EFFECT OF GARLIC (Allium sativum) EXTRACT ON FUNGAL SPOILAGE AND PRESERVATION OF ONION (Allium cepa) BULBS
Loading...
Date
2022
Journal Title
Journal ISSN
Volume Title
Publisher
Nigerian Journal of Mycology
Abstract
The study investigated the occurrence and virulence of some fungal pathogens
causing rot of onions. Antifungal potentials of garlic extract against these fungi and
its effects on shelf life were also studied. Ten percent aqueous garlic extract was
used in fungal growth inhibition of artificially inoculated onion bulbs as well as
whole bulb preservation experiments and sterile distilled water served as control in
both experiments. Results showed that Aspergillus niger, A. niger, Penicillium and
Rhizopus sp occurred in rotting onion bulbs and Aspergillus niger was found to be
the most virulent, having a mean rot diameter of 1.94mm, followed by A. flavus (0.42
mm), Rhizopus sp (0.15 mm), while Penicillium sp was the least virulent in causing
rot in the bulbs, with 0.12 mm. Onion bulbs inoculated with blank agar disc showed
no rot symptoms. There were significant differences between the control and treated
samples at p<0.05. Garlic extract was effective in inhibiting mycelial growth of all
fungal pathogens in the pretreated onion bulbs (Aspergillus niger (2.84 mm),
Aspergillus flavus (1.61 mm), Penicillium (0.48 mm) and Rhizopus spp ( 0.54 mm)
and were significantly lower than control at p<0.05. Whole onion bulbs (treated and
control) remained healthy without any sign of rot until 4 weeks after storage however,
mean rot reduction of 58% was observed in onion bulbs treated with 10% garlic
extract at 9 weeks after storage. The untreated (control) samples developed rot
symptoms after four weeks of storage. Garlic extract could be used to elongate shelf
life of onions due to its antifungal and preservative potentials.