Biological Control of Bacteria Onion Diseases using a Bacterium, Pantoeaagglomerans 2066-7

Epiphytic microorganisms isolated from the olive knots, apple fruits and trees, quince, compost and water from different areas were screened for antagonistic activity against Pseudomonas marginalis, Pseudomonas viridiflava, Xanthomonas retroflexus and Pantoea ananatis on onion bulbs. From 77 microorganisms tested for antagonistic properties against bacteria onion diseases, the strain 2066-7 of Pantoea ananatis was selected. Complete control against Pseudomonas marginalis and Pseudomonas viridiflava at 107 CFU. ml-1 concentration of 2066-7 and an inhibition percent higher than 90 % against Xanthomonas retroflexus and Pantoea ananatis were obtained on wounded onion bulbs inoculated with 105 CFU. ml-1 of pathogens under cold conditions. The inhibitions percent were decreased under 25C and 30C.