Thursday, June 15, 2023






(Perennia’s Wild Blueberry Production Newsletter)





Dear Growers,

As we see more petal fall (pin head stage) and forming of early green fruits, we are halfway through the production season before harvest! The timely rain we got at the beginning of June and a few good pollination days we had over this past weekend certainly were helpful and we needed it! On the sprout side, the plant emergence is ranging from 50%-90% across the province. We are fast approaching the start of the tip-dieback stage.


Table of Contents:


Nova Scotia Weather Update

Nova Scotia Wild Blueberry Crop Development Update and Management Recommendations

2023 Wild Blueberry Management Updates: Diseases, Weeds and Pollination


Upcoming Events


Hugh Lyu

Wild Blueberry Specialist, Perennia; 902-890-0472

June 15, 2023




Nova Scotia Weather Update


Weather is so critical but we often don’t understand it enough.

This year, we have been sharing more information on weather and how it is affecting growers’ management. A special thank you to Jeff Franklin (AAFC- Kentville), as well as the weather station owners, who contribute a lot of great information to help us understand this production season’s weather and the challenges we are facing.

Here is the latest information on different factors affecting crop development and yield potential.


2023 Degree Day Accumulations

The degree day accumulations are based on the weather data from Kentville weather station and this is giving us an overall idea of this production season’s temperature trend in Nova Scotia.


Figure 1: Heating degree day accumulations for plant (above 5°C) and insect (above 10°C) development from March 1 to June 12 for the past 17 seasons. Provided by Jeff Franklin (AAFC).

-          The trend of cumulative degree days being below the 5- and 10-year average continues.

-          Approximately 10% less plant development heat units compared to the 5-year average, and 12% less compared to the 10-year average.

-          Approximately 20% less plant development heat units compared to 2022, and 25% less compared with 2021.


June Rainfall Update


-          The recent rainy period was fairly widespread with much-needed rain for western NS.

-          Most locations there have received over 100 mm so far in June, which may be more than what those locations received in April and May combined. Northern and Eastern NS have received 70-100 mm of rain so far this month.


-          For context, a normal amount of precipitation for Kentville in June is 81.6 mm for the entire month. Within the first week of June, ~130 mm of precip was recorded there (KRDC).


Some other locations for June:


Precip for June (as of June 13) (mm)



Bear River




West Caledonia








Upper Rawdon


Mackay Siding


Middle Musqoudoboit














Blue Mountain


College Grant


Skye Mountain




Soil Temperature in Relation to Moisture (from Perennia Tree Fruit Blog, thanks to Michelle Corten and Jeff Franklin for providing this great information)

If you are wondering how deeply the 130 mm of rainfall from early June might have travelled in the soil profile, Jeff Franklin offers this graph of soil temperature over the period of heavy rainfall. Soil temperature at 50 cm depth appeared to respond to the cooling effect of the rainfall meaning that moisture likely reached 50 cm depth.



Figure 2: Soil temperatures at various depths at the Kentville Research Station in 2023 in relation to the 130 mm of rainfall in early June.


Wild Blueberry Weather Station GDD Summary- as of June 13


Here is the latest GDD summary from the wild blueberry weather stations.

Figure 3. Wild Blueberry Weather Staitons GDDs- June 13



Nova Scotia Wild Blueberry Crop Development Update and Management Recommendations


Based on Figure 3 (GDD summary from wild blueberry stations), here is a quick summary of the crop stages across different regions. Please note, this information was based on my observations, GDD research and weather station information.

Regions/ Counties

Crop Fields

Sprout Fields

Annapolis, Digby, Yarmouth, Shelburn, Queens

Early green fruits (halfway through this stage and should start to see late green fruit (blushing)):



Plant tip dieback- start













What is a tip die back stage?


As the plant transitions from vegetative growth to reproductive growth (budding) the upper-most leaf will curl, dimple and eventually die/drop.

Hants, Cumberland (excluding late fields)

Petal Fall (Pin Head) with small size early green fruits

70%- 80% plant emergence

Other Mainland Fileds

Passed full bloom, in the middle of petal fall and a small percentage of early green fruit forms

50%-70% plant emergence

Cape Breton

About 70% bloom in crop fields

50%-60% plant emergence


Regions/ Counties

Next Management Recommendations

Annapolis, Digby, Yarmouth, Shelburn, Queens

Crop fields: scouting for monilinia blight and Botrytis blossom blight symptoms (I will share a few photos) and evaluate if this year’s fungicide program was successful


Crop fields: preparing insect traps to monitor SWD and Blueberry Maggots


Sprout fields: determine if current sprout fields need soil and tissue sampling

Hants, Cumberland (excluding late fields)

Crop fields: scouting for monilinia blight and Botrytis blossom blight symptoms


Sprout fields: fertilizer application; post-emergence herbicides (Callisto, Venture L etc. for broadleaf weeds and grasses control)

Other Mainland Fileds

Crop fields: finishing pollination; scouting for monilinia blight and Botrytis blossom blight symptoms


Sprout fields: fertilizer application; post-emergence herbicides (Callisto, Venture L etc. for broadleaf weeds and grasses control)

Cape Breton

Crop fields: finishing pollination; scouting for monilinia blight symptoms; applying fungicides as needed for blossom blight and leaf diseases control


Sprout fields: fertilizer application; post-emergence herbicides (Callisto, Venture L etc. for broadleaf weeds and grasses control)


2023 Wild Blueberry Management Updates: Diseases, Weeds and Pollination



-          Monilinia Blight:


During the typical monilinia blight infection period (May), it was very dry. The monilinia blight infection was low to very low this year. However, I still spot some patches and fields with monilinia blight. Most of the cases, it was because at least one fungicide application wasn’t conducted in those fields. I encourage you to take a look at your crop fields as symptoms are obvious this time of the year.


This photo was taken in a field located in Antigonish


Here are a few photos from before but they show very obvious Monilinia blight symptoms.

(This photo's credit goes to Dr. Paul Hilderbrand)




-          Botrytis Blossom Blight:

I think we are picking up more Botrytis blight this year than Monilinia blight (for fields in Cumberland, especially Parrsboro and fields near the coast). The rain period we got at the beginning of June contributed to this infection as a majority of fields are in mid to full bloom. If you didn’t get a chance to put on Botrytis spray around the first week of June, then you might want to have a check of your crop fields. Please go to those early patches, tall and dense areas and weedy areas. We found Botrytis in a few Parrsboro fields and growers can bring those photos with you while you are checking fields.




We continue to see sheep sorrels and hair fescues being the main weed species that we are dealing with in wild blueberry fields.

If you applied Kerb last fall (or this spring if you managed to apply at a good time), pre-emergence herbicides (Spartan, Chikara, Ignite etc) this spring and post-emergence products (Option and Callisto) last month or recently, now it is a good time to go to your sprout fields and check results.

I didn’t mention Velpar as I was disappointed with this product’s efficacy. I would remind growers who continue to use Velpar on their weed management program to check results and determine if this product is still a good fit in your spraying program.  



-          Overwinter bee losses: the most recent number I heard about overwinter bee losses (on average) is 15%-20% which is still an acceptable range. Bees survived overwintering and gained sizes fast this spring. There is enough moisture during the pollination period for most of the fields in the province.

-          2023 pollination: although we were concerned about the weather (wet and windy) during pollination season, we did get a few good pollination days during peak bloom timing. This was helpful but for early fields that reached mid-bloom before June, it would be a concern.

-          2023 blooms: during the open bloom period, I noticed and felt that there were more blooms this year. I also heard growers have more input on bees this year. I hope this is a good return.



-          Agriculture Wildfire Response Assistance


Financial assistance will be available soon for Nova Scotia farmers and agri-food business owners affected by evacuation orders related to wildfires. The program will provide a one-time grant of $2,500 to registered farmers located in the mandatory evacuation zones in Halifax Regional Municipality and Shelburne County.


Details on the grants and how funds will be distributed will be posted soon to the Department's website. Inquiries can be emailed to the Department:


-          Agricultural Clean Technology Program, adoption stream- ACT A


Agriculture and Agri-Food Canada - Agricultural Clean Technology (ACT) Adoption Stream is reopening. The applications will be accepted starting Thursday, June 1 to a deadline of Thursday, June 22.


Program details are now on the AAFC website and note the funding level for this program is a maximum of 40%. Note only one application per client and previous ACT Adoption recipients will not be eligible to apply again. There is a new online application portal.



-          More programs from the Nova Scotia Department of Agriculture, please check the program link:





Upcoming Events

-          Maine 2023 Blueberry Hill Farm Field Day

·         For Details and registrations, please check this link:


-          WBPANS 2023 Field Day, Tuesday, July 18

·         Where: Queens County Exhibition Grounds, Caledonia, NS

·         Registration: Deadline: June 30.

Please note: this year, Quebec and NB don’t have field days.