Sunflower Head Rot Diseases: Sclerotinia Head Rot

Head rotting diseases of sunflower are particularly destructive due to their direct impact on the tissues of the head (capitulum, receptacle), which may result in loss of yield and reduction in seed or flower quality. This article focuses on Sclerotinia head rot, caused by Sclerotinia sclerotiorum, which is among the most yield-limiting diseases of sunflower globally. As Sclerotinia sclerotiorum is among the most common plant pathogen of many crops, we place emphasis on diagnostic techniques most relevant to sunflower and signs and symptoms that distinguish the disease from other sunflower head rots. This article is the fifth in a series of Diagnostic Guides on sunflower diseases, produced in an effort to improve identification, diagnostics and management of this globally important crop.