Allelopathic Effect of Ficus benjamina Leaf Extract, Litter, and Mulch on Germination and Growth of Sunflower

Abstract Allelopathy is an important biological process, which has direct or indirect effects on the germination and growth potentials of plants. Awareness about the allelopathic properties of plants which prevail in agricultural systems can help growers to amend crop cultivation patterns accordingly. In this study, we evaluated the allelopathic effects of Ficus benjamina on germination and early seedling growth of four hybrids of sunflower (Oliver, Parsun-3, SFH-80 and NK-S-278). Ethanolic and hot-water aqueous extracts from leaves, while litter and mulches of the test allelopathic plant significantly reduced germination, radicle and hypocotyle growth of sunflower. Germination percentage was drastically reduced in all the four sunflower hybrids by ethanolic, hot-water and litter extracts; however, compared to control, mulching assay significantly increased germination in hybrids Oliver (76%), Parsun-3 (42%), SFH-80 (78%) and NK-S-278 (30%) at 2, 4, 8 and 12g extract concentration, respectively. Hypocotyle and radicle length of test hybrids were significantly reduced in each assay type. Among tested assays, ethanolic extracts revealed more drastic effects on the studied parameters than hot-water, litter, and mulching. Sunflower hybrid NK-S-278 was more severely affected, while Parsun-3 exhibited resistance to the allelopathic stress. Inhibitory effects were more prominent with increasing concentration of the extracts. The order of the phytotoxic effects of tested bioassays was ethanolic extract˃ hot-water˃ litter˃ mulching. The study suggested that Ficus leaves may possess potent allelochemicals with growth inhibitory effects on sunflower seedlings. It is suggested that further study might be required to check the allelopathic effect of Ficus benjamina on germination and growth of these sunflower hybrids in field conditions.