Michella's Vineyard

The information included here is from an article on the Cornell University website.

‘GR 7’ is an early / mid-season red wine grape for use
primarily in red wine blends. It is distinguished from other red
wine grapes grown in cool climates by its high degree of winter
hardiness, adaptation to mechanized production systems, and
ability to survive in older plantings where other red wine grapes
are lost due to tomato and tobacco ringspot virus infections. ‘GR
7’ is a highly productive, easy to manage cultivar, and is the sixth
wine grape to be developed by the New York State Agricultural
Experiment Station of Cornell University.
ORIGIN
‘GR 7’ resulted from the cross, ‘Buffalo’ x ‘Baco noir’, made
in 1947. Fruit were first observed in 1953 and vines were
propagated that year for further tests under the number NY 34791.
In later testing, it was re-named GR 7 (Geneva Red 7) for ease of
identification. Initially, the seedling vine was described as vigor-
ous and productive. More detailed records began when vines were
propagated and planted to additional sites in 1955 and 1964. It
was distributed in the 1970’s via the New York Fruit Testing
Association for trials with cooperators.
DESCRIPTION
Own-rooted vines grown in phylloxera (Daktulosphaira
vitifoliae Fitch.) infested soils are productive and vigorous.
Commercial plantings of other red wine grape hybrids, such as
‘Baco noir’, ‘De Chaunac’, and ‘Chelois’, have limited longevity
due to the ringspot virus complex. Over the course of 10 to 20
years, such vineyards suffer severe vine losses and fruit produc-
tion declines. Adjacent plantings of ‘GR 7’ are long-lived and
appear to be resistant to either the viruses or their vectors.
‘GR 7’ was tested in a replicated trial of 27 red wine grapes
at Dresden, NY, in cooperation with the Taylor Wine Co. Harvest
data were collected between 1979 and 1983. In this trial, ‘GR 7’
proved to be vigorous and very productive in comparison with
other red wine varieties (Table 1). Annual cane pruning weights
exceeded 2.0 lbs. per vine, and fruit yield averaged 6.7 tons/acre,
comparing favorably with ‘De Chaunac’ and significantly better
than ‘Chambourcin’. The average weight per cluster was 0.26 lbs.
(Table 1).
In a two-vine planting at Geneva observed from 1996 to 2002,
vines of ‘GR 7’ produced 30 lbs. fruit/vine, with 0.31 lbs/cluster and a mean berry weight of
1.56 g. By comparison, ‘Concord’ in 2001 and 2002 averaged
12.1 lbs. fruit/vine, with 0.21 lbs/cluster and mean berry weight
of 3.34 g. The annual cane pruning weight per vine was 4.9 lbs/
vine (range 2.5 to 7.2) for ‘GR 7’. Commercial experience has
shown that ‘GR 7’ is well adapted to mechanized production
systems. Hedge and minimal pruned ‘GR 7’ vines have sustained
productivity and achieved satisfactory fruit maturity over several
years.
‘GR 7’ vines are rated as very winter hardy at Geneva. Trunk
damage has not been observed and primary bud cold hardiness is
excellent. Following extensive winter cold damage (1980/81) at
Geneva, vines of ‘GR 7’ had 17 per cent shootless nodes,
comparing favorably with ‘De Chaunac’ (22%), ‘Marechal Foch’
(19%), and ‘Concord’ (5.9%) and better than ‘Baco noir’ (61%)
and ‘Chambourcin’ (93%). Between the winters of 1996/97 and
2001/02, mid-winter primary bud cold hardiness was measured
by differential thermal analysis (Pool et al. 1990). The predicted
temperature of 50% primary bud kill (LTE 50) for ‘GR 7’ was –
17.1 F (range –14.6 to –20.4 F). During this same period, the
LTE 50 for ‘Concord’ was similar; mean of –17.4 F (range –16.4)