Allelopathic Influence of Withania somnifera Leaf Extracts on the Germination and Seedling Growth of Wheat Genotypes

Abstract

The experiment was conducted from February to March, 2023 in Lab-02, Department of Plant Physiology and Biochemistry, Bihar Agricultural University, Sabour, Bhagalpur, Bihar, India, to study the allelopathic properties of Ashwagandha on germination and seedling growth of wheat. The allelopathic influence of Withania somnifera leaf extracts on the germination and seedling growth of four wheat genotypes (HD2967, HD2285, WH147 and WL711) was systematically investigated. The study revealed that aqueous leaf extracts of Withania somnifera significantly inhibited seed germination and seedling growth across all genotypes. The degree of inhibition varied among the genotypes, with the susceptible genotypes (WH147 and WL711) exhibiting a greater reduction in germination percentage and Germination Relative Index (GRI) compared to the tolerant genotypes (HD2967 and HD2285). Physiological observations demonstrated a progressive decline in root length, shoot length, and root and shoot dry weights with increasing concentrations of the leaf extract. The biochemical analysis showed a marked reduction in sugar and protein content in wheat seedlings treated with the leaf extract, while a stimulatory effect was observed on total amino acid content. These findings suggest a strong inhibitory effect of Withania somnifera leaf extracts on the overall physiological and biochemical parameters of wheat seedlings, particularly in susceptible genotypes. This study highlighted the allelopathic potential of Withania somnifera and its possible implications for wheat crop productivity and management strategies, especially in the context of weed control and crop compatibility in intercropping systems.