Data/hora: 15/06/2024 11:03:37

Biblioteca(s): | Embrapa Mandioca e Fruticultura.
Data corrente: | 18/12/2001
Data da última atualização: | 18/12/2001
Autoria: | CLEMENTE, H. S.; MARLER, T. E.
Afiliação: | College of Agriculture and Life Sciences, University of Guam, Mangilao, Guam 9623.
Título: | Drought stress influences gas-exchange responses of Papaya Leaves to Rapid Changes in Irradiance
Ano de publicação: | 1996
Fonte/Imprenta: | Mangilao, Guam: J. Amer. Soc. Hort. Sci, v.121, n.2, p.292-295, 1996
Idioma: | Inglês
Conteúdo: | Field-grown 'Red Lady' papaya (carica papaya L.) plants were used to measure foliar gas-exchange responses to rapid changes in irradiance levels to determine if papaya stomata are able to track simulated sun-to-cloud cover transitions. Natural sunlight and neutral shade cloth placed over the leaf were used to provide high photosynthetic photon flux(PPF) of about 2000umol.m-2.s-1 until leaves reached steady state within the cuvette, followed by three minutes with low PPF of about 325umol.m-2.s-1, and a return to PPF of about 2000umol.m-2.s-1. Net CO2 assimilation (A) declined from an initial 20umol.m-2.s-1 to about 9umol.m-2.s-1 within 20 seconds of initiating low PPF, and remained fairly stable for the duration of the three minutes of low PPF. Stomatal conductance (gs) declined within 60 seconds of initiating low PPF, from 385 to about 340umol.m-2.s-1 during the three minutes duration of low PPF.
Palavras-Chave: | Net CO2 assimilation; Photosynthetic photon flux; Tropical.
Thesagro: | Carica Papaya.
Thesaurus Nal: | cloud cover; stomatal conductance; water use efficiency.
Categoria do assunto: | --
Registro original: | Embrapa Mandioca e Fruticultura (CNPMF)
Exemplares: | CNPMF - (19354-1) - ADD - SP - -- - S12057 -  - S12057 - DIS