The Effect of Flooding Stress of Varying Durations at Different Growth Stages on Wheat Yield and its Components

This study investigated the effects of flooding stress on bread wheat ( Triticum aestivum L.) at different growth stages and flooding durations. Two wheat cultivars, flood-tolerant Gönen 98 and susceptible Meta 2002, were subjected to flooding treatments of 10-, 20-, and 30-days during tillering, stem elongation, and heading stages. The research examined various agronomic characteristics, including plant height, number of fertile stems, number of fertile and sterile spikelet, number of grains per unit area, thousand-grain weight, unit area grain yield, biomass and harvest index. Results showed that flooding tolerance varied significantly across growth stages, with stem elongation being particularly susceptible to flooding stress. Short-duration flooding had minimal negative effects and sometimes acted as beneficial irrigation. However, long-duration flooding led to significant reductions in yield components, medium- or long-duration flooding causing up to 74% reduction in some parameters. The study also introduced a Stress Effect Rate (SER) to assess the impact of flooding stress in greater detail. SER values varied depending on flooding duration and growth stage, providing insights into periods of heightened susceptibility to water stress. These findings highlight the importance of considering growth stage-specific flooding tolerance in wheat breeding programs and in developing management strategies for wheat cultivation in flood-prone areas.