2026 Production Updates and Seasonal Outlook for NS_ 5th light 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

 

 

2026 Production Updates and Seasonal Outlook for NS_ 4th light Line Post_ May 14

Hi everyone,

We are seeing rapid crop development in both sprout and crop blueberry fields following the recent warm temperatures and abundant moisture across the province. Traditionally, crop development varies by several days to weeks among regions and microclimates; however, this spring we are observing more uniform plant development across Mainland Nova Scotia.

 

Crop Fields — Blight Risk Increasing

Most Mainland crop fields are expected to surpass 40% F2, meaning blight protection is now required as soon as field conditions permit spraying.

Cape Breton crop fields are also progressing quickly and are expected to reach the 40% F2 threshold by this weekend, requiring blight applications early next week.

This timing will likely create spray scheduling challenges, as growers may encounter:

·         high winds,

·         intermittent rainfall,

·         and narrow optimal fungicide application windows.

Please continue monitoring weather forecasts closely and take advantage of available spray opportunities. Fruit buds are currently at highly susceptible developmental stages, and leaf buds also contribute to disease risk.

Once leaf buds unfold and reach the V2 stage (approximately 2–5 mm; Figure 1), they can host blight spores and support secondary infection cycles, which may later impact open flowers. This year, leaf bud development appears faster than fruit bud development in some fields, and drought-affected patches may show leaf growth without viable fruit buds.

 

Sprout Fields — Emergence and Herbicide Timing

Sprout field emergence has begun in many regions, particularly where growing degree days (GDD) have reached approximately 200 (Figures 2 and 3).

If you are planning herbicide applications:

·         Chikara and Ignite — Fields should be scouted carefully before application. After this week, applications may no longer be safe due to crop emergence.

·         Velpar, Sinbar, and Spartan — Applications remain acceptable but should be completed as soon as possible.

Many sprout fields experienced significant stress during last year’s drought. Emergence and early development remain a concern, and additional stress from late herbicide applications could further reduce stand recovery. Please consider alternative weed management strategies or products where risk is high.

 

Looking Ahead

Weather conditions after Friday and into the weekend and early next week appear more favourable for spraying operations. We encourage growers to prepare equipment and management plans to take advantage of these windows.

I hope everything goes smoothly during this busy period. We will provide another update following the long weekend.

Have a safe and productive week.

Hugh Lyu
May 14, 2026

 

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

 

 

Figures 2 and 3. Wild Blueberry Sprout Plant Emergence

 

 

Wild Blueberry Weather Station GDDs and Crop F2 Stage Updates

 

 

 

We will continue providing updates on F2 stage percentages across different production regions as information becomes available throughout the season.

 

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	30% F2
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
College Grant	>40% F2
Pictou County
Sunny Bare	>40% F2
Blue Mt.	>40% F2
Moose River	>40% F2
Antigonish County
Monastery	>40% F2
New France	>40% F2

 

Nutrient Roles in the Wild Blueberry Crop Year Production

 

Hello everyone,

We are hearing increasing concerns about differences in fruit bud size and development across wild blueberry fields this spring. In many crop fields, bud break and separation have begun across the province, giving us clearer insight into how last year’s drought is influencing this season’s crop potential.

Variation in bud size can directly affect development rate, flowering timing, and ultimately yield potential. These differences largely reflect variability in nutrient reserves stored in the plants. Adequate nutrient availability and proper developmental timing are critical for achieving a strong average yield.

Last fall, blueberry wood nutrient analysis conducted by Dr. Harrison Wright (AAFC) indicated that several nutrient levels were lower than those observed in 2024, particularly some key micronutrients. Reduced nutrient reserves following drought stress are likely contributing to the uneven bud development we are now observing.

In this short blog post, we would like to review the fundamentals of nutrient needs during the wild blueberry crop year. Over the coming weeks, we will continue discussing this topic through additional updates and grower resources.

During our next Virtual Wild Blueberry Grower Meeting on May 20, we will welcome guest speaker Jessica D’Entremont (NutriAg), who will provide a brief presentation on nutrient functions and practical approaches to managing nutrient inputs in crop fields, with particular attention to liquid fertilizer products. A second guest speaker will also present on mulching practices in wild blueberry production at the same meeting.

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

We hope this short communication helps growers better understand the key roles of nutrients during the crop year, supports decision-making regarding liquid fertilizer use, and contributes to improved berry quality and yield potential.

 

Nutrient Importance in Wild Blueberry Production

Wild blueberries grow naturally in acidic, low-fertility soils; however, adequate nutrient availability remains essential for maintaining plant vigor, optimizing fruit yield, and sustaining long-term field productivity. Nutrients influence every stage of crop development, including vegetative growth, flower bud formation, pollination success, fruit set, berry size, and winter survival.

Plant nutrients are grouped into macronutrients, required in relatively large quantities, and micronutrients, needed in smaller amounts but equally vital for normal plant function. Deficiencies or imbalances in either group can limit plant growth, reduce flowering potential, and negatively affect fruit quality.

Wild blueberry production operates within a two-year cycle. The sprout year focuses on vegetative growth and the establishment of future yield potential, while the crop year relies heavily on stored nutrients and carbohydrates accumulated during the previous season to support flowering and fruit development.

 

Nutrient Function During the Crop Year

Following vegetative growth achieved during the sprout year, plants enter the crop year with pre-formed flower buds and stored nutrient reserves. These reserves largely determine early-season performance, influencing bud break, flowering progression, pollination success, fruit set, and early berry growth.

Recent blueberry wood analysis indicates reductions in several key nutrients — particularly Calcium (Ca), Magnesium (Mg), Zinc (Zn), and Boron (B) — ranging from approximately 13% to 36% below the previous years’ levels. Combined with seasonal stresses, including last year’s drought effects, these reductions highlight the importance of targeted nutrient supplementation during the crop year.

Because crop-year nutrient uptake opportunities are limited, careful selection of nutrients and application timing is critical for supporting reproductive development and maximizing yield potential.

 

Secondary Macronutrient: Calcium (Ca) — Cell Strength & Fruit Firmness

Calcium plays a central role in maintaining plant structure and fruit quality during the crop year. It is essential for cell wall formation, resulting in stronger plant tissues, improved berry firmness, and enhanced post-harvest shelf life.

Adequate calcium availability supports:

• Active root growth
• Shoot tip development
• Reduced fruit breakdown and soft berries

Calcium is relatively immobile within the plant, meaning deficiencies cannot be corrected by redistribution from older tissues. A consistent external supply is therefore required during periods of rapid growth, flowering, and berry formation.

 

Micronutrients Essential for Flowering and Fruit Set

Several micronutrients become especially important during the crop phase of wild blueberry production.

Boron (B) — Flowering & Pollination Success

Boron is one of the most critical micronutrients during the crop year. It supports pollen viability and pollen tube growth, enabling successful fertilization and seed development. Adequate boron directly improves fruit set and berry size, while deficiencies often lead to poor berry formation and reduced yields.

Zinc (Zn) — Growth Regulation

Zinc contributes to plant growth regulation through its role in hormone production. It supports healthy shoot and leaf development and helps synchronize plant growth stages, ensuring uniform flowering and fruit development across fields.

Manganese (Mn) — Metabolic Activity

Manganese functions primarily as an enzyme activator involved in photosynthesis and key metabolic processes. Adequate manganese supports overall plant metabolism and helps maintain energy production required during flowering and fruit growth.

 

Management and Liquid Fertilizer Product Selection in 2026 Crop Fields

The crop year provides only limited opportunities to supplement nutrients. Integrating liquid fertilizers into scheduled fungicide applications allows producers to efficiently support crop nutrition without additional field passes.

Producers should focus on two key application windows.

1. Bud Break / Bud Separation

(Monilinia Blight Spray Timing)

Nutrients to consider

• Boron (B)
• Zinc (Zn)

Locally available products

• BoronMax — 0.3 L/acre
• ZincMax — 0.5 L/acre
• Zinc DL — 1.0 L/acre

 

2. Flowering Period

(Botrytis Bloom Blight Spray Timing)

The objective is to support successful flowering, fertilization, and early berry development.

Nutrients to consider

• Calcium (Ca)
• Boron (B)
• Magnesium (Mg)
• Zinc (Zn)

Locally available products

• SillCalMax — 1.0 L/acre
• BoronMax — 0.3 L/acre
• ZincMax — 0.5 L/acre
• TruPhos Magnesium — 1.0 L/acre
• Cal-Bor-Moly — 3.0 L/acre
• Zinc DL — 1.0 L/acre