BotrytisSclerotinia

BotrytisSclerotinia is an informal term used in plant pathology to refer collectively to two major groups of necrotrophic fungal pathogens: Botrytis and Sclerotinia. The most important species in each group are Botrytis cinerea and Sclerotinia sclerotiorum. Both genera have a very broad host range and are responsible for economically significant diseases in fruit, vegetables, ornamentals, and field crops worldwide.

Botrytis cinerea, commonly called gray mold, infects flowers, fruits, leaves, and stems, often under wet or humid conditions. Symptoms include a fuzzy gray-brown mold, water-soaked lesions, and decay, frequently progressing during storage or transport. Sclerotinia sclerotiorum causes white mold or Sclerotinia stem rot, producing dense white mycelium on plant surfaces and, under favorable conditions, black, hard sclerotia that survive in crop debris and soil.

Life cycles differ in detail but share key features. Sclerotinia overwinters as sclerotia in plant debris or soil and releases apothecia in spring that discharge ascospores, initiating infection when tissues are wet. Botrytis overwinters in plant material and may form sclerotia; conidia are produced on infected tissues and spores require free moisture to infect a wide range of hosts.

Management relies on integrated practices: cultural controls such as sanitation, removing infected debris, crop rotation, and managing canopy air flow and irrigation to reduce leaf wetness; timing and choice of fungicides, resistance management, and, where available, biological control agents. Both pathogens remain persistent threats in greenhouses and field production, especially under humid, moderate-temperature conditions.