 353416 citations.

Layered Double Hydroxides: New Technology in Phosphate Fertilizers Based on Nanostructured Materials

Abstract: Layered Double Hydroxide (LDH) intercalated with phosphate ions (LDH-phosphate) was synthesized by ion-exchange method from a precursor containing nitrate ions between the layers. The materials were characterized by X-ray diffraction (XRD), attenuated total reflectance–Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetric analysis coupled to differential scanning calorimetry and mass spectrometry (TGA-DSC-MS), specific surface area (BET), scanning electron microscopy (SEM), and elemental analysis. We hypothesized that LDH-phosphate can be used as a slow release fertilizer and help increase phosphate fertilization efficiency in tropical weathered soils. This new fertilizer technology was tested in a kinetic study of P release and a bioassay with controlled conditions of light, humidity, and temperature using maize (Zea mays) as our indicator plant. The bioassay was performed using an adaptation of the Neubauer method, wherein the LDH-phosphate was compared to the commercial triple superphos...

Seasonal abundance and sexual variation in morphometric traits of Oxelytrum discicolle (Brulle, 1840) (Coleoptera: Silphidae) in a Brazilian Atlantic Forest

Abstract: Ferreira, P.S.F.; Pires, E.M.; Guedes, R;N.C.; Mendes, M. and Coelho, L.A. Seasonal abundance and sexual variation in morphometric traits of Oxelytrum discicolle (Brulle, 1840) (Coleoptera: Silphidae) in a Brazilian Atlantic Forest. Biota Neotrop. May/Aug 2006, vol. 6, no. 2, http://www.biotaneotropica.org.br/v6n2/pt/abstract?article+bn02206022006. ISSN 1676-0611 A total of 293 specimens of Oxelytrum discicolle were sampled weekly over a period of two years using a black light trap. The study took place in an Atlantic Forest reserve located near Vicosa city, Minas Gerais State, Brazil. The period of peak abundance of O. discicolle occurred during the wet season between the months of October and March. Statistical analysis showed that the abundance of individuals was significantly and positively correlated with temperature, but not with rainfall or relative humidity. Of 28 morphological measurements taken on each collected specimen, seven were found to be sexually dimorphic; however, neither morphology nor the degree of sexual dimorphism varied significantly among seasons.

Crescimento e acúmulo de nitrogênio em cana-de-açúcar cultivada em solo coberto com palhada

Abstract: Este trabalho teve o objetivo de avaliar a utilizacao do nitrogenio da ureia e a influencia da palhada na produtividade de soqueira de cana-de-acucar. O experimento foi instalado no campo, num solo Podzolico Vermelho-Amarelo no Municipio de Piracicaba, SP, com dois tratamentos: mistura de vinhaca e ureia aplicada em toda a area sobre o solo coberto com palhada; ureia enterrada em sulcos nos dois lados das linhas da cana-de-acucar, com previa aplicacao de vinhaca sobre o solo sem palhada. O delineamento experimental foi o de blocos casualizados, com quatro repeticoes. Foram realizadas comparacoes de produtividade da cultura, do acumulo de N pela parte aerea, da utilizacao do N da ureia pela cultura ao final do ciclo. O desenvolvimento vegetal foi representado por curvas de acumulo de massa de material seco e pelos indices fisiologicos de taxa de producao de materia seca e taxa de crescimento relativo, que foram semelhantes nas condicoes, com ou sem a presenca da palhada de cana-de-acucar. Do N total acumulado na parte aerea da soqueira de cana-de-acucar, 10 a 16% foram absorvidos do fertilizante. A eficiencia de utilizacao do N da ureia pela soqueira de cana foi em media de 17%, e nao houve diferencas entre os tratamentos.

Six novel begomoviruses infecting tomato and associated weeds in Southeastern Brazil.

Abstract: The incidence of tomato-infecting begomoviruses has sharply increased in Brazil following the introduction of the B biotype of the whitefly vector in the early 1990s. Five definitive species and six tentative species have been described since then. Here, we report the detection of members of an additional six novel species, three in tomato and three infecting weeds that are commonly associated with tomato fields: Blainvillea rhomboidea, Sida rhombifolia and Sida micrantha. Tomato and weed samples were collected in two major tomato-growing regions of southeastern Brazil in 2005 and 2007. Two of the novel viruses were present in tomato plants collected in Paty do Alferes, Rio de Janeiro state. Three novel viruses were present in weed samples collected in Coimbra, Minas Gerais state. One virus was present in tomato samples collected at both locations. Genome features indicate that all six species are typical New World, bipartite begomoviruses. However, the viruses belonging to two of the novel species did not cluster with the Brazilian viruses in a phylogenetic tree. These species could represent a distinct lineage of New World begomoviruses, found in Brazil for the first time.