Skip Navigation

This Article
Right arrow Full Text (PDF)
Right arrow E-letters: Submit a response
Right arrow Alert me when this article is cited
Right arrow Alert me when E-letters are posted
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Alert me to new issues of the journal
Right arrow Add to My Personal Archive
Right arrow Download to citation manager
Right arrowRequest Permissions
Right arrow Disclaimer
Google Scholar
Right arrow Articles by BLACK, C. R.
Right arrow Search for Related Content
PubMed
Right arrow Articles by BLACK, C. R.
Agricola
Right arrow Articles by BLACK, C. R.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us  
What's this?

© 1979 Oxford University Press

RESEARCH-ARTICLE

A Quantitative Study of the Resistances to Transpirational Water Movement in Sunflower (Helianthus annuus L.)

C. R. BLACK 1

Department of Botany, University of Aberdeen St. Machar Drive, Aberdeen, AB9 2UD

Hydroponic sunflower plants were used in a quantitative study of the relationship between total plant and leaf resistances to transpirational water movement and transpiration rate. The results demonstrate that both resistances are flux-dependent and decline 5–6-fold during a comparable increase in transpiration. The resistance of excised leaves including the petiole was approximately half the total plant resistance.

Subsequent analyses of the water potential gradients and transpirational fluxes in whole plants permitted calculation of the magnitude of the partial resistances imposed by roots, stem, petiole, and leaf. The root and leaf resistances were approximately 50% and 30% of the total resistance respectively. Stem and petiolar resistances were relatively small and both influenced water movement to the upper leaves similarly. The values obtained are compared with previous published results obtained using diverse experimental techniques.


Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us    What's this?




Disclaimer: Please note that abstracts for content published before 1996 were created through digital scanning and may therefore not exactly replicate the text of the original print issues. All efforts have been made to ensure accuracy, but the Publisher will not be held responsible for any remaining inaccuracies. If you require any further clarification, please contact our Customer Services Department.