Fungi are the most significant and
predominant pathogens infecting a wide range of host
plants and causing economically important losses to crop
produce in transit and storage. In this study, fungi
associated with postharvest rot of onion bulbs and their
effects on the proximate composition was investigated.
Diseased onion bulbs were obtained from three markets
around Lagos State University, Ojo Nigeria. Potato
Dextrose Agar (PDA) and Malt Extract Agar (MEA)
were used for isolation. Pathogenicity test was conducted
to determine the causal organism(s) from isolated fungi.
Proximate analysis was carried out on infected onion
bulbs to ascertain the effects of fungi on the moisture,
ash, crude fat, protein and ascorbic acid contents. The
fungi isolated from the bulbs were Aspergillus flavus,
Aspergillus niger, Rhizopus sp. and Penicillium sp.
Pathogenicity tests showed that all isolated fungi induced
disease symptoms when inoculated on healthy onion
bulbs. The fungi were found to cause an increase in the
moisture content of the bulbs and a general reduction in
the nutritional composition of the bulbs.
Keywords : Onion Bulbs, Postharvest Rot, Fungal Pathogens, Nutritional Composition.