Growth characteristics and yield of contrasting rice genotypes under long-term stagnant flooding

•Stagnant flooding (SF) significantly delayed maturity and reduced survival, tiller number, crop growth rate and leaf area index.•Plant height and specific leaf weight increased under SF probably as adaptive strategies to increase survival.•Grain yield decreased progressively with increasing water depth (32%–57%).•SF-tolerant genotype showed the highest grain yield under SF, because of its more panicles and greater biomass production.•Grain yield of the SUB1 genotype was lower than that of non-SUB1 genotype.