Summary
It was previously reported that leaf water status of cowpea (Vigna unguiculata) exhibited only small changes with progressive soil drying over extended periods of time. In these studies, under field conditions, it was demonstrated that when soil water was not limiting, xylem pressure potential (ψ x ) exhibited a linear relationship with transpirational flux density with no obvious hysteresis. With progressive soil drying, values of ψ x and transpiration rate fell below the regression line established for nonlimiting soil conditions. It is proposed that paired measurements of ψ x and transpirational flux density made between midday and sunset can provide a measure of the extent to which soil conditions are limiting water uptake. The relation between ψ x and transpiration exhibits a family of curves, with more negative slopes and decreases in maximum transpiration rate indicating progressive limitation due to soil drying.
Similar content being viewed by others
References
Bates LM, Hall AE (1981) Stomatal closure with soil water depletion not associated with changes in bulk leaf water status. Oecologia (Berl) 50:62–65
Cowan IR, Milthorpe FL (1968) Plant factors influencing the water status of plant tissues. In: Kozlowski TT (ed) Water deficits and plant growth, vol 1, Development, control, and measurement. Academic Press, New York, p 137–193
Elfving DC, Kaufmann MR, Hall AE (1972) Interpreting leaf water potential measurements with a model of the soil-plant-atmosphere continuum. Physiol Plant 27:161–168
Hall AE (1982) Humidity and plant productivity. In: Rechcigl M Jr (ed) Handbook of agricultural productivity, vol I. CRC Press, Inc., Boca Raton, Florida, p 23–40
Hall AE, Schulze E-D (1980) Drought effects on transpiration and leaf water status of cowpea in controlled environments. Aust J Plant Physiol 7:141–147
Kappen L, Oertli JJ, Lange OL, Schulze E-D, Evenari M, Buschbom U (1975) Seasonal and diurnal courses of water relations of the arido-active plant Hammada scoparia in the Negew Desert. Oecologia (Berl) 21:175–192
Kaufmann MR (1976) Water transport through plants: current perspectives. In: Wardlaw, IF, Passioura JB (eds) Transport and transfer processes in plants. Academic Press, New York, p 313–327
Kaufmann MR (1981) Development of water stress in plants. Hort Science 16:34–36
Sterne RE, Kaufmann MR, Zentmeyer GA (1978) Effect of Phytophthora root rot on water relations of avocado: Interpretation with a water transport model. Phytopathology 68:595–602
Turk KJ, Hall AE (1980a) Drought adaptation of cowpea. II. Influence of drought on water status, and relations with seed yield. Agron J 72:421–427
Turk KJ, Hall AE (1980b) Drought adaptation of cowpea. IV. Influence of drought on water use, and relations with growth and seed yield. Agron J 72:434–439
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Bates, L.M., Hall, A.E. Relationships between leaf water status and transpiration of cowpea with progressive soil drying. Oecologia 53, 285–289 (1982). https://doi.org/10.1007/BF00389000
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00389000