Effects of crude extracts of <i>Aspergillus fumigatus</i> and <i>Penicillium citrinum</i> on the biomass of <i>Eleusine indica</i> (L.) Gaertn

Abstract

In a pot experiment, two fungal strains namely Aspergillus fumigatus and Penicillium citrinum were evaluated for their herbicidal properties on the biomass of Eleusine indica using the biomass reduction method. Crude extracts of Aspergillus fumigatus and Penicillium citrinum made up of 10 treatments at three levels each with positive and negative controls in three replications in a Completely Randomised Block Design was adopted. Infections were evident within 48 hours after the application of the various treatments. At 1, 3, 5 and 7 days after application of the treatments, the percentage biomass yields and biomass reductions of E. indica were determined. The data collected were subjected to analysis of variance and the means separated using Duncan Multiple Range Test. The percentage reductions in biomass yields (88.46% and 35.61%) of Eleusine indica especially at the highest inocula concentration (1010 spores/ml) of the crude extracts showed significant differences (p≤ 0.001). The results indicate that both crude extracts possess the potentials for herbicidal control of Eleusine indica with evidence that the concentrated crude extracts of Aspergilus fumigatus had the greatest impact on its biomass yields. Therefore, it is recommended that further work be carried out on the purification of both crude extracts to confirm the effective biological metabolites accountable for their herbicidal properties and also evaluate these herbicidal properties on other weed species adopting different time and methods of application.

Keywords: Fungal strains, Herbicidal properties, Biological metabolites, Concentrated crude extracts, Biomass yields and Biomass reductions