This Article Full Text (PDF) A correction has been published Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Fiscus, E. L. Search for Related Content PubMed PubMed Citation Articles by Fiscus, E. L. Agricola Articles by Fiscus, E. L.

Articles

Diurnal Changes in Volume and Solute Transport Coefficients of Phaseolus Roots

United States Department of Agriculture, Agricultural Research Service, Colorado State University, Fort Collins, Colorado 80523, Crops Research Laboratory, Colorado State University, Fort Collins, Colorado 80523

Volume (J_v) and solute (J_s) fluxes through Phaseolus root systems were observed over a 24-hour period. The volume flux was varied in a pressure chamber by altering the hydrostatic pressure in 10 steps, from 0 to 0.41 megapascals. All root systems showed strong diurnal peaks in volume flux. The five transport coefficients (, , J_s^*, L_p, and ^*) were estimated from a nonlinear least squares algorithm. Analysis of the data revealed that all the coefficients exhibited a diurnal rhythm. When the total differential of the volume flux was considered it was possible to show that the diurnal changes in volume flux were due to a complex interaction between the diurnally shifting coefficients with the role of each highly dependent on the level of volume flux. At low volume fluxes, , J_s^*, and ^* accounted for nearly all the diurnal change in volume flux. At high volume fluxes, however, the major influence shifted to L_p and ^*, while and J_s^* became relatively unimportant. Thus, ^* was the only coefficient of interest across the entire range of J_v and appeared to be the single most important one in determining the diurnal rhythm of J_v under conditions of a constant applied pressure.

This article has been cited by other articles:

				N. Miyamoto, E. Steudle, T. Hirasawa, and R. Lafitte Hydraulic conductivity of rice roots J. Exp. Bot., September 1, 2001; 52(362): 1835 - 1846. [Abstract] [Full Text] [PDF]