Navegando por Autor "Abreu, Giselle F."

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Armazenamento de água em faixas molhadas sob cafeeiros irrigados com diferentes critérios de manejo de irrigação
(Embrapa Café, 2013) Colombo, Alberto; Alvarenga, Lívia A.; Scalco, Myriane S.; Ribeiro, Randal C.; Abreu, Giselle F.
A crescente demanda por recursos hídricos acentua a necessidade de redução do desperdício de água através de um manejo mais adequado da irrigação. No caso particular da cafeicultura irrigada, que nos últimos anos apresentou crescimento com predominância da irrigação por gotejamento, o aprimoramento das técnicas de manejo da irrigação por gotejamento é uma necessidade. O manejo adequado do gotejamento depende do conhecimento do padrão espacial de distribuição de umidade no interior da faixa molhada formada sob as linhas de irrigação. Neste trabalho, foram utilizadas malhas de 24 tensiômetros para determinar o armazenamento de água no interior de faixas molhadas formadas sob gotejadores, de vazão de 3,78 L h-1, uniformemente espaçados de 40 cm, submetidos a dois critérios distintos de irrigação (turno fixo e tensão de 60 kPa). Estimativas de armazenamento baseadas em análises unidimensionais, considerando apenas variações na profundidade, foram comparadas com estimativas bidimensionais. Os resultados indicam que com menor turno de irrigação a análise unidimensional não é adequada. Para maior turno de irrigação, a análise bidimensional é dispensável, sendo a unidimensional suficiente para o cálculo do volume da água armazenada na faixa molhada.
Influence of hulling and storage conditions on maintaining coffee quality
(Academia Brasileira de Ciências, 2023-12-11) Abreu, Giselle F.; Rosa, Sttela D.V.F.; Coelho, Stefânia V.B.; Pereira, Cristiane C.; Malta, Marcelo R.; Fantazzini, Tatiana B.; Vilela, Amanda L.
Storage is important in the coffee post-harvest. Determining the maximum period that coffee can remain storaged is important aiming to reduce losses in quality and, consequently, allow the producer to achieve maximum profitability. The aim was to determine the suitable storage period for natural and fully washed coffees, under different conditions. Beans were dried to 11% moisture content after dry processing (natural coffee, dry cherry coffee) and wet processing (parchment coffee, fully washed). Before storage, part of the coffee was hulled and part was not. The coffee was stored under refrigerated air (10ºC and 50% relative humidity) or in an environment at 25ºC. In the periods of 0, 3, 6, and 12 months, samples were taken for sensory, electrical conductivity and tetrazolium evaluation. Refrigerated environment favors conservation of sensory and physiological quality of the natural hulled coffee beans and fully washed coffee. Hulled beans of natural and fully washed coffee stored under refrigerated conditions have the initial quality conserved for up to 12 months and in non-controlled environmental, for up to 3 months. Mechanical damage caused by hulling, associated with the lack of tissue fruit parts, contributes to reduction hulled coffee quality in storage, regardless of the processing.
Water storage in wetted strips under irrigated coffee trees with different criteria of irrigation management
(Associação Brasileira de Engenharia Agrícola, 2013-03) Colombo, Alberto; Alvarenga, Lívia A.; Scalco, Myriane S.; Ribeiro, Randal C.; Abreu, Giselle F.
The increasing demand for water resources accentuates the need to reduce water waste through a more appropriate irrigation management. In the particular case of irrigated coffee planting, which in recent years presented growth with the predominance of drip irrigation, the improvement of drip irrigation management techniques is a necessity. The proper management of drip irrigation depends on the knowledge of the spatial pattern of soil moisture distribution inside the wetted strip formed under the irrigation lines. In this study, grids of 24 tensiometers were used to determine the water storage within the wetted strip formed under drippers, with a 3.78 L h -1 discharge, evenly spaced by 0.4 m, subjected to two different management criteria (fixed irrigation interval and 60 kPa tension). Estimates of storage based on a one-dimensional analysis, that only considers depth variations, were compared with two-dimensional estimates. The results indicate that for high-frequency irrigation the one-dimensional analysis is not appropriate. However, under less frequent irrigation, the two-dimensional analysis is dispensable, being the one-dimensional sufficient for calculating the water volume stored in the wetted strip.