Meet, greet and learn in Missouri

Dr. Turner Sutton, plant pathologist, North Carolina State University, talks to the tailgaters about disease identification.
Photos by Steve Trusty.

Grape growers gathered across Missouri and Arkansas for five Tailgate Meetings that were part of the Institute for Continental Climate Viticulture and Enology’s (ICCVE) mission to help grape growers grow better grapes, make better wine and grow their market. The ICCVE is a part of the University of Missouri (MU) and is partially funded by the Missouri Wine and Grape Board, which directs funds from a statewide tax on wine sales for research, education and marketing.

The meeting at Pirtle Vineyards in west central Missouri near Dearborn hosted over 40 attendees from 35 growers or potential growers from Missouri and Kansas. Here are some of the highlights of the meeting.

Sustainability certification

Andy Allen, extension viticulturist, ICCVE, reported that a sustainability self-assessment workbook was in the final stages of proofing and should be posted on the web site (http://iccve.missouri.edu) shortly. This workbook will initially be used for growers to assess how they are doing in meeting best management practices (BMPs) for their area as developed by the ICCVE in conjunction with the growers. These BMPs include procedures to control or limit damage caused by insects, weeds and disease. Allen said, “This workbook will help growers maintain sustainable vineyards and puts us well on the road to meeting the long-term goal of developing a Sustainability Certification program. That program should be ready by 2012.”

Allen further noted that this certification program can go a long way in helping Missouri and Arkansas grape growers market their products, as well as helping them grow better crops. “Sustainability is a popular hot button right now. The term is rather nebulous, but it comes down to managing your business in an economically, environmentally and socially friendly way. You want to minimize the impact on the environment, do things socially responsible, but you also must maintain a profit. If there is no organic control for a pest, you’d better pick the best nonorganic one or risk losing your crop and maybe your business,” he said.

Jackie Harris, MU viticulture extension assistant, holds a grape root borer trap, just one of the ways to scout for and provide optimum control of grape pests.

If grape growers are going to market their product outside their own stands, there will be increasing demands to show sustainability. Businesses like Wal-Mart are insisting their suppliers have a plan and proof in place. The ICCVE workbook will be a great tool in looking at what you are doing and where you can improve. Because different grapes have different needs react in their own way to varying weather factors, not all of a grower’s vineyard is going to require the same type and level of care. The workbook allows for individual record-keeping for each block of vines. Sustainability is important even if you only sell locally, as the general public is becoming more attuned to businesses that are eco-friendly.

Timing of sprays

Allen also talked about the importance of timing in spray applications. “Time your sprays according to need, not the calendar,” he said. MU and others around the country have conducted research on the life cycles of insects and diseases, and they now know many factors that affect the emergence of a pest in quantities that require control, and they have determined the degree days needed for an insect to hatch. There are formulas to help predict, with quite a bit of certainty, the most effective time to spray for a particular insect. More information can be found on the MU website or by checking with your extension agent. Some diseases are predictable based on humidity or the amount of time the leaves are wet, and by keeping track of these factors, growers can more accurately time applications of fungicides.

Scouting for pests is also important. Utilize traps for insects, and know what the threshold is for deciding on control. MU has modeled many insects’ life cycles to determine what affects their growth and how to time applications to the right point in the cycles if control is warranted.

ICCVE, in conjunction with county extension horticulture specialists, has set up a series of weather stations around the state. They are tracking the factors that affect insect or disease emergence and posting the information on the website. Growers can monitor these reports for their area and make decisions based on the data, their own records, the varieties of grapes they are growing and past experience with pests.

To further help attendees understand the use of the weather data, Jackie Harris, MU viticulture extension assistant, explained a handout showing what the data looks like. She had charts for different diseases and different regions of the state. The charts, which are updated weekly, put together the needed information to help growers pinpoint the best time to spray.

Grape disease

Dr. Turner Sutton, plant pathologist from North Carolina State University, talked about disease identification. “It is important to know what the grape diseases look like and how to identify them, but it is also important to know that once you spot a disease it may be too late to control it,” he said. He went over spray programs recommended in North Carolina and provided his thoughts on how their programs pertain to Missouri. He told growers that some of the diseases they contend with in the East don’t overwinter in Missouri’s cold, so they have an advantage there. He also urged growers to work together to come up with the most effective control programs.

Vineyard canopy management

Allen talked about the latest research on canopy management, stating that, “Canopy management is the attempt to control and direct grapevine vigor and growth in such a way as to maximize both production and fruit quality without negatively affecting vine health and growth.” He reported there are a number of ways to manage the canopy, including hedging, shoot thinning, shoot positioning and leaf removal. “If you can only do one of these, leaf removal is the most effective and important,” he said. The leaves should be removed a week or two after fruit set. If you do it too early, the carbohydrate production is reduced; if you do it too late, the berries are formed under shade and subjected to sunburn when the leaves come off. If you get a late start on removal, but still need to open the vines some for air exchange, remove leaves below the fruit, as the upper leaves will still provide shade while the lower level removal allows some air into the canopy.

Vineyard nutrition program

Allen addressed vineyard nutrition with an emphasis on petiole sampling, stating that soil samples only tell you what is present in the soil. The soil may tie up some of the nutrients present so they are not available to the plant. Growers really need to know what is in the plant. Soil samples from mature vineyards need to be taken every two or three years. Once vines start production, petiole samples should be taken once or twice a year. He provided a handout that gave the details needed for petiole sampling and utilizing the information received.

Dr. Turner Sutton, extension viticulturist, Andy Allen, host extension horticulturist, Marlin Bates and Assistant Extension Viticulturist Jackie Bates at Pirtle Vineyard for the West Central Missouri Grape Growers June Tailgate Meeting.

Allen said that timing of application for nutrients is important. “Don’t apply too early or too late. Vines need leaves on them in order to get uptake of the fertilizer,” he said. He noted that if a considerable amount of nitrogen was needed, it’s best to split the application, half at bloom and half at veraison (onset of ripening).

Grape exchange program

Missouri now has a grape exchange program for those wanting to buy or sell grapes. Postings are made weekly from mid-June through harvest. Wineries looking for grapes can list their needs and vineyards wanting to sell grapes can list their varieties and tonnage available. Contact information is given for each listing. For more information, visit the Missouri Grape Growers Association website at www.missourigrapegrowers.org.

Conclusion

With close to 100 wineries listed on the Missouri Wine and Grape Board website (www.missouriwine.org), it is evident that Missouri vineyards are making a comeback. With the help of the ICCVE, other associations and each other, Missouri will inch its way back toward the number two grape growing status it held in the mid-1800s.

The author is a longtime contributor to Growing based in Council Bluffs, Iowa.