Yield reduction under climate warming varies among wheat cultivars in South Africa

Abstract

Understanding extreme weather impacts on staple crops such as wheat is vital for creating adaptation strategies and increasing food security, especially in dryland cropping systems across Southern Africa. This study analyses heat impacts on wheat using daily weather information and a dryland wheat dataset for 71 cultivars across 17 locations in South Africa from 1998 to 2014. We estimate temperature impacts on yields in extensive regression models, finding that extreme heat drives wheat yield losses, with an additional 24 h of exposure to temperatures above 30°C associated with a 12.5% yield reduction. Results from a uniform warming scenario of +1°C show an average wheat yield reduction of 8.5%, which increases to 18.4% and 28.5% under +2 and +3°C scenarios. We also find evidence of differences in heat effects across cultivars, which suggests warming impacts may be reduced through the sharing of gene pools amongst wheat breeding programs.

The fingerprints of climate warming on cereal crops phenology and adaptation options

“…Based on 1961–1990 data, they projected an increase of 2.8 °C in mean temperature of 2031–2060 and robust change in rainfall pattern and projected 16–20% yield reduction in response to the climate changes. Shew et al 99 studied climate-warming impact on 71 cultivars across 17 locations in South Africa from 1998 to 2014 through extensive regression models. The outcomes showed that heat drives wheat yield losses.…”

Multi-Environment Screening of Durum Wheat Genotypes for Drought Tolerance in Changing Climatic Events

“…is the 10th most commonly cultivated cereal worldwide and one of the most important food crops in the Mediterranean Rim with an important role in the human diet [1,2]. However, its production is threatened by climate change and extreme weather events [3][4][5]: North Africa, including Tunisia, is recognized as a climate change hotspot region [6][7][8] and is, therefore, particularly vulnerable to drought stress [9][10][11][12][13], which limits growth, development, and crop yield [14][15][16][17]. By 2030, Tunisia is expected to suffer from an annual average increase in temperature of 1.1 • C and thus an annual acute decrease in precipitation and water resources [6].…”

Adapting Agriculture to Climate Change through Growing Season Adjustments: Evidence from Corn in China

“…Farmers may adapt to a changing climate through adjusting the time they plant and harvest crops. Numerous hypothetical simulations have suggested that optimal adjustments in growing seasons would lead to substantial mitigation in yield losses under future climate (e.g., Ortiz‐Bobea and Just 2013; Kawasaki and Uchida 2016; Baum et al 2020; Shew et al 2020). However, these optimal rearrangements may not necessarily occur in reality due to various constraints farmers may face in achieving adaptation.…”

“…This article makes important contributions to the understanding of climatic impacts on agricultural production by providing the first causal estimate of temperature and precipitation effects on growing‐season adjustments. In the literature, some studies have shown large yield benefits of rearranging growing seasons through hypothetical simulations under projected future climate (e.g., Ortiz‐Bobea and Just 2013; Kawasaki and Uchida 2016; Baum et al 2020; Shew et al 2020). But these estimates correspond to a theoretically best scenario that does not necessarily occur in reality due to potential constraints.…”