Reducing Cadmium Accumulation and Increasing Grain Yield with Proper Timing of Flood Irrigation in the Second Season of Ratoon Rice

•Ratoon crop (RC) is prone to accumulating Cd under rainfed conditions.•RC takes up the most Cd during the period from initial heading to full heading.•Flooding during heading period effectively reduces the grain Cd concentration of RC.•Flooding during heading period is beneficial for improving the grain yield of RC.