Allelopathic potential of <i>Artemisia biennis</i> (biennial wormwood)

Abstract

In this study, Artemisia biennis was seeded in a greenhouse and raised to an average plant height of 100 cm. Aboveground plant portions were harvested and partitioned into leaves and stems, and dried; while roots were either removed from some soil (soil – roots) or left in soil (soil + roots). Greenhouse studies were conducted to evaluate the allelopathic potential of A. biennis leaves, roots, and stems; and soil – roots, and soil + roots on Solanum melanocerasum plant height and fresh weight plant –1 . When 5 g of root and stem biomass were added to soil, S. melanocerasum plant height and fresh weight plant –1 was reduced by 75 and 88%, respectively. In contrast, 5 g of leaf biomass caused an increase in S. melanocerasum plant height and fresh weight plant –1 by 35% and 43%, respectively; whereas, 20 g of leaf biomass depressed both variables by 50% and 65%, also respectively. Plant height was more suppressed when S. melanocerasum grew in soil – roots as opposed to soil + roots, whereas fresh weight plant –1 was similar between soil treatments. S. melanocerasum plant height was reduced by 70 and 55% when grown in soil – roots and soil + roots, respectively. In contrast, S. melanocerasum fresh weight plant –1 was reduced by 76% in both soil treatments. The reduction in S. melanocerasum plant attributes in this study is indicative of the allelopathic potential of A. biennis . Furthermore, A. biennis allelopathy is differenttially expressed among plant parts, primarily in roots. This may explain how A. biennis is capable of dominating a habitat once it becomes established. The presence of extractable compounds with herbicidal activity could increase the potential usefulness of A. biennis .