TITLE:
Stable Carbon Isotope Discrimination (δ13C) of Cotton Burrs and Seeds as a Season-Long Integrator of Crop Water Stress
AUTHORS:
Dennis C. Gitz III, Jeffrey T. Baker, Robert J. Lascano
KEYWORDS:
Irrigation-Scheduling, Germplasm Screen, Water Management
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.13 No.12,
December
29,
2022
ABSTRACT: Plant-based irrigation management schemes typically use surrogates such
as canopy temperature, alone, or in conjunction with environmental variables,
to infer the degree of “crop stress” (biological strain) induced by drought.
Few systematic studies of the relationship between “crop stress”, as defined by
such surrogates, and physiological estimates of water use efficiency (WUE)
exist over both daily and seasonal time scales relevant to agronomic irrigation
control. The systematic application of stable carbon isotope discrimination (δ13C) might allow post hoc evaluation of irrigation scheduling schemes and might also be a useful
germplasm screening tool if the source(s) of variability can be uncovered
and/or controlled. Results from preliminary efforts comparing leaf and cotton
seed δ13C to season-long
water deficits showed that seeds are more useful indicators of season-long
water stress and water use efficiency during crop development.