Allelopathic Effect of Extraction Solution of Leaves and Corms of Saffron (Crocus sativus) in Phenological Stages on Seed Germination of Jimson Weed (Datura stramonium)

Aims: Saffron is one of the plants, whose allelopathic effect of various organs have been reported to affect seed germination of some weed species. The present research was conducted with the aim of evaluating the allelopathic effect of extraction solution of leaves and corms of saffron (Crocus sativus) in phenological stages on seed germination of jimson weed (Datura stramonium). In this experimental study, an experiment was conducted to study the allelopathic effects of saffron on jimson weed seed germination at research farm, Tarbiat Modares University Faculty of Agriculture in autumn 2014. The experiment was arranged as factorial split plot in a completely randomized design with 3 replications. The treatments included factorial combination of 2 extract types (water and alcohol), 3 tissue compositions of saffron organs, different concentrations of aqueous, and alcoholic extracts as the main plots and 3 different phonological stages of saffron were considered as sub-plots. One-way analysis of variance was performed through generalized linear model (GLM), using SAS 9.1 software, and drawing charts was done, using Excel2013 software. Findings: The concentration and phonological stage of saffron had a significant effect on the germination percentage of Datura stramonium, but the main effect of organ type on this trait was not significant. The aqueous extract of saffron did not have significant effect on the germination of Datura stramonium germination at the phonological stage of the daughter corms at a concentration of 2g/l in comparison with other phonological stages, but at a concentration of 4g, it significantly decreased the seed germination. Extract of saffron has an allelopathic potential, and germination traits, including germination percentage and plumule and radicle length of Datura stramonium in different phonological stages of saffron are affected by the aqueous and alcoholic extracts of different organs.