Simulating the impacts of and adaptation options for increasing air temperature on chalky rice grains in the Kyushu region of Japan

In the Kyushu region of Japan, occurrence chalky rice grains caused by high air temperatures is a concern for major local cultivar, Hinohikari. To avoid heat stress, cultivar shift to Nikomaru, which highly tolerant temperatures, expected in this region. However, it unknown how effective shifting avoiding heat‑induced under possible temperature future. Therefore, present study, we aimed simulate impacts increased on Hinohikari and Nikomaru based 10 future climate scenarios, derived from combination five general circulation models two representative concentration pathway (RCP) scenarios. Under RCP2.6 RCP8.5, median percentages averaged over entire were 29.6% 42.8% 2041‑2060 31.4% 83.6% 2081‑2100, respectively. While reduced them approximately 20‑30%, damage could not be below 10% RCP8.5. Furthermore, tested effects other adaptation options: late transplanting. Although implementing both options, transplanting, was somewhat middle 21st century, suppress incidence 2081‑2100 options mitigation measures may needed end century temperatures.