Fig. 3. Root oxidation activity of rice cv. (A) Zhendao 88 and (B) Shanyou 63 under various irrigation treatments. The abbreviations CI, WMD, and WSD indicate conventional irrigation, alternate wetting and moderate soil drying, and alternate wetting and severe soil drying, respectively, during grain filling (6–48 d after heading). Measurements were made when soil water potentials were –25 kPa in WMD and –50 kPa in WSD. Data are averages observed for the two study years. Vertical bars represent ± standard error of the mean (n = 12) where these exceed the size of the symbol.