Herbicidal properties of Peganum harmala under laboratory condition

Medicinal plants often contain natural substances having herbicidal effects on specific weed species [2,4]. Peganum harmala belongs to family Zygophyllaceae and several parts of this plant are used in folk medicine to treat several illnesses [1,3]. The aim of the present investigation was to evaluate potential herbicidal activity of P.harmala on growth of Amarantus retroflexus under laboratory condition. Fresh above-ground material (16g) of P. harmala was soaked in 100ml distilled water for 24h. After filtering and centrifuging, the extract was diluted with sterile distilled water to give final concentrations of 4, 8, 12 and 16% (w/v). Twenty five seeds of A. retroflexus were placed in Petri dishes containing 5ml of each P. harmala aqueous extract (or distilled water for control). Treatments were arranged in a completely randomized design with 3 replicates. After 8 days, final germination percentage and root and shoot length and seedling dry weight were measured. Results indicate that aqueous extract fresh biomass of P. harmala show strong inhibitory effect on seed germination of A. retroflexus. At highest extract concentration, 30% reduction in germination was observed when compared to control. Both root and shoot lengths were severely affected and the effect was higher on root than on shoot length. Dry seedling weight was significantly reduced. This reduction was approximately 79% for the highest extract concentration based on control. In conclusion, this research demonstrated that P.harmala is not only useful for its pharmacological properties but might be also used for biological control of weeds.

References: 1. Agedilova, M. T. et al. (2006) Chem Nat Comp 42: 226–227

2. Dongzhi, L. et al. (2004) Biocontrol 49: 187–196

3. Farouk, L. et al. (2008)J Ethnopharmacology 155: 449–454

4. Qasem, J.R. (2002) Allelopathy J 10: 105–122