Several speakers commented that 2009 has been unusually wet. One local farmer said the result has been a record grass crop. Keith Striegler, head of the wine and grape department at the University of Missouri, called it "a New York summer," complete with rains off the Great Lakes.
Andy Allen, viticulture specialist with the University's Extension Service, said growing grape vines has always been a challenge due to a wide range of diseases. The San Joaquin Valley in California has developed into a hub of grape and wine production, because it is arid. Growing grapes east of the Rockies, Allen said, is a constant battle against a wide range of diseases.
Japanese beetles hit the area in "devastating proportions" in the past two years, Allen confirmed.
"Japanese beetles adore grapes," Allen said. "They can strip a vine in a few days. Starting in June there are six to eight weeks of pure utter devastation."
Allen advised spraying with pesticides to kill the beetles every five to seven days. An easily acquired pesticide such as Sevin works well, as does Danitol or Imidan. Spreaders, stickers and wedding agents can also help.
In general, Allen advocated a proactive approach to stopping insect and disease problems. He found grapevines to be "a fairly agri-chemical intense crop" that can be easily damaged. Common European grape crops like Cabernet, Merlot and Shiraz are very susceptible to diseases here. Native varieties or crossbreds with European grapes fair better, like the Norton, which is the state grape.
The Southwest Research Center is in its second year of having a vineyard, where several ideas are being tested. Allen said a big key to success with grape is where the vineyard is located, making sure the site gets plenty of sun and air flow to promote dryness and avoid fungal diseases. Cutting out diseased wood or old berries to avoid the potential for bacteria is key to maintenance.
More common problems likely to surface include Anthracnose or bird's eye rot, the similar Phomopsis, all of which can be headed off with lime sulfur spraying at the pre-dormant stage. Later in the spring, black rot and powdery mildew become culprits, requiring different sprays. Sour rot is common in Missouri. Downy mildew surfaces after rains. Allen provided spraying guides with specific products and schedules for all small fruit crops.
Striegler took visitors out into the vineyard itself to show several approaches being studied. Since plants need protection from weeds, a covering is recommended for the vines to shield them from spray by herbicides. Single use milk cartons, costing 10 cents each, or reusable grow tubes, a wrap-around cardboard shield costing up to 90 cents each, are being used in different parts of the vineyard to see which is more effective over time.
Where deer are common, Striegler said grow tubes can block the plant from nibbling. He has three different lengths of grow tubes in the center's vineyard. The longest, costing twice as much, cover the plant higher than deer can reach.
The center uses Chamberson grapevines with some grafted on resistant root stock. It can take four years to get a grape crop. Striegler is working toward getting a crop in three years. Different approaches are being used, such as growing two trunks per plant or letting several vines grow out then cutting back to the best two, to see which is the most productive.
Establishing a vineyard can cost $10,000 to $15,000, Striegler said. Many cannot afford to wait four years before getting any income back. The center plans to study its approaches over a 10-year period, develop recommendations and let growers decide how to use the results.
Traditional home gardeners got to see heirloom tomatoes, Rumanian beans and other varieties of familiar crops in a garden walk with center horticulturist Andy Thomas. The center's American persimmon grove, one of the largest in the country, provided a chance for Thomas to explain researchers have much to learn. Persimmons, though easily grown in Missouri, have had little research done on them.
There are both male and female persimmon trees, Thomas explained, the males needed for the females to produce fruit. It is not clear how the combination works or in what quantity. Thomas wished he had been at the center to promote the process. Grapes are wind pollinated, he said, but persimmons may benefit from extra help.
The center has persimmons where the American and Asian strains have been crossed, but those trees have never borne fruit, Thomas said. Personally, he prefers the pawpaw as an underdeveloped Missouri fruit tree, but more calls come in about the persimmons. Oddly, of all the local fruit-bearing plants, persimmons proved to be of no interest to Japanese beetles, Thomas added.
One experiment the center is trying is watching how a prairie grows. A five-acre plot has been seeded with around 60 species of plants and allowed to grow. While private lawns tend to be a "biological wasteland," Thomas said, the prairie has been interesting to watch and somewhat unexpected. Differing plants have dominated from season to season and year to year.
After three years, more varieties are surfacing while others that once dominated take on a more minor role. Thomas said at the end of the growing season, the prairie is burned off and allowed to start over in the spring.