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Nova Viçosa, Brazil

de Aquino L.A.,CRP UFV | Aquino R.F.B.A.,Campus Rio Paranaiba | Silva T.C.,Instituto Federal Do Norte Of Minas Gerais | dos Santos D.F.,Instituto Federal Do Norte Of Minas Gerais | Berger P.G.,Avenida PH Rolfs
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2012

This work aimed to evaluate the effect of phosphorus application in rainfed and irrigated crop on shoot dry matter, the absorption and nutrient exportation, and yield of cotton crop. The experiment was carried out in a Psament in the northeren part of Minas Gerais State, Brazil. The experimental design was in randomized blocks with four replications in a factorial arrangement of two doses of P2O5 x two cropping systems. Two additional treatments in each system without phosphorus application completed six studied treatments. Accumulation of dry biomass, absorption and exportation of nutrients, and yield of seed cotton were evaluated. Phosphorus levels did not influence the accumulation of shoot dry biomass. P supply increased the exportation of P, Ca, Mg, S, and Mn under irrigated and of N, K, and Fe regardless of the cropping system. Irrigation increased the dry biomass of leaves, stems, and shoots at 80 days after emergency, and the absorption of N, P, K, Ca, Mg, S, Cu, Fe, Mn, Zn, and B, as well as their exportation by the crop. There was an increase in the number of bolls per plant, fiber yield and productivity through the irrigation use. Increasing productivity with P application was conditioned to irrigation. Source


Martinazzo A.P.,Federal University of Fluminense | Melo E.C.,Federal University of Vicosa | Correa P.C.,Federal University of Vicosa | Santos R.H.S.,Avenida PH Rolfs
Revista Brasileira de Plantas Medicinais | Year: 2010

The species Cymbopogon citratus, known as lemon grass, is widely used for medicinal purpose and in the pharmaceutical, food, cosmetic and perfumery industries. Due to the need for more specific knowledge of pre-processing management, this work aims to equate and analyze some drying aspects that allow preview the product quality alterations. The leaves from this species were cut at different lengths and dried at different temperatures. Different equations for modeling the drying curves were adjusted to the experimental data. The dried product was also evaluated for color and essential oil content. The results showed that the Modified Page model resulted in the best adjustment for the experimental data. The temperature of 50°C was the best for drying the species leaves, resulting in less essential oil loss and higher green color maintenance. Source


Pinto M.O.,Embrapa Milho e Sorgo | Good-God P.I.V.,Federal University of Vicosa | Moreira M.A.,Avenida PH Rolfs
Pesquisa Agropecuaria Brasileira | Year: 2013

The objective of this work was to validate the association of single nucleotide polymorphism (SNP) markers for the genes FAD3A, FAD3B, and FAD3C with the linolenic acid content (18:3) in soybean seeds and to analyze the influence of the genetic parameters of these markers on this trait. One hundred and eighty-five F2 progenies derived from a cross between A29 (mutant for the three FAD3 genes, 1% 18:3 content) and Tucunaré (wild-type genotype, 11% 18:3 content) were genotyped. The molecular markers for genes FAD3A, FAD3B, and FAD3C explained the variations in 18:3 content of the F2 and F2:3 segregating populations. In addition, allelic substitutions in the FAD3A locus provide greater variations in 18:3 content than substitutions in the other two loci. Source


Abrahao S.A.,Federal University of Mato Grosso | De Carvalho Pinto F.D.A.,Federal University of Vicosa | De Queiroz D.M.,Federal University of Mato Grosso | Santos N.T.,Avenida PH Rolfs | De Souza Carneiro J.E.,Avenida PH Rolfs
Revista Ciencia Agronomica | Year: 2013

This study aimed to develop classifiers based on different combinations of spectral bands and vegetation indices from original, segmented and reflectance images in order to determine the levels of leaf nitrogen and chlorophyll in the bean, and to define the best time and best variables. A remote-sensing system was used, consisting of a helium balloon and two small-format digital cameras. Besides the individual spectral bands, four vegetation indices were tested: simple ratio, normalized difference, normalized difference in the green band, and modified-chlorophyll absorption. The classifiers proved to be efficient in determining levels of leaf nitrogen and chlorophyll. The best time for determining leaf N content was at 13 DAE (stage V4). The best classifiers for that time used as input variables two indices from segmented reflectance images, one index related to the canopy structure and the other related to chlorophyll, with a Kappa ranging from 0.26 to 0.31. The best time to discriminate leaf chlorophyll content was 21 DAE (stage V4). The best classifier used as input variables two original images, one in the red band and one in the blue with a Kappa of 0.47. Source


de Aquino L.A.,UFV Campus Rio Paranaiba | da Silva F.D.B.,Avenida PH Rolfs | Berger P.G.,Avenida PH Rolfs
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2013

This work aimed to assess nutritional status, agronomic characteristics, and productivity of sunflower cultivars under irrigation. Embrapa 122 V-2000, Hélio 250, Hélio 251, Hélio 253, Hélio 358, Hélio 360, IAC Iarama, and Dow Agroscience M 734 and MG 02 cultivars were sown in randomized block design with four replications. The number of leaves per plant in full bloom was higher in hybrid Hélio 250, Hélio 251, Hélio 253, Hélio 358, Hélio 360 and Dow Agroscience MG 734 and M 02 related to open-pollinated cultivars Embrapa 122 V-2000 and IAC Iarama. Foliar contents of N, P, K, Ca, Mg, and S were 40.91, 3.51, 35.91, 33.91, 6.23, and 7.88 g kg-1, respectively. Embrapa 122 V-2000 and IAC-Iarama cultivars showed an average content of P in the index leaf lower than the other cultivars. Foliar contents of Zn, Cu, Fe, and Mn were 75.15, 24.11, 98.39, and 348.10 mg kg-1, respectively. Mean content of B in index leaf of hybrid and open-pollinated varieties was 119.25 and 140.35 mg kg-1, respectively. Hélio 250, Hélio 251, Hélio 253, Hélio 358, Hélio 360, and Dow Agroscience M 734 and MG 02 cultivars had higher productivity than Embrapa 122 V-2000 and IAC Iarama. Source

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