Abstract
Considering that southern Africa is warming twice as fast as the global average, climate change poses a serious threat to food security in the region. Adaptation measures must account for how climate change may impact maize development during critical stages. An analysis of climate change impacts on dryland maize phenology was conducted in Bloemfontein and Lichtenburg. The climate projections generated by six Global Climate Models under the Representative Concentration Pathways (RCP) 4.5 and 8.5 were used. Analyses were performed for four representative planting dates: November 15 (early), December 15 (optimal), January 15 (late), and February 5 (very late). Days to maturity decreased (by approx. 5-10 days) as years progressed from the baseline period (1991-2020) to the far future period (2051-2080), at both locations with higher rates projected under RCP 8.5. This study suggests that longer summers with receding freeze dates in these regions might improve adaptability. Climate change will likely affect both the vegetative and reproductive stages of maize, decreasing the days to maturity at optimal planting dates. The number of days above 35°C at the optimal planting date is expected to increase by 20%–30% as climate change progresses, which limits grain filling and yield. As planting dates were delayed, the days to maturity of maize in both regions decreased, trending towards the optimal number of days to maturity (100-110 days). Coupled with the receding freeze date projected under future climates, planting may shift later in the region.
Presenters
Robert ManganiLecturer, Plant and Soil Sciences, University of Pretoria, Gauteng, South Africa
Details
Presentation Type
Paper Presentation in a Themed Session
Theme
Assessing Impacts in Diverse Ecosystems
KEYWORDS
CLIMATE CHANGE, EXTREME TEMPERATURES, GROWING DEGREE DAYS, HEAT STRESS, CORN
