IDENTIFICATION OF PHENOLICS IN MANGO LEAVES EXTRACT AND THEIR ALLELOPATHIC EFFECT ON CANARY GRASS AND WHEAT

Abstract

Phytotoxic ability of aqueous extracts of new and old mango leaves at different concentrations i.e., 2.5, 5.0, 7.5 and 10% against canary grass and wheat were tested In vitro and In vivo. Results revealed that all the extracts significantly inhibited the germination and growth of canary grass In vitro as well as In vivo. Maximum inhibition i.e. more than 80% to all the parameters of canary grass was observed by 10% extract In vitro. In pot experiment 66% reduction, in the dry weight of canary grass was observed when the old leaves water extract was applied before emergence. All the treatments showed non significant results about the germination of wheat In vivo. Old mango leaves extract was found better as compared to new ones, because it moderately enhanced the wheat germination and growth, while new mango leaves induced some reduction regarding the shoot length and grain weight of wheat. Total phenolic contents were higher in new mango leaves as compared to old ones. 4-hydroxybenzaldehyde, m-coumaric, p-coumaric, 4-hydroxy benzoic, vanillic, caffeic, gallic and protocatechuic acids were phenolic compounds identified through Mass Spectrometry and High Performance Liquid Chromatography analyses of mango leaves. It has been concluded that old mango leaves extract could be used as a herbicide to suppress canary grass and to enhance wheat growth.