General characteristics of bacterial pathogens based on the biochemical and physiological tests indicated that 41 isolates Out of 88 bacterial isolates collected from rotted onion bulbs  were identified as; Erwinia cacticida (2), Erwinia carotovora subsp. atroseptica (5), Erwinia carotovora subsp. betavasculorum (6), Erwinia carotovora subsp. carotovora (16), Pantoea spp (5) and Burkholderia cepacia (7).  Storage trial for fresh harvest and cured onion bulbs collected from field plots irrigated, withholding irrigation four months before harvest and 4 different levels of fertilizers (N, K) treatments. Assessment of bacterial bulb rot disease incidence (DI%) were carried out every 2 months regular intervals during 10 months of storage for onion bulb samples after external treatments with propionic acid spray (0,025%), Streptomycin sulfate spray (100 ppm) and actinomycetes (Streptomyces coelicolor) dust formulation. Results indicated that highest DI % in check treatment after 10 months of onion bulb storage was 20.68%. Compared with this control treatment; significant reduction in DI% was found in most treatments after all periods of onion bulbs storage. The highly significant reduction in DI% attributed to spray with propionic acid were 2.13%, 1.51%, 1.27%, 0.67% and 0.0%; followed by dust treatment with actinomycetes were 4.32%, 3.71%, 3.23%, 1.86% and 1.50% after 2, 4, 6, 8 and 10 months; respectively. However; low significant difference or reduction in DI% was found between irrigation and withholding irrigation treatments. Among fertilizers treatments; N1K1 treatment (150kg N+ 24kg K2O/fed) showed significant reduction in DI% reached to 4.41%, 5.54%, 6.34%  and 7.18% after 2, 4, 6 and 8 months of storage but after 10 months was not significant.