Clement U. Okeke, Chisom F. Iroka and Chukwu N. Okereke
The comparative effect of crude leave extract of Moringa oleifera on germination and growth of Amaranthus spinosus and Amaranthus hybridus was studied. The plants seeds selected were planted in polyethylene bags filled with loamy soil, different extract concentrations of 5%, 10% and 15% were obtained from the leaf of M. oleifera using manual extraction method. The plants were well watered with the extracts of three different concentrations and allowed to grow under natural environmental condition. Parameters measured include: weekly height of plants, number of leaves produced by each plants at the end of the week, weekly stem girth and weekly leaf area of plant. The study showed that the extract of Moringa oleifera had negative effect on the growth of Amaranthus spinosus and Amaranthus hybridus. The effect was significantly higher at higher concentrations of the extracts. Moringa oleifera extract significantly reduced the leaf number, leaf area, stem height, fresh weight and dry weight in Amaranthus spinosus and Amaranthus hybridus when compared to those of the control. Additionally, the germination of Amaranthus spinosus and Amaranthus hybridus were delay considerable to the fourth and fifth weeks and in some replicate no germination was observed. The study further showed that the sensitivity of Amaranthus spinosus and Amaranthus hybridus to plant extracts differ. From the study Moringa oleifera had more negative effect on Amaranthus spinosus, hence, revealing more inhibitory activity on the growth of Amaranthus spinosus than on Amaranthus hybridus.
