PHYTOTOXIC EFFECT OF EUGENOL TOWARDS TWO WEEDY SPECIES

Abstract

A study was undertaken to assess the inhibitory / allelopathic potential of eugenol–a volatile monoterpene
found in Eugenia spp. and several other aromatic plants, against two weedy species viz. Cassia occidentalis and
Bidens pilosa. Eugenol significantly inhibited the germination of both the weeds even at very low concentration.
However, the effect was more on B. pilosa compared to C. occidentalis. Likewise, the seedling growth
measured in terms of seedling length and dry weight of both the test weeds was appreciably reduced in
response to the test monoterpene. Not only the growth, even the content of the total chlorophyll and cellular
respiration in both the test weeds were appreciably reduced, thereby indicating that eugenol negatively affects
the photosynthetic efficiency and the energy metabolism of the weed species. Based on the study, it is
concluded that eugenol possesses weed-suppressing ability and can be used for future weed management
programmes either directly or by serving as a lead molecule.