The response of woody borreria (Hedyotis verticillata Lam.) towards curry leaves (Murraya koenigii (L.) Spreng.) aqueous extract at the vegetative growth

Abstract

The massive used of synthetic chemical herbicides in crop production to meet the increasing demand had cause negative impacts on the environment and ecosystem. Allelopathy approach of potential crops is a suitable alternative that should be explored to have sustainable weed management. The present study was conducted to determine the phytotoxic effect of aqueous curry leaves (Murraya koenigii (L.) Spreng.) extract on the emergence and seedling growth of the bioassay species, woody borreria (Hedyotis verticillata Lam.) under laboratory and nursery condition. The seed and seedling of bioassay species were treated with different concentration of aqueous curry leaves extract at 0, 20, 40, 60, 80 and 100g/L (laboratory) and 0, 50, 100, 150, 200 and 250g/L (nursery). The results showed that the aqueous curry leaves extract possesses a significant inhibition on seed emergence, shoot fresh weight and radicle length of H. verticillata at 100g/L concentration, where it reduced by almost 100% when applied as pre-emergence under laboratory condition. Meanwhile, the curry leaves extract at highest concentration of 250g/L significantly reduced the weed shoot fresh weight by 31% as compared to control and 50g/L concentration when treated at soil surface as postemergence under nursery condition. Conversely, there is insignificant reduction in shoot height and root length of H. verticillata across all the applicate rates. These results suggest that curry leaves can be a good source to develop pre-emergence natural herbicide for weed management which is also eco-friendly for the environment and human beings.