Effect of climate change-induced water-deficit stress on long-term rice yield

Yield changes responding to crop water status The mean total yield change relating to the CWS on the cultivars in cool cropping seasons over the periods 1925–1944, 1945–1983, and 1996–2019 are -43.2, 37.0, and -56.1 kg ha-1 in the initial stage, respectively, -77.5, -39.0, and -12.3 kg ha-1 in the crop development stage 19.3, 19.8, and 11.2 kg ha-1 in the reproductive stage, and -146.4, 39.1, and -12.4 kg ha-1 in the matu- rity stage, respectively (Table 1). The mean total yield change related to the CWS on the culti- vars in the warm cropping seasons over the periods 1925–1944, 1945–1983, and 1996–2019 are -1.3, -16.5, and 8.2 kg ha-1 in the initial stage, -12.9, 8.1, and -0.4 kg ha-1 in the crop devel- opment stage, 9.0, 4.1, and -2.3 kg ha-1 in the reproductive stage, and -2.8, 8.0, and -9.3 kg ha-1 in the maturity stage, respectively (Table 1). Discussion In most cultivated areas of Taiwan, two cropping seasons are maintained throughout the year. The cool cropping season starts in late February or early March (initial stage) and ends in late Fig 4. Regression coefficient of rice yield on crop water status under initial (a and e), crop development (b and f), reproductive (c and g), and maturity (d and h) stages in cool (a, b, c, and d) and warm (e, f, g, and h) cropping seasons. Filled circles represent the value of a cultivar. Open circles represent the average value of a group of cultivars having overlapped cultivation period. The length of the black line on the open circle represents

the value of standard deviation. Horizontal dash lines separate the groups of cultivars having overlapped cultivation periods. In each panel, the upper, mid, and lower zone represent the periods of 1925–1944, 1945–1983, and 1996–2019, respectively. https://doi.org/10.1371/journal.pone.0284290.g004 Table 1. Total rice yield change (kg ha-1) related to crop water status over the periods 1925–1944, 1945–1983, and 1996–2019 under initial (INI), crop development (DEV), reproductive (REP), and maturity (MAT) stages in the cool and warm cropping seasons. 1925–1944 1945–1983 1996–2019 INI DEV REP MAT INI DEV REP MAT INI DEV REP MAT Cool cropping season Mean -43.2 -77.5 19.3 -146.4 37.0 -39.0 19.8 39.1 -56.1 -12.3 11.2 -12.4 SD 112.3 72.7 23.5 156.2 92.0 38.5 13.7 27.0 265.2 42.9 16.7 31.0 Warm cropping season Mean -1.3 -12.9 9.0 -2.8 -16.5 8.1 4.1 8.0 8.2 -0.4 -2.3 -9.3 SD 10.1 8.9 19.1 3.6 10.7 5.5 8.3 18.2 6.9 4.5 12.6 2.0 https://doi.org/10.1371/journal.pone.0284290.t001 PLOS ONE Effect of climate change-induced water-deficit stress on long-term rice yield PLOS ONE | https://doi.org/10.1371/journal.pone.0284290 April 17, 2023 8 / 14