Allelopathic impact of Chromolaena odorata on the local crops in Mizoram, India

Abstract

Allelopathy is the major biological advantage of an invasive alien plant, often inhibitory to the germination and growth of other plants within their space. This study aimed to demonstrate the allelopathic effect of Chromolaena odorata extracts on seed germination and seedling growth of four commonly grown crops as test plants in Mizoram.  Chromolaena odorata was observed as one of the dominant invasive alien plants in the natural forests of Mizoram with increased abundance and lower diversity in the invaded areas during frequent field visits. Petri plate and pot bioassay study revealed that the increasing concentrations (control, 2.5, 5, 7.5, 10 and 15%) of aqueous extracts or leachates inhibited seed germination, root and shoot length, vigour index. Bioassay treatment of the test plants with a higher concentration of C. odorata extract exhibited a significant inhibition of germination and test plant growth.  Preliminary phytochemical analysis exhibited the presence of Alkaloids, Tannins, Saponins, Terpenoids and Flavonoids. The inhibitory effects on seed germination confirmed the inhibitory allelopathic potential of Chromolaena odorata in cultivated lands of Mizoram which may be attributed to presence of the allelochemicals in the leaf and stem extracts of the IAPs.