Friday, July 14, 2023

A field located in Murray Siding, Colchester NS.



Hugh Lyu

Wild Blueberry Specialist, Perennia; 902-890-0472.

July 14, 2023





Table of Contents: 

Nova Scotia Wild Blueberry Production Mid-Season Updates

2023 Season GDD and Crop Development Updates

Upcoming Management Recommendations

Funding Opportunities



Nova Scotia Wild Blueberry Production Mid-Season Updates


We are halfway through the season and harvest is only a few weeks away. We are starting to see mature berries in crop fields and this is a sign and reminder for growers to start monitoring blueberry maggot and SWD.

Based on personal observations and communications with growers from different regions, I want to give a quick mid-season summary of this season’s crop development. I will give a more throughout update in next Tuesday’s field day and I hope to hear more updates from more growers.

-          Projected yield for NS: less than 50 million lbs (below the average). In 2022, when I did a mid-season report, I commented “We had decent weather and good growing conditions for all wild blueberry regions”. This year, it is variable. The weather condition was not great, especially in June. For your record, the provincial average yield is 50 million lbs, but with the critical factors that I want to mention below, we are looking below this number. I have seen great fields, as well as fields with heavy weed and disease pressures with very likely low yield. It is a mixed year.

-          Winter damage: we observed higher winter damage than in the previous three years. Minimal to no snow coverage in wild blueberry fields this past winter was reported by growers and the “Polar Vortex” event that occurred in February brought negative impacts to overwinter blueberry stems and contributed to higher winter kill. Personally, I would rate the winter damage around 5-10%.

-          Frost events: two major frost events occurred on May 24 and May 30 this year. Some frost-prone fields continued to get higher frost damage than other fields, but overall, frost damage wasn’t a huge concern for the majority of fields in Nova Scotia. With that, we are still losing some crops from low temperatures during bloom periods (5%).

-          Pollination: although we had higher winter damage than before, a lot of growers and myself claimed that this year we actually had more blooms than last year. However, June wasn’t friendly with only a few good pollinations days in the province (June 8-13) and it was variable from region to region. This would certainly reduce yields for many regions. If growers maintain or increase their pollination input this year, it would be helpful to produce more fruit sets. This was observed in a few fields where the grower increased beehives and brought in additional bumble bees. If growers observe good blooms but didn’t feel like the fruit sets are looking great, it is due to bad pollination weather and not enough bees to work on those good days.

-          Weeds: I am seeing cleaner wild blueberry fields (those fields growers actually have input!) in Nova Scotia. The industry and growers give weed management more attention and input which starts to pay back now. A clean field in the sprout year doesn’t mean that you will have a clean field in the crop year. Please take some time these two months to check your sprout fields and determine what is needed next spring. A lot of weeds are in flowering and some of them are in the optimum control timing. If you need support on this, feel free to reach out to me. Top weeds to mention for this year: hair fescue, sheep sorrel, goldenrod species, hawkweed, spreading dogbane, purple vetch (I am seeing more and more of this weed and becoming a bigger patch), bird’s foot trefoil and rushes.


-          Diseases: we didn’t have bad monilinia blight infection this year because it was dry in May. However, June had perfect infection weather and the right crop stage to develop botrytis blight on blossoms. It is expected to see botrytis blight infection in all production regions in NS this year. Cumberland fields would have a higher infection due to early bloom and longer flowering window this year. Infections are more common to see in top and dense blueberry canopies and weedy areas. With fungicide input, I don’t think the infection of botrytis blight was very high. However, with the level of infection that I saw in different fields, a small percentage of yield loss in some crop fields is expected (5-10%).


2023 Season GDD and Crop Development Updates


Even though we don’t have new wild blueberry crop stage GDD thresholds for growers to compare with their local GDD, it is still important and interesting to understand how your season progress. Below, is 12 stations accumulative GDDs that I track throughout the season.

Figure 1. Wild Blueberry GDD Summary_ July 13, 2023


In Cumberland, we are seeing more inland fields advancing. Wentworth and Westchester Station were two late areas in the spring, but after mid-June, fields in those areas are catching up.

In Cumberland and Colchester, some of the early fields I saw have around 10% of ripening. The majority of fields only have a small percentage of blue.


Upcoming Management Recommendations


Crop fields:

1.      Insects, trapping for SWD and Blueberry Maggot:


To trap and understand SWD:


For blueberry maggot: Yellow rectangles coated with sticky material and an attractive bait are used for monitoring the blueberry maggot. When the first capture is found, it is better to give a few days for more adults to emerge.


Please remember to check the products’ pre-harvest interval (PHI) and check with your processor before you apply products in the fields.


2.      Weeds, start to cut above-blueberry canopy weeds to ease the harvesting process. Also, note down what weeds you have at this time. This information is helpful to develop next year’s weed management program.


Sprout fields:

1.      Leaf disease management in sprout fields. Please read my last post about this topic.


a.       Because we had a wet June and high temperatures in July, this condition is great for Septoria leaf disease.

b.      We also are entering the peak time for leaf rush and powdery infection.

c.       If your local weather station is getting to 1300 GDD (around 80-90% tip dieback), you should start to apply the first leaf disease treatment. For many, the last week of July and the first week of August are two good weeks to apply fungicides in sprout fields.

d.      You should try to get at least 1 fungicide application in sprout fields before we start harvesting.

e.       The weather in August will determine if a second leaf disease application is needed for leaf rush control. In a humid year, it is recommended to do so. The summer of 2021 was humid and that year we had a bad leaf rush infection which caused early defoliation in many fields.

f.        Growers should try to get leaf disease application on before Mid-Septermber (speaking for central area fields). Anything that applies after that would likely reduce fungicides’ value.


2.      Leaf tissue and soil sampling: if growers want to collect tissue and samples for analysis, it is a good time to do that now (tip-dieback stage). Here are two resources to help with the sampling and interpretation of the reports:


a.       Soil and leaf sampling in wild blueberry production:

b.      Nova Scotia Wild Blueberry Leaf Nutrient Ranges:


Funding Opportunities


NSDA SCAP Program – Highlight – Resilient Agriculture Landscapes Program (RALP), Application deadline: July 31, 2023

The objective of the Resilient Agricultural Landscape Program (RALP) is to increase the environmental resiliency of agricultural landscapes by accelerating the adoption of on-farm land use and management practices that maximum provisions of multiple ecological goods and services (EG&S). Ecological goods and services are the benefits society derives from healthy
functioning ecosystems. This includes the maintenance and provision of healthy soil and water
resources, wildlife habitat and biodiversity, as well as adapting to the impacts of climate change
(e.g., increasing carbon storage and resilience to floods and droughts).

There are currently four project streams for this year, they include:


Stream 1 – Reduced Tillage - An agricultural management approach that aims to minimize the frequency or intensity of tillage operations to promote economic and environmental benefits. Includes zero tillage, reduced tillage, and strip tillage.

Stream 2 – Pollinator Habitat - Promoting pollinator habitat supports climate change adaptation, carbon sequestration, and biodiversity.

Stream 3 – Ponds - The objective of ponds is for water retention on the landscape, climate change adaptation, water quality and quantity, and biodiversity.

Stream 4 – Buffers and Shelterbelts - Buffers support climate change adaptation, carbon sequestration, water quality, and biodiversity. Buffers and shelterbelts can also provide improved habitat on highly sensitive areas of the landscape.


Projects must provide an incremental benefit in ecological goods and services.


For more information go to this site at RALP Program Information




1.      Nova Scotia Wild Blueberry Field Day (WBPANS), July 18 @ Queens County Fair (9560 Nova Scotia Trunk 8, Caledonia, NS B0T 1B0)

2.      Wild Blueberry Harvest Festival, August 19- September 4, 2023 (