In-Vitro Effect of some Commonly Found Botanicals on the Growth and Sporulation of Choanephora Cucurbitarum (Berkeley and Ravenel)

Abstract

A soft rot infection of Abelmoschus esculentus, Amaranthus hybridus and Vigna unguiculata was observed in home gardens and Government farms in the 2010 cropping season. This disease caused remarkable yield loss in these crops. Due to residual effects of synthetic chemical control, it became necessary to test the potency of some botanicals on the growth and  sporulation of the fungus as a control measure.  The  procedures involved isolation and identification of the fungus and potency trials of aqueous and ethanolic extracts of the  botanicals on the assay fungus. The isolated fungus was confirmed  as Choanephora cucurbitarum. The extracts were obtained from Zingiber officinale Roscoe, Gmelina arborea Roxb, Chromolaena odorata Linnaeus and Azadirachta indica A. Juss. Different concentrations of the extracts (0%, 10%, 20%, 30%, 40% and 50%) were used. With ethanol extract, there was complete inhibition of growth by all plant extracts and at all concentrations;  and a little growth in aqueous extracts with Azadirachta indica showing the highest inhibitory effect, while C. odorata showed the lowest inhibitory effect on the first day, (A. indica, 0.1 ± 0.0 ≥ G. arborea, 0.1 ± 0.0 ˃ Z. officinale, 0.2 ± 0.0 ˃ C. odorata, 0.3 ± 0.0). On the last day, the level of inhibition was as follows A. indica, 0.4 ± 0.0 ˃ G. arborea, 0.6 ± 0.0 ˃ Z. officinale, 0.7 ± 0.0 ≥ C. odorata 0.7 ± 0.0. The inhibitory effect increased with increase in the percentage concentration of the extracts. The  potency  was also due in part to the phytochemical constituents of the plant extracts which was observed from the screening test that Saponins, Tannins, Alkaloids, Cardiac glycosides, Flavonoids, Reducing Compounds, Polyphenol, Phlobatannins, Anthraquinones and Hydroxymethyl anthraquinones were either present or absent.

Ke words: Botanicals, Cross-River, Phytochemicals, Extract, Susceptibility.