Time filter

Source Type

Nova Viçosa, Brazil

Neto J.V.,Epagri Estacao Experimental de Ituporanga | da Silva L.F.d.O.,Federal University of Lavras | Lucio A.D.,Federal University of Santa Maria | de Oliveira A.F.,Epamig | da Oliveira M.C.,Federal University of Lavras
Revista Ciencia Agronomica | Year: 2011

This study aimed to evaluate formulations of fertilizer in the finalization of the olive tree seedlings. The research was conducted at the Experimental Farm EPAMIG of Maria da Fé - MG. The experiment was a completely randomized in split-plots, with four replications and 12 seedlings for plot. Was evaluated three varieties of olive tree (Ascolano 315, Grappolo 541 and Arbequina), in the plots, and six formulations of fertilizer more witness, in the subplots. The work began on 12/09/2008 and sixty days after was evaluated the number of shoots and the average length of shoots (cm); and the hundred and twenty days, the height of the plant (cm), number of roots, length of the roots (cm), dry matter weight of the leaves and stem (g) and dry matter weight of the root (g). The varieties Ascolano 315 and Grappolo 541 had more shoots and Arbequina developed greater length of shoots and seedlings higher; the formulations 1 and 2 produced seedlings highest in 120 days, for the varieties studied; Ascolano 315, Grappolo 541 and Arbequina present no difference between them for the variable dry matter weight of the root for different formulations. However, the formulations have difference in relation to number of roots, length of the roots, dry matter weight of the leaves and stem and dry matter weight of the root when applied in each variety, especially the formulations 1 and 2. Source

Jesus Junior W.C.,Federal University of Espirito Santo | Paula Junior T.J.,Epamig | Lehner M.S.,Federal University of Vicosa | Hau B.,Leibniz University of Hanover
Tropical Plant Pathology | Year: 2014

This review deals with the phenomenon of plant disease interactions. The epidemiological implications of foliar diseases occurring simultaneously on the same crop are important because the establishment of disease management strategies depends on the knowledge of disease interactions. We discuss some concepts and the terminology related to the interaction studies and present related examples with special emphasis on interacting wheat diseases. © by the Brazilian Phytopathological Society. Source

da Rocha R.P.,Federal University of Vicosa | de Melo E.C.,Federal University of Vicosa | Corbin J.B.,University of Valencia | Berbert P.A.,State University of Norte Fluminense | And 2 more authors.
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2012

This work aimed to study the drying kinetics of thyme and subsequent adjustment of different mathematical models to the experimental data and to determine the effective diffusivity and the activation energy. In order to conduct the experiment the temperatures of 30, 40, 50, 60, 70 oC were used. The experimental design employed was in randomized blocks with three repetitions. For the adjustment of the mathematical models to the experimental data non-linear regression was performed using Simplex-Quasi-Newton method. The results showed that the Page model was the one that promoted the best fit of the experimental data to describe the drying kinetics of the thyme leaves. The values of effective diffusivity coefficients ranged between 3.69 × 10-12 and 1.19 × 10-10 m2 s-1 and the value of activation was 77.16 kJ mol-1. Source

Ramos B.Z.,Federal University of Lavras | Toledo J.P.V.F.,Brazilian National Council for Scientific and Technological Development | de Lima J.M.,Federal University of Lavras | Serafim M.E.,Federal University of Mato Grosso | And 3 more authors.
Revista Brasileira de Ciencia do Solo | Year: 2013

Unbalanced amounts of Ca2++, Mg2+ and K+ in soils as a consequence of high gypsum applications can be due to the relationship in size (ionic radius) and charge density (charge/ ionic radius) of each ionic species. The higher the ionic strength, the stronger is the bonding of these cations with the opposite charge ions such as OH-, SO4 -2. Thus, excessive gypsum applications, disregarding the charge balance of the soil colloidal system, the ionic balance of the solution, and the CEC, can result in significant leaching of these nutrients throughout the soil profile. The aim of this study was to evaluate the effect of high gypsum rates (0, 7, and 56 t ha-1) on the pH and Ca2++, Mg2+, and K+ contents in aqueous soil extracts of a dystrophic Red Latosol with coffee. The soil was sampled in the coffee rows in the following depths: 0.15- 0.25; 0.35-0.45; 0.75-0.85; 1.15-1.25, and 2.35-2.45 m, 16 months after gypsum application. The experiment consisted of four treatments: G-0 - 2 t ha-1 of gypsum was applied in total area during soil preparation, with brachiaria between coffee rows; G-7 - same as in G-0 plus 7.0 t ha-1 of gypsum applied to the coffee rows; G-56 - same as in G-0 plus 56 t ha-1 of gypsum applied to the coffee rows; and CV-7 - same as in G-7 but without brachiaria between the coffee rows. The experiments were conducted in triplicate, in a randomized block design. After 16 months, there was a reduction of the pH of the soil solution in the layers 0.15-0.25, 0.35-0.45, and 0.75-0.85 m. Gypsum improved the root environment in deeper layers, increasing Mg2+ and Ca2++ concentrations in the soil solution, but reduced K+ below 0.85 m. The amounts of exchangeable Ca2+ and Mg2+ found in the soil solution were above the critical level while exchangeable K+ was within the range indicated for the crop. Source

Pereira R.R.C.,UFAM | Moraes J.C.,Federal University of Lavras | Prado E.,Epamig | Dacosta R.R.,Sao Paulo State University
Scientia Agricola | Year: 2010

The greenbug Schizaphis graminum (Rond.) (Hemiptera: Aphididae) is one of the main pest-insects of wheat (Triticum aestivum, L.). Resistance inducing agents as silicon (Si) and acibenzolar-s-methyl (ASM) can provide some protection against insects and diseases. The effect of Si and/or ASM on the development and probing behaviour of S. graminum in wheat plants was evaluated. Wheat plants (cultivar Embrapa 22) were treated with Si (silicic acid at the rate of 1%) and acibenzolar-S-methyl (ASM) at the rate of 0.5%. The effects of these treatments on greenbugs were analyzed by development parameters, honeydew excretion and probing behavior monitored by Electrical Penetration Graphs (EPG). The development and honeydew experiments consisted of ten replications each and EPG experiment was replicated 25 times. The application of both resistance inducing agents reduced fecundity, prolonged the duration of pre-reproductive period, and decreased honeydew production. Induced resistance was localized mainly at phloem level and caused a strong reduction of phloem sap ingestion, but some effect of ASM at parenchyma/mesophyll level could not be discounted as far fewer aphids reached the sieve elements. Source

Discover hidden collaborations