REPORT ON THE DEVELOPMENT AND USE OF COUGARBLIGHT 98C- A SITUATION-SPECIFIC FIRE BLIGHT RISK ASSESSMENT MODEL FOR APPLE AND PEAR.

In the Pacific Northwest United States, fire blight infection risk models are generally inaccurate.
Most commonly, high infection risk predictions are not followed by actual outbreaks in orchards.
Less commonly, fire blight outbreaks occur when no infection was predicted.
Most older models are based on assumptions that over-simplified the dynamic situation presented to growers who are trying to make daily fire blight control decisions.
Over the past 13 years, the “Cougarblight” (Smith) Fire Blight Risk Assessment Model has been developed to address the daily fire blight infection risk in the decision-makers’ orchard, rather than in the region around it.
Issues of present host susceptibility, relative pathogen presence, and potential growth rate of bacterial colonies on the flowers’ stigma are all addressed prior to potential flower wetting.
While the concepts behind the risk model are somewhat technical, the orchardist does not need to understand its’ justification to use it, nor do they need a computer to use it.
This model has successfully used for the past seven years by many concerned growers and advisors in the Pacific Northwest USA, and has been adopted as the standard fire blight model by both Washington State University and Oregon State University.

VIII International Workshop on Fire Blight

T.J. Smith

Fire Blight, Model, Apple, Pear, Erwinia amylovora

https://doi.org/10.17660/ActaHortic.1999.489.73