Early–maturing cultivar of winter wheat is more adaptable to elevated [CO2] and rising temperature in the eastern Loess Plateau

Understanding the impacts of rising temperature and elevated [CO2] on different crop cultivars is critical to devising agronomic strategies and cultivar selection in the context of climate change adaptation. The growth period, biomass, and yield of two wheat cultivars (early– vs. late–maturing) were simulated by the Agricultural Production Systems sIMulator (APSIM) validated with pot experiments under the scenarios of elevated [CO2] and 2 °C warming based on the baseline climate for 1961–2016 at Taigu in North China. We also investigated the effects of extreme high temperature on the yield and yield components of these wheat cultivars. We found that APSIM well simulated the changes in the growth period, leaf area index (LAI), biomass, and yield induced by 2 °C warming and elevated [CO2]. Long–term simulations showed that 2 °C warming decreased the growing period between sowing and jointing for both cultivars. 2 °C warming and elevated [CO2] affected the wheat yield mainly by altering the grain numbers. Extreme high temperature decreased the grain numbers and yield of the late–maturing cultivar but not the early–maturing one. The findings suggest that early–maturing cultivar would be better adapted to elevated [CO2] and rising temperature than the late–maturing one in the eastern Loess Plateau.