Morphological, Physiological and Yield Responses of Some Rice Varieties (Oryza sativa L.) as Exposed Under High Temperature in Indonesia

Background and Objective: Temperature increase caused by global warming can affect plants growth and production, including the rice plant. The purpose of this study was to determine the morphological, physiological and yield responses of some rice varieties exposed under high temperature. Material and Methods: The study was conducted in Cikarawang, Bogor from June, 2014 to February, 2015 and used Randomized Block Design (RBD) with 2 factors, difference temperature (T1: 28.3, 22.1 and 38.2EC, T2: 32.1, 22.8 and 47.9EC and T3: 33.1, 23.4 and 50.1EC) as average, minimum and maximum daily temperature, respectively and eight rice varieties. Rice plants were exposed under difference temperature treatment since 56 days after seeding until harvest time. Results: Results showed that high temperature inhibited exsertion of panicle all varieties. Leaf temperature increased 3-6EC at average temperature exposure 32.1 and 33.1EC. Silungonggo showed highest leaf temperature (34.7EC), whereas IR 64 showed the lowest (33.4EC). There was decreasing yield from 68.1-92.0% at average temperature of 32.1EC. Conclusion: Varieties which had better yield had well exsertion of panicle, low leaf temperature and high percentage of filled grain. The IR 64 had the lowest leaf temperature, Menthik Wangi and Jatiluhur had well exsertion of panicle but still have low percentage of filled grain.