Blog Post_ July 23, 2024

Hi, everyone

Berries are ripening quickly. From weather station data, personal observations, and growers’ feedback, the ripening % is from 50% to 85%, depending on your area and field conditions. It is an early harvesting season. The earliest areas in the province are looking to begin harvest on August 1. Before that, we still have a few obstacles to address, especially Spotted Wing Drosophila (SWD) and Blueberry Maggot!

In this post, I will focus on:

-       Nova Scotia GDD and Soil Temperature Updates

-       Wild Blueberry GDD and Crop Stage Updates

-       SWD and Blueberry Maggot Management

 

Nova Scotia GDD and Soil Temperature Updates

Figure 1: Heating degree day accumulations for plant (above 5°C) and insect (above 10°C) development from March 1 to July 22 for the past 17 seasons. Provided by Jeff Franklin (AAFC Plant Physiology).

As indicated in Figure 1, this season’s growing trend continues to be ahead of the provincial averages. This information also explains why we are calling for an early harvest compared to the previous years. From Jeff Franklin’s comments: “This trend is expected to continue so we may finish July with the highest accumulated degree days on record.”

Higher than-average temperatures could contribute to higher and more stable soil temperatures. In Figure 2, the current season’s soil temperature (red line) was above the 10-year average since July. Warm soil temperatures could expedite berry ripening and insect infestations.

Figure 2. Kentville Research Station Soil Temperature

 

 

Wild Blueberry GDD and Crop Stage Updates

 

Let’s take a look at 15 weather stations’ GDD accumulations in different wild blueberry regions and their ripening status.

 

The average for all 15 stations is 1407 GDD (Figure 1). Some of the earliest areas in the Southshore, Hants, Westchester Station, Parrsboro flat, Newville Lake regions are looking around 70-85% ripening, which will be the first few areas to begin harvesting in NS. Thus, we are looking about 50-85% ripening across the province, depending on your situation. Figure 4 is a quick sheet to show last year’s ripening % and GDD numbers, which can serve as reference points to predict this year’s harvest schedule. Around 1700 GDD, crop fields could reach around 90% ripening and also be marked as the harvesting point if growers decide to.

 

Here is another quick tip if you are trying to calculate how many more days before harvesting. The average daily GDD accumulation in July is around 20 GDD, which means this time of the year we are gaining about 20 GDD daily.

 

Figure 3. Wild Blueberry GDD_ April 1 to July 23

 

The latest GDD summary is also useful for sprout fields and their management. All sprout fields in NS are looking above 90% tip die back. Please don’t forget your leaf disease management. Ideally, one application should be done pre-harvest. A second application might be required if wet conditions develop in the late summer.

 

Figure 4. Wild Blueberry Ripening % and GDDs (based on 2023 season data)

 

 

SWD and Blueberry Maggot Management

We are in a very high SWD and maggot pressures season. The key driver is the weather, and berries ripen earlier, which serve as early food sources for emerging adult insects.

Since the beginning of this spring, the soil temperatures have been above the provincial average for the most of time in this growing season, especially in March. Higher soil temperature is favored by insect eggs as they can emerge and develop early.

From field reports, we are seeing early captures and higher numbers of adults in traps. Growers are encouraged to put traps out to monitor. A lot of industry partners are working together to share their monitoring information.

An early first insecticide application might be needed in the next few days for many growers. At this point, I would encourage growers to develop a management plan. Please also double-check with your processors regarding their approved insecticide products. Please continue to monitor for the next few weeks.

 

Lastly, I want to share some information about SWD and Maggots and I hope they are helpful.

SWD- Perennia: https://www.perennia.ca/wp-content/uploads/2020/02/SWD-factsheet_March2020.pdf

 

SWD- UMaine: https://extension.umaine.edu/blueberries/factsheets/insects/210-spotted-wing-drosophila/

 

Blueberry Maggot- UMaine: https://extension.umaine.edu/blueberries/factsheets/insects/201-monitoring-for-the-blueberry-maggot/

 

Blueberry Maggot- NB: https://www2.gnb.ca/content/dam/gnb/Departments/10/pdf/Agriculture/WildBlueberries-BleuetsSauvages/C230e.pdf

 

 

Have a great harvest season!

 

Hugh

Blueberry Fruit fly and other reminders

I've been getting some reports of large numbers of fruit flies on traps in Cumberland county, with it being more sporadic in central and eastern parts of the province.  Things are behind normal but we should be checking traps now!!

Also, now is the time to be putting leaf rust sprays on your sprout fields, to protect against leaf rust infection and allow your leaves to stay on the plant longer into the fall.

Check the production guide for available control options https://www.perennia.ca/wp-content/uploads/2018/03/wild-blueberry2019.pdf

(Remember always check with your buyer to see what is allowable for their markets)

It has been a strange year and harvest looks like it might be starting later than normal.  Monitoring for SWD is something to not forget about, as we get closer to harvest.  SWD hasn't been a huge issue in Nova Scotia over the last several years, but one lesson we can learn from the last two years, is to not count on mother nature, we need to keep an eye on what is happening in our fields.  https://www.perennia.ca/wp-content/uploads/2018/04/monitoring-for-spotted-wing-drosophila.pdf

Harvest underway and SWD

Many have started harvest, but it's still pretty early to tell how fields are coming off.

Of note: We are starting to see a scattering of positive SWD adult captures in Northern NS.  The numbers are very low and typically found in field borders close to wild raspberry and other brambles.

If growers are trapping they should be checking the traps every few days, particularly on fields that won't be picked for a couple of weeks.

If you do start to see increasing numbers check the following link for allowable products. http://www.perennia.ca/wp-content/uploads/2015/08/SWD-Factsheet-emergency-reg-July-2017.pdf

Remember!! be very cautious of pre-harvest intervals and check with your buyer for what products work for their markets.

I will update the blog if the numbers start to increase.

SWD Update - August 26th

I've gotten some reports from some others trapping SWD around the province.

There have been some sporadic single captures of males over the last two weeks.  Most of the captures have been found in the earlier harvest areas of Parrsboro.  Many of the captures we have seen over the last couple of weeks are on field borders and in the woods.  This is consistent with what we have seen in the past.

One field, in the Parrsboro area, did have 3 male captures this week in a crop trap.  (the trap was placed out in the field).  At this point, this is an isolated field.

So, we are still not seeing widespread captures but localized captures in several areas.  The numbers are still low and to date we do not have confirmed larvae in the fruit in any area.

If you have a field that is still two weeks away from harvest, I would strongly encourage you to monitor for SWD. Here is the factsheet on monitoring - SWD monitoring

At this point, there is no need to consider spraying a field that will be harvested within the next 5-6 days.

Just a reminder of what is registered if you do need to spray in the next couple of weeks.  Products for SWD

Remember to contact your buyer, if you do spray, to see what is allowable for their markets and pay close attention to pre-harvest intervals.

I will update early next week.

SWD found in Central NS

We have our first confirmed capture of SWD in Central Nova Scotia for 2015.  It was not a blueberry field but it should put blueberry growers on alert, as it is likely we will start to see initial adult captures in fields within the next week.

From what we know so far, SWD adult captures are slow to build in isolated wild blueberry fields.  Once a field has first capture, as a grower, you have a several days to a week window to get the crop harvested, with low risk of fruit infection.   If you are still two weeks away from harvest and are capturing adults a control should be considered.

Here is the link for allowable products for control of SWD. ( SWD product guide )

Pay particular attention to Pre-Harvest intervals.

Consult with your broker or processor first for which products are allowable for their markets.

Note: We have not found SWD in any wild blueberry fields in Northern Nova Scotia yet, but it has been found in this part of the province.

Blueberry Maggot and spotted wing

I was in several fields today and saw plenty of blueberry maggot on sticky traps. Of note I did not see them in every field. It is important to get your traps out ASAP.


SWD - This week we did have a confirmed capture of 1 male SWD in the Annapolis valley. This is earlier than expected and earlier than the last couple of years. Out of 45 traps being monitored in the valley, 1 fly in one trap was found.
We may not see flies for another couple weeks in central and northern NS, however, growers should be putting their traps out now.

This does not necessarily mean we will have a bad SWD season, but growers do need to be vigilant with their monitoring as we approach harvest.

I will keep you updated here and on the blight line through harvest.

Berries turning blue, time to monitor

I've been seeing the first blue'ish berries around central NS.  Now is the time to get Blueberry maggot traps into your fields.


Also SWD traps should be placed on field borders beginning this week.


UPDATE:


The PMRA has just revoked the approval of Ripcord for use on Highbush and Lowbush blueberries for SWD control.


As a result we still have Malathion, Delegate and Entrust as products with an emergency registration for control of SWD.  Exirel has a full registration on blueberries for SWD control, but there are some import restrictions in other countries.


Contact your processor or buyer to see what is allowable for their markets.


Here is the updated guide Allowable products for control of SWD

SWD factsheets

I have posted two updated factsheets on our website.


Monitoring for Spotted Wing Drosophila ( Monitoring for SWD )


and


Emergency Registrations for SWD ( SWD products )


You can review how to monitor for this pest and see which products are allowable by the PMRA for use. 


(Remember - ALWAYS CHECK WITH YOUR BUYER OR PROCESSOR TO SEE WHAT IS ALLOWABLE FOR THEIR MARKETS)


I will be posting swd captures in blueberry fields on this blog when we start to see them appear.


Other notes:


We are at the tail end of bloom in the central part of the province. Many early fields look to have a pretty good fruit set. 


As the bees move out it is time to think about monitoring for blueberry fruit fly as well. Blueberry fruit fly numbers were high last year, it is important to get your yellow sticky traps out as the first berries start to turn blue.

End of Harvest

Well maybe there are a few stragglers, but the majority of the crop is sitting in a freezer somewhere.

This was a challenging year, with high blueberry maggot adult captures in July, SWD appearing earlier than hoped and the significant amount of fruit and leaf disease increased but hot and humid weather throughout most of late June and July.

I would like to have a debrief with growers and scouts over the next couple of weeks to see how SWD monitoring worked, how effective they felt applied controls worked and how much damage they saw.  I will be contacting various growers to see how things went from their perspective.

We've learned quite a bit, from a research standpoint this year, but the learning curve for managing this pest in a wild blueberry situation is still pretty steep.

Some things we do know:

1) SWD is throughout mainland NS
2) SWD will lay eggs in lowbush blueberry
3) SWD adults will begin to appear in Northern NS blueberry fields in early to mid August (give or take a week depending on the year)\
4) Picking early and fast is stressful, but really goes a long way to avoiding the large adult populations later in the season.

We will be giving growers updates and new approaches to this pest at the AGM and throughout the winter. Stay tuned.

Spotted Wing Drosophila Update (SWD)

There have been confirmed captures of SWD in the Mt. Thom area.  It is likely that there are low level populations throughout Mainland Nova Scotia.

Continued monitoring is important!

SWD appearing in more areas in Northern NS

We saw our first capture in Northern NS last week in the Parrsboro area.  We are now seeing initial captures across the region.

In the Parrsboro area, there are multiple adult captures in some fields.  Growers in this area should strongly consider a weekly spray program until the end of harvest to limit damage.

There are confirmed initial captures in the Wentworth area as well as the Musquodoboit valley.

There are suspected captures in other areas as well.  It is likely, based on trends in other jurisdictions, that there are sporadic populations building across the region.

All growers should be monitoring their fields.  Given the captures it would be a very good idea to check the traps more frequently (every 3-4 days).

Fields that are to be harvested within 3-4 days do not need to be sprayed.  For fields that are more than a week away from harvest, growers should consider control options, unless you are intensively monitoring and have not caught any adults as of yet.

Products registered for emergency use of SWD

Check with your processor or broker for allowable products for their markets.
 

SWD in Northern Nova Scotia-Updated

We have one confirmed case of SWD in Cumberland county, as of yesterday: Diligent River area.

This area is on the lowland area and not in the higher and later developing fields.

Captures are still at low levels and only at a couple of sites at this point.

Based on experience from other areas, SWD starts sporadically and then expands as populations build

What does this mean?

1) If you are in those areas, keep monitoring your fields

2) In these areas if you are within 4-5 days of finishing your harvest, keep picking, the risk to those fields is low.

3) If you won't be harvesting a field or a group of fields for a week or more in these areas, you should consider a control option. 

If you are monitoring your fields individually, you can wait until you get your first capture before spraying (check frequently)
Emergency registered products for control of SWD

(Check with your processor/broker before you spray!)

If you are outside of these areas, you do not need to apply control options yet. However, monitoring  is very important right now, particularly if you are in an early developing area!!

Based on trends we have seen across the country I expect populations to build over the next two weeks and we will start seeing initial captures in other areas.

I will keep you updated on captures in other areas

SWD update - August 9th

As of mid-day on August 9th there are no reported captures of SWD in Northern and Central Nova Scotia.

There have been scattered captures the last two weeks in the Annapolis valley, at very low levels and at very few locations.

As we begin wild blueberry harvest this week, it is important for growers to keep an eye on their SWD traps, particularly in fields that are more than a week away from harvest.

The weather looks very promising for a great start to the harvest season, (once Saturday passes) with forecasted sunny conditions and temperatures in the low 20s.

Reminders and tricks about SWD trapping

 

When trapping for SWD there are a few important points you should keep in mind.

 

 

1) Check the traps weekly or more often if possible.

2) Replace the Apple Cider Vinegar each week. (fill the cups at least 1/3 full, the vinegar will evaporate)

3) Some people take the used vinegar off site to dump it, this is probably the least risky approach. Do not dump it on blueberry plants, it is acetic acid and it will defoliate plants!!

4) Place one trap in the shade on the edge of a field (It does not need to be in the field)

5) Place a trap near wild raspberry or blackberry patches on the edge of fields

6) Plastic lids likely need to be replaced on a weekly basis as they become brittle in the sun. Saran wrap and an elastic might work (don't cover the holes)

 

Monitoring in your fields is the best way to determine when or if you need to spray your fields.

 

As of today, Wednesday July 31st, I have no reports of SWD found in any wild blueberry fields in Nova Scotia.



 

Spotted Wing Drosophila

As of July 29th, no SWD have been found in wild blueberry fields!

I wanted to make this point because late last week there was a report of a positive capture of two SWD adults in the Annapolis Valley (1 male and 1 female). They were found in a hedgerow.

This is an initial capture, and we will know more about how the population is starting to grow later this week.  Remember the Annapolis valley is typically a week or more ahead of Northern and Central Nova Scotia, with respect to crop development and heat unit accumulation.

Note: The traps we are using this year appear to be slightly better than the ones used in previous year.  That could be part of the reason we have an earlier capture in the valley this year.  That being said we are slightly ahead of last year with respect to heat accumulation.

What does this mean for wild blueberry producers?

1) Continue monitoring in your fields

2) SWD has not been found in wild blueberry growing areas in Nova Scotia, yet this year.

3) There is no need to begin control measures until SWD is found in your fields or at minimum the local area surrounding your fields.

4) If you have any question or are concerned about misidentifying the fly, contact me!

Here is a close-up picture of the SWD male from the website (Spotted Wing Drosophila in Ontario )
I will be updating positive captures and general locations as they are brought to my attention on this blog.

Peter Burgess

Emergency Registrations for Spotted Wing Drosophila Approved

The PMRA has approved 5 products for emergency use on Spotted Wing Drosophila.

These registrations are on several crops for the 2013 season (including Wild Blueberry)

Ripcord
Malathion
Delegate
Entrust (organic allowable product)
Pyganic (organic allowable product)

These products are approved for use on Bushberry crops (including wild blueberry and highbush blueberry), caneberry (including raspberry), stone fruits, grapes and strawberry.

Click on the link below, it highlights the product rates, re-entry intervals (REIs), use patterns and pre-harvest intervals (PHIs) for each product in each crop.

Emergency Registrations for SWD

For Wild Blueberry it is important to talk with your processor to see which products work for their markets.

Click below for the SWD monitoring factsheet.

SWD Monitoring Factsheet

I will be doing some monitoring in wild blueberry fields starting in July and will be posting any captures on this blog.

Monitoring for Spotted Wing Drosophila "SWD" in wild blueberry

SWD is a new invasive soft fruit pest that could affect wild blueberries this year. The key for controlling this pest, is to determine when it begins to enter a field and target controls around that first capture.  Monitoring is very important. "SWD" won't be in a blueberry field at any significant levels until the field begins to ripen.  It does not over winter in the field and it is attracted to ripening fruit (any ripening fruit).

Here is a homemade trap that you can build.

There are a lot of unknowns with this new pest, but we have a decent idea on how to trap for it. You can place the traps in the fields around mid July.

Here is a new factsheet that shows you how to monitor for this pest. (click on the link)

http://www.perennia.ca/Fact%20Sheets/IPM/General/SWD%20factsheet_May2013.pdf

Also Click the link below to go to the OMAFRA SWD website. This site has tons of information on this pest.

http://www.omafra.gov.on.ca/english/crops/facts/swd-management.htm

The PMRA is currently reviewing Emergency Insecticide Registrations for control of SWD in all soft fruit for 2013 in Canada.  Their decisions are expected to come soon.  I will pass around a management guide when the insecticides are approved for usage.

Feel free to contact me with any questions.

Peter Burgess
Horticulture Specialist, Perennia
(902) 896-0277