Relative Aggressiveness of Aspergillus flavus and A. parasiticus on Maize in Mississippi. Natale Zummo, USDA-ARS and Mississippi State Agricultural and Forestry Experiment Station, Mississippi State, MS 39762. G. E. Scott, USDA-ARS and Mississippi State Agricultural and Forestry Experiment Station, Mississippi State, MS 39762. Plant Dis. 74:978-981. Accepted for publication 15 May 1990. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1990. DOI: 10.1094/PD-74-0978.

Aspergillus flavus and A. parasiticus were equally aggressive for colonization of field-grown maize (Zea mays) kernels after inoculation of ears. The incidence of infection was higher after pinbar inoculation than after needle inoculation. Uninoculated cobs that overseasoned in the field during 1986–1987, 1987–1988, or 1988–1989 contained predominantly A. flavus. Moreover, sclerotia of A. flavus, but not of A. parasiticus, were found in the pith tissues of the cobs. Thus, A. flavus appears to have a greater capacity for survival in maize cob debris than does A. parasiticus. Conidia populations of A. flavus were higher than those of A. parasiticus in maize fields when ears were developing. Therefore, A. flavus may have greater potential than A. parasiticus for serving as inoculum for natural infection of maize kernels.