Assessment of allelopathic effect of tobacco on germination and early growth of rapeseed

In order to investigate the residual effect of different tobacco cultivars on germination and seedling growth of rapeseed, an experiment was conducted at laboratory and glasshouse during 2007 as factorial based on completely randomized design with four replications. Extracts of root and shoot from two different types of tobacco (Virginia and Basma) and different concentrations of extracts (0, 40 and 80%) were the treatments. Results showed that germination percentage and rate, shoot and root length in rapeseed (Hayola 401) in laboratory experiment and root and shoot length and ratio, shoot to root dry weight ratio, leaf area, seedling emergence and vigor and chlorophyll contents were significantly affected by different tobacco root and shoot extracts. According to results root extract of Virginia and shoot extract of Basma had the highest and the lowest effect in terms of mentioned traits, respectively. Among studied characters, germination rate had highly correlation with germination percentage and seedling vigor.