Hi, everyone
We are looking to have some decent spraying weather in
the next few days. The next potential long wet period could be mid-next week. Before
the weekend, I want to share these quick updates.
Have a good spraying weekend!
Hugh
GDD Updates_
May 10, 2024
Figure
1. GDD Summary, May 10, 2024
Wild Blueberry Sprout and Crop Development Stages
Sprout fields:
Growers are encouraged to
complete pre-emergence herbicide applications as soon as possible.
New blueberry leaf buds are
starting to form and in some early areas/fields, leaves are unfolding. The
plant emergence is still in the early stages (0-5%) which indicates the safe
window to spray herbicides is getting shorty and it is getting riskier as more buds
and leaves are formed in sprout fields.
Crop fields:
Please refer to Table 1 for regional F2 % predictions.
In the last few days,
many areas in NS experienced a 12-24 wet period which created potentially favorable
conditions for apothecia* to re-active and produce disease spores. Under 10 °C
conditions, those structures only need about 6 hours to get activated and produce
spores. Today’s conditions seemed to be favorable and potential infection risk
is expected in crop fields with a high percentage of opening fruit buds.
*Apotheica is a small
cup-shaped and spore-bearing structure that is produced by overwintering mummy
berries on the ground.
If you didn’t get a
chance to spray crop fields with fungicide before this wet period, you can
still put something on after the fields are dry. Most of Monilinia Blight
products would have around 48-72 hours back action depending on what you use.
If you can spray successfully in this time frame, the risk of getting a blight
infection will be lower.
Air temperature and
wetness duration are two critical factors in determining the severity of
Monilinia infection periods. Please refer to the below figure and your local
weather conditions to decide if a fungicide application is needed and when will
you need to spray.
Figure 2. Severity Rating of Monilinia Infection Periods
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 |
|
|
|
|
South West Nova Scotia |
|
|
Queens County |
>40%- April 24 |
|
|
|
|
Hants County |
>40%- April 29 |
|
|
|
|
Cumberland County |
|
|
West Advocate |
>40%- April 29 |
|
Kikhill |
>40%- April 29 |
|
Halfway River |
>40%- April 29 |
|
|
|
|
Colchester County |
|
|
Belmont |
68% F2- May 10 |
|
Murray Siding |
88% F2- May 10 |
|
Camden |
40% F2- May 10 |
|
|
|
|
Halifax Regional Municipality |
>40%- May 8 |
|
|
|
|
Guysborough County |
30% F2- May
10 |
|
|
|
|
Pictou and Antigonish County |
|
|
Blue Mt. (NSW017) |
54% F2- May 10 |
|
Moose River (NSW061) |
41% F2- May 10 |
|
|
|
|
Cape Breton |
10-15% F2-
May 10 |