Allelopathic Effect of Tobacco (Nicotiona tobaccum L.) on Germination and Early Growth of Soybean (Glycine max L.)

In order to investigating the effect of different tobacco cultivars residue on germination and seeding growth of soybean an experiment was conducted at laboratory and glasshouse in college of Sari Agricultural Sciences and Natural Resources University during 2007 as a 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 these extract (0, 40, and 80%) were the treatments. Results showed that germination percentage and rate shoot and root length in soybean (Cultivar of Hill) in laboratory experiment and glasshouse experiment was significantly affected by different tobacco root and shoot extracts. According to results Virginia root and Basma shoot extracts had the highest and the lowest effect in terms of mentioned traits, respectively. Leaf area, seedling emergence and vigor and chlorophyll contents were significantly affected by different tobacco root and shoot extracts. In laboratory, Virginia root, had the highest inhibitory in terms of root length, while the lowest amount was related to Basma shoot. Moreover, shoot length of soybean significantly decreased by Virginia root and shoot compared to control. In glasshouse condition, however, 80% concentration of extract from Basma root and 40 and 80% concentration from Virginia shoot caused the most reduction in root length of soybean. Among studied characters, germination rate had high correlation with germination percentage and seedling vigor.