The allelopathic effects of three crop residues on the germination and radicle length of Sphenostylis sternocarpa Hochst Ex. Rich. (African Yam Bean)

Abstract

The allelopathic effects of aqueous extracts of Cajanus cajan stem, Maize inflorescence and Rice husk were examined on the germination and growth of Sphenostylis sternocarpa, an important indigenous pea in South Western Nigeria. The three crop extracts inhibited the germination and the lengths of radicle of this crop. The inhibition was concentration dependent as no germination was observed in the extract–treated seeds until 72 hrs of the experiment. Analysis of the germination revealed that there were no significant (P > 0.05) differences on the effects of extracts from the three crop residues on Sphenostylis sternocarpa at 24 hrs and 48 hrs experimental times when compared to the control experiment. At 72 hrs, there were no significant differences on the effects of Cajanus cajan stem and rice husk treated seeds when compared to the control experiment but the seeds treated with extracts from the maize inflorescences showed significant differences when compared to the control. No growth was recorded in the radicle until 96 hrs of the experiment in all the extract – treated seeds from the three crop residues while the control germinated at 72 hours.

Keywords: Allelopathy, allelochemical, biomolecules, Sphenostylis sternocarpa, inhibition, radicle.