High night temperatures during grain number determination reduce wheat and barley grain yield: a field study

Abstract

Warm nights are a widespread predicted feature of climate change. This study investigated the impact of high night temperatures during the critical period for grain yield determination in wheat and barley crops under field conditions, assessing the effects on development, growth and partitioning crop-level processes driving grain number per unit area (GN). Experiments combined: (i) two contrasting radiation and temperature environments: late sowing in 2011 and early sowing in 2013, (ii) two well-adapted crops with similar phenology: bread wheat and two-row malting barley and (iii) two temperature regimes: ambient and high night temperatures. The night temperature increase (ca. 3.9 °C in both crops and growing seasons) was achieved using purpose-built heating chambers placed on the crop at 19:000 hours and removed at 7:00 hours every day from the third detectable stem node to 10 days post-flowering. Across growing seasons and crops, the average minimum temperature during the critical period ranged from 11.2 to 17.2 °C. Wheat and barley grain yield were similarly reduced under warm nights (ca. 7% °C(-1) ), due to GN reductions (ca. 6% °C(-1) ) linked to a lower number of spikes per m(2) . An accelerated development under high night temperatures led to a shorter critical period duration, reducing solar radiation capture with negative consequences for biomass production, GN and therefore, grain yield. The information generated could be used as a starting point to design management and/or breeding strategies to improve crop adaptation facing climate change.

Space Distribution of Highland Barley GNS and its Relationship with Environmental Factors in the Qinghai-Tibet Plateau

“…This study is basically identical with the results of Du et al (2002;Chalak et al, 2015;Ugarte et al, 2007). However, Guillermoa et al (2015) thought night temperature increased in the reproductive growth period of barley, GNS decreased; Reinhardt et al (2013) thought the night temperature was about 30°C in the reproductive growth period of barley, GNS decreased significantly. The effect of climate factors on barley GNS is relatively complex, interaction of multiple factors makes a single factor analysis more difficult.…”

“…Night temperature increase influences the accumulation of dry matter; extreme high temperature influences pollination and spikelet differentiation and then affects GNS. The research results of Guillermoa et al (2015;Reinhardt et al, 2013) have no contradiction; on the contrary, large temperature difference in the Qinghai-Tibet Plateau provides corresponding basis for the increase of highland barley GNS. Högy et al (2013) thought that barley plant in Stuttgart, Germany, temperature had no significantly effect on barley GNS, which is inconsistent with most research results.…”

Challenges and Responses to Ongoing and Projected Climate Change for Dryland Cereal Production Systems throughout the World

“…Positive benefits of adaptation are also predicted, offsetting expected declines in wheat, maize, and rice yield globally by 7-15% [92]. There is agreement across simulation, controlled environment, and field experiments that the grain yield of wheat is expected to decrease 5-6% • C −1 despite including the additional benefits of CO 2 fertilization [3,11,[93][94][95]. There is, however, little information about the sensitivity of wheat during its various phenophases and the impact of projected higher night temperatures.…”

Interannual-to-multidecadal Hydroclimate Variability and its Sectoral Impacts in northeastern Argentina

“…The increase of minimum temperature results in increased wheat and barley respiration rates and shorter grain filling period diminishing their yields (Magrin et al, 2009;Verón et al, 2015). According to García et al (2015), wheat and barley yields were reduced under increased minimum temperatures by 7% without considering technological improvements. The life cycle of maize has been 15 affected by fewer frost events that allow early planting dates (Maddonni, 2012).…”