Time filter

Source Type

de Alcantara Neto F.,CPCE UFPI | de Amaral Gravina G.,Laboratorio Of Engineering Agricola | Souza N.O.S.,University of Brasilia | de Carvalho Bezerra A.A.,CCA UFPI
Revista Ciencia Agronomica | Year: 2010

The objective of this work was to evaluate some biometric characteristics and the soybean grain yield, cultivated in a soil with low content of phosphorus and submitted to different rates of phosphorus fertilization. The experiment was located in Gilbués-PI, South of the Piauí state, from December 2007 until April 2008, in an Oxisoil. The experiment followed a randomized blocks design, with the treatments arranged as six doses of phosphorus (0; 40; 60; 100; 120 and 140 kg ha-1 of P2O5) with four replications. It was evaluated the height of plants, height of first pod insertion and the grain yield. The levels of P had influenced as a quadratic response the height of the plants, being the maximum height estimated as 56.69 cm for the quantity of 95.60 kg ha-1 of P2O5. The height of insertion of the first soybean pod was had not influenced by the P fertilization and had a mean estimated as 10.64 cm. A quadratic response of the grains productivity to the rates of P was observed, being the maximum productivity estimated as 2.614.7 kg of grains of soybean for 94.8 kg ha-1 of P2O5.

dos Santos J.L.V.,Laboratorio Of Tecnologia Of Alimentos | de Resende E.,Laboratorio Of Tecnologia Of Alimentos | Martins D.R.,Laboratorio Of Tecnologia Of Alimentos | de Gravina G.A.,Laboratorio Of Engineering Agricola | And 2 more authors.
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2013

In this study the fruit quality was characterized at different harvest points for storage of varieties of passion fruits: BRS Gigante Amarelo, BRS Ouro Vermelho and BRS Sol do Cerrado. The physical characteristics of fruits (appearance, mass loss and peel color) and chemical parameters of juice (content of acidity, pH, ascorbic acid, total soluble solids, total soluble sugars and reducing sugars) were characterized. The method of Simple Random Sampling (SRS) was applied, with 0.05 level of signifcance, and means were compared using the "t" Test for Confdence Intervals. Fruits harvested in the early ripening stages showed a higher mass loss as well as the worst juice quality. It was concluded that fruits of different cultivars harvested in summer seasons must present at least 55% of yellow peel color to render the lower mass loss, the best quality of juice and to extend the storage time.

de Azevedo Pinto L.K.,LTA CCTA UENF | Martins M.L.L.,LTA CCTA UENF | de Resende E.D.,LTA CCTA UENF | Thiebaut J.T.L.,Laboratorio Of Engineering Agricola
Revista Brasileira de Fruticultura | Year: 2011

This study was carried out with the objective to investigate the behavior of the enzymes pectinmethylesterase (PME) and β-galactosidase (β-Gal) during the ripening of the papaya cv. 'Golden' The fruits with 15% of yellow peel color were stored in a cold chamber at 20°C and 85-95 % RH for 11 days. During this stored period it was determined the skin color, pulp firmness and pH. The PME activity observed during the papaya storage showed that this enzyme participated in the hydrolyze process of the cell wall mainly at the beginning of the ripening. The β-Gal activity increased from the 1 st day to the end of stored period where reached the maximum activity, although this increase was not gradual. A decrease in the pulp firmness and pH occurred until the 3 rd day of storage. In this same period, the fruits showed peel color with hue angle values around 80, which corresponds to yellow color. It was verified that the PME acts effectively in the ripening of papaya, however, the decrease in the activity of this enzyme in early periods of storage indicates that the β-Gal has an important role in the firmness loss of papaya cv. Golden.

Dos Santos Esteves B.,State University of Norte Fluminense | De Lima Lousada L.,State University of Norte Fluminense | de Sousa E.F.,Laboratorio Of Engineering Agricola | Campostrin E.,Laboratorio Of Melhoramento Genetico Vegetal
Ciencia Rural | Year: 2015

The methodologies which are considered the most promising for irrigation management are those based on the analysis of the water status of the plants themselves. This justifes the study and improvement of indicators based on automatic and continuous measures to enable real-time monitoring data, as indices from sap fow, dendrometry and leaf turgor pressure techniques. The aim of this paper is to analyze such methodologies in order to demonstrate their principles, advantages and challenges. In conclusion, the methodologies analyzed still have many technological advances and challenges before being presented to the fnal user. The future research should work these tools for elaboration of technical indexes that allow their simplification, on the instrumental point of view, and the interpretation of their results. © 2015, Universidade Federal de Santa Maria. All Rights Reserved.

Rubim R.F.,Laboratorio Of Fitotecnia | Freitas S.P.,Laboratorio Of Fitotecnia | Vieira H.D.,Laboratorio Of Fitotecnia | Gravina G.A.,Laboratorio Of Engineering Agricola
Journal of Seed Science | Year: 2013

For an adequate conservation of seeds it is essential previously establishing the ideal conditions for their storage. Thereby, this study aimed at evaluating influence of packaging types and storage environmental conditions on physiological quality of fennel seeds. The seeds were stored into three different packaging types (cotton bags, multiwall paper bags, and glass containers), and stored under two environmental conditions (laboratory and cold chamber) during a twelve months period. Physiological seed quality was assessed before storage and at every two months after storage through tests of germination, germination speed index, and electrical conductivity. Experiment was performed on a completely randomized design with treatments arranged in a split-split plot arrangement in time (two environmental storage conditions × three packaging types × six storage periods + a control treatment), with four replications. Fennel seeds packaged into glass containers have maintained their physiological quality stable over the twelve storage months regardless storage environmental conditions; being considered the best container for storing fennel seeds; and cotton packaging was considered as the least efficient for both storage under laboratory environmental conditions as well as for storage under cold chamber conditions.

Pinto L.K.A.,Laboratorio Of Tecnologia Of Alimentos Lta | Martins M.L.L.,LTA | De Resende E.D.,LTA | Thiebaut J.T.L.,Laboratorio Of Engineering Agricola | Martins M.A.,Laboratorio Of Solos
Revista Brasileira de Fruticultura | Year: 2013

This study was carried out with the objective to evaluate the effect of controlled atmospheres containing different concentration of oxygen on the activity of β-galactosidase and pectinmethylesterase enzymes, on the skin color and pulp firmness in 'Golden' papaya. The fruits were kept for 36 days under the following controlled atmospheres: 1% of O2 and 0.03% CO2 with ethylene absorber, 3% of O2 and 0.03% of CO2 with ethylene absorber, 5% O2 and 0.03% of CO2 with ethylene absorber and environmental atmosphere without ethylene absorber. Relative humidity was set at the range 85-95% and temperature maintained at 13°C. Fruit stored under atmospheres of 1% of O2 and 0.03% CO2 had a β-galactosidase and pectimethylesterase activities delayed compared with the fruits storage under the other atmospheres evaluated. There was also, a delay in the development of color and pulp softening in fruits stored under atmospheres of 1% of O2 and 0.03% O2.

Esteves B.S.,State University of Norte Fluminense | De Sousa E.F.,Brazilian National Council for Scientific and Technological Development | Mendonca J.C.,Laboratorio Of Engineering Agricola | De Lima Lousada L.,State University of Norte Fluminense | And 2 more authors.
IRRIGA | Year: 2014

The objective of this study was to determine the crop coefficient (Kc) of sugar cane grown in Cambisol by the energy balance/Bowen (β) ratio methodology and the criteria of exclusion of inconsistent data. A micrometeorological station was installed in a sugar cane commercial farming, in an area of 13 ha in Campos dos Goytacazes, Norte Fluminense region, RJ state, Brazil. ETc obtained from the Bowen ratio was used to determine Kc when the soil was within the limit of water management and values of β were physically consistent. Approximately 62% of the evaluated data were classified as acceptable to be used for crop evapotranspiration estimates using the Bowen ratio. Mean values of Kc by the energy balance/Bowen (β) ratio methodology were 0.79, 0.90, 1.25 and 1.04, for the establishment, tillering, stem development and maturation stages, respectively. Total evapotranspiratation of the crop obtained in the sugarcane growing cycle was 1088.19 mm. © 2014 Universidade Estadual Paulista - UNESP. All rights reserved.

Loading Laboratorio Of Engineering Agricola collaborators
Loading Laboratorio Of Engineering Agricola collaborators