Hi everyone,
With another week of rapid crop development, we are excited to see the bloom
season beginning in blueberry fields across Nova Scotia. Bloom stages currently
range from early bloom to approximately 10–15% bloom in most Mainland crop
fields, indicating the need to introduce bees to support pollination. We expect
the majority of fields to reach mid to full bloom by the end of next week.
There is no longer a Monilinia Blight infection risk once fields enter the
bloom stage. Infection symptoms should become visible within the next week, and
we will continue providing updates on blight levels this season. So far, this
appears to be a light and fast-ending blight season due to the recent dry and
windy conditions.
As we move further into bloom, we will also begin discussing other important
diseases, including Botrytis Bloom Blight (Grey Mould) and one of the earliest
leaf diseases, Septoria Leaf Spot.
In this post, we are focusing on frost risks during bloom, as Nova Scotia
experienced two frost mornings this week. Fortunately, based on the bloom stage
and temperatures recorded across blueberry regions, frost injury was not
considered a concern. Please refer to the next section for more information on
blueberry frost risks.
Sprout fields are also entering a rapid growth period as leaves continue to
expand and new leaf buds emerge. Growers are encouraged to plan post-emergence
herbicide applications (Callisto, Venture, Clethodim products) and fertilizer
timings over the next two weeks.
Enjoy blueberry bloom season — and the sound of the bees buzzing when
visiting blueberry fields!
Hugh
Blueberry Frost Risks
As blueberry fields enter
early flowering, spring frost can pose a significant risk to blooms if low
temperatures occur for an extended period while a high percentage of flowers
are open. Figure 1 shows the minimum tolerated temperatures for different stages
of blueberry buds and flowers.
When blueberry plants
reach the fully open-flower stage, temperatures of -2.2 °C or lower can cause
permanent damage to floral structures and reduce yield potential, especially if
the cold conditions persist for more than 3–4 hours.
Figure
1. Blueberry Frost Risks
Fortunately, most fields
are not yet at full bloom, and bloom percentages remain relatively low. The
minimum temperatures recorded during the two frost mornings (May 22 – Figure 2;
and May 23 – Figure 3) did not pose a significant frost risk to the current
crop stages and bloom development in most fields. However, some localized areas
and earlier-developing fields or patches may have experienced frost damage,
particularly in Oxford and Debert/Belmont.
Next week will be a critical period as bloom percentages continue to increase, raising concerns about potential frost risks.
Figure 2- May 22 Lowest Temperatures across the Region
Figure 3- May 23 Lowest Temperatures across the Region
Wild Blueberry Weather Station GDDs Updates
