Response of Germination and Growth of Thorn-apple (Datura stramonium L.) Seedlings to Allelopathic Effects of Winter wheat (Triticum aestivum L.)

Abstract

Greenhouse and laboratory experiments were conducted to determine the allelopathic effects of Winter wheat (Triticum aestivum L.) on Thorn-apple (Datura stramonium L.) germination and seedling growth, Growth of D. stramonium, as indicated by plant height and weight, was significantly reduced when grown in soil previously cropped to Winter wheat   compared with that cropped to D. stramonium. Soil incorporation off fresh Winter wheat   roots and both roots and shoots reduced D. stramonium germination, plant height and weight when compared with a no-residue control. In bioassays, Winter wheat   extracts reduced D. stramonium hypocotyl length, hypocotyl weight, radicle weight, seed germination, and radicle length. Increasing the water extract concentrations from 4 to 20 g per 100 ml of water of all Winter wheat   parts significantly increased the inhibition of D.stramonium germination, seedling length and weight. Based on 6-day-old  D. stramonium radicle length, averaged across all extract concentrations, the degree of toxicity of different Winter wheat   plant parts can be ranked in the following order of inhibition: leaves > flowers > mixture of all plant parts > stems > roots.