Submitted to: National Cotton Council Beltwide Cotton Conference
Publication Type: Abstract Only
Publication Acceptance Date: January 6, 2003
Publication Date: January 9, 2003
Citation: Burke, J.J. Physiological limitations to cotton production on the High Plains of Texas. National Cotton Council Beltwide Cotton Conference[abstract]. 2003. P. 1652. CD-ROM File. Technical Abstract: Rainfall shortly after cotton planting may result in soil crusts that form a barrier to seedling emergence and narrows the temperature range at which chlorophyll accumulates in cotyledons. Low temperatures, in combination with rainfall, directly inhibit root development by reducing enyzme activities, and indirectly reduce growth through seedling invasion by the seedling disease complex. High soil temperatures at the seeding depth may reach 45 to 50C under dryland conditions. Irrigation can reduce soil temperatures to a more favorable range; however, if water is not available then the seedlings must either cope with the elevated temperatures or die. Developmentally-regulated heat shock proteins are present in the germinating cotton seedling; however, they are unavailable to function in enhancing thermotolerance. The temperature sensitivity of the apparent Km of enzymes was used to provide a thermal range providing optimum enzyme activity. The temperature sensitivity of the reappearance of Photosystem II chlorophyll fluorescence following a high light treatment provided data similar to that of the Thermal Kinetic Window, but in a fraction of the time. These techniques led to the development of an irrigation control system named the Biologically Identified Optimal Temperature Interactive Console (BIOTIC). Realization of the inhibitory effect of temperatures outside of the optimum range have led us to the development of a Metabolic Fitness assay that is a valuable tool in identifying genetic deversity in temperature sensitivity in cotton germplasm. We developed a solid pollen germination media and showed optimum pollen germination and rapid tube elongation occurred between 28 C and 31 C under 80% relative humidity. Pollen germination declined above 32 C.