Hi everyone,
This week’s rain is timely and extremely welcome. The moisture helps improve
soil conditions and reduce dust in blueberry fields after last week’s hot,
windy conditions. Good soil moisture is essential for strong nectar production
in wild blueberry flowers, which helps attract bees for pollination.
As we enter early summer, most attention is focused on blueberry flowers,
particularly pollination, blight disease management, and frost concerns. The
recent frost mornings (May 22–24) caused some damage to open flowers; however,
the overall damage level remained low, and frost concerns were mainly limited
to three areas: Oxford, Debert/Belmont, and Sunnybrae (Pictou). Below are
updates and outlooks for the next 1–2 weeks.
Crop Fields
·
Damage to blueberry flowers. We will
begin seeing more visible symptoms of frost and disease damage on flowers. I
have already observed Monilinia Blight (Mummy Berry) infections on leaves in
this year’s crop fields, and some growers have also reported frost damage to
flowers. It is still early to observe significant Botrytis Blight symptoms, as
infection activity is only beginning this week with the recent wet weather.
Figure 1 is an excellent resource from the University of Maine Wild
Blueberry Research and Extension Group, illustrating blueberry flower damage
and providing clear images and key points for distinguishing frost injury from
disease symptoms.
Figure 1. Photo and information credits: University of Maine Wild
Blueberry Research and Extension Group.
·
Bloom-period disease management. During
bloom, two high-priority blueberry diseases — Botrytis Blossom Blight and
Septoria Leaf Spot — become active and can cause significant yield losses.
Fungicide applications remain an effective management tool during June;
however, application frequency, product selection, and timing must be carefully
planned to balance disease control and pollinator protection.
We strongly recommend that producers begin planning their bloom-period
fungicide applications now, as favourable conditions for disease infection and
susceptible bloom stages are currently occurring across Nova Scotia.
Sprout Fields
·
Post-emergence herbicide application. The
timing for Callisto and Venture L applications is approaching in sprout fields.
Following this week’s rainfall and improved soil moisture conditions, field
conditions are becoming more favourable for application.
If goldenrod is your primary target species and you are using the growing
degree day (GDD) guideline to time your Callisto application, we continue to
recommend targeting approximately 400 GDD or when goldenrod reaches about 20 cm
in height, based on current research and successful field experiences (Table 1).
·
Granular fertilizer application. Many
sprout fields are approaching or exceeding 50% plant emergence, which is
generally considered a good timing window for supplying nutrients to support
active vegetative growth through the remainder of the growing season. Improved
soil moisture conditions will also help nutrient availability and fertilizer
uptake.
Table 1. Wild Blueberry Weather Station GDDs Updates
