This paper presents the sixty-sixth annual review of the milling season in Southern Africa, focusing on performance data from sugar mills across multiple countries. It analyzes trends in cane quality, sucrose percentage, extraction rates, and sugar quality. The study discusses the impact of weather and crop conditions on the 1990-1991 season, highlighting challenges faced due to dry periods, mild winters, and heavy rain. The document emphasizes the importance of cane quality and its correlation with processing efficiency and sugar quality.