BLUE FOCUS NEWSLETTER- May 2024

  

BLUE FOCUS NEWSLETTER- May 2024

(Perennia’s Wild Blueberry Production Newsletter)

Photo Credit: Sarah Sachaefer

 

Dear Growers,

Welcome to the wild blueberry bloom season! What a big change in the last two weeks in central NS where we switched from clusters of fruit buds to almost mid-bloom in a week. According to the weather station data, we had above-average temperatures over the previous two weeks in the province. The provincial degree day accumulations based on Kentville station indicated that we are ahead of 5- and 10-year averages. It is almost 2-3 days ahead of the normal schedule. In this update, we will talk about precipitation data as well.  

Below this newsletter, you will find the regular updates on wild blueberry production and management. Good luck with pollination and spraying! Please make sure you protect pollinators when performing field activities. Thank you for all the hard work from wild blueberry growers and their helpers, as well as the beekeepers!

 

Hugh Lyu

Wild Blueberry Specialist, Perennia

hlyu@perennia.ca; 902-890-0472.

May 31, 2024

 

Table of Contents: 

Nova Scotia Weather

Wild Blueberry GDD Updates and Management Recommendations

Management Resources and Tools

Upcoming Events

 

 

 

Nova Scotia Weather

 

2024 Degree Day Accumulations- Kentville

The below figure would give you an idea of how the season is progressing related to air temperature. This is based on Kentville Research Weather Station. Thank you, Jeff Franklin (AAFC) and Michelle Cortens for your contribution.

 Figure 1: Heating degree day accumulations for plant (above 5°C) and insect (above 10°C) development from March 1 to May 27 for the past 17 seasons. Provided by Jeff Franklin (AAFC).

 

Table 1: Heating degree day accumulations for plant (above 5°C) and insect (above 10°C) development from March 1 to May 27 for the past 17 seasons. Provided by Jeff Franklin (AAFC).

The degree day accumulations beginning on March 1 are ahead of the 5- and 10-year averages (Figure 1). There are about 40 GDD differences between the 5-year average and 2024. That’s about 2-3 days ahead of the recent years’ schedule.

 

Cumulative Precipitation (Kentville)

From late April to the end of this month, we had a fairly dry season but there were still some significant wet periods (May 8-9 and May 16-17). A dry season during the Monilinia Blight infection season is positive thus the initial observations of Monilinia Blight infection in NS are low.

The Kentville area received 25 mm of rain in May compared to the 25-year average of 75 mm as of May 29. Figure 2 shows the cumulative precipitation over the last five years and the 10-year average in Kentville Research Station. We had some significant rainfall events in March and early April so we have been above the 10-year average but a deficit precipitation will likely bring it below the average.

Figure 2: Both rainfall and the rainfall equivalent from snow at the Kentville Research Station from 2019 to 2024. Provided by Jeff Franklin (AAFC).

 

 

Wild Blueberry GDD Updates and Management Recommendations

 

Here is a summary of the most up-to-date GDD from 16 weather stations in wild blueberry fields.

 

Figure 3. GDD summary- April 1- May 31, 2024

 

Sprout fields:

 

In province-wide, we are looking at above 50% plant emergence across the majority of sprout fields.

 

At this point:

 

-       It is very risky to apply pre-emergence herbicides to sprout fields.

-       Consider post-emergence herbicide application (Callisto, Venture L, etc.) and spot spray

-       Consider granular fertilizer application

-       Consider sulfur application (soil pH management)

-       Please monitor insect pests, such as flea beetle, blueberry thrips, and leaf beetles. Figure 4 shows flea beetle infestation in a sprout field in early June. If damage is observed, growers should consider insecticide application if it is early or consider fertilizer application in damaged spots to help plants to re-grow.

Figure 4. Flea Beetle Infestation in a Sprout field

 

Crop fields:

The majority of crop fields in NS are in the early to mid-bloom stages. Please consider the following activities based on your own situation:

-       Placing beehives or bumble bees in crop fields to increase pollination efficiency

-       Blossom Botrytis Blight Management

-       Frost watch

 

 

Management Resources and Tools

 

Perennia Online Pest Management Guide

Beginning this year, all of the pest management guides are now available from an online tool. On the tool, you will find wild blueberries under the small fruit pest guides section. You can search and filter the information and/or print. To help you navigate the guide, we have developed a brief tutorial video as well as a how to use guide.

Upcoming Events

 

1.     Join us on June 7, 2024, from 1:00 PM - 4:00 PM and learn how to properly care for your Davis Vantage Pro 2 weather station! During this in-person workshop, we’ll discuss the Davis recommended annual maintenance steps and some common troubleshooting. We will also cover how to access your station’s data. If you would like to follow along with the instructions on accessing your data, please bring a mobile device and the login information for your station, so you can access your account. Registration: https://www.perennia.ca/eventer/davis-vantage-pro-2-weather-station-maintenance-workshop-murray-siding/edate/2024-06-07/.

 

2.     Wild Blueberry Growers Meetings: June 12, June 26, July 10

For meeting details and registration, please visit this link: https://www.perennia.ca/eventer/in-season-wild-blueberry-meeting-series-2024-production-season/edate/2024-03-27/.

 

3.     Free Webinar on Pesticide Drone Application: June 19, 1 PM Halifax time; Over Zoon.  To register: https://us02web.zoom.us/meeting/register/tZEvdu6hqjksGdES3pLq80Y8qvsuWtKge2fU#/registration

 

4.     WBPANS Field Day. To register: https://nswildblueberries.com/field-day/.

 

 

2024 Production Updates and Seasonal Outlook for NS_ 9th Blight Line Post_ May 29

GDD Updates_ April 1- May 27

Figure 1. GDD Summary, April 1- May 27

Nova Scotia Wild Blueberry Crop Stage Updates

Sprout fields:

 

In province-wide, we are looking at above 50% plant emergence across the majority of sprout fields.

At this point:

 

-       It is very risky to apply pre-emergence herbicides to sprout fields.

-       Consider post-emergence herbicide application (Callisto, Venture L, etc.) and spot spray

-       Consider granular fertilizer application

-       Consider sulfur application (soil pH management)

-       Please monitor insect pests, such as flea beetles, blueberry thrips, and leaf beetles. Figure 2 shows flea beetle infestation in a sprout field in early June. If damage is observed, growers should consider insecticide application if it is early or consider fertilizer application in damaged spots to help plants re-grow.

Figure 2. Flea Beetle Infestation in a Sprout Field

 

Crop fields:

 

The majority of crop fields in NS are in the early to mid bloom stages. Please consider the following activities based on your own situation:

-       Placing beehives or bumble bees in crop fields to increase pollination efficiency

-       Blossom Botrytis Blight Management

-       Frost watch

 

 

Quick Monilinia Blight Infection Report for the 2024 Season

 

May is a month with a high risk of Monilinia blight infection in wild blueberry crop fields because of the right crop stage and the Maritime spring weather pattern. As most of you are aware, May is pretty dry. The Kentville weather station recorded 25 mm of rain in May and that’s below the 75 mm 10-year average in the area. Although we received some rain in the last two days, May is very likely running into a precipitation deficit in the province.

The good news is that the Monilinia blight infection risk is low. We had two provincial-wide wet periods (May 8-9 and May 16-17) according to the weather station data, but it was short and mild. Most growers apply at least 1 Monilinia blight fungicide which was very helpful.

After this marathon-like spraying period, most of us will look at fields most closely and frequently. If I see obvious infections due to Monilinia blight, I will share.

 

A free webinar on Pesticide Drone Application.

-       This is a free webinar to talk about pesticide drone application. Time: June 19, 1 PM Halifax time. Zoom. To register: https://us02web.zoom.us/meeting/register/tZEvdu6hqjksGdES3pLq80Y8qvsuWtKge2fU#/registration

 

Have a great week!

Hugh

 

2024 Production Updates and Seasonal Outlook for NS_ 8th Blight Line Post_ May 22

 GDD Updates_ May 21, 2024

Figure 1. GDD Summary, May 21, 2024

Blueberry Frost Risks

As we are getting closer to early flowering, spring frost can pose a severe risk to blueberry blooms if low temperatures occur in crop fields with a good percentage of open flowers.

Below, you can see each blueberry bud/flower stage has a minimal tolerant temperature. For example, fully open wild blueberry flowers could get structural damage under -2.2 c for just 3-4 hours (Figure 2).

This information will be helpful for growers to determine their crop fields’ damage risk and level based on their crop field crop stage and local weather conditions (wild blueberry weather stations or Environment Canada). 

 Figure 2. Blueberry Frost Risks

 

 

Frost Damage? Disease Infection? Monilinia VS Botrytis?

Many growers are wondering how to tell the differences between frost damage and disease infection on leaves and flowers. The UMaine Wild Blueberry Extension team produced a very nice factsheet and this is a good one to print and keep handy. 

Figure 3. Photo and information credits: UMaine Wild Blueberry Research and Extension Group

2024 Production Updates and Seasonal Outlook for NS_ 7th Blight Line Post_ May 15

Hello everyone, 

Here are the mid-week wild blueberry production updates. The weather across the province is looking decent and there are some good windows to spray.

Wild blueberry crop fields in Nova Scotia are in the middle to late susceptible period to Monilinia Blight (Figure 1). Please monitor your local weather forecasts and crop development to plan management activities accordingly.

 

Figure 1. Susceptible stages of wild blueberry to Monilinia Blight infection

 

GDD Updates_ May 14, 2024

 

Figure 2. GDD Summary, May 14, 2024

Wild Blueberry Sprout and Crop Development Stages

Sprout fields:

Pre-emergence herbicides should be applied ASAP. Sprout fields and areas with more than 230 GDD are risky to receive treatment applications, especially if you are going to put on Chikara and Ignite.

 

Crop fields:

Most areas in mainland Nova Scotia are now well above the 40% F2 stage of plant development which makes them susceptible to infection. A couple of sites we monitor in the Cumberland area are around 80-90% F2 in a tight cluster stage (Figure 3). Watch and monitor your weather forecasts closely. Higher temperatures require less duration of wetness to bring a high risk of infection. We are looking at around 15- 20 degrees Celsius in the next couple of days/

Please note, that an application should give protection to plants for about 7-10 days. If you already applied 1^st spray, please check your record and note your own protection windows. There is a chance a second spray might be needed if we are getting some wet periods in the next few days.

We also recommend growers apply fungicides before a forecasted rain or soon after the rain stops and your fields are dry. Ideally, within 48 hours.

 

Figure 3. Wild blueberry tight cluster stage

 

 

2024 Production Updates and Seasonal Outlook for NS_ 6th Blight Line Post_ May 10

 

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