Heat, wheat and CO₂: The relevance of timing and the mode of temperature stress on biomass and yield

Abstract

Atmospheric CO2 enrichment affects C3 crops both directly via increased carbon gain and improved water use efficiency and indirectly via higher temperatures and more frequent climatic extremes. Here we investigated the response of spring wheat (Triticum aestivum L. cv. Triso) to CO2 enrichment (550 vs. 380 µmol/mol) and heat, applied as a constant +4°C increase or a typical heat wave either before or after anthesis, or as two typical heat waves before and after anthesis. We applied a climate chamber approach closely mimicking ambient conditions. CO2 enrichment increased above‐ground biomass and yield by c. 7 and 10%, but was not able to compensate for adverse heat stress effects, neither before nor after anthesis, with few exceptions only. Yield depression due to heat stress was most severe when two heat waves were applied (−19%). This adverse effect was, however, compensated by CO2 enrichment. Applying heat stress before or after anthesis did not exert different effects on yield for both +4°C warming and heat wave application. However, +4°C depressed yield more than a heat wave at ambient CO2, but not so at elevated CO2. Thus, the interactive effects were complex and prediction of future wheat yield under CO2 enrichment and climate extremes deserves more attention.

Genotypic Variability on Grain Yield and Grain Nutritional Quality Characteristics of Wheat Grown under Elevated CO2 and High Temperature

“…The few experiments conducted to investigate the interactive effects of elevated CO 2 and high temperature reported that the stimulation of crop performance and yield by CO 2 enrichment was counteracted by increasing temperature [ 27 , 30 , 31 ]. Therefore, the exploration of genotypic variability might be a promising approach for the selection of improved crop varieties to ensure food security and the improvement of our knowledge on plant production and adaptation to future climatic conditions.…”

“…In spite of these grain improvements, a global trend towards lower grain quality in highly yielding agronomical conditions and modern cultivars has been reported since breeders are mainly selecting for grain yield but not grain quality [ 25 ]. To date, most of the studies have focused on the impact of elevated CO 2 and temperature on wheat productivity or quality under controlled and field conditions [ 9 , 20 , 23 , 26 , 27 ]. However, little attention has been paid to the combined effects of CO 2 enrichment and high temperature, together with the genotypic diversity, to explore the impact not only on grain yield but also on nutritional quality for human health.…”

Endogenous Hormones Inhibit Differentiation of Young Ears in Maize (Zea mays L.) Under Heat Stress

“…The "greenhouse effect" is becoming more intense, and rising temperatures have become a global problem affecting crop growth and yield. In recent years, frequent extreme weather and meteorological disasters have become the main factors restricting crop production (Högy et al, 2019). It has been predicted that the global temperature will increase by 1.5-6 • C in the future (Müller et al, 2017), causing the expectation that heat stress will become the main abiotic stress factor for crop production in times to come.…”

Effect of foliar spray of kinetin on the enhancement of rice yield by elevated CO2

“…Adaptation strategies are urgently required, but they need to be viable, ecological and environment‐friendly (Chen, Cui, et al., 2014; Yao et al., 2017). Among the various climatic variables that will likely change, atmospheric CO 2 concentration is projected to stimulate plant photosynthesis, plant net primary productivity and crop yields (Ainsworth, 2008; Bunce, 2017; De Costa et al., 2003; Hasegawa et al., 2013; Högy et al., 2019; Long, 2006; Masuya et al., 2020; Sakai et al., 2001; Wang et al., 2016), a phenomenon known as the CFE. Elevated CO 2 concentration will also increase the efficiency of using resources such as water and nutrients (Kimball, 2016), which could potentially reduce the environmental load from agriculture (Shokat et al., 2020).…”