Hi, everyone
We are more than halfway through this year’s harvesting
season in Nova Scotia. Mother nature has greatly supported bringing decent
weather over the last two weeks. The weather in the province for the next two
weeks looks decent, according to the forecast.
We have heard from growers about the yield situation in NS,
which is concerning for some regions and fields. The keyword to describe 2024
NS’ wild blueberry yield is “Inconsistency”.
There are some yielding well fields, but some claimed below
average to poor yields. In those disappointing fields, growers didn’t see the
consistency between estimated yield vs final yield. They also reported the
inconsistency in yields from different patches and areas of the same field.
The first inconsistency is the yield differences from
average to good yield anticipation after bloom to below average or poor yield
outcomes. In mid-July, we had a good feeling about this year’s crop and we
estimated this year’s yield would be around 50-55 million lbs at that time.
Based on growers’ reports and comments from some receiving stations, we will be
lower than this estimation. The good side is that the berry quality looks great
this year. We have good-sized and firm berries.
The second inconsistency is the yield differences between
production/ micro-climatic regions, areas/ patches within the same field, and lastly,
yield variations under the same management program from the same farming
operation. All those differences are closely linked to fields’ weather patterns
in this production cycle (2 years), field topography and soil conditions,
management input (fertilizer and pest management products), pollination, and
more.
Why fields did do poorly and why did a field have very low
to almost no fruits in some areas? In this blog, we quickly summarized all
possible yield reduction factors that might hurt your crop in 2024.
They are:
-
Weather- Rainfall from June to August 2023
-
Weather- Conditions from November 2023 to March
2024
-
Weather- 2024 production season weather
challenges
-
Pollination
-
Field input level
Weather- Rainfall from June to August 2023
Do you remember we had a very wet summer in 2023? That’s not
a good thing that we want to remember but the 2023 summer rainfall seemed to
have a long-lasting impact on agricultural production, especially in this
year’s wild blueberry yield. A challenging and gradually changing climate
brings more frequent and intense weather events to NS which impacts farming,
resulting high risk of crop losses and higher production input needed in pest
management. In 2023, we had wet bloom periods and a long-wet summer. The amount
of rainfall from June to August was almost 2-3 times more than the provincial
average in 2023 in NS, and the differences between regions were significant,
eg. Most of Cumberland areas- ~500-600+ mm vs Guysborough- ~600-800+ mm (Figure
1).
Figure
1. Summer Rainfall from June to August 2023
This unusual weather pattern impacted 2024 wild blueberry
yields in the following areas:
·
Increased weed pressures
In general, last year’s sprout
fields would have high weed pressures, particularly in fields without herbicide
input and fields with too much fertilizer input. In order to keep fields clean,
growers would need to have higher herbicide input but there is a lack of
capacity to achieve this goal due to multiple reasons.
Red sorrel is one of the top
concerning weeds in crop fields this year. Red sorrel competes with wild blueberries
for nutrients. Red sorrel infestation in wild blueberry fields also reduced
blueberry pollination efficiency by attracting pollination forces to red sorrel
and other flowering plants’ blooms. As a result, growers might experience low
to poor yield in areas with nearby blooming weed patches. Different growers
might have different major weed problems, and red sorrel is a major weed issue
that reduces field productivity across all production regions in NS.
·
Increased leaf disease pressures
A wet summer and early fall also
contributed to higher leaf disease pressures and higher fungicide inputs in
2023. If fields weren’t treated with proper leaf disease management fungicides
last year, there could be a direct effect on plant health, particularly in
fruit bud development and yield potential.
·
Abnormal wild blueberry plant development
The primary reason for the abnormal plant development for the 2023-2024
fields was the oversupplying of water and nutrients. The following factors
might worsen the rainfall effect on blueberry’s development if your fields
have:
a.
Field topography and soil conditions. From
observations, areas with those features seemed to do better than others: side
hills, sandy areas, flat areas, or any areas without water accumulating for a
long period of time. Each field’s condition is different, so we are seeing
yield variations from field to field, and even within the same field.
b.
High fertilizer input. This is one of the
primary and direct nutrient sources for sprout blueberry plants in 2023. There
might be still a good amount of nutrients from last year to supply this year’s
crop fields and that’s why we are seeing many secondary or new stem growth in
crop fields this season (Figure 2). With the help of well-saturated soil,
granular fertilizer is easier to dissolve and ready to be taken up by plants.
c.
Fields in micro-climatic areas with higher
rainfall amounts than other production regions in 2023, like Pictou,
Guysborough, and HRM (Figure 1). Generally speaking, fields in the above areas
have more secondary vegetation growth.
d.
Fields received more than the average amount of
rainfall or intense rainfall events in the 2024 season. Through the
communications with growers and the wild blueberry weather station data, we learned
that some areas/fields received a significant amount of rain in a very short
time frame. If you are concerned about yield, maybe a nearby weather station
can provide some background information to explain the reasons.
Any factors that contribute to bringing more water to fields
and making water sit in fields might worsen the rainfall effect and result in a
wide range of abnormal growth areas in fields.
What’s an abnormal growth and development for wild blueberry
plants? We have a general and reliable understanding of a normal wild blueberry
plant from the periods of concern would be producing different plant parts in
the optimum timings and allowing fruit buds to get productive by staying healthy
and receiving adequate nutrients and heat.
A general timeline of the wild blueberry crop development
schedule can be found under this factsheet: https://www.perennia.ca/wp-content/uploads/2018/03/Nova-Scotia-Wild-Blueberry-Crop-Development-Schedule-and-Management-Recommendations-2024.pdf.
In NS, sprout wild blueberry stems grow leaves up to mid-July and under the
right condition, sprout stems will reach tip dieback stage (Figure 3). The tip dieback
is a sign of sprout stems stop elongating and start fruit bud formation.
Ideally, sprout wild blueberry plants should start producing fruit buds by the
end of August.
Figure 3. Wild
Blueberry Tip Dieback Stage
However, with the water and nutrient effects, last year’s
plants had vigorous growth which delayed tip dieback and fruit bud formation.
Last year’s fall weather was also ideal for plant growth, particularly in
September and October 2023 (Figures 7 and 8). The status of fruit bud formation and development will
determine yield potential, and because of the uniqueness of each clone or area,
you might experience:
a.
Good and timely bud formation.
When fruit buds were formed properly, they developed
into strong and productive buds which gave a picture of super bloom and some
bumper areas and fields (Figure 4).
Figure
4. A productive wild blueberry patch
b.
Late bud formation.
A late bud formation resulted in yield
reduction by delaying plant development in blooms and fruits. In harvested
fields, the percentage of green and red berries was higher than normal (Figures
5 and 6).
A late bud formation could also impact
berry size and quality.
Figures
5 (top) and 6 (bottom) Large amounts of green and unripe berries in a ready-to-harvest
field
c.
No fruit bud formation before the end of the sprout
year.
This situation caused the most damage to yield than the last one. If no fruit buds were produced before the beginning of the crop year, those stems continued their life cycle by producing and developing newly formed fruit buds this year, which created competition in the same plant. Those affecting plants needed to supply nutrients for fruit development and unnecessary fruit bud formations in a cropping year. In the same wild blueberry crop plant, we observed fruit production, fruit bud formation, blooming, and late green and red fruits at the same time in cropping fields. We didn’t see good field uniformity in terms of wild blueberry growth stages which made this year's management schedule harder to plan and caused some percentages of yield reduction.
d.
The last point is not about fruit bud formation
but the amount of new secondary growth in a cropping field is concerning
(Figures 2 and 6). Because of our decent growing season, we also observed many new sprout stems produced in cropping fields, which continue to develop into
further stages. This creates competition within the same blueberry plant when multiple
plant stages occur in the same growing season. This unnecessary plant
growth depleted growing resources and influenced wild blueberry plants’ normal physiological
plant development cycle.
Growers need to examine each individual field to understand
which situation impacted yield. A secondary growth is best to see before
harvesting but a harvested field can provide information on how much resources were
wasted to produce non-fruit parts in your fields.
Weather- Conditions from November 2023 to March 2024
I don’t think this point caused a high and wide range of concerns regarding the yield. During this period, we were concerned about above-average warm air and soil temperatures (Figures 7 and 8). This might have impacted overwintering stems and fruit buds with the concerns of overwintering kill and chilling requirements for good fruit sets. Fields with uncovered wild blueberry patches by snow were in a greater risk environment for winter and spring damage.
Figure 7. Air temperatures in
Kentville Research Weather Station, Oct 1, 2023, to March 15, 2024
Figure 8. Soil
temperatures (5 cm) in Kentville Research Weather Station, Oct 1, 2023
to March 15, 2024
The biggest concern with warmer temperatures, particularly
in the soil level, was one of the reasons why this year’s crop developed rapidly
ahead of the normal schedule, especially during the bloom period. This caused early ripening in some fields which brought a greater risk for yield reduction
because of natural fruit dropping or wildlife. We were already a few days
earlier than last year’s first harvesting date. A receiving station that I
followed opened on August 11 2023 and in 2024, they opened on August 1. I think
some fields might experience a small percentage of fruit losses especially if
there were severe leaf diseases in the field.
Weather- 2024 production season weather challenges
Most people would agree that this growing season is probably
one of the best in recent years in terms of weather conditions. However, we continue
to experience early and warm springs with an early and fast plant development in
the region. The biggest concern about this would be the timing of beehive
placement in wild blueberry fields. This year, some crop fields were late
getting pollination forces and a couple of wet periods might have also impacted
pollination efficiency in some areas. We will discuss pollination in the next point.
We also learned that the impacts of significant weather events were in a regional trend and the weather systems were more intense. This year, the yield differences and variations between neighbouring production regions are big. I think that’s a result of the changing of weather patterns and systems in NS due to climate change.
Pollination
Each field has different management inputs before harvesting.
Pollination input is one of the biggest variable costs which results in
significant yield differences in pollinated and unpollinated fields. Here are
some points for you to consider if you think pollination is an issue this year.
1.
Low to no honey bee and bumble bee input could
directly reduce yield.
2. The strength of hives and the timing of hive placement also had considerable impacts on pollination in 2024
3.
Regional pollination weather. Again, it is
worthwhile to check the nearby weather station for bloom period historical
data.
4.
Red sorrel population. The high red sorrel population
increased the competition between wild blueberry blooms and weed species’
flowers (Figure 9).
5.
Late-bloomed areas did not receive adequate and
timely pollination because of the water and weather issues we discussed above.
Figure 9. A red
sorrel patch in a fruiting wild blueberry field
Field input level
In order to get an average yield, growers are expected to have some minimal inputs, such as weed and disease management. Growers might experience a significant yield reduction if the input was reduced, particularly in pollination and herbicide inputs.
I want to thank growers and industry partners for providing the
information. If you like to share your harvesting stories, please reach out to
me.
I hope everyone finishes harvesting nicely.
-Hugh
