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

and -407.0 to 617.3 mm, respectively (Fig 3a–3d). The average values ± SDs of CWS were -327.2 ± 58.6, -323.1 ± 75.4, -263.9 ± 122.7, and -177.9 ± 195.1 mm under the four growth stages, respectively (Fig 3a–3d). In the warm cropping season, the CWS on rice growth under initial, crop development, reproductive, and maturity stages ranged between -455.7 to 333.8, -466.2 to 136.4, -435.2 to -260.1, and -416.3 to -244.8 mm, respectively (Fig 3e–3h). The average values ± SDs of WDS were -208.3 ± 173.4, -322.9 ± 123.5, -380.2 ± 24.9, and -366.2 ± 24.3 mm under the four growth stages, respectively (Fig 3e–3h). The CWS on rice growth under the ini- tial, crop development, reproductive, and maturity stages declined by 96.9, 58.9, 24.7, and 198.6 mm in the cool cropping season, respectively (Fig 3a–3d), and declined by 63.7, 18.1, 8.6, and 3.8 mm in the warm cropping season, respectively (Fig 3e–3h) from 1925 to 2019. Effects of crop water status on rice yield The long-term temporal variation in the estimated effects of the CWS on the grain yield of 12 rice cultivars in the cool and warm cropping seasons from 1925 to 2019 are shown in Fig 4. A positive value of the regression coefficient reflects a coincident pattern between grain yield and CWS, and a negative value indicates an inverse response of grain yield to CWS. In the cool cropping season, the average regression coefficients under the initial and maturity stages revealed positive values in 1925–1944 and 1996–2019, but a negative average value over the

period 1945–1983 (Fig 4a and 4d); the average regression coefficients under the crop develop- ment stage revealed all positive values and decreased throughout the experimental period (Fig 4b); and the average regression coefficients under the reproductive stage revealed all negative values and increased throughout the experimental period (Fig 4c). In the warm cropping sea- son, the average regression coefficients under the initial stage revealed positive values in the periods 1925–1944 and 1945–1983, but a negative average value from 1996–2019 (Fig 4e). The average regression coefficients under the crop development and maturity stages revealed posi- tive values in the periods 1925–1944 and 1996–2019, but a negative average value from 1945– 1983 (Fig 4f and 4h). The average regression coefficients in the reproductive stage revealed a negative value from 1925–1944 and 1945–1983, but a positive value from 1996–2019, and increased throughout the experimental period (Fig 4g). Fig 3. Yearly trend of crop water status on rice growth 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. Grey line represents the linear regression line. * represents p- value < 0.05. https://doi.org/10.1371/journal.pone.0284290.g003 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 7 / 14