OHIO AGRICULTURAL RESEARCH AND DEVELOPMENT CENTER OHIO STATE UNIVERSITY EXTENSION Maturity at OSU Research Vineyard

Imed Dami and Diane Kinney, Viticulture Program, Department of Horticulture & Crop Science, The Ohio State University.

The OSU Viticulture Program has initiated a new outreach activity by posting fruit ripening progression of grape varieties grown at the OSU research vineyards on our new website, “Buckeye Appellation” (ohiograpeweb.cfaes.ohio-state.edu). Typically, monitoring fruit maturity begins at veraison (initiation of fruit ripening) to determine when the fruit is ripe to pick. A berry sample is collected weekly to measure weight, soluble solids (sugars), pH and acidity of the juice. At the research vineyard in Wooster, we have began sampling in early August and the following table summarizes the results. Due to winter damage in 2014 and 2015, we are reporting fruit maturity numbers of mostly hybrids, which all have a crop this year. The date of berry sampling and corresponding heat units or growing degree days (GDD) are included. GDD is a more accurate indicator of fruit ripening than the calendar date and measures the heat accumulation at the Wooster location. The GDD in your location could be higher or lower than that at our site. Typically, at the Wooster research vineyard, grape ripening of similar varieties is about 1 to 2 weeks behind central and southern Ohio, and 1 to 2 weeks ahead of more northern latitude vineyards and on Lake Erie shores. To learn more about monitoring fruit maturity and berry sampling, please read OSU factsheet at the following link: ohiograpeweb.cfaes.ohio- state.edu/sites/grapeweb/files/imce/pdf_factsheets/determining%20Fruit%20Maturity.pdf. We hope you find this new resource informative and helpful to your business. As always, please contact Dr. Imed Dami ([email protected]) if you have questions regarding this.

Grape maturity of grape varieties at the Wooster research vineyard in 2015:

Sampling Date: 8/4/2015 GDD=1822

Variety 50-Berry weight (g) SS* (%) pH TA (g/L) SS/TA

Frontenac 66 15.4 2.47 27.48 6 Frontenac gris 64 16.5 2.45 25.78 6 69 14.5 2.59 21.09 7 73 16.1 2.45 24.13 7 Aromella 89 11.3 2.33 26.73 4 87 15.2 2.68 14.36 11 Grape maturity of grape varieties at the Wooster research vineyard in 2015:

Date: 8/11/2015 GDD=1938

Variety 50-Berry weight (g) SS* (%) pH TA (g/L) SS/TA

Frontenac 64 17.1 2.55 25.17 7 Frontenac gris 68 18.3 2.55 21.72 8 La Crescent 73 18.2 2.49 21.46 8 Marquette 82 16.4 2.45 17.73 9 Aromella 91 13.1 2.53 15.34 9 Regent 87 15.2 2.70 13.22 11

Date: 8/18/2015 GDD=2087

Variety 50-Berry weight (g) SS* (%) pH TA (g/L) SS/TA 130 13.9 2.43 17.97 8 Chardonnay 57 13.9 2.47 16.27 9 Frontenac 63 19.7 2.64 21.84 9 Frontenac gris 66 20.6 2.66 22.36 9 La Crescent 83 20.4 2.55 19.02 11 Marquette 81 19.2 2.55 17.92 11 Aromella 106 15.1 2.41 15.97 9 Regent 116 17.1 2.79 11.74 15 Riesling 70 13.9 2.35 18.58 7 90 13.6 2.26 23.18 6

*SS: soluble solids, which estimate sugar concentration in grape juice using a refractometer. pH: measures active acidity (strength of H+ ions) in grape juice using a pH meter. TA: titratable acidity, or total acidity, measures actual amount of organic acids in grape juice. SS/TA: fruit ripening index. Grape maturity of grape varieties at the Wooster research vineyard in 2015:

Date: 8/25/2015 GDD=2223

50-Berry weight (g) SS* (%) pH T.A. (g/L) SS/TA Variety Chambourcin 120 17.0 2.55 17.81 10 Chardonnay 67 17.1 2.54 15.43 11 Frontenac 63 21.5 2.70 18.77 11 Frontenac gris 62 22.6 2.73 17.47 13 La Crescent 80 22.8 2.75 16.92 13 Marquette 86 21.5 2.70 16.60 13 Aromella 109 17.2 2.63 12.73 14 Regent 99 19.7 3.05 9.01 22 Riesling 90 19.1 2.75 11.24 17 Traminette 112 17.5 2.49 16.87 10

Date:9/02/2015 GDD=2358

Variety 50-Berry weight (g) SS* (%) pH T.A. (g/L) SS/TA

Aromella 91 19.3 2.88 14.06 14 Chambourcin 120 18.4 3.01 14.88 12 Chardonnay 73 20.3 3.07 9.73 21 Frontenac 63 23.1 3.16 15.55 15 Frontenac gris 63 23.9 3.19 15.26 16 La Crescent 83 23.5 3.07 13.30 18 Marquette 80 23.3 3.10 13.24 18 Regent 98 19.7 3.32 8.39 23 Riesling 77 18.3 2.95 11.96 15 Traminette 106 18.5 2.86 12.67 15

*SS: soluble solids, which estimate sugar concentration in grape juice using a refractometer. pH: measures active acidity (strength of H+ ions) in grape juice using a pH meter. TA: titratable acidity, or total acidity, measures actual amount of organic acids in grape juice. SS/TA: fruit ripening index. Grape maturity of grape varieties at the Wooster research vineyard in 2015:

Date:9/08/2015 GDD=2527

Variety 50-Berry weight (g) SS* pH T.A. (g/L) SS/TA

Aromella 93 20.0 3.10 10.70 19 Chambourcin 130 18.8 3.10 13.39 14 Chardonnay 67 21.2 3.29 7.99 27 Frontenac 58 24.8 3.35 14.23 17 Frontenac Gris 57 24.7 3.38 12.97 19 La Crescent 77 24.0 3.25 14.43 17 Marquette 50 24.8 3.24 11.65 21 Regent 101 21.6 3.55 7.13 30 Riesling 71 19.1 3.17 9.16 21 Traminette 101 19.7 3.10 10.26 19

Date:9/15/2015 GDD= 2619

Harvest 50-Berry Variety SS* pH T.A. (g/L) SS/TA Date weight (g)

Aromella 85 20.4 3.08 11.03 18 Chambourcin 119 21.2 3.16 11.43 19 137 19.7 3.12 12.04 16 Chardonnay 15-Sep 55 21.4 3.18 6.86 31 Frontenac 59 24.6 3.34 13.62 18 Frontenac gris 61 25.4 3.30 11.18 23 La Crescent 81 25.2 3.31 12.34 20 Marquette 85 24.7 3.31 11.60 21 Regent 14-Sep 115 20.3 3.54 6.95 29 Riesling 15-Sep 89 18.4 3.13 7.71 24 Traminette 103 22.4 3.08 9.23 24

*SS: soluble solids, which estimate sugar concentration in grape juice using a refractometer. pH: measures active acidity (strength of H+ ions) in grape juice using a pH meter. TA: titratable acidity, or total acidity, measures actual amount of organic acids in grape juice. SS/TA: fruit ripening index.

Grape maturity of grape varieties at the Wooster research vineyard in 2015:

Date:9/23/2015 GDD= 2762

Harvest 50-Berry weight Variety SS* pH T.A. (g/L) SS/TA Date (g)

Aromella 23-Sep 90 20.4 3.22 11.10 18 Chambourcin 119 21.9 3.17 10.49 21 Chardonel 103 22.8 3.20 11.48 20 Chardonnay 15-Sep 55 21.4 3.18 6.86 31 Frontenac 23-Sep 59 25.3 3.29 12.85 20 Frontenac gris 23-Sep 59 27.1 3.29 10.59 26 La Crescent 77 25.4 10.93 23 Marquette 21-Sep 78 25.9 3.26 10.7 24 Regent 14-Sep 115 20.3 3.54 6.95 29 Riesling 15-Sep 89 18.4 3.13 7.71 24

Date:9/28/2015 GDD= 2783

Harvest 50-Berry Variety SS* pH T.A. (g/L) SS/TA Date weight (g) Aromella 23-Sep 90 20.2 2.97 11.10 18 Chambourcin 125 22.4 3.2 8.25 27 Chardonel 127 21.5 3.07 9.15 23 Chardonnay 15-Sep 55 21.4 3.18 6.86 31 Frontenac 23-Sep 59 25.3 3.29 12.85 20 Frontenac gris 23-Sep 59 27.1 3.29 10.59 26 La Crescent 28-Sep 79 26.3 3.36 10.80 24 Marquette 21-Sep 78 25.9 3.26 10.70 24 Regent 14-Sep 115 20.3 3.54 6.95 29 Riesling 15-Sep 89 18.4 3.13 7.71 24 Traminette 103 21.9 3.06 8.25 27

*SS: soluble solids, which estimate sugar concentration in grape juice using a refractometer. pH: measures active acidity (strength of H+ ions) in grape juice using a pH meter. TA: titratable acidity, or total acidity, measures actual amount of organic acids in grape juice. SS/TA: fruit ripening index.

Grape maturity of grape varieties at the Wooster research vineyard in 2015:

Date:10/9/2015 GDD= 2871

Harvest 50-Berry Variety SS* pH T.A. (g/L) SS/TA Date weight (g)

Aromella 23-Sep 90 20.2 2.97 11.10 18 Chambourcin 7-Oct 130 22.4 3.24 9.08 25 Chardonel 8-Oct 134 21.6 3.24 9.00 24 Chardonnay 15-Sep 55 21.4 3.18 6.86 31 Frontenac 23-Sep 59 25.3 3.29 12.85 20 Frontenac gris 23-Sep 59 27.1 3.29 10.59 26 La Crescent 28-Sep 79 25.3 3.17 12.28 21 Marquette 21-Sep 78 25.9 3.26 10.70 24 Regent 14-Sep 115 20.3 3.54 6.95 29 Riesling 15-Sep 89 18.4 3.13 7.71 24 Traminette 8-Oct 110 22.6 3.24 8.20 28

*SS: soluble solids, which estimate sugar concentration in grape juice using a refractometer. pH: measures active acidity (strength of H+ ions) in grape juice using a pH meter. TA: titratable acidity, or total acidity, measures actual amount of organic acids in grape juice. SS/TA: fruit ripening index.