2.1 Plant sample and leachate preparation
Redroot pigweed fresh materials were collected from crop fields of Khosroshahr (East Azerbaijan, Iran) and thoroughly powdered after oven drying under lab conditions. The plant species was identified by Agricultural and Natural Resources Research Centre of Iran (ANRC, Tabriz, East Azerbaijan, Iran).
For leachate preparation, 0.25 gr of powdered material were suspended in 100 ml of sterile double distilled water and mixed for 24 hours using a horizontal rotary shaker (120 rpm). Then, the suspension was filtered using two layers of sterile cheesecloth and filtrate considered as leachate 0.25 % (Shahrokhi et al., 2012; Mlakar et al.,2012; Bakhshayeshan-Agdam et al., 2015).