The antifungal activity of resistance inducers ; Mono potassium phosphate ( KH₂PO₄) ,Chitosan clay Nano composite (ccnc), Humic acid  (HA) , Sodium meta silicate(Si) Si were tested in controlling Pyrenophoratere anamorph : Drechslerateres the causal organism of net blotch disease of barley . The evaluation was carried out at barley adult plant stages using two rowed hulled Giza 127,Giza 128 and six rowed hulls Giza 129 andGiza 130in greenhouse and open field conditions at two locations ; Itay El-Baroud and Sakha agricultural Research stations in Behaira and KafrElsheik Governorates , Egypt in 2013/ 14 growing season . Under artificial  inoculation in greenhouse all concentrations of the four tested inducers were  significantly reduced ondisease severity (DS)Chitosan clay Nano composite (ccnc) , Mono potassium phosphate ( KH₂PO₄) ,Humic acid  (HA) and Sodium meta silicate(Si)respectively compared with the control. The highest correlation was observed between DS and  peroxidase , 1,3- glucanase  after 15 days.Under field condition there was similar result of greenhouse .  Spraying barley plants of the studied varieties   with the tested inducers showed significantly correlation between disease severity and each of thousand kernel weight (TKW) , plot weight , total protein , total lipids , total fiber , crude ash and  total carbohydrates compared with the control.  It is worth mentioning that six rowed hulls barley Giza 129 and Giza  130  were more responsive to the positive effects of inducers compared with two rowed hulled barley Giza 127 andGiza 128 .