2025 Production Updates and Seasonal Outlook for NS_ 3rd Blight Line Post_ May 9

Friday, May 9, 2025


Hello, everyone

Here is another quick update on blueberry growth stage and blight management before the weekend. A low-pressure system is in the forecast, which is expected to impact Nova Scotia this Saturday, bringing another wet period and blight concerns for Mainland crop fields. Over the last three days, the weather system that moved through the region has brought considerable rain to production regions (Figure 1). Combining with the average daily temperatures during the wet periods, the environment is suitable for mummy berry cup development and disease infections on susceptible crop fields.

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Figure 1. Rain reports from CTV Weather

 

Cape Breton fields are still early for Monilinia Blight infection. 

Mainland fields: For Mainland growers, if you made the first blight application on Monday or Tuesday (May 5 and May 6) or earlier, please note that the protection window is 7-10 days. If you haven’t made a blight application yet and plan to do so, a spray can be scheduled in the next couple of days, weather permitting. This would apply to fields in Pictou, Antigonish and Guysborough areas, as the F2 stage is fast approaching 40-50% F2.

Next week (May 11-17), most crop fields and production regions on the mainland will still be at risk of infection from Monilinia Blight until we see white, unopened blooms (Figure 2). Some of Southshore’s fields are nearing the end of the Monilinia Blight season, and flowers are beginning to open. Generally speaking, most of the other Mainland fields are about 1-1.5 weeks behind southern fields, so we should continue to monitor them closely over the next 7-10 days.

Figure 3 is the infection risk table for Monilinia Blight based on air temperature and wetness hours. As you can see, the current spring conditions pose a high risk of infection, unlike the last few dry springs when blight pressures were low.

Some early infection symptoms may be detected in fields by the end of next week.

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Figure 2. Wild Blueberry Susceptible Fruit Bud Stages to Monilinia Blight (DAAF- NB)

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Figure 3. Severity Rating of Monilinia Blight Infection Periods (Dr. Paul Hilderbrand, AAFC)

 

Lastly, please check out the latest GDD accumulations from selected stations to estimate crop stages.

 

Have a great weekend!

Hugh

 

 

Wild Blueberry Weather Station GDD and Crop Stage Updates

 

We selected the following 19 weather stations to report their seasonal GDD accumulations. Please compare the cumulative GDD from your weather station with local GDD recommendations on wild blueberry crop stages: https://www.novascotiawildblueberryblog.com/p/phenology-tracker.html.

 

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Figure 1. Selected Wild Blueberry Weather Stations and GDD Updates (April 1- May 8)

 

Table 1. Wild Blueberry Weather Stations and GDD Updates (April 1- May 8)

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