Grape production in the Midwest is increasing at a rapid rate. Very little if any are being grown organically due to the fact that little is known about organic disease control on grape in the Midwest. Sulfur is a good material to use for control of most of the major diseases but sulfur treatments will injure some cultivars of grapes. Many cold hardy grape cultivars have never been tested for sulfur sensitivity. The object of the project is to determine which varieties of grapes are tolerant to sulfur applications. Originally we planned to test four varieties however we have been fortunate enough to increase that to nine varieties.
With the assistance of Charles Shapiro, Professor of Agronomy and Horticulture from the UNL Haskell Agriculture Lab Research Center in Concord Nebraska the layout for the plantings were finalized. In the spring of 2004 we planted nine varieties of grapes. The vines are planted 8 foot apart in the row with the rows 10 foot apart just as a normal vineyard would be planted. They are a combination of juice, wine, and table grapes. They were maintained throughout summer and fall to insure the best over wintering results possible which will create a strong healthy vine ready for the sulfur application in the spring.
In the spring of 2005 each variety will be divided into three treatment groups. The first group will be the control group; the second will receive half-rate treatments and the third full-rate treatments. The treatments will be noted as “T-1” the control group, “T-2” half-rate applications and “T-3” full-rate applications. Three rows will make one repetition; each row in the repetition will be allocated one of the three treatments.