Sclerotinia sclerotiorum is the causal agent of Sclerotinia stem rot on peanut (groundnut) in South Africa

Abstract

Sclerotinia stem rot on South African groundnut was previously attributed to Sclerotinia minor, but recent infections prompted a re-evaluation. Isolates underwent a species-specific PCR and phylogenetic analysis, confirming them as S. sclerotiorum. Koch’s postulates were fulfilled, demonstrating pathogenicity. Inoculation caused disease symptoms, with subsequent re-isolation matching the original strains. This study identifies S. sclerotiorum as the causative agent of Sclerotinia stem rot on groundnut in South Africa.