News Fruit Production
Check it out: Fire blight prediction maps

With bloom beginning in the earliest regions of the province, risk of blossom infection in now possible. As such, OMAFRA has made its fire blight prediction maps available for the 2024 growing season.

Click here to view the maps.

Since 2023, OMAFRA has partnered with WeatherSource to provide OnPoint Weather, a mapping service that provides growers with the current seven-day predicted risk of fire blight infection for various regions in southwestern Ontario. The mapping is based on the Cougar Blight model. The Cougar Blight model predicts risk based on the following assumptions:

1. Enough heat units have accumulated to reach a threshold level of inoculum;
2. A wetting event (rain, dew, etc) occurs to wash the bacteria into the blossom; and
3. The average temperature is above 15.5C.

Separate maps are available to assess the risk of fire blight in apples and pears, the two fruits most commonly affected by fire blight. Under optimal conditions, fire blight can destroy an entire orchard in a single growing season.

The maps are animated and will cycle through the daily fire blight risk predictions based on the seven-day weather forecast. Users can cycle through the seven-day forecast for blight risk. The four maps available are:

• Apples: Fire blight occurred in the orchard last year, and is now in the neighbourhood
• Apples: Fire blight occurred in the neighbourhood last year
• Pears: Fire blight occurred in the orchard last year, and is now in the neighbourhood
• Pears: Fire blight occurred in the neighbourhood last year

Currently, much of southern Ontario is categorized as low risk or caution, with a few select ones categorized as high-risk.