Junzeng Xu
Hohai university, China
Title: An application on rice of reasonably using canopy temperature to improve the precision of water stress monitoring
Biography
Biography: Junzeng Xu
Abstract
Crop water stress index (CWSI) has been recognized as a water stress indicator and as a potential tool for irrigation scheduling. In present study, CWSI calculated based minimizing the low temperature impact was suitable to improve the precision of water stress monitoring. Thermal images were taken with FLIR thermal infrared imager at 14:00. Upper, sunlit and non-covered temperatures derived from canopy images, and canopy temperature cumulative frequency curves were discovered as discrete distribution under different degrees of water stress. CWSI used canopy temperature as the main driver for evaluation, and was calculated based on average temperature over a certain quantile. Regression equation between different CWSI and photosynthetic activity were built to find which one is the most sensitive index. Statistical analysis revealed that higher correlation coefficients were found after minimizing the low temperature. Further, the most sensitive CWSI also showed better relation to root soil moisture. CWSI thresholds were redefined. Optimal diagnose of the water stress was based on reasonably using canopy temperature. The results of this study were promising in precise irrigation scheduling.