The warm weather we had over the last few days certainly
advanced plant development. We didn’t really have windows for pre-emergence
herbicide application in Mainland fields and other late fields (Antigonish and
Cape Breton) have windows this week to get it done (before 200 GDD).
Most of the mainland fields are in a susceptible
period to monilinia blight (Figure 1), so please continue to monitor incoming
weather for this and next week. Other fields are also fast approaching 40%. It is
looking like by the end of this weekend and early next week, all Nova Scotian
fields will be under the susceptible period in terms of crop stages.
Figure
1. Wild blueberry susceptible stages to monilinia blight infection
Growing Degree
Days (GDD) Summary and Plant Development Updates
Figure
2. GDD Summary, May 9, 2023
Here is a summary of the most up-to-date GDD from 13 weather
stations in wild blueberry fields. If we look at the average GDD, we are around
200 GDD which is a threshold and safe point to apply pre-emergence herbicides.
Please refer to my last blog post for information on
sprout and crop fields management recommendations: http://www.novascotiawildblueberryblog.com/2023/05/2023-updates-and-seasonal-outlook-for_5.html
Nova Scotia
(Kentville station) Soil Temperature Update
Here is another update on the soil temperatures
contributed by Jeff Franklin (AAFC- Kentville).
Figure
3. Soil temperature update- May 8
It is looking like soil temperature might be on the
rise after May 9, which can contribute to faster plant development and that’s
what we learned in 2022. If this trend continues, we might see an early bloom
year. Blueberry growers and beekeepers should watch for that and be prepared.
However, things can change so I will continue to update this information as I
receive them. Right now, it is too early to make a clear statement about this.
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 |
15%
F2- May 9 |
|
|
|
|
Antigonish
County |
20%
F2- May 9 |
|
|
|
|
Pictou
County |
25% F2- May 9 |
|
|
|
|
Guysborough
County |
35% F2- May 9 |
|
|
|
|
HRM
(Dean, Musquodoboit…) |
>40% F2, watch the weather
forecast and prepare for spraying |
|
|
|
|
Colchester County |
>40% F2, watch the weather
forecast and prepare for spraying |
|
|
|
|
Cumberland County |
>40% F2, watch the weather
forecast and prepare for spraying |
|
|
|
|
Hants County |
>40% F2, watch the weather
forecast and prepare for spraying |
|
|
|
|
South West Nova Scotia |
>40% F2, watch the weather
forecast and prepare for spraying |