Allelopathic Effects of L. Leaf Aqueous Extracts on Germination and Seedling Growth of L. and L

Allelopathy is the chemical interactions between plants that might lead to either stimulation or inhibition of growth, community structure, and plant invasions. L. is a noxious invasive weed that negatively affects seed germination, seedling growth, and increases the mortality of the crop plant. The objective of this work was to assess allelopathic effect of leaf aqueous extract on germination and seedling growth of (pepper) and (carrot). The aqueous extract of Lantana leaf samples was used as a source of allelopathic effects. Data were collected for germination and seedling growth parameters. The result indicated that the highest concentration of the allelopathic extract (20 mg/L) has demonstrated significantly the highest germination inhibition rate GIR (60.00%), germination speed V (2.54 U/day) for as GIR (70.00%), mean germination time MGT (0.36 days), and GI (0.67%) for seeds. The highest concentration of the allelopathic extract (20 mg/L) has recorded the highest plumule inhibition rate PIR (59.63%) and radical inhibition rate RIR (48.95%) for seeds, as well as PIR (27.47%) and RLR (79.49%) for . The largest negative allelopathic index (-60.00% or allelopathic intensity of 60.00%) was recorded for seeds, whilst (-63.43% or allelopathic intensity of 63.43%) was recorded for seed germination. For seed germination, the first principal component (PC1) has got high positive loads from GI (0.36), RLR (0.31), GR (0.34), allelopathic index AI (0.34), relative length of plumule RLP (0.24), and V (0.30). By contrast, PC1 for seed germination has got the highest negative component loads recorded by GIR (-0.34), PIR (-0.24), MGT (-0.35), and RIR (-0.31). In allelopathic effect on seed germination, the first principal component (PC1) has got high positive scores from relative length of radical RLR (0.31), RLP (0.33), germination rate GR (0.33), V (0.33), and AI (0.33). Likewise, the high negative component loads were recorded by GIR (-0.33), PIR (-0.33), RIR (-0.31), and MGT (-0.32). The result of the present study demonstrated that GIR, PIR, and RIR were directly related to negative allelopathic activity.