A review of climate change impact on canola physiology and yield in Mediterranean-type climates: Challenges and opportunities for the Western Cape

Abstract

Climate change is reshaping canola (Brassica napus L.) production by altering physiological responses and yield outcomes through rising atmospheric carbon dioxide (CO₂), increasing temperatures and shifting rainfall patterns. Canola is an important cash crop valued for its agronomic and economic benefits in crop rotations. However, increasing climatic variability threatens yield stability, particularly in Mediterranean-type climate systems. This review assesses how elevated CO₂, higher temperatures and changes in water availability individually affect canola physiology, phenology and yield. Web of Science™ and CAB Abstracts® were used with complementary keywords linking climate drivers to canola physiology and yield. Thirty articles met inclusion and were narratively reviewed, with effects on key physiological and yield parameters classified as positive, neutral or negative. Elevated CO₂ enhances photosynthetic capacity, water-use efficiency and biomass accumulation. Moderate warming may improve early growth and reduce frost risk in cooler regions, while excessive heat during reproduction reduces pollen viability, seed yield and oil concentration. Declining and increasingly variable rainfall further restricts these characteristics. Adaptation measures such as cultivar selection, optimised sowing dates, conservation and precision agriculture, and breeding for stress tolerance will be critical to maintain yield and quality under future climates.