2026 Production Updates and Seasonal Outlook for NS_ 10th Blight Line Post_ June 15

Figure 1. Post- Pollination and Green Fruit Stages

 

Good afternoon, everyone,

We are experiencing a very long and protracted bloom and pollination season due to uneven bloom development both within fields and across production regions. Some early fields received commercial bees as early as the week of May 18–22, and we are still observing white-blooming patches that require pollination.

The best way to describe the 2026 bloom season is that flowering is occurring in multiple stages. This may be a consequence of last year's drought, which resulted in differences in plant health, fruit bud size, and nutrient reserves. Please continue to monitor your blueberry fields closely, as this is a good time to assess crop stage, blight infection, and overall yield potential. Many fields could still benefit from another week or more of strong pollination activity.

 

Monilinia Blight Infection Updates

We have been observing higher levels of Monilinia blight infection associated with the continued emergence of F2 stages, which are also appearing unevenly, similar to bloom development. In addition, input concerns (none or single application) and limited spray windows appear to have reduced the effectiveness of fungicide application, leaving some susceptible bud stages unprotected over the extended infection period.

 

Botrytis Blight Infection Updates

With the prolonged bloom season, concerns about Botrytis blossom blight have increased because flowers remain susceptible for a longer period. However, most of the damage symptoms observed to date have been associated with Monilinia blight. I have observed some Botrytis infection symptoms, primarily in very dense canopies and only affecting a small number of flowers (Figures 2 and 3).

The extended bloom period may also influence disease development and delay the appearance of post-infection symptoms. We will continue to monitor conditions and provide updates as additional information becomes available.

 

Have a great week!

Hugh

June 15, 2026

 

 

 

Figures 2 and 3. Botrytis Blossom Blight Infections

 

Table 1. Wild Blueberry Weather Station GDDs Updates

 

 

 

 

2026 Production Updates and Seasonal Outlook for NS_ 9th Blight Line Post_ June 8

Figure 1. Blooming Wild Blueberry Field

 

Good afternoon, everyone,

The photo above (Figure 1) likely provides an accurate snapshot of the current stage of the blueberry crop and the most critical activity in Nova Scotia's wild blueberry fields: the bloom and pollination season.

The key crop-year management activities are now wrapping up as fields rapidly progress into the late-bloom and petal-fall stages. This period also marks the appearance of key disease symptoms, allowing for a better assessment of this year's pest pressure and a more accurate prediction of 2026 crop potential.

We have been observing Monilinia blight symptoms since early June. Although infection windows were limited and the susceptible crop stage was relatively short, symptoms continue to be found in crop fields across multiple production regions. Missed or delayed fungicide applications may be contributing factors to the increased incidence observed this year. Please see the photos below, which show typical Monilinia blight symptoms at this time of year (Figures 3-5).

To date, I have not observed any Botrytis blossom blight infections; however, Septoria leaf spot has been identified in several late-bloom and petal-fall fields near Truro (Figure 6).

Most sprout fields across the province have reached 60–70% plant emergence or higher. Plant emergence and development are generally progressing normally despite concerns about the impacts of last year's drought on the current cycle. Growers are encouraged to continue granular fertilizer applications and post-emergence herbicide treatments, including Callisto, Venture L, Poast, and Clethodim products, where permitted by their processors.

Lastly, please save the date for July's virtual wild blueberry production update meeting. Additional details and registration information are available on the event page: July Wild Blueberry Grower Meeting.

 

Have a great week!

Hugh

June 8, 2026

 

Figure 2. July Wild Blueberry Grower Meeting

 

 

Figure 3. Monilina Blight Infection on Flowers

Figure 4. Monilina Blight Infection on Flowers

 

 

 

Figure 5. Monilinia Blight Infection on Flowers

 

 

 

 

Figure 6. Septoria Leaf Spot

 

 

 

Table 1. Wild Blueberry Weather Station GDDs Updates

 

 

 

 

2026 Production Updates and Seasonal Outlook for NS_ 8th Blight Line Post_ June 2

Hi everyone,

After last week's unseasonably cold and wet weather, we are finally expecting several favourable days this week that should significantly improve pollination conditions. This year's bloom and pollination period appears to be longer than in recent seasons, when pollination was often compressed into a one- to two-week window. Uneven bud development resulting from last year's drought stress, combined with this spring's weather patterns, has contributed to a more extended bloom period across many fields.

Most fields are currently in mid- to full bloom. This week will be particularly important, as many flowers that remained unopened during last week's rainy weather are now opening and will require favourable pollination conditions to maximize berry set and fruit quality.

In addition to pollination, growers should continue to monitor two other important challenges during the bloom period: frost events and disease management, particularly Botrytis Blight and Septoria Leaf Spot.

Please review the crop updates below regarding upcoming management priorities and post-frost evaluations.

 

Crop Fields’ Upcoming Management

 

Monilinia Blight (Mummy Berry Disease) Infection Symptoms

·         The primary infection period for Monilinia blight was relatively short this season due to rapid crop development through the F2 stage, combined with dry and windy field conditions during the key infection window.

·         Many growers applied a single blight fungicide application, which should provide sufficient control under the disease pressure experienced in 2026.

·         Symptoms resulting from primary infections caused by ascospores are now beginning to appear on fully expanded leaves and, in some cases, on unopened flower clusters.

·         This week and the coming weeks provide an excellent opportunity to scout fields for Monilinia blight symptoms while conducting other field activities.

·         Infected shoots typically exhibit blighted leaves that become brown and wilted. 

·         Identifying infected areas now can help assess disease incidence and evaluate the effectiveness of this season's disease management program.

 

 

Bloom-Period Disease Management

• The two most important diseases affecting wild blueberry production during bloom are Botrytis Blossom Blight (Grey Mould) and Septoria Leaf Spot.
• Timely fungicide applications during the bloom period are effective in reducing disease infection and protecting yield potential.
• If you have not yet applied a bloom-period fungicide but are planning to do so, consider making the application as soon as field and weather conditions permit.
• The warmer temperatures forecast later this week, combined with recent and expected moisture, are favourable for Botrytis Blossom Blight infection. These conditions can also promote the release and dispersal of Septoria spores (conidia), which are spread by rain splash and prolonged leaf wetness.
• Fields with a history of Botrytis Blossom Blight or Septoria Leaf Spot should be monitored closely throughout bloom, particularly following extended periods of wet weather.
• Maintaining adequate disease protection during bloom is important for minimizing flower infection, preserving fruit set, and supporting berry yield and quality later in the season.

 

 

2026 Frost Events and Damage Assessment

 

Over the past two weeks, we have experienced two significant frost events across many wild blueberry production regions. Both events lasted multiple days (May 22–24 and May 31–June 2), and frost injury to open blooms has since been observed and reported from several areas of the province.

At this stage of crop development, frost injury can sometimes be mistaken for symptoms of Monilinia blight. However, there are several key differences. Frost damage typically affects most or all flower clusters on an individual stem, particularly when flowers are fully open and exposed during freezing temperatures. In contrast, Monilinia blight infections are often limited to a single flower cluster or shoot, while neighbouring clusters on the same stem remain healthy.

The severity of frost injury is also closely related to flower development. Closed or partially opened flower clusters generally have greater tolerance to freezing temperatures and often sustain less damage than fully open blooms.

Growers are encouraged to conduct post-frost assessments over the coming days as symptoms become more visible. Evaluating the extent and distribution of flower injury will help determine potential impacts on fruit set and yield.

These frost events pose another significant challenge for the 2026 crop, adding to existing concerns about the 2025 drought, pollination conditions and disease management. The overall impact on wild blueberry production and provincial yield potential will become clearer as bloom progresses and fruit set begins.

 

 

 

Table 1. Wild Blueberry Weather Station GDDs Updates

 

 

 

 

2026 Production Updates and Seasonal Outlook for NS_ 7th Blight Line Post_ May 27

 

Hi everyone,

This week’s rain is timely and extremely welcome. The moisture helps improve soil conditions and reduce dust in blueberry fields after last week’s hot, windy conditions. Good soil moisture is essential for strong nectar production in wild blueberry flowers, which helps attract bees for pollination.

As we enter early summer, most attention is focused on blueberry flowers, particularly pollination, blight disease management, and frost concerns. The recent frost mornings (May 22–24) caused some damage to open flowers; however, the overall damage level remained low, and frost concerns were mainly limited to three areas: Oxford, Debert/Belmont, and Sunnybrae (Pictou). Below are updates and outlooks for the next 1–2 weeks.

Crop Fields

·         Damage to blueberry flowers. We will begin seeing more visible symptoms of frost and disease damage on flowers. I have already observed Monilinia Blight (Mummy Berry) infections on leaves in this year’s crop fields, and some growers have also reported frost damage to flowers. It is still early to observe significant Botrytis Blight symptoms, as infection activity is only beginning this week with the recent wet weather.

Figure 1 is an excellent resource from the University of Maine Wild Blueberry Research and Extension Group, illustrating blueberry flower damage and providing clear images and key points for distinguishing frost injury from disease symptoms.

Figure 1. Photo and information credits: University of Maine Wild Blueberry Research and Extension Group.

 

·         Bloom-period disease management. During bloom, two high-priority blueberry diseases — Botrytis Blossom Blight and Septoria Leaf Spot — become active and can cause significant yield losses. Fungicide applications remain an effective management tool during June; however, application frequency, product selection, and timing must be carefully planned to balance disease control and pollinator protection.

We strongly recommend that producers begin planning their bloom-period fungicide applications now, as favourable conditions for disease infection and susceptible bloom stages are currently occurring across Nova Scotia.

 

Sprout Fields

·         Post-emergence herbicide application. The timing for Callisto and Venture L applications is approaching in sprout fields. Following this week’s rainfall and improved soil moisture conditions, field conditions are becoming more favourable for application.

If goldenrod is your primary target species and you are using the growing degree day (GDD) guideline to time your Callisto application, we continue to recommend targeting approximately 400 GDD or when goldenrod reaches about 20 cm in height, based on current research and successful field experiences (Table 1).

·         Granular fertilizer application. Many sprout fields are approaching or exceeding 50% plant emergence, which is generally considered a good timing window for supplying nutrients to support active vegetative growth through the remainder of the growing season. Improved soil moisture conditions will also help nutrient availability and fertilizer uptake.

 

Table 1. Wild Blueberry Weather Station GDDs Updates

 

 

 

 

2026 Production Updates and Seasonal Outlook for NS_ 6th Blight Line Post_ May 23

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

 

 

 

2026 Production Updates and Seasonal Outlook for NS_ 5th Blight Line Post_ May 19

Hi everyone,

I hope you were able to take advantage of the recent stretch of suitable spraying weather to complete urgent applications, including pre-emergence herbicides in sprout fields and blight protection sprays in crop fields. Warm temperatures over the long weekend have accelerated wild blueberry plant development, and we are now transitioning into a new crop-management period. Both sprout and crop fields are showing rapid progression in growth stages.

In sprout fields, management attention will increasingly shift once plant emergence exceeds higher emergence percentages. Following this past Sunday, the application of “hot” pre-emergence herbicides is no longer considered safe due to increased risk of crop injury. Growers are encouraged to carefully scout fields and evaluate emergence levels before deciding whether additional herbicide applications are appropriate. For post-emergence herbicides such as Callisto and Venture L, applications remain slightly premature. Current forecasts suggest mid-summer–like conditions this week, with hot and dry weather expected, which may further influence herbicide timing decisions.

Most discussions this week are centred on crop fields. Many of you have been actively scouting and observing varying pictures of crop potential across fields. At this stage, estimating yield remains challenging. However, rapid bud development has advanced many fields to the F3–F5 stages (Figure 1). With continued warm weather over the next few days and drier conditions ahead, the risk of additional Monilinia blight (mummy berry) primary infection appears low. Once plants progress beyond the pink and white prebloom stage (F5), primary infection from ascospores is no longer a concern. Based on current conditions, it appears that one Monilinia blight spray may be sufficient for many crop fields this season.

The next major milestone to watch is bloom development, which will provide a clearer indication of crop potential and yield outlook.

We will continue monitoring crop development across the province and greatly appreciate growers sharing field observations. These reports help improve our understanding of plant responses following the 2025 drought and support better management recommendations moving forward.

Lastly, a reminder that the next virtual wild blueberry grower meeting will take place tomorrow morning (May 20, 8:30–9:30 AM). This special session will feature two guest speakers discussing:

·         Future blueberry field improvement practices (mulching)

·         Nutrient management strategies for wild blueberry production

To register, please visit:
Wild Blueberries Virtual Grower Meetings 2026 Registration

If you need assistance, please get in touch with Hugh Lyu at 902-890-0472 or hlyu@perennia.ca.

At the end of this blog post, you will also find a survey supporting Dalhousie Agricultural Campus research students studying farm equipment sanitation practices in Atlantic Canada. Your participation is greatly appreciated.

Have a great week — and welcome to summer!

Hugh

Figure 1. Wild Blueberry Crop Year Leaf and Fruit Bud Stages

 

Wild Blueberry Weather Station GDDs and Crop F2 Stage Updates

 

Table 1. Percentage of Wild Blueberry Floral Bud F2 stage

 light green (0-20% F2), dark green (20-30% F2), yellow (30-40% F2) and red (40-100% F2)

Wild blueberry production regions, NS	The average percentage of floral buds at F2
Cape Breton	>40% F2, Blight Spray is Needed in Crop Fields
Cumberland County	>40% F2, Blight Spray is Needed in Crop Fields
Colchester County	>40% F2, Blight Spray is Needed in Crop Fields
South West Nova Scotia	>40% F2, Blight Spray is Needed in Crop Fields
Hants County	>40% F2, Blight Spray is Needed in Crop Fields
Halifax County/ Musquodoboit Valley	>40% F2, Blight Spray is Needed in Crop Fields
Guysborough County	>40% F2, Blight Spray is Needed in Crop Fields
Pictou County	>40% F2, Blight Spray is Needed in Crop Fields
Antigonish County	>40% F2, Blight Spray is Needed in Crop Fields