Water Use Efficiency (WUE) of some rice varieties under high-temperature stress

Rice is a staple food for much of the global population, yet its productivity is significantly impacted by climate change, particularly temperature variations that affect water availability. Water use efficiency (WUE) is a critical factor, as plants must balance water loss and heat dissipation. High temperatures increase transpiration rates but can decrease WUE, thereby reducing productivity. This research aimed to study the WUE of several rice varieties under high-temperature stress. Different temperature levels (ambient, medium, and high) were used as main plots, and rice varieties (Ciherang, Jatiluhur, IR64, and Way Apo Buru) as subplots. Fourteen-day-old rice seedlings were planted in a container box (67x47x37 cm) with a spacing of 20x20 cm, and water volume was recorded weekly during the growing period. The study found that air temperature increases of 1.6-2.2°C significantly affected plant height, shoot dry weight, SPAD values, stomatal density, and water consumption; however, rice production decreased by 3-8%. The increase in air temperature improved WUE in the Ciherang and Jatiluhur varieties. Jatiluhur had the highest water consumption (37.74 L), while IR64 had the lowest (28.64 L). This research concluded that the Jatiluhur variety demonstrated the highest water consumption and WUE, suggesting its potential for breeding programs to enhance resilience to climate change.