ISSN:
1399-3054
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
An experiment was conducted in SPAR systems at Florence, S.C., to obtain a data set for use in the simulation of the effect of drying soil on photosynthetic rates in cotton. The plant water status was monitored using leaf water potential and stem diameter meaurements. Reductions were noted in apparent photosynthesis rates after only 5 days of soil drying, and as anticipated, there was uniform displacement of the diurnal cycle of leaf water potential, and corresponding decreases in transpiration and CO2 uptake. The photosynthesis-light response curves indicated that an average two-fold reduction in photosynthesis rates occurred for solar radiation greater than 250 W/m2. Stem diameter change (from a nonstress pre-sunrise value) and integrated stem stress were found to be good indicators of maximum daily plant water stress. The integrated stem stress gave a measure of the duration of the stress along with its magnitude. A simulation method for predicting leaf water potential from stem diameter measurements was used to show that the magnitude and duration of plant water stress increased uniformly during the experiment. This increase was representative of the decreased rates of photosynthesis measured. These data will be used in the simulation of cotton growth and yield.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1399-3054.1979.tb06305.x
