Vineyard Pest Alert

 Happy Friday Dear Growers!

I hope you all had a lovely Canada Day, and enjoyed some of the festivities last week.

Let’s get right into it, as there is quite a bit to talk about.

Weather and Disease Pressure:

We will be receiving rain over the next week, so please keep vigilant about your sprays and ensure that you are well covered.

The next 4-6 weeks are peak infection periods for powdery mildew, downy mildew, and black rot. Keep an eye out for the initial signs of powdery mildew. Remember, once you see visible symptoms on vine leaves, the infection has likely already been present for about a week. Make sure to stay on schedule with your spray regimen to prevent falling behind.

For products and application rates, please access Perennia’s pest management tool here: https://www.perennia.ca/pest-guides/

At this time, I would also ask growers to consider leaf thinning – especially for the vigorous varieties- to promote good airflow and spray coverage.

Vineyard Pests:

The update below is provided by Dr. Deb Moreau at Agriculture and Agri-Food Canada.

Observations:

(1)     Phylloxera numbers are increasing. I am not seeing developing crawlers within galls yet, but I would expect eggs to hatch in the near future and new galls on developing tips.

(2)    Spotted wing drosphila (Drosophila suzukii), first captures in our area about a week or so ago. This is quite early to be observing sustained trap captures but base 10 heat units are well over 10-year averages. This pest can be found in grape but does require any management until much later in the season, when fruit is at risk of splitting or if there is a lot of sour rot in the block.

(3)    Leafrollers: I have seen some early leafrollers but very few in number.

(4)   Japanese Beetle: I have been finding good numbers of Japanese beetle (Popillia japonica) and in various locations within the Valley and on grape. Unfortunately, this is earlier than expected based on past years.  This is an invasive beetle, and the adults will cause feeding damage to grape leaves.

Japanese Beetle

What to look for:

·       Adult beetles average 15 mm in length

·       Metallic green head and thorax with coppery brown back

·       There are small white tufts along the sides and at the back

·       The antennae are clubbed at the end

·       Where you find one, there are often more (they tend to cluster)

·       When disturbed, they will drop to the ground.

 

Damage

·       Adults will feed on the upper surfaces of leaves in the top portion of the canopy

·       Extent of damage will vary but can be severe in some vines and varieties

·       New, young vines are especially vulnerable to adult feeding damage

·       In NS, we typically start seeing the adults feeding by mid-late July

 

Management

·       For small blocks and where number of beetles are low, visual monitoring on the growing tips for feeding damage or adult beetles is key. Beetles can be handpicked off vines daily and placed in a small container of soapy water.

Growers should consult the available spray guide if needing to manage higher populations over  large areas. The adults can fly, so timely targeting of sprays will be key.

Leafhoppers (grape, potato, and three banded leafhopper) are on the rise. Initial symptoms include hopper burn (browning on the leaf margins).  

Again, for effective products, access the Pest Management tool, and follow label instructions.

Precipitation, GDD and Growth Stage Updates:

Data provided by Jeff Franklin at the Kentville Research and Development Centre.  

Precipitation:

Month	25-Year Average (mm)	Current Year (mm)
April	81.5	54.0
May	74.0	29.8
June	95.5	83.0
July	81.3	0.0 **
August	94.5
September	104.1
October	115.8

*Up to July 4, 2024

 GDD:

Growing degree days, base of 10 °C starting on April 1
Current Year	10-Year Average
377.3	312.4

*Up to June 6.

 Growth Stages:

Date of Assessment	Marquette	L’Acadie blanc	New York Muscat
4-Jul	peppercorn to pea size	cap fall complete	cap fall almost complete

 Kentville Research and Development Centre.

 

          1) L’Acadie: 4 July2024            2) Osceola Muscat: 4 July 2024                         3) Frontenac Gris: 4 July 2024                                                                      

• Marquette: The vigorous variety, is about peppercorn size or just smaller depending on your location.
• L’Acadie, the benchmark is a little behind, with cap fall complete and fruit set at just about 2mm in size; Osceola Muscat looks to be just slightly ahead and NY Muscat just behind both of the white varieties.
• Chardonnay is at about 80% cap fall and Frontenac Gris just about peppercorn size.    

Upcoming Blogs:

The next couple of blogs will be focusing on vine balance- fruit load to canopy ratio.

We have had a great start to the season, vineyards are lush, and we are seeing a heavy crop load on almost every variety. I understand that this is great news as growers look to recoup costs from the last vintage. Please keep in mind that the vines are still recovering and overbearing them with fruit will weaken them over time. We will delve more into this in the next couple of weeks.

              COVER CROP DISCUSSION AT BENJAMIN BRIDGE- 24 July @ 5:30-7pm

The date is fast approaching!

Join me and our industry panelists for a glass of wine, snacks, and an opportunity to gather some timely information.

Steve Ells, Dr. Medhi Sharifi and Caitlin Congdon will be on hand to share their expertise and answer your questions. The session is supported by the OFCAF program.

Phew! I know that this post is quite a bit to take in, so thank you for your time this week and I look forward to seeing you soon.

Cheers!

Katarina