ABSTRACT

Variability in cotton yield is a major concern to cotton producers that has been associated with high temperatures and drought during boll development. Earlier work has indicated a strong negative correlation between high temperatures and low cotton (Gossypium hirsutum) yields in Arkansas. The current project was designed for field and growth room studies to (a) evaluate techniques for measuring temperature tolerance in cotton, and (b) to screen obsolete and modern cultivars for temperature tolerance. Preliminary results of these studies indicated that membrane leakage showed the most sensitivity for quantifying temperature tolerance in the field. In addition to membrane leakage, fluorescence also showed some sensitivity for quantifying temperature tolerance with the advantage that is much easier for field use. Similarly, measurement of catalase activity was sensitive but time consuming and more appropriate for laboratory analysis. The comparison of obsolete and modern cultivars did not show many significant differences, however the obsolete cultivars were more responsive to higher temperatures indicating more stress tolerance. This research will continue to evaluate genotypic temperature tolerance at higher temperatures (>30ºC), and also to screen available cotton germplasm.