The Crush - June 2021 - 1

theCrush
Volume 48 Issue 6 June 2021
FEATURE STORY
Winegrape Varieties for a Changing Climate
TRIALS EVALUATE WARMER CLIMATE WINEGRAPES
By Ted Rieger
Global climate trends indicate increasing temperatures in wine
growing regions worldwide that are expected to affect all stages
of vine growth, and overall productivity and grape quality.
Problems associated with quality winegrape production in
warm climates are inadequate acid accumulation and retention,
poor color development, and difficulties with aroma and flavor
precursor development.
Dr. Greg Jones, a climatologist and director of the Evenstad
Center for Wine Education at Linfield University in McMinnville,
Ore., has studied issues related to weather, climate and viticulture
for 30 years. During a recent online presentation hosted by the
Fresno State Department of Viticulture and Enology, Jones said
modeling of climate data and trends indicates the potential for
2-6 F warming in wine regions globally by 2040-2060. However,
he said, " During the past 15-20 years, many regions have already
seen conditions that were expected to be more like averages for
2050. " Jones said all California climate zones have warmed during
the growing season from 2.0-3.3 F between 1895 and 2020, and
average temperature increases are expected to continue.
Jones studies " variety-climate thresholds " to try to understand
what is the optimum climate/temperature range for growing
specific winegrape varieties for even ripening, balance and
quality. He created a " grapevine climate/maturity groupings "
chart for 21 more common varieties based on relationships
between phenological requirements and growing season average
temperatures for quality wine production. He said pinot noir has
one of the narrower threshold ranges, about 13-17 C for average
growing season temperatures for quality production. Jones
is among a growing number of voices in viticulture who
questions why, with thousands of known
grape varieties, less than 20 account for
the vast majority of global winegrape
production. " We have so many varieties
Tannat in the Kearney trial was found to perform well in a warm climate.
Photo: Ted Rieger
available that we don't know much about, " he said. " Are we
growing the best varieties for quality production in the right
climates? "
GLOBAL VARIETY TRIALS
Climate suitability field trials in winegrape regions worldwide
are evaluating existing varieties that are currently grown and
associated with warmer regions in Italy, Spain, Portugal, southern
France, Greece and the Republic of Georgia. In Bordeaux, France,
the VitAdapt experimental vineyard is evaluating 52 varieties
representing the above regions in addition to Bulgaria and
France's Languedoc. Based on trial results, Bordeaux appellation
The Crush - June 2021

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