THE OBJECTIVE of this research was to determine the effect of .chemical inducers on leaf area index, chlorophyll content, relative water content and yield characters, antioxidant enzyme activities and disease severity in barley plants under biotic (Blumeria graminis f.sp. hordei (Bgh) and abiotic (water deficit) stresses. This study was carried out at the Experimental Farm of Faculty of Agriculture, Kafrelsheikh University using water treatments (water deficit by two irrigations and well-watered by five irrigations) and four treatments of chemical inducers including control, salicylic acid (SA),oxalic acid (OXA) and Benzothiadiazole (BTH) in the rate of untreated plants, 200 mg L-1, 1 g L-1 and 0.9 mM L-1, respectively. Water deficit appreciably decreased significantly almost all the studied parameters compared with well-watered treatment. However, chemical inducers application improved all the studied parameters under water deficit. The activity of antioxidant enzymes (catalase and peroxidase) showed significant increases in plants treated with chemical inducers under water deficit. Chemical inducers have been found effective in mitigating the negative effects of water deficit and disease severity in both seasons. SA was increased almost all the studied parameters in both seasons more than OXA and BTH. These results indicated that chemical inducers (SA, OXA and BTH) are convenient and could be recommended to increase the productivity and resistance the adverse conditions.