Allelopathic effects of Thymus kotschyanus on seed germination and initial growth of Bromus tomentellus and Trifolium repens

Abstract

The allelopathic influence of aqueous extracts of Thymus kotschyanus on Bromus tomentellus and Trifolium repens germination (%), germination speed, and seedling growth (length, fresh and dry weight) was examined. It was noted that aqueous extracts had a considerable inhibitory effect on target plant germination, and the effect at 50%, 75%, and 100% concentration was found to be significantly higher than that at lower concentrations (5% and 25%) and control treatment (distilled water). Seedling length in addition to fresh and dry weights was also reduced significantly over control. The inhibitory effect was increased as the extract concentration was increased. B. tomentellus showed a higher sensitivity against T. kotschyanus in allelopathic effects compared to T. repens, which indicates that B. tomentellus planted in rangelands with leaf litter of T. kotschyanus will be adversely affected in terms of its germination, growth, and ultimately low forage production.

Key words： allelopathy; germination; Thymus kotschyanus; Trifolium repens; Bromus tomentellus

Acknowledgements

We would like to thank Mr. Nazarzade and Dr. Naseri for laboratory assistance.

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