In which regions is the black knot fungus most commonly found?

The black knot fungus is primarily associated with temperate forests because it thrives in environments where its host trees, particularly certain species of cherries and plums, are found. Temperate forests provide the right climate conditions—moderate rainfall and varying seasonal temperatures—that facilitate the life cycle of the fungus.

In these forests, black knot infects the branches of susceptible trees, leading to the formation of characteristic dark, swollen galls that can disrupt tree growth and vitality. The presence of these host trees and the environmental conditions found in temperate regions make them the most conducive to the development and spread of this fungal disease.

While urban areas may have some occurrences of black knot due to landscaping that includes susceptible tree species, it is not the primary setting where the fungus proliferates. Desert regions and tropical rainforests do not support the life cycle of black knot fungus effectively due to their extreme conditions and the absence of suitable host trees. Thus, temperate forests remain the most commonly affected regions for this particular fungal pathogen.