Antimicrobial and phytotoxic properties of Conyza bonariensis

Abstract

The present study was conducted to evaluate Conyza bonariensis for its antimicrobial and phytotoxic potentials. The crude methanolic extract and its subsequent solvent fractions were tested for its antibacterial, antifungal and phytotoxic effects. Regarding the antimicrobial effect, tested samples were effective against Escherichia coli, Pseudomonas aureginosa, Klebsella and the rest bacteria showed resistance against all the tested samples. The chloroform and ethyl acetate fractions showed maximum activity with zone of inhibition 14 and 13 mm, while the n-hexane fraction was not effective at lower dose. The standard drug (streptomycin) was far most effective than the tested extracts having zone of inhibition 35 mm. The maximum fungicidal effect against Cladosporium cucumerinum was demonstrated by ethyl acetate followed by chloroform and crude extract with percent inhibitory activity of 38, 32 and 29 respectively. The ethyl acetate fraction was also most effective against Candida albicans with percent activity of 35 followed by chloroform and crude methanolic extract with percent inhibitory effect of 28 and 25. The maximum phytotoxic effect was produced with chloroform fraction followed by ethyl acetate with LD₅₀ values 16.6 and 17.78. On the basis of the present research work, Conyza bonariensis is recommended for its antimicrobial and phytotoxic effect.

Keywords: Conyza bonariensis, antibacterial, antifungal, phytotoxic.