Biomass allocation strategy of an invasive alien weed Hyptis suaveolens (L.) Poit.: Implication for its sustainable management

Abstract

Biomass allocation is a necessary plant-trait associated with invasiveness of an alien weed. Present work aimed at understanding the invasibility of a tropical American weed Hyptis suaveolens L. in Indian dry tropics. Plant traits of this weed at mature stage (shoot length, basal diameter; number of leaves, branches, inflorescences, nodes; biomass of leaf, stem, branch and reproductive components and their mass fractions) and soil characteristics were investigated. Highest aboveground biomass was allocated to stem (42.5%) followed by reproductive part (29.5%), leaf (19.7%) and branch (8.3%). Mean phenotypic plasticity index of biomass fraction traits was relatively higher compared to plant-level morphological traits, indicative of differential biomass allocation strategy as an invasive trait in this weed; where relatively higher reproductive allocation and lower weight of seeds could be attributed to its expansionist invasive character. Thus, the study has implication for sustainable management of Hyptis suaveolens in India.