Submitted to: Biennial Grain Sorghum Research and Utilization Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 2/19/2001
Publication Date: N/A
Technical Abstract: Plant growth and development is enhanced at a species specific optimal temperature. Leaf temperatures increase as soil water becomes limiting. Coupling the temperature optimum with leaf temperature measurements provides a unique irrigation management opportunity. The biologically identified optimal temperature interactive console (BIOTIC) uses the laboratory identified biological optimum temperature, leaf canopy temperature measurements, and humidity measurements to provide producers irrigation scheduling regimes. We determined the temperature optimum for sorghum to be 29C and used this information to schedule irrigations in the field. A sorghum yield of 6674 lbs/acre was obtained for the irrigated plots compared with 2-3000 lbs/acre averages under dryland conditions. Because field-grown sorghum experiences high and low temperature stresses throughout the season, and even throughout a single day, we have investigated the genetic diversity in sorghum thermotolerance. Assay systems have been developed to evaluate a short-term inducible high temperature protection system, a long-term inherent high temperature protection system, and the levels of cold tolerance in sorghum germplasm. Initial analyses showed a high degree of genetic variability for each of these temperature characteristics. The results of this study suggest that improved sorghum varieties need to express high levels of protection under multiple thermotolerance screens to optimize field performance in variable environments.