It might sound too early to worry about Monilinia Blight
management in Nova Scotia wild blueberry fields, but the earliest fields were
around 20% F2 in West Caledonia, Queens as of April 10. Based on the grower’s
record, the producer might be looking about 6 days earlier to apply his first monilinia
blight in the same field compared to 2022.
In some wild blueberry meetings over the last two
weeks, I shared Nova Scotia’s winter weather information, March air, soil and
precipitation updates, and spring forecasts. Based on that information, we
are seeing more signs of warm spring and early plant development in Nova Scotia.
Growing Degree
Days (GDD) Summary and 2024 Spring Plant Development Prediction
This year, we are going to report GDDs from 17
stations (see Figure 1) which cover the major wild blueberry production regions
in NS. There are different ways to obtain GDDs by choosing the station you
like. To learn how to obtain GDDs, please read this blog post: http://www.novascotiawildblueberryblog.com/2023/04/2023-wild-blueberry-pest-guide-new.html.
Figure
1. 17 Wild Blueberry Stations for GDD updates
Here is a summary of the most up-to-date GDD from 17 weather
stations in wild blueberry fields.
Figure
1. GDD Summary, April 10, 2024
Wild Blueberry Floral
Bud F2 Stage
Please see the below summary table of the percentage of
wild blueberry floral bud at the F2 stage. You can also click on this map to
check those numbers. Detailed information is also available under the Wild
Blueberry Blog- GDD&
Phenology Tracker.
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 |
|
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Cape Breton |
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Cumberland County |
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|
|
|
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South West Nova Scotia |
|
|
Queens County |
18%-
April 10 |
|
Digby county |
8.6% - April 11 |
|
Annapolis County |
1.6%- April 11 |
|
|
|
|
Halifax County |
|
|
|
|
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Guysborough County |
|
|
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|
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Colchester County |
|
|
|
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Pictou and Antigonish County |
|
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|
|
General Information about Monilinia Blight and Management
It is important to monitor plant development stages in
your fields, especially if this disease has occurred in your fields previously.
I encourage growers to go out to the fields and see how floral buds are
developing.
When looking at fruit buds do not count obviously dead
fruit buds. To do that, you can walk your fields in a “W” pattern and collect
20-30 stems randomly. From those collected stems, count the total number of
floral buds and the number of buds at the F2 stage or beyond. You can simply
dive the number of F2 buds by the total number and times 100. This would you
the % of F2. Please don’t count obviously dead floral buds.
Figure
1. Wild Blueberry Floral Buds in F1 and F2 stages.
For monilinia to infect blueberry plants, there should
have mummy berry spores, blueberry buds at a susceptible stage (F2 and above)
and an infection period of long enough wet period and temperature. Only treat
for Monilinia when blueberry buds are at least at 40% and before the next
forecasted wet period.
For products to prevent monilinia infection, please
refer to Perennia’s updated pest management guide for wild blueberry (2022): https://www.perennia.ca/wp-content/uploads/2018/03/Wild-Blueberry-Pest-Guide-2022_FINAL.pdf.
Other available
resources:
1.
ATTTA
pollinators guide: Protecting Pollinators from Pesticdes- Wild Blueberry.
2.
Our
Atlantic Tech Transfer Team is pleased to share their latest guide, Protecting
Pollinators from Pesticides – Wild Blueberry! Available in both English and
French, the focus of this guide is on minimizing the impacts of pesticides on
pollinators in wild blueberry production. Check it out today!
https://www.perennia.ca/wp-content/uploads/2024/03/P2C_WildBlueberry_Guide_ENG-FINAL.pdf
https://www.perennia.ca/wp-content/uploads/2024/03/P2C_WildBlueberry_Guide_FR-FINAL.pdf
3.
Perennia’s
Online Pest Management Guide Tool
We are
excited to introduce Perennia’s online pest management guide tool. With this
new tool, you will be able to access relevant and up-to-date information about
pesticide options in an easy-to-use way. This interactive tool is searchable
and will help you save time and improve decision making when selecting pest
management products. Organized in tables, these guides can be printed and can
be accessed in a way that works best for you.
Please
visit this link: https://www.perennia.ca/onlinepestmanagementguide/.