Phytotoxic activity of essential oil of Pogostemon benghalensis against Avena fatua and Parthenium hysterophorus.
A study was conducted to explore the phytotoxic potential of Pogostemon benghalensis essential oil with an aim to determine its herbicidal activity against two weeds viz., Avena fatua L. (wild oat) and Parthenium hysterophorus L. (congress grass). In laboratory bioassay, Pogostemon oil showed significant inhibitory effect on seed emergence and seedling length of both the test weeds. Oil treatment had more effect on seedling length of P. hysterophorus than A. fatua. Further, spray experiment was conducted under experimental dome conditions to evaluate phytotoxic activity of the oil. Under experimental dome conditions, A. fatua was found to be more sensitive than P. hysterophorus. When sprayed with Pogostemon oil emulsion, a declining pattern in seedling length and total chlorophyll content was recorded. The results from the present study suggested that Pogostemon oil possess phytotoxic potential and could thus serve as a strong candidate for weed management purposes.