Phytotoxicity of essential oil from Piper nigrum L. on some selected food crops as a potential herbicide in Africa

Abstract

Phytotoxicity of the essential oil (EO) of Piper nigrum L.\xa0against Solanum lycopersicum L., Zea mays L. and Vigna\xa0unguiculata L. was studied. The GC-MS analysis of the\xa0essential oil of P. nigrum shows that linalool (21.73 %) was\xa0the major component of the essential oil. The EO retarded\xa0the growth of the root and the shoot of S. lycopersicum, Z.\xa0mays and V. unguiculata. The inhibition of the root ranged\xa0from 64.8-82.8% after 120 hours with a concentration\xa0of 4 mL/L, while for the shoot, 100% inhibition was\xa0observed with 4 mL/L of the EO formulation after just 96\xa0hours. The phytotoxic effect on the leaves was highest in\xa0V. unguiculata and least in S. lycopersicum. Phototoxicity\xa0was also observed when the EO formulations were applied\xa0to the root of the seedlings of Z. mays and V. unguiculata\xa0recorded 100% distress of the seedlings when 3 mL/L of\xa0the graded concentration was used after 24 hours. EO\xa0from P. nigrum is a potential bio-herbicide with a wide\xa0spectrum of use on plants.