Identifying Drought Tolerant Wheat Genotypes Using Wireless Infrared Thermometer In The US Southern High Plains.

Drought is one of the deleterious abiotic factors limiting dryland wheat yield in the US Southern High Plains. Selection of wheat cultivars with drought tolerance has been critical for improving wheat yield in the region. Canopy temperature, measured with a hand held infrared thermometer (IRT), has been utilized to identify a drought tolerant wheat genotypes. A hand held IRT, however, cannot be used to record continuous season-long canopy temperature. In this study, we used low-cost consumer-quality wireless infrared thermometers to measure canopy temperature continuously for a long period of time. Twenty winter wheat genotypes were grown under rainfed conditions in 2012 at Bushland, Texas. The genotypes included 10 Texas A&M developed cultivars (TAM) and experimental lines (TX), and other 10 cultivars from OK, KS, and CO. The canopy and air temperatures were measured every minute from booting to grain filling stage for 47 d. Canopy temperature depression (CTD) was calculated as a difference between air and canopy temperature. The diurnal and seasonal changes in CTD followed the changes in air temperature and solar radiation. There were significant differences among genotypes for CTD. The differences in CTD were larger among the 10 Texas genotypes than other 10 cultivars. The preliminary data indicated that low-cost consumer-quality wireless IRT are useful in collecting season-long data that allow the analysis of wheat canopy temperature at different growth stages and diverse climatic conditions, and in the identification of drought tolerant genotypes. The genotypes with relatively higher CTD (cool canopy) in afternoons from heading to grain filling may be connected to higher yield under drought conditions.