Biocontrols for Fire blight: What's in a Name? BlightBan C9-1, BlightBan A506 and Bloomtime

BlightBan C9-1 (Nufarm Agricultural Inc.) and Bloomtime (Northwest Agricultural Products) are registered biological control agents or biopesticides made available to Canadian apple and pear growers. These biopesticides contain different strains of a commonly occurring orchard bacteria Pantoea agglomerans. Most people are not aware that there are actually two products called Blightban. Here in Canada, Blightban C9-1 is registered, while in the US growers have access to Blightban A506 (Pseudomonas fluorescens). 

BlightBan A506 was the first commercial biological control product for fire blight and it was registered in the US in 1995. A506 uses the bacterium Pseudomonas fluorescens A506. This bacterium multiplies rapidly and colonizes open flowers competing with the bacteria that cause fire blight (Erwinia amylovora) for nutrients on the blossoms. This antagonist must be applied before E. amylovora is present in order to be effective. 

BlightBan C9-1 contains another bacterium Pantoea agglomerans strain C9-1. C9-1 produces multiple antibiotic compounds on its own that inhibit the multiplication of the fire blight pathogen in the floral cup. C9-1 must be applied to the flower before the arrival of the pathogen in order for it to be effectiveness. BlightBan C9-1 is currently in the registration process in the US. 

Researchers, A.M. Svircev (AAFC-Vineland), A. Castle (Brock University), Peter Sholberg (AAFC-PARC), Vincent Philion (IRDA-QC) and V. Toussaint (AAFC-QC) are conducting demonstration trials with BlightBan C9-1 and Bloomtime using research orchards artificially inoculated with E. amylovora. In Ontario, trials with the same biopesticides are being carried out by B. Solymar, EarthTramper Consulting Inc. The efficacy of both biopesticides is greatly influenced by environmental conditions and proper timing of application. Biopesticides are not stand alone products and should never be used on their own to manage fire blight. 

The biopesticides, BlightBan C9-1 and Bloomtime, should be used in an integrated fire blight control program which includes the use of a risk assessment model (Cougarblight or Maryblyt) and Streptomycin 17. Agriculture and Agri-Food Canada information factsheet on "New Biopesticides Help Manage Fire Blight: Good News for Apple and Pear Growers" is available at AAFC-Vineland, Reception Desk.