Effect of aqueous extract of the invasive species Tobacco (Nicotiana glauca L.) on seedlings growth of Juniper (Juniperus procera L.)

Abstract

This study was conducted to evaluate the allelopathic effects of aqueous extracts from different vegetative parts (root, stem, and leaf) of the invasive exotic species Nicotiana glauca on seedling growth of a native species Juniperus procera. Two concentrations of 5g/l and 20 g/l were employed in the treatment. Stem extracts of both concentrations increased the seedlings' mortality over 88%. Extracts had a negative effect on root dry weight (P=0.015) and root to shoot ratio (P=0.004). Root and leaf extracts showed different effects on seedling growth parameters such as total root length, root surface area, root volume, number of root tips, root dry weight, shoot dry weight, and root to shoot ratio . Leaf extract promoted growth with increasing concentration, while root extract deterred growth parameters.