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Evaluation of Two Temperature Stress Indices to Estimate Grain Sorghum Yield and Evapotranspiration
Author(s) -
Ajayi Ayodele Ebenezer,
Olufayo Ayorinde A.
Publication year - 2004
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj2004.1282
Subject(s) - sorghum , evapotranspiration , vapour pressure deficit , canopy , water stress , yield (engineering) , agronomy , point of delivery , environmental science , biology , botany , transpiration , materials science , ecology , photosynthesis , metallurgy
This study was performed to examine the relationship between canopy temperature ( T c )–based stress indices and grain yield and evapotranspiration (ET) of sorghum [ Sorghum bicolor (L.) Moench]. The crop was subjected to 14 differentially irrigated treatments of which two were controls maintained at well‐watered and dry conditions during three consecutive years. Soil water content and T c were measured, and relationships between T c –based stress indices [stress degree day (SDD), temperature stress day (TSD), and crop water stressed index (CWSI)] and yield as well as ET were examined. The T c –air temperature ( T a ) difference varied from −2 to +8°C in the stressed treatments and maintained a negative value for most of the time in the well‐watered treatment. The relationship between T c − T a and vapor pressure deficit, commonly referred to as baseline in the determination of CWSI, was examined on function of wind speed and global solar radiation. Although observations showed that T c can be influenced by climatic condition, this study confirmed that it can serve as a useful indicator of water stress in the case of sorghum. High correlation found between T c –based stress indices TSD, SDD, and CWSI and ET as well as grain yield suggest the possibility of using these relationships for predictive purposes.