Submitted to: Crop Protection Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/4/2017
Publication Date: 3/10/2017
Citation: Dugan, F.M., Lupien, S.L., Armstrong, C.M., Chastagner, G., Schroeder, B.K. 2017. Host ranges of Penicillium species causing blue mold of bulb crops in Washington State and Idaho. Crop Protection Journal. 96:265-272. Interpretive Summary: Blue mold of edible and ornamental bulb crops is a serious postharvest disease caused by fungi in the genus Penicillium. Originally attributed to single causal agent, Penicillium corymbiferum (= P. hirsutum), the disease is now known to be caused by several different species in genus Penicillium. However, the host range of each of the species is ill-defined, especially in North America. Edible and ornamental bulbs were artificially inoculated with isolates of blue mold recovered from the Pacific Northwest, USA. It is clearly demonstrated that these isolates, each representative of a given Penicillium species, differ significantly in host range and virulence (aggressiveness). Several instances comprise first reports of a given species of Penicillium causing blue mold of bulbs in North America.
Technical Abstract: First reported from the Pacific Northwest (PNW) of U.S.A. as causal agents of blue mold on edible and/or ornamental bulbs are Penicillium albocoremium (from Tulipa sp.; pathogenic on Allium sativum, A. cepa, A. stipitatum, Iris hollandica and Tulipa sp.), P. crustosum (from Narcissus; pathogenic on A. cepa and I. hollandica), P. paraherquei (from A. cepa; pathogenic on A. sativum and A. cepa), and P. radicicola (from Iris Casablanca; pathogenic on A. sativum, A. cepa and I. hollandica). Penicillium expansum and P. glabrum, from A. cepa, were verified as pathogens of A. sativum, A. cepa and Iris hollandica, and P. expansum was also pathogenic on Tulipa sp. Pronounced differences between Penicillium agents of blue mold in host range and in virulence have implications for crop rotation, postharvest storage and marketing.