Botrytis: what it is, how it develops, and how to effectively eliminate it from fruit

Botrytis cinerea is a widespread phytopathogenic fungus and one of the main agents responsible for rot in numerous crops. It is a necrotrophic fungus, capable of colonizing living plant tissues and obtaining nutrients as it causes the death of infected cells. It can develop on a wide variety of plant debris and plant organs, where it produces abundant mycelium and reproductive structures. Dispersal occurs primarily through conidia, which are produced in large quantities on affected tissues and can be transported by air currents, water splashes, rain, tools, insects, and tissue contact. Conidia can remain on plant surfaces until they find favorable conditions for germination. Germination and subsequent infection are especially favored by the presence of free water or very high ambient humidity and moderate temperatures. Penetration can occur directly through susceptible tissues, but wounds, cuts, abrasions, insect damage, and weakened tissues constitute important entry points. Once infection begins, the fungus develops hyphae that spread through the tissues, progressively destroying plant cells and causing necrotic and subsequently rotten areas. On infected tissues, it can produce new conidiophores and conidia, generating a continuous source of inoculum capable of colonizing other plant organs. Botrytis cinerea can also survive unfavorable periods through resistant structures, especially sclerotia, and through mycelium present in infected plant debris. Crop debris, affected fruit, and dead tissue can act as important reservoirs of the fungus between growing seasons. The disease can develop rapidly when moderate temperatures, high humidity, poor ventilation, and prolonged water exposure on the tissues coincide. Therefore, removing infected tissues, reducing humidity, and preventing wounds are essential to limiting the production and spread of inoculum.