Wine Grape A-2245, named 'Opportunity'

Description:

'Opportunity’

Average harvest date for ‘Opportunity’ was 30 Aug. Juice pH averaged 3.5, titratable

acidity averaged 0.5%, and soluble solids averaged 17.3%. Yield of ‘Opportunity’

averaged 10.9 kg/vine, considered a good commercial yield for a white wine grape in Arkansas.

Crop ratings averaged 7.7, a reflection of good crop and consistent cropping was seen in most

years. Cluster weight averaged 234.3 g. Clusters were rated very full (10 on a 1-10

scale) with berries attached very tightly. Berries averaged 2.7 g. Fruit cracking was not

observed for ‘Opportunity’ following summer rains near harvest. Notes on the fruit evaluated

visually prior to wine production showed that the clusters were compact (tight) and medium-

large in size with medium-sized berries. The skin of the grape was thin with a tannic

characteristic.

 

Rating for vigor averaged 7.2, reflecting medium-high, but not excessive, vigor.

Health of the vines was consistently rated good also, averaging 7.4. Some Mg chlorosis

symptoms were observed in some years but did not appear to affect vine performance.

Observations each year included examination of the vines for presence of diseases. Again, it

should be noted that the vines were sprayed with a commercial fungicide program up until late

June to early July each year. Some rotting of berries was observed in many years particularly

near harvest. This is likely due to the extended period since the last fungicide spray was applied

(as mentioned earlier) plus the tight cluster architecture that contributes to bunch rot. Careful

control of rot nearing harvest will need to be undertaken to ensure disease-free fruit of

‘Opportunity’. In contrast, in the very dry and hot summer of 2012, no fruit rot was noted. The

organism causing this rot was not identified. In over 20 years of observation, powdery mildew

was seen on leaves in two years, and even in the very severe powdery mildew year of 2015, only

slight leaf infection was noted. Downy mildew was not observed on the vines, even in the severe

infection year of 2013 when this disease was very common in the research vineyard. Black rot

nor anthracnose were noted on the vines, but these earlier-season diseases were likely controlled

by fungicide applications and no resistance is implied for these. It is hoped that the minimal

observation of common diseases reflects the potential to manage disease pressures with average

or possibly slightly reduced applications of fungicides.

The adaptation of ‘Opportunity’ to the climate at Fruit Research Station was found to be very good, and

reflective of its potential for reliable production in the Mid-South. Winter injury was not

observed during its testing, reflecting good hardiness for this location. Heat damage was not

noted, even with some of the excessively hot summers such as 2012. In testing in New York,

‘Opportunity’ had five of six vines surviving by 2006, but did experience bud and trunk damage

in the winters of 2003-04 and 2004-05 where winter minima were below -23°C. Late ripening in

New York was noted as a limitation in this shorter-season climate. Commercial growers’ in

Arkansas evaluating this cultivar noted that ‘Opportunity’ is resilient in the vineyard and should

be hand-picked at harvest.

Juice and wine quality of ‘Opportunity’ was consistently good for wine production as

reflected by composition. For wine production, the soluble solids of this juice

occasionally usually needed to be adjusted, but the pH and titratable acidity were ideal. The

yield at crushing was 7.0 kg of grapes for 3.8 L of juice, similar to other white wine grapes in

Arkansas. Fermentation should be done at 15°C to retain fruity characteristics of the wine. Wines

of ‘Opportunity’ were compared to cultivars ‘Chardonel’, ‘Symphony’, ‘Verdelho’, and

‘Viognier’ also from FRS.

The wine evaluation panels with the Arkansas grape and winery industry indicated a

positive impression of ‘Opportunity’ wine. Comments included “great potential, with spice like

‘Semillon’, and bouquet of the cultivar Cayuga”.  ‘Opportunity’ wine has a fruit-forward aroma

with good body and green apple flavor. The acidity can be marked with this wine, but balanced

with adjustment to the residual sugar.  The wine can be a positive addition to the Arkansas grape

and wine industry due to the versatility ranging from sweet, to dry, or to oaked.  The only

negative comment concerned the ability of ‘Opportunity’ to compete with established white

wine cultivars adapted in Arkansas such as ‘Seyval’, ‘Cayuga’, and ‘Chardonel’. It is hoped that

‘Opportunity’ will complement these cultivars in commercial production.

 

https://www.youtube.com/watch?v=_jSYLpsjIcY

 

 

 

 

 

 

 

 

Patent Information:
Category(s):
Fruit Crops
For Information, Contact:
Sarah O'Brien
Intellectual Property Manager
University of Arkansas TCO
479-575-2608
saobrien@uark.edu
Inventors:
John Clark
James Moore
Renee Threlfall
Justin Morris
Keywords:
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