Chapter 6 - Penicillium expansum (Blue Mold)

Abstract

Blue mold disease, caused by Penicillium expansum (Link), is the most economically important postharvest disease of fruit and vegetables in storage. In addition to causing food spoilage, some strains of the fungus produce the mycotoxin, patulin. In this chapter, pre- and postharvest factors that affect the incidence of blue mold development are discussed. Synthetic fungicides provide control of blue mold disease and the resistance development in P. expansum to benzimidazole fungicides in the 1980s has led to the search for novel reduced-risk fungicides, biological control agents (BCA) and other control alternatives. To address the barriers that limit the efficacy of conventional and biological control methods, future research and implementation should focus on developing integrated disease management strategies that combine conventional and biological control systems with one or more of the physical, chemical, biological and genetic control methods, to provide effective management of postharvest blue mold. This chapter will examine the nature of the postharvest pathogen, P. expansum and the blue mold disease it causes in fruits and vegetables, factors affecting infection before harvest, at harvest and postharvest, and conventional and alternative methods for controlling the pathogen and the blue mold disease in storage. The literature search indicates that blue mold disease in apples and P. expansum have been thoroughly studied because of their economic importance in horticulture and the ability of some strains to produce the mycotoxin, patulin, that affects humans, however, other P. expansum and crop combinations have been less intensely studied.