Comparison of leaf, spike, peduncle and canopy temperature depression in wheat under heat stress uri icon

abstract

  • This study examines genotype X organ-temperature depression (TD) interactions and whether differences in plant morphology influence organ-TD and its correlation with canopy temperature depression (CTD) and grain yield. Field experiments were conducted with 13 spring wheat genotypes planted on three dates in the 2000-2001 winter cropping cycle in NW Mexico. Surface temperatures of flag leaves, peduncles, spikes and canopy were measured with a hand-held infrared thermometer. Morphological and yield components were also measured. Results indicated that there is genetic variability for organ-TD. CTD showed strong positive correlations with organ-TD and grain yield. Organ-TD and CTD were positively correlated with leaf area index, and CTD was probably little affected by leaf rolling. Spike temperature was generally higher than leaf temperature, but lower than ambient air temperature. The interactions between grain yield and spike-TD and CTD were not significant. Results of this study indicate that CTD does not mask confounding interactions between organ temperatures and thus can be used reliably to measure TD during grain filling under heat stress conditions. (C) 2002 Elsevier Science B.V. All rights reserved.

publication date

  • 2002
  • 2002
  • 2002