Allelopathic Effect of Lantana camara L. Leaf Aqueous Extarcts on Germination and Seedling Growth of Capsicum annuum L. and Daucus carota L.

Abstract

Allelopathy is the interactions between plants that might lead to either stimulation or inhibition of growth. Lantana camara is a noxious invasive weed. The objective of this work was to assess allelopathic effect of Lantana camara leaf aqueous extract on germination and seedling growth of Capsicum annuum and Daucus carota. The aqueous extract of L. camara leaf sample was used as a source of allelopathic effects. The C. annuum and D. carota seeds were used for experimental testing of allelopathic effects. Data were collected for germination and seedling growth parameters including germination rate (GR); germination inhibition rate (GIR); mean germination time (MGT); germination index (GI); Relative length of plumule (RLP); germination speed (V); relative length of radicle (RLR); plumule inhibition rate (PIR); radicle inhibition rate (RIR); allelopathic index (AI). The result indicated that the highest concentration of the allelopathic extract (20 mg/L) has demonstrated significantly the highest GIR (60.00%), germination speed (2.54 U/day) for D. carota as GIR (70.00 %), MGT (0.36 days) and GI (0.67 %) for C. annuum seeds. The highest concentration of the allelopathic extract (20mg/L) has recorded the highest PIR (59.63%), and RIR (48.95%) for D. carota seeds, as PIR (27.47%), RLR (79.49%) for C. annuum. D. carota seeds had the largest negative allelopathic index (-60.00% or allelopathic intensity of 60.00%), while the germination of C. annuum seeds had the largest negative allelopathic index (-63.43 % or allelopathic intensity of 63.43%). Significant negative correlations were observed between the germination speed (-0.807), GIR (-1.00), RIR (-0.762), and the negative allelopathic index (AI) for D. carota seeds. The plumule inhibition rate (-0.903), radicle inhibition rate (-0.835), germination inhibition rate (-0.987), and mean germination time (-0.922) were all negatively correlated with the significant negative allelopathic index (AI) for C. annuum seed germination. We can conclude that GIR, PIR, and RIR were directly correlated with AI based on the results of the ANOVA and correlation coefficient analysis.