Abstract
Bacterial blight disease due to Xanthomonas campestris pv. translucens results in yield losses in barley, Hordeum vulgare L., especially in warm climates. Bio-based bactericides represent a safe alternative to harmful chemicals for controlling a wide range of phytopathogens. The bacterial strains (Brevibacterium linens, Bacillus subtilis, B. thuringiensis) were tested as antagonistic potential against X campestris disease in barley seedlings. Antagonists were applied as seed biopriming and soil drench in X. campestris infested soil. Soil-drenching treatment was more efficient than the biopriming application. A significant increase in shoot length with a clear decrease in seed germination was recorded. Fresh and dry weights of shoot and root lengths of the treated plants were markedly improved. The remarkable antagonistic activity of B. linens, B. subtilis, and B. thuringiensis against X. campestris could be attributed to the capability to produce bioactive molecules that can trigger systemic resistance in the infected seedlings.