The study was conducted to determine the feasibility of canopy temperature based crop water stress index (CWSI) for scheduling irrigation of Indian mustard (Brassica juncea). Field crop experiments were conducted in Hamirpur, Himachal Pradesh (India) during three consecutive cropping seasons (2015, 2016 and 2017). The experimental field was divided into five plots with different levels of irrigation treatments based on depletion of total available soil water (TASW) in the crop root zone. The maximum soil moisture depletion (SMD) of TASW at 10%, 30% and 50%, full irrigated (non‐stressed) and extremely dry (full stressed) conditions were maintained in respective plots. Relationships were developed between canopy‐air temperature differential (T_C‐T_A) and vapour pressure deficit (VPD) for non‐stressed and fully stressed conditions to generate non‐water‐stressed baseline (NWSB) and maximum water‐stressed baseline (MWSB) baselines for Indian mustard crop. The CWSI was computed for different SMD of TASW by using a proven empirical approach based on the baselines. The irrigation treatment corresponding to 30% SMD with a mean CWSI of 0.4 resulted in optimal yield and maximum water use efficiency. Results of the study suggest that established CWSI value can be used to detect stress and schedule irrigations for Indian mustard.

中文翻译：

---

基于水分利用效率考量的印度芥菜（Brassica juncea）灌溉计划的作物水分胁迫指数

进行该研究以确定基于冠层温度的作物水分胁迫指数（CWSI）进行印度芥菜（Brassica juncea）灌溉计划的可行性。在连续三个种植季节（2015年，2016年和2017年），在印度喜马al尔邦的哈米尔布尔进行了田间作物试验。根据作物根区总可用土壤水的枯竭，将试验田分为五个不同灌溉处理水平的地块。在各个样地中，TASW的最大土壤水分消耗（SMD）分别为10％，30％和50％，完全灌溉（无压力）和极度干燥（完全压力）条件。冠层空气温差（T _C - T _A）和非压力和完全胁迫条件下的蒸气压亏缺（VPD），以生成印度芥菜作物的非水分胁迫基线（NWSB）和最大水分胁迫基线（MWSB）基线。通过使用可靠的基于经验的经验方法，针对TASW的不同SMD计算CWSI。灌溉处理对应30％SMD，平均CWSI为0.4，可实现最佳产量和最大用水效率。研究结果表明，已建立的CWSI值可用于检测压力和安排印度芥菜的灌溉。