EFFICACY OF GARLIC (Allium sativum) BULB AND GINGER (Zingiber officinale) RHIZOME EXTRACTS IN CONTROLLING SEED-BORNE FUNGI OF RICE (Oryzae sativa)

The efficacy of garlic bulb and ginger rhizome extracts were tested in-vitro at different concentrations against four seed-borne fungi (Aspergillus flavus, Bipolaris oryzae, Curvularia lunata and Fusarium moniliforme) isolated from rice. Bulbs of garlic and rhizomes of ginger were blended with distilled water to make 60% w/v and 40% w/v concentrations of botanical extracts. Surface of Potato Dextrose Agar plates were coated with 2 mls of the botanical extracts and sterile distilled water (control), inoculated with disc of the fungal isolates (8 mm) and incubated at 28°C. The mycelial growth of the fungi was measured at 24, 48, 72, 96 and 120 hour periods to determine the rate of growth of the fungi on the coated plates. Statistically, mycelial growth of test fungi on plant extract-coated plates were different from the control. Both extracts at 60% w/v and 40% w/v concentrations were able to inhibit mycelia growth of all four test organisms. Garlic bulb extracts performed better in their inhibitory abilities than ginger extracts (P <.001). Among the botanical extracts, 60% w/v of garlic extract was observed to be the most effective whilst 40% w/v of ginger was the least efficacious. Potencies of these botanical extracts can thus be used to develop a technology or product to treat rice seed to manage diseases in rice production.