Yield and Physiological Responses of Modern versus Obsolete Cultivars Grown under Water-deficit Conditions

Year-to-year variability in yield is a major concern in U.S. cotton production. Recent literature and hypotheses indicate that this yield variability is mostly related to extreme environmental conditions, particularly high temperatures and drought, as well as a peak in genetic improvements in yield. It is speculated that modern and obsolete cultivars partition dry matter and energy pools differently within the boll and at the seed level, making the modern cultivars potentially more sensitive to environmental stresses. The goal of this current field study was to quantify the effect that water-deficit stress had on modern versus obsolete cultivars in terms of lint yield, components of yield, and physiological plant responses that might hinder the overall development of yield.