Quantifying water stress of safflower (Carthamus tinctorius L.) cultivars by crop water stress index under different irrigation regimes

• DOI: 10.1016/j.heliyon.2022.e09010
• Publication Date: 2022-02-24T03:30:19Z
• Authors: Ehsan Bijanzadeh; Seyed Mojtaba Moo...; Fatemeh Bahadori
• Keywords: Carthamus; Water Stress; Water use; Growing season

Infrared thermometry allows evaluating water status of the crop by measuring stress index (CWSI), without need physical contact to leaves. In order quantify CWSI and finding best irrigation regime a two-year field experiment was conducted in safflower during 2017 2018 growing seasons at Darab, Fars province, Iran. Two cultivars (Goldasht Local Isfahan) four regimes consisted well-watered [Irrigation based on 100% capacity (FC)], mild (75% FC), severe (50% most (25% FC) were arranged as split plot according randomized completely block design with replicates. The relationship between vapor pressure deficit (VPD) canopy-air temperature differences (Tc-Ta) plotted under upper (fully stressed) lower baselines (non-stressed) equations. two cultivars, VPD increment, distance base lines increased. Goldasht, baseline (Tc-Ta)ul, 7.8 °C 8.9 2018. From April July when air warmed, Tc-Ta differential increased up highest seasonal (0.72-0.77) obtained Isfahan stress. 2017, stress, relative content (RWC; 55%), color quality (6-7) use efficiency (WUE; 2.69 g m-2 mm-1) observed Goldasht which more than Isfahan. It might be attributed tolerance evaporation first year. total consumed (R2 = 0.88∗∗), RWC 0.87∗∗), 0.75∗) seed yield 0.83∗∗) related, negatively. Overall, 0.28-0.33 had higher RWC, quality, WUE, an acceptable yield, could conditions for safflower.