effect of leaf extracts of sweet wormwood and castor bean in reducing population of root-knot nematode (meloidogyne incognita) on cucumber

one of the methods for controlling cucumber root-knot nematode is the use of plant extracts that have nematicidal effect. in this research, sweet wormwood and castor bean were selected and their anti-nematode activity has been investigated against cucumber root-knot nematode (meloidogyne incognita) in laboratory and greenhouse. experiments were carried out by using randomized completely design as factorial in laboratory conditions and greenhouse. for this purpose, the effect of alcoholic extracts of leaf of sweet wormwood and castor bean with concentrations of 0, 50, 100, 200, 300, 400, 500 and 1000 ppm in three times of 24, 48 and 72 hours on the percentage of immobility of second stage juveniles and hatching of eggs were evaluated. after proofing the nematicidal activity of treatment, the investigation was held in greenhouse with adding of leaf extract of plants into pots having infested cucumber seedlings to this nematode. the results indicated the higher nematicidal activity in alcoholic extract of leaf of castor bean 61.33% and sweet wormwood 55.67 % in concentration 1000 ppm after 72h. the results of this investigation showed that the use of extract of these plants can be replaced with chemical nematicides for controlling root-knot nematode especially in greenhouses.