Moderate heat stress prevented the observed biomass and yield stimulation caused by elevated CO in two well-watered wheat cultivars.

Heat stress (HS) under well-watered conditions was not detrimental to leaf photosynthesis or yield but modified the elevated CO response of photosynthesis and yield in two contrasting wheat cultivars. Climate change is increasing the frequency of extreme events such as heat waves, adversely affecting crop productivity. While positive impacts of elevated carbon dioxide (eCO) on crop productivity are evident, the interactive effects of eCO and environmental stresses are still unclear.

Does Elevated [CO] Only Increase Root Growth in the Topsoil? A FACE Study with Lentil in a Semi-Arid Environment.

Atmospheric carbon dioxide concentrations [CO] are increasing steadily. Some reports have shown that root growth in grain crops is mostly stimulated in the topsoil rather than evenly throughout the soil profile by e[CO], which is not optimal for crops grown in semi-arid environments with strong reliance on stored water. An experiment was conducted during the 2014 and 2015 growing seasons with two lentil () genotypes grown under Free Air CO Enrichment (FACE) in which root growth was observed non-destructively with mini-rhizotrons approximately every 2-3 weeks.

Early vigour in wheat: Could it lead to more severe terminal drought stress under elevated atmospheric [CO ] and semi-arid conditions?

Early vigour in wheat is a trait that has received attention for its benefits reducing evaporation from the soil surface early in the season. However, with the growth enhancement common to crops grown under elevated atmospheric CO concentrations (e[CO ]), there is a risk that too much early growth might deplete soil water and lead to more severe terminal drought stress in environments where production relies on stored soil water content. If this is the case, the incorporation of such a trait in wheat breeding programmes might have unintended negative consequences in the future, especially in dry years.

A reduced-tillering trait shows small but important yield gains in dryland wheat production.

Reducing the number of tillers per plant using a tiller inhibition (tin) gene has been considered as an important trait for wheat production in dryland environments. We used a spatial analysis approach with a daily time-step coupled radiation and transpiration efficiency model to simulate the impact of the reduced-tillering trait on wheat yield under different climate change scenarios across Australia's arable land. Our results show a small but consistent yield advantage of the reduced-tillering trait in the most water-limited environments both under current and likely future conditions.

Carbon sink strength of nodules but not other organs modulates photosynthesis of faba bean (Vicia faba) grown under elevated [CO ] and different water supply.

Photosynthetic stimulation by elevated [CO ] (e[CO ]) may be limited by the capacity of sink organs to use photosynthates. In many legumes, N -fixing symbionts in root nodules provide an additional sink, so that legumes may be better able to profit from e[CO ]. However, drought not only constrains photosynthesis but also the size and activity of sinks, and little is known about the interaction of e[CO ] and drought on carbon sink strength of nodules and other organs.