Data/hora: 15/06/2024 05:33:38

Biblioteca(s): | Embrapa Territorial.
Data corrente: | 26/05/2004
Data da última atualização: | 13/03/2015
Autoria: | ANGELOCCI, L. R.; MARIN, F. R.; OLIVEIRA, R. F. DE; RIGHI, E. Z.
Afiliação: | LUIZ ROBERTO ANGELOCCI, USP; FÁBIO RICARDO MARIN, CNPM; RICARDO FERRAZ DE OLIVEIRA, USP; EVANDRO ZANINI RIGHI, USP.
Título: | Transpiration, leaf diffusive conductance, and atmospheric water demand relationship in an irrigated acid lime orchard.
Ano de publicação: | 2004
Fonte/Imprenta: | Brazilian Journal of Plant Physiology, Campinas, v. 16, n. 1, p. 53-64, 2004.
Idioma: | Inglês
Conteúdo: | Leaf vapor diffusive conductance (gl) and transpiration (T) measurements in an irrigated orchard of the acid lime ?Tahiti? were carried out in a subtropical climatic condition in the State of São Paulo, Brazil. Measurements were made using steady-state null-balance porometers and were taken throughout the day, on several occasions from February to November, 1998. During September and October, measurements were performed on exposed and shaded young and fully expanded leaves, as well as on old leaves inside the tree canopy. The old leaves showed lower values of gl and T when compared to the other groups. In the other months, measurements were taken only with exposed and shaded fully expanded leaves. The highest values of gl and T were obtained from February to April. For exposed leaves gl was higher from early morning to midday, decreasing thereafter with some oscillation in the afternoon. Shaded leaves produced a pattern of increasing gl and T from 8:00-9:00 a.m. to midday, followed by a decrease when values matched those of the exposed leaves in the afternoon. In April, the first measurement in midmorning showed low gl and T values, increasing sharply in the exposed leaves until midday and then decreasing until the end of the afternoon. Between May and November, gl and T decreased sharply compared to the previous months. Boundary line and regression analysis were used to find the mathematical relationships between mean values of gl for the tree and photosynthetic photons flux density, temperature, and vapor pressure deficit of the air measured in the orchard. Based on this analysis, the reasons for the gl and T diurnal and annual variation patterns are discussed, with emphasis on the effects of atmospheric variables upon stomatal regulation.
Palavras-Chave: | Air temperatuture; Photosynthetic photon flux density; Porometry; Vapor pressure deficit.
Thesaurus Nal: | Stomata.
Categoria do assunto: | --
URL: | http://ainfo.cnptia.embrapa.br/digital/bitstream/item/120363/1/1336.pdf
Registro original: | Embrapa Territorial (CNPM)
Exemplares: | CNPM - (1336-1) - UPC - AP - PP - 04/021 - AP - 2004.021 - DIS