This is the first Monilinia update for 2022.
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 |
|
|
|
|
Cape Breton |
|
|
|
|
|
Cumberland County |
|
|
Oxford |
April
20- 6% |
|
Mapleton (Lynn Mt.) |
April
20- 5% |
|
Halfway River |
April
20- 10% |
|
|
|
|
South West Nova Scotia |
|
|
Queens County |
April 23- 42% |
|
Digby County |
April 23- 27% |
|
Annapolis County |
April 23- 28% |
|
|
|
|
Hants County |
|
|
|
|
|
Halifax County |
|
|
|
|
|
Guysborough County |
|
|
|
|
|
Colchester County |
|
|
Murray Siding |
April
21- 4.95% |
|
Belmont |
April
21-2.62% |
|
Glenholme |
April
21-2.38% |
|
Debert (WBPANS office) |
April
21- 0.09% |
|
Debert (Debert Airport) |
April
21- 1% |
|
|
|
|
Pictou and Antigonish County |
|
|
|
|
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.
Growing Degree
Days (GDD) Summary
Here is a summary of the most up-to-date GDD from
weather stations in wild blueberry fields. Please go to the Wild Blueberry Blog-
GDD&
Phenology Tracker to find out how you can use GDD to predict the wild
blueberry stage in your fields.
Figure
2. GDD Summary, April 21, 2022
Other observation- weeds and winter damage
For most
of the fields I visited this week and last week, I started to see red sorrel emergence
and it concerns me when I saw the numbers of them in the field and the size of
them. Look under your hair fescue clipping from last fall as a good layer of
grass clipping creates a good barrier for them. Since we still have time before
blueberry plants emerge in sprout fields (blueberry plants start to emerge- 270
GDD), I would strongly encourage you to look at your fields and plan for your
spring herbicide application to treat red sorrel if needed. If you are planning
to use the new herbicide Chikara, you need to treat hair fescue before most
plants emerge.
Observation
on fields I visited and when I talk to growers over the last two weeks, there is
limited winter damage, and it is not a concern like other crop sectors have.