Penicillium digitatum, Penicillium italicum (Green Mold, Blue Mold)

Abstract Green and blue molds, caused by the pathogens Penicillium digitatum and Penicillium italicum, respectively, are the most economically important postharvest diseases of citrus fruit in all production areas with low summer rainfall. Both fungi are strict wound pathogens that affect all citrus species and cultivars and can infect the fruit in the field, the packing house, and during distribution and marketing. Taxonomy and morphology of the pathogens and factors that can influence fruit infection and disease development are described in this chapter. Penicillium digitatum is the first phytopathogenic Penicillium species whose complete genome has been entirely sequenced. Implications of basic and applied research on host–pathogen interactions and disease control strategies are discussed. Conventional control with postharvest chemical fungicides like imazalil and alternative non-polluting physical, low-toxicity chemical and biological control methods are reviewed. Emphasis is given to advances developed over the last few years. Satisfactory disease control relies on an integrated disease management (IDM) approach in which all preharvest, harvest and postharvest factors are considered.