Lachnum

Lachnum is a genus of ascomycete fungi that are primarily recognized as saprotrophs but can also function as weak pathogens on weakened plant tissues. In agricultural and forest pathology, they are often observed causing bark necrosis and the dieback of small stems and twigs, particularly in stressed or damaged specimens.

The host range of Lachnum includes various woody plants, shrubs, and sometimes perennial herbaceous species. These fungi tend to colonize tissues that have been previously compromised by environmental stress, insect feeding, or mechanical damage, exploiting the weakened physiological state of the host to establish their mycelium.

The primary diagnostic sign of the infection is the formation of small, often hairy, cup-shaped apothecia on the surface of the bark or stem. These fruiting bodies can be white, yellow, or orange in color. Infected areas typically show discoloration, cracking of the bark, and eventual necrosis, leading to the wilting and death of distal plant parts.

Development and spread of Lachnum are favored by high humidity and the presence of surface moisture. The fungi reproduce via spores that are easily dispersed by wind and rain splashes. Dense, poorly ventilated planting sites create an ideal microclimate for the rapid colonization of susceptible plant materials during wet seasons.

Prevention and control strategies focus on maintaining optimal plant health and hygiene. Essential measures include:

• Regular pruning of dead or infected branches.
• Removal and destruction of infected plant debris.
• Improvement of air circulation within the canopy.
• Application of balanced fertilizers to boost natural resistance.
• Use of fungicides in nursery settings to mitigate severe outbreaks.