Fungal species composition and abundance on stored corn as influenced by several management practices and maize weevil (Coleoptera: Curculionidae)

Abstract

The purpose of this study was to examine the effect of several management tactics and Sitophilus zeamais Motschulsky (maize weevil) on fungal species composition and abundance on stored corn (maize). The most abundant fungi isolated from Pioneer hybrids 3378 and 3320 were Fusarium sp., Penicillium spp., Rhizopus sp., Aspergillus glaucus and A. flavus. High temperature (36 °C) inhibited the growth of Fusarium sp., Penicillium spp., Rhizopus sp. and A. flavus, while the growth of A. glaucus increased. Low initial kernel moisture content (9.7%) appeared to inhibit the growth of some fungi ( Fusarium sp. and A. glaucus) while the growth of others ( Penicillium spp. and A. flavus) increased. Surface disinfection with bleach reduced populations of Penicillium, Rhizopus, A. glaucus and A. flavus, while permitting an increase of Fusarium. Biotic factors also exert considerable control over fungal populations. Hybrid selection affected all major species except Fusarium. The mere introduction of maize weevils, even when killed within 24 h by malathion, increased the abundance of Penicillium spp. and A. glaucus.