Italian farmers annually produce 700 million tons of pears, which require protection with fungicides from a disease known as brown spot. The fungus overwinters in leaf litter on the orchard floor and spores are released in the spring under wet conditions. Spots appear on the fruit and internal rots occur as the result of fungal invasion. Severe outbreaks can result in defoliation of the pear tree and fruit dropping off the tree.

“Stemphylium vesicarium is the causal agent of brown spot, the main fungal disease of pear in Italy since the late 1970s. … Many pear orchards in Po valley, the main pear growing area in Italy, are affected by this fungal disease that may cause heavy loss of production, up to 100%. … Besides some cultural practices, scheduled preventative applications of dithiocarbamates, dicarboximides, strobilurins and tebuconazole (DMI) from petal fall to fruit ripening are the only way to control the disease.”

Authors: G. Alberoni, M. Collina, D. Pancaldi and A. Brunelli
Affiliation: University of Bologna
Title: Resistance to dicarboximide fungicides in Stemphylium vesicarium of Italian pear orchards.
Publication: European Journal of Plant Pathology. 2005. 113:211-219.