Mycoblastaceae

The Mycoblastaceae family consists of lichenized fungi belonging to the order Lecanorales. It is crucial for agricultural professionals to distinguish these organisms from plant pathogens. Unlike fungi that cause crop diseases, Mycoblastaceae are symbiotic lichen associations that do not harm the host plants they colonize.

These organisms primarily function as epiphytes, inhabiting the bark of trees as a physical substrate. They do not penetrate the inner tissues of the tree or extract nutrients from the plant. Instead, they derive their nutrition from atmospheric moisture, minerals found in dust, and photosynthesis via their algal partners, posing no threat to the vitality of orchards.

From an ecological standpoint, the presence of these lichens can be interpreted as an indicator of good air quality, as they are often sensitive to high levels of industrial pollution. In modern agronomy, they are not classified as a disease, and their presence on bark should not trigger the use of pesticides or aggressive chemical treatments intended for parasitic fungi.

Symptoms of their presence include the development of crustose or squamulose thalli on tree trunks and branches. These growths appear as grey, yellow, or brown patches. Unlike parasitic diseases such as apple scab or cytospora canker, these lichens do not cause tissue necrosis, wilting, or structural decay of the host plant.

Management practices for managing excessive lichen cover are primarily centered on orchard maintenance. Strategies include proper pruning to improve air circulation and sunlight penetration, which naturally discourages lichen colonization. Whitewashing trunks with lime is a traditional and effective method that modifies the surface pH of the bark, preventing lichen establishment without harming the tree.