PEST MANAGEMENT UPDATE
DISEASE CONTROL OPTIONS
Bloom is a transition time for vines and is often the first stress period following budbreak. Shoot growth slows down while the plant focuses energy on flowering and berry set. Nutrient demands change with more demand for potassium and micronutrients such as boron so watch for any signs of foliar discolourations especially on older leaves. Hidden levels of trunk injury (specifically phloem) from winter injury often begin to become apparent resulting in shortened shoots and possibly shoot collapse in severe cases.
DISEASE MANAGEMENT
For the next 5-6 weeks we will be under high pressure for Powdery Mildew especially if the weather becomes warm and wet. Powdery mildew infections can occur with as little as 2-3 mm of rain when temperatures are between 20-25oC. It is extremely important to maintain good powdery mildew protection throughout the entire bloom phase to avoid early mildew infections occurring on the fruit. Be sure you are using a strong powdery mildew fungicide with your bloom sprays where you are expecting any crop to be harvested in 2023.
 |
| Powdery Mildew on lower leaf surface |
Cool and wet weather are ideal for infections from Downy Mildew to occur. Infections are expected to start expressing over the upcoming days from rain events experienced over the past few weeks. In susceptible cultivars such as Chardonnay, Riesling, and Vidal, watch for the development of new oil- spots on leaves in the mid- to upper-canopy before your next fungicide application to determine if you need to include a product like Phostrol in with your next spray.
For all conventionally managed vineyards, continue relying on good locally
systemic fungicides like Torrent, Revus, Forum or Zampro for downy mildew
protection during this pressure period. Be sure you are rotating between
chemical groups for proper resistance management. Revus, Forum and Zampro
are all from the same fungicide group (group 40) and should not be used in back-
to-back sprays.
Use Torrent (group 21) in your next application if you used one of these group 40 fungicides last time.
Organic growers should continue using products like LifeGard or Stargus against downy mildew and can mix in a copper product if you feel pressure is elevated or have some active infections starting to express. There are no resistance concerns with these new biological fungicides so back-to-back sprays are acceptable and encouraged to maintain high levels of disease resistance within the plant.
.jpg) |
| Downy Mildew on lower leaf surface |
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| Downy Mildew shepherds crook |
 |
| Black Rot on leaf |
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| Black Rot closeup showing black specks (pycnidia) |
Refer to the following chart that outlines most of the fungicides available for use this season along with rates, re-entry intervals and efficacy on the big three diseases of concern right now.
|
Product |
Group |
Rate (/ha) |
Re-Entry Interval** |
Activity on Powdery Mildew |
Activity on
Downy Mildew |
Activity on Black Rot |
|
Cevya |
3 |
250 mL |
12 h |
3/3 |
0/3 |
3/3 |
|
Fullback |
3 |
731 mL |
12 h / 7 d |
3/3 |
0/3 |
3/3 |
|
Mettle |
3 |
365 mL |
12 h / 15 d |
3/3 |
0/3 |
3/3 |
|
Nova |
3 |
200 g |
12 h / 7 d |
3/3 |
0/3 |
3/3 |
|
Aprovia Top |
3+7 |
643 mL |
12 h / 2 d |
3/3 |
0/3 |
1/3 |
|
Inspire Super |
3+9 |
836 mL |
7 d |
3/3 |
0/3 |
3/3 |
|
Priwen |
5 |
600 mL |
12 h / 17 d |
3/3 |
0/3 |
0/3 |
|
Cantus |
7 |
315 g |
12 h |
3/3 |
0/3 |
0/3 |
|
Sercadis |
7 |
250 mL |
12 h |
3/3 |
0/3 |
0/3 |
|
Luna Tranquility |
7+9 |
600 mL |
12 h / 24 h |
3/3 |
0/3 |
0/3 |
|
Pristine |
7+11 |
735 g |
Dry / 21 d |
3/3 |
2/3 |
3/3 |
|
Merivon |
7+11 |
300 mL |
Dry / 21 d |
3/3 |
2/3 |
3/3 |
|
Miravis Prime |
7+12 |
1.0 L |
12 h |
3/3 |
0/3 |
0/3 |
|
Property |
50 |
366 mL |
12 h |
3/3 |
0/3 |
0/3 |
|
Vivando |
50 |
750 mL |
12 h |
3/3 |
0/3 |
0/3 |
|
Gatten |
U13 |
690 mL |
12 h |
3/3 |
0/3 |
0/3 |
|
Diplomat |
19 |
926 mL |
When Dry |
3/3 |
3/3 |
1/3 |
|
|
|
|
|
|
|
|
|
Torrent |
21 |
200 mL |
12 h |
0/3 |
3/3 |
0/3 |
|
Forum |
40 |
450 mL |
12 h |
0/3 |
3/3 |
0/3 |
|
Revus |
40 |
500 mL |
12 h |
0/3 |
3/3 |
0/3 |
|
Zampro |
40+45 |
1.0 L |
12 h |
0/3 |
3/3 |
0/3 |
|
|
|
|
|
|
|
|
|
Copper Products |
M |
See label |
4-48 h |
2/3 |
2/3-3/3 |
1/3 |
|
Sulphur Products |
M |
4-5 kg |
24 h |
3/3 |
0/3 |
0/3 |
|
Oil Products |
M |
1% v/v |
12 h |
2/3 |
0/3 |
0/3 |
|
Manzate |
M |
3 kg |
12 h / 7 d |
0/3 |
3/3 |
3/3 |
|
Folpan |
M |
1.25 kg |
24 h |
0/3 |
3/3 |
1/3 |
|
Captan |
M |
3.0 kg |
12 h / 55 d |
0/3 |
3/3 |
1/3 |
|
Maestro |
M |
3.0 kg |
12 h / 55 d |
0/3 |
3/3 |
1/3 |
|
|
|
|
|
|
|
|
|
LifeGard |
P6 |
333 g |
4 h |
1/3 |
3/3 |
3/3 |
|
Stargus |
BM2 |
4.0 L |
4 h |
0/3 |
2/3 |
2/3 |
|
Serifel |
BM2 |
500 g |
4 h |
2/3 |
0/3 |
0/3 |
|
Serenade |
BM2 |
3.3 kg |
When Dry |
1/3 |
0/3 |
0/3 |
|
Oxidate |
NC |
1% v/v |
4 h |
1/3 |
1/3 |
1/3 |
|
ProBLAD |
BM1 |
3.3 L |
When Dry |
3/3 |
0/3 |
0/3 |
|
Timorex
Gold |
46 |
2.0 L |
4 h |
2/3 |
1/3 |
0/3 |
Botrytis protection should commence in susceptible cultivars during the immediate post-bloom period. Botrytis can get an early start in some years, infecting the loose floral debris that can get trapped within the clusters or infecting the flower itself while the flower parts are dying back. Early botrytis infections typically remain as latent infections until veraison, when they begin to express bunch rot symptoms from the inside of the cluster outward. In botrytis prone cultivars (most white vinifera cultivars, Pinot Noir & Gamay), choose products with good activity against botrytis during the post-bloom period. High rates of Luna Tranquility, Inspire Super or using Miravis Prime will provide full protection against both botrytis and powdery mildew and are convenient to use during times when both diseases require protection.
INSECT MANAGEMENT
Vineyards that are continuing to observe feeding injury from Erineum Mites are encouraged to look at the use of oils on sulphur sensitive hybrids. For oils, the recommended label rate of 1% v/v is sufficient. Some growers have been reporting higher than usual levels of Erineum Mite activity and associated feeding injury especially in blocks of cvs. Vidal, Sauvignon Blanc, and Riesling this season. Erineum mite activity typically slows down around bloom, but these cooler conditions are extending the activity period this season.
Watch for leafhopper activity starting and low levels of foliar injury. The recent rain events and overall cooler temperatures have helped to keep alternate host crops lush which lowers the overall pressure on grapevines. Do not use permethrin-based products like Pounce or Perm-Up if you are using oils as they have a warning about potential incompatibilities with oil mixes. In organic blocks the best leafhopper control has been achieved by routinely using oil products and applying a spray of Pyganic at first identified presence of leafhoppers in the vineyard.
Watch for signs of new Phylloxera activity on the upper leaves. Susceptible hybrid cultivars include Baco Noir, Foch, DeChaunac, Chambourcin, Marquette and Frontenac. Blocks that apply Movento pre-bloom should see superior results with no evidence of any new gall formation. Remember that Movento is a slow acting material and the best results have been seen with applications made pre-bloom prior to peak activity. You may not see the same level of control post-bloom since feeding has already occurred and galls are formed. A post-bloom Movento application will more effectively control and mealy bugs or scale insects that may be present.
The recommended Movento timing to address Mealy Bug and Scale will be once bloom is complete. It is a good idea to consider controlling these insects if you have concerns regarding virus transmission and active mealy bug crawlers or evidence of scale identified
in your vineyard blocks earlier this season.