Study of Allelopathic Effects of Two Native Cover Plants Commonly Used in Green Area (Potentilla reptans and Frankenia hirsute)

Potentilla reptans and Frankenia hirsuta are native plants of Khorasan region which have the potential to be used as cover plant in green space. One of the environmental functions of cover plants is the reduction of weeds in green space. Different approaches are presented for the reduction of weeds, of which the newest one is using allelopathic property of plants. The present research is conducted to study the allelopathic property of Frankenia and Potentilla in a factorial experiment based on completely randomized design with four replications. The first factor was four extract concentrations of 0, 2.5, 5 and 10% and the second factor was plant type. The results showed that the extract of each cover plant had suppressing effect on growing traits of lettuce and reduced germination percentage, germination speed, root length and stem length compared to control treatment. Furthermore, increase in the concentration of extract increased suppressing effect on both plants, and extract of Frankenia had higher suppressing effect compared to Potentilla.