Consulta: creatorFacets:"Almeida,Willian F. de"
Registros recuperados: 5
Data/hora: 12/06/2024 14:39:19

Backpressure effects on the flow-pressure relation of driplines
Provedor de dados: Engenharia Agrícola
Autores: Thebaldi,Michael S; Lima,Luiz A; Almeida,Willian F. de; Andrade,Rafaella R.
ABSTRACT For drip irrigation design and management, it is necessary to know the relation between flow and pressure acting on emitters. In the case of subsurface drip irrigation, the backpressure phenomenon may change the hydraulic characteristics of emitters. Thus, this study aimed at determining such relationship between flow and pressure of different driplines in surface and subsurface conditions; aiming to find possible differences in hydraulic behavior. We tested four emitter types; two pressure compensating (D5000 and Hydro PCND) and two non-pressure compensating (TalDrip and Jardiline). Emitter flow rates were attained in atmospheric conditions and submerged in water, in which submergence levels represented backpressure. Assays were performed using...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Discharge exponent; Proportionality constant; Trickle irrigation.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162016000100055

Drip pulses and soil mulching effect on american crisphead lettuce yield
Provedor de dados: Engenharia Agrícola
Autores: Almeida,Willian F. de; Lima,Luiz A.; Pereira,Geraldo M.
ABSTRACT An experiment was conducted in a greenhouse at the Federal University of Lavras cultivated with American lettuce, cv. Raider-Plus. The aim of this study was to evaluate the effects of irrigation water depths applied by drip pulses and of soil coverage on crop yields and efficiency of water use. The experimental design used was randomized blocks with eight treatments and three replications, totaling twenty-four plots. The treatments consisted of soil with and without coverage (double-sided white and black plastic) associated with four irrigation management levels. Irrigation management consisted in reposition of irrigation depths based on crop evapotranspiration (ETc) with D1-100% of ETc, applied continuously (control), and D2 - 100% of ETc, D3 -...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Water-use efficiency; Greenhouse; Water depth.
Ano: 2015
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162015000601009

Effects of water deficit in two phenological stages on production of japanese cucumber cultived in greenhouse
Provedor de dados: Engenharia Agrícola
Autores: Oliveira,Eduardo C.; Carvalho,Jacinto de A.; Silva,Wellington G. da; Rezende,Fátima C.; Almeida,Willian F. de.
The experiment was performed in the experimental area of the Engineering Department Federal University of Lavras, Minas Gerais State, Brazil. It aimed at identifying the adequate irrigation management of the greenhouse-cultivated Japanese cucumber (Cucumis sativus L.). complete randomized design, with four levels of soil water potential (15; 30; 60 e 120 kPa) at two phenological phases (vegetative and reproductive), and 5 replications. Overall, the results showed decrease of yield according to increase of soil water potentials. During the reproductive stage, Japanese cucumber plants were more sensitive to water deficit, resulting in further decrease in yield compared to applied water deficit during the vegetative stage of the culture.
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Cucumis sativus L.; Greenhouse; Irrigation management.
Ano: 2011
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162011000400006

Germination and early growth of physic nut submitted to levels of salinity
Provedor de dados: Engenharia Agrícola
Autores: Lima,Luiz A.; Almeida,Willian F. de; Lima,Pedro L. T.; Oliveira,Eduardo C.; Shock,Clinton C.
Two experiments were conducted to evaluate the effect of salinity on early physic nut plant development. In the first trial, physic nut seeds were exposed to seven levels of salinity (0, 2, 4, 6, 8, 10 and 12dS m-1) with eight repetitions, using a substrate of paper soaked with solutions of CaCl2 and KCl. The treatments were evaluated based on the initial germination, total percentage of germination, and time necessary to germination of 50% of the seeds. Increased salinity reduced the first germination count and delayed the time to 50% germination. From 10dS m-1, there was a reduction in germination percentage. The second trial evaluated the effect of salinity on the growth of physic nut seeds. This trial, carried out inside a greenhouse, with a completely...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Jatropha curcas L.; Seeds; Seedlings; Greenhouse.
Ano: 2013
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162013000600004

Yield of green beans subjected to continuous and pulse drip irrigation with saline water
Provedor de dados: Revista Brasileira de Engenharia Agrícola e Ambiental
Autores: Almeida,Willian F. de; Paz,Vital P. da S.; Jesus,Ana P. C. de; Silva,Jucicléia S. da; Gonçalves,Karoline S.; Oliveira,Andressa S. de.
ABSTRACT In view of the imminent need for efficient water use and the search for adequate management techniques to reduce the effect of salinity on plants, a study was conducted to evaluate the effect of continuous and pulses drip irrigation with saline water on green bean yield and water use efficiency. The experiment was conducted in a greenhouse, in a completely randomized design, with treatments distributed in a 2 x 5 factorial arrangement. The first factor was type of drip irrigation, i.e., continuous or pulse, while the second factor was the levels of water salinity (electrical conductivity of 0.3, 1.5, 2.5, 3.5 and 4.5 dS m-1), with five replicates, and two plants per replicate, totaling 50 experimental units. The following variables were analysed:...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Phaseolus vulgaris; Pot; Greenhouse; Water use efficiency.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662018000700476