By Terence Bradshaw

Grapes continue to be slow to ripen. Warm days later this week should move early cultivars (Brianna, St Croix) along a bit, but most grapes need quite a bit more heat accumulation before harvest.

9/13/2019 Cultivar	Brix	pH	%TA (g/100ml)
				Brianna	16.1	2.85	0.71
Verona	16.5	2.75	1.40
St. Croix	17.2	2.93	1.28
Louise Swenson	18.8	2.97	0.89
St. Pepin	19	2.94	1.46
Crimson Pearl	19.8	2.86	1.17
Petite Pearl	20.6	2.9	1.11
Itasca	21.8	2.95	1.19
Data collected 9/13/2019 at UVM Horticulture Research & Education Center Vineyard, South Burlington, VT.

Where trade names or commercial products are used for identification,

no discrimination is intended and no endorsement is implied.

Always read the label before using any pesticide.

The label is the legal document for the product use.

Disregard any information in this message if it is in conflict with the

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The UVM Tree Fruit and Viticulture Program is supported by the

University of Vermont Agriculture Experiment Station, a USDA NIFA E-IPM

Grant, and USDA Risk Management Agency Funds.

By Terence Bradshaw

September is here, and grape harvest will soon be ‘on’ in Vermont vineyards. While the spring was generally wet overall, diligent management should have left you with relatively disease-free grapes and vines. The dry, hot/warm weather since July has been great for grape maturity, but these recent cool nights are likely to slow development.

This year, we will once again be posting fruit / juice maturity values on the UVM Fruit Program website. Watch for that link in the next couple of days, as I just switched computers so still have to load my web editing software. Until then, I am posting a snapshot of the data below. We don’t have all of our cultivars here yet, but you’ll notice some new ones from our new NE-1720 cultivar evaluation trial. We may pick Brianna next week, but the rest have some time to go.

9/9/2019	Brix	pH	%TA (g/100ml)
Briana	16.2	2.92	0.83
Louise Swenson	17.7	2.97	1.07
Crimson Pearl	19.0	3.02	1.36
Itasca	23.0	3.11	1.19
Petite Pearl	17.7	2.99	1.15
St. Peppin	18.3	2.98	1.50
Verona	15.9	2.78	1.63
Data collected at UVM Horticulture Research & Education Center Vineyard, South Burlington, VT. Accumulated degree days (base 50°F, BE model) since April 1 = 2118.

How do you assess grape maturity using juice data? Please see our relatively new fact sheet, Pre-Harvest Winegrape Juice Testing. That sheet also contains some target values for when to harvest each of the winegrape cultivars in our vineyard.

Where trade names or commercial products are used for identification,

no discrimination is intended and no endorsement is implied.

Always read the label before using any pesticide.

The label is the legal document for the product use.

Disregard any information in this message if it is in conflict with the

label.

The UVM Tree Fruit and Viticulture Program is supported by the

University of Vermont Agriculture Experiment Station, a USDA NIFA E-IPM

Grant, and USDA Risk Management Agency Funds.