The effect of Pseudomonas putida BTP1, Bacillus subtilis Bs2500, Bs2504, and Bs2508 strains on the incidence (I) and severity (S) of barley leaf stripe disease caused by Pyrenophora graminea was evaluated under field conditions. Three barley cultivars varying in resistance level were used. The resistance achieved in our study was long-lasting. P. putida BTP1 and Bs2508 were in general the most effective strains in reducing significantly both I and S of barley leaf stripe disease vis-a-vis three cultivars in two growing seasons 2013/2014. The disease was reduced up to 66% in Arabi Abiad treated with P. putida BTP1. The susceptible landrace cultivar Arabi Abiad exhibited a significant induction of resistance by Bs2508 and BTP1. However, the resistant cultivar Banteng did not exhibit significant further increase in resistance by these bacterial strains. The grain yield of bacterized plants artificially inoculated with P. graminea was not affected, except that of the cultivar Arabi Abiad treated with Bs2508 and Bs2504. Triggering of resistance by treating seeds with the bacterial strains would be of great value in agriculture, especially in case of barley infection by P. graminea at an early stage of plant development.
