VIEW ARTICLE

Postharvest Pathology and Mycotoxins

Aspergillus Colonization of Indian Red Pepper During Storage. M. Seenappa, Graduate student, Department of Biology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1; L. W. Stobbs(2), and A. G. Kempton(3). (2)(3)Assistant professor, and associate professor, respectively, Department of Biology, University of Waterloo, Waterloo, Ontario, Canada N2L 3G1. Phytopathology 70:218-222. Accepted for publication 10 September 1979. Copyright 1980 The American Phytopathological Society. DOI: 10.1094/Phyto-70-218.

The mycoflora on the surface of dried red pepper from India included several Aspergillus spp. When stored at 70% relative humidity (RH) in an incubator at 28 C for 10 days only members of the A. glaucus group developed. Infection sites, subsequent penetration, and eventual colonization of stalks, pods, and seeds were observed by scanning electron microscopy. Germ tubes from conidia gained entry to the stalks through stomata. Infection of pods occurred through crevices caused by mechanical damage. This was followed by colonization of the inner fruit wall. Healthy, intact seeds were susceptible to A. halophilicus which invaded via appressoria and infection pegs. When peppers were stored under high relative humidity, the predominant fungal species changed completely. A. flavus and A. ochraceus predominated at 85% RH, whereas A. flavus alone predominated at 95% RH. Aflatoxin production correlated with A. flavus growth during storage and is thus a function of relative humidity. Extent of colonization of the surface of the pepper pods was related to the relative humidity of storage; no surface growth was observed at 70% RH. The surface of the pepper pods supported visible growth of hyphae and conidiophores developed only after storage at 85 and 95% RH.