Allelopathic effect of Pinus roxburghii on an understorey plant, Bidens pilosa

Abstract

Allelopathic effect of Pinus roxburghii was studied on Bidens pilosa through laboratory and greenhouse experiments. The aqueous extracts of green needles, needle litter and bark were found to inhibit germination and initial growth of B. pilosa in laboratory bioassays. The inhibitory effect on germination root length, shoot length and biomass was also observed on amendment of powdered needle litter in soil in greenhouse pots. The inhibitory effect increased with increase in conc. of extracts or amount of litter amended. The amended soil was found to be rich in phenolics, the known potent allelochemics. The study indicates that such interactions may also be operational in forests of P. roxburghii.