Allelopathic Effects of Aqueous Extracts of an Invasive Alien Weed Parthenium hysterophorus L. on Maize and Sorghum Seed Germination and Seedling Growth

Abstract

Studies were carried out under laboratory conditions to investigate the allelopathic effects of aqueous extracts of Parthenium hysterophorus L. shoot (stem + branch), leaf, inflorescence, root and whole plant (leaf + shoot +inflorescence + root) at 0, 5, 10 and 15% (w/v) concentrations on maize (Zea mays L.) and sorghum (Sorghum bicolor L. Moench) seed germination, seedling growth (shoot and root length) and biomass production. The treatments were laid out in completely randomized design with factorial arrangement in four replications. The trial was conducted twice. Results showed that significant (p < 0.01) differences between plant parts and whole plant except for stems and root length of maize, where the effect was significant (p < 0.05) and non significant, respectively. Inflorescence and whole plant extracts at all concentration, shoot at 15% and leaf at 10 and 15%, completely inhibited seed germination of the crops. In contrast, aqueous extract of shoot and root at 5% proved to be lower deleterious effect, while at higher concentration greatly reduced the aforementioned parameters. The roots were more sensitive to allelopathic effect than shoot. In was suggested that integrated weed management practices should be designed and employed to control this invasive weed from maize and sorghum fields to sustain the production of the crops.

Keywords: Allelopathic, aqueous extract, maize, Parthenium, sorghum