|THAPA, SUSHIL - TEXAS AGRILIFE|
|JESSUP, KIRK - TEXAS AGRILIFE|
|PRADHAN, GAUTAM - NORTH DAKOTA STATE UNIVERSITY|
|RUDD, JACKIE - TEXAS AGRILIFE|
|LIU, SHUYU - TEXAS AGRILIFE|
|DEVKOTA, RAVINDRA - TEXAS AGRILIFE|
|BAKER, JASON - TEXAS AGRILIFE|
|XUE, QINGWU - TEXAS AGRILIFE|
Submitted to: Field Crops Research
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/5/2017
Publication Date: 12/8/2017
Citation: Thapa, S., Jessup, K., Pradhan, G., Rudd, J., Liu, S., Mahan, J.R., Devkota, R., Baker, J., Xue, Q. 2017. Canopy temperature depression at grain filling correlates to winter wheat yield in the U.S. southern high plains. Field Crops Research. 217(2018):11-19.
Interpretive Summary: Drought is a major contributer to yield losses in wheat. The identification of wheat varieties that can maintain yield when water is limiting is essential to the improvement of wheat yields in adverse environments. The ability to identify differences in water use among wheat varieties is needed by breeders. In this study infrared thermometers were used to monitor the temperature of several wheat varieties in the field over three years. Differences in variety responses to water deficits were documented and related to differences in yield. These results indicate the usefulness of temperature measurements in understanding crop water use. Breeders can use this tool to differentiate among varieties of interest.
Technical Abstract: Wheat breeding has improved drought tolerance over the years. However, our knowledge on drought tolerance in relation to the canopy temperature (CT) and grain yield is limited. A three-season wheat field study ending 2012, 2015, and 2016 was conducted at Bushland, Texas to investigate the relationship between canopy temperature depression (CTD) and yield during the grain filling. For each season, 20 elite wheat genotypes were grown under dryland conditions, and CT was measured by Smart Crop wireless IRT sensors every 15 minutes continuously for 12-15 days during mid-grain filling. There was a genotypic variation for CTD regardless of time of the day; however, the variation was more evident during the day time (10:00 - 18:00 h), with the smallest CTD (i.e., warmer canopy) at 14:00 - 15:00 h. In a dry season of 2012, Dumas, TAM 112, and TAM 304 had greater CTD (i.e., cooler canopy) than other genotypes. In two wet/near normal seasons (2015 and 2016) Duster, TAM 111, TAM 110, TAM 112, and TAM 105 had greater CTD. There was a significant (P < 0.05) positive linear relationship between grain yield and day-time CTD. Hence, a cooler plant canopy during the mid-grain filling in winter wheat appears to be an important indicator of greater drought tolerance and yield under dryland condition. This knowledge may help breeders to conduct high-throughput field phenotyping in large breeding populations.