Quantifying the impacts of waterlogging on cotton at different growth stages: A case study in Hubei Province, China

Waterlogging severely restricts cotton (Gossypium hirsutum L.) production worldwide. To assess the impacts of waterlogging on cotton yield, a series of field experiments with multi-form waterlogging were conducted during four cotton growth stages in Hubei Province, China from 2003 to 2011. Moreover, regional waterlogging events were characterized by the sum of excess rainstorm amount index (SER) and the sum of excess standardized precipitation and evapotranspiration index (SESPEI); accordingly, the spatiotemporal variations in waterlogging in Hubei Province during 1961-2019 were analyzed. The results showed that the 1980s was the most waterlogging-prone decade and northeastern Hubei was the most waterlogging-prone region for Hubei. The impact of surface waterlogging on cotton was greater than that of subsurface waterlogging, and the impact of their combined stress was lower than the additive effects of individual stresses. The most waterlogging-sensitive cotton growth stage was the flowering and boll-forming stage, whereas the most waterlogging-proneness growth stage was the budding stage. A normalized waterlogging index integrating both waterlogging sensitivity and proneness indicated that the budding and the flowering and boll-forming stages were the periods when cotton suffered the greatest waterlogging impacts. Both the SESPEI and SER were significantly (p < .05) and negatively related to the detrended cotton yield, and the former was found more efficient in describing the negative effects of waterlogging. In conclusion, different forms of waterlogging should be accounted for in-field drainage schedules, and extra attention should be paid during the budding and the flowering and boll-forming stages of cotton, especially for northeastern Hubei.