The allelopathic effects of selected weeds species on germination and growth of maize

Abstract

In Southeastern Nigeria, weeds such as Chromolaena odorata, Ageratum conyzoides, Eleusine indica, Tridax procumbens and Euphorbia hirta thrive. The decaying remnants of these weeds left on or in the soil have been found to contain a variety of chemical compounds. The effect of aqueous leaf extracts of these weeds on Zea mays seed germination and growth was investigated. Results of this study showed that plant species and their concentrations had a significant effect (p<0.05) on the parameters measured. The root length of Z. mays was more affected negatively by Chromolaena odorata than the other weed species. The inhibition of Zea mays seed germination by the studied aqueous extracts was as follows: Tridax procumbens (27.33%) > Euphorbia hirta (26.16%) > Ageratum conyzoides (23.45%) > Eleusine indica (22.42%) and Chronolaena odorata (18.73%). Eleucine indica had more inhibitory effect on shoot length (42.83%), seedling length (41.70%) and seedling vigour index (51.79%) of Zea mays. This was compared to aqueous leaf extract of Chromolaena odorata, Ageratum conyzoides, Tridax procumbens and Euphorbia hirta. The results suggest that potential allelopathic substances produced by studied weed species may hinder germination and growth of Zea mays.