Back to top

Faculty Focus

Five Questions for Tim Martinson 

Tim Martinson joined the section of horticulture in the School for Integrative Plant Science (formerly the Department of Horticulture) as senior extension associate with the statewide viticulture extension program in 2007, after serving as area extension educator with the Finger Lakes Grape Program from 1997-2006. He came to Cornell in 1985 to pursue graduate studies in entomology, and received his Ph.D. in 1990.  Martinson co-edits Appellation Cornell and Veraison to Harvest, and directs the multistate “Northern Grapes Project”, with 11 cooperating institutions in the upper Midwest and Northeastern states.

What inspired you to work with grapes?
I have never had a five-year plan like some people. I was trained as an insect ecologist, and spent several years at the station on various research projects associated with grape insect pests before entering extension with the Finger Lakes grape program.   I learned about viticulture from Rick Dunst, Jim Kamas and Tim Weigle at the Lake Erie Vineyard Laboratory in Fredonia, in the course of completing a five-year study of the impact of eastern grape leafhopper on Concord yield and quality.  That’s where I learned about yield components, and the considerable influence that growing conditions in one year can have on grapes over the following two to three years.   That’s incredibly fascinating, and the chance to work with other researchers at Cornell and growers on a variety of aspects of grape production and grower education was, and continues to be very appealing.

What are the major challenges in viticulture in New York?
Coping with a variable climate.  Growers in cool-climate regions with significant rainfall face challenges that warm-climate growers in arid production areas in the west don’t have to deal with (they have their own challenges).  The list is long:  Five major fungal diseases to manage, winter injury (three major episodes since I started in 1997), and short growing seasons.  The most important difference is that fall frost often dictates when harvest will end.  Growers don’t have the luxury of extended ‘hang time,’ and can’t count on having functional leaf area to replenish vine reserves in the fall after harvest like their counterparts in California. 

This fact means that growers have to be nimble in adjusting their growing practices from season to season.  Growers need to be ready to adjust pruning practices to cope with winter injury, and to replace trunks and cordons (or vines) as needed.  They have to manage canopies to provide cluster exposure to reduce diseases and improve spray coverage.  They also have to manage cropping levels to insure that their grapes get ripe (or meet processor standards) and set the vines up for the following growing season. 

Managing cropping levels is an area where our research and extension programs have had a major impact.  Concord growers now have the ability to use mechanical crop thinning to maximize crop potential.  In a warm year they can leave extra crop on the vines and be confident it will get ripe; in a cool year they can get their grape harvesters out in August and remove excess crop to insure that their grapes reach processors standards and are harvested in a timely manner.  This tool is the result of 15 plus years of research and field trials in which growers and extension have worked together to make it practical.

What projects are going on in your program right now?
Over the past four years, I’ve led the Northern Grapes Project, which focuses on cold-hardy wine grape varieties developed at the University of Minnesota and through private breeding programs in the upper Midwest.  These cold-hardy varieties survive winter temperatures down to -30 degrees Fahrenheit and have made it possible to grow grapes in the upper Midwest and New York regions outside of our traditional growing areas.  There are now about 5000 acres of grapes and 300 wineries in 12 states from North Dakota, Minnesota, Wisconsin and Iowa to Vermont and Massachusetts.  The project involves collaborations with 25 research and extension specialists at 11 universities and 20 regional growers associations in 12 states.  It’s exciting to work with growers and small wineries who have started their businesses within the last 10 years.

Other projects include the bud hardiness monitoring project and grape maturity sampling across New York.  Both provide data that are used in Veraison to Harvest on our Bud hardiness page to provide data-based information to growers in New York.   And over the years the resulting data is accumulating to improve our understanding of how our variable weather impacts grape maturity and winter injury.

Has anything about the grape and wine industry in New York surprised you?
I am amazed at how fast new practices work their way into the industry.  Since starting my career in extension I have seen many changes.   Vinifera growers in the Finger Lakes have adopted intensive canopy management practices, including ‘Scott Henry’ vertically-divided training systems and mechanical leaf removal to improve cluster exposure.  Concord growers in western New York and Pennsylvania used mechanical crop thinning on 60% of the acreage in 2013.  Long Island growers have established the first Sustainable Viticulture certification program in the East.  And perhaps most surprisingly:  Grapes are being commercially grown in Watertown, the Upper Hudson Valley, and the Champlain region.   I never would have predicted that.

To me, this is a tribute to the close collaboration I’ve seen among growers, juice processors and wineries, who share information freely – and also to the research and extension staff at Cornell.  I’ve had the opportunity to collaborate with plant pathologists, virologists, entomologists, geneticists, enologists, and economists and numerous growers and winemakers.  These relationships are what makes my job fun.

What was the best piece of research advice you have received?
One year's data doesn't provide the whole story. Always provide growers with your best advice, based on the most recent, up to date research information you have.  If the next growing season changes your interpretation of the facts, then use that information to tell growers that you have changed your mind.