The antifungal activity of ten plants extracts was tested in controlling Pyrenophora teres the causal organism of net blotch of Barley in vitro and in vivo. Effects of the aqueous extracts varied depending on concentrations. In in vitro study the aqueous extracts of Anacyclus valentinus and Tetraclinis articulate at 1500 ppm caused highest reduction of mycelia growth of P.teres(72.27 and 87.05 % respectively), while extracts of Mentha pepirita and Foeniculum vulgare caused the lowest inhibition of the pathogen. In in vivo experiments the plants extracts were tested for their preventive and curative efficacy against net blotch. Barley plants were treated either aqueous extracts 1 day before or2 days after artificial inoculation. The highest reduction of diseases severity was achieved by the extract of Tetraclinis articulata. The same extracts were then tested as seed treatments, against seed-borne fungi. The best control against barley seed mycoflora was obtained with the extract of Inulavis cosa(72.8%). Results revealed that the selected plant extracts were active on both Pyrenophora teres in vitro, on disease severity in vivo and can be used as potential seed treatments for net blotch disease control.