Organic Grape Production

PROJECT BACKGROUND
As of October 1, 2005, Nissen Brothers Vineyards has seven acres of grapes, two acres of wild plum, and two acres of chokecherries planted, with an additional two acres of grapes being planned for next year’s planting.

The Nissen farm employs many sustainable practices in raising livestock and growing grain. The pastures are cross-fenced and a rotational grazing system is employed. The oats and corn crops are overseeded with turnips that provide excellent late summer and early winter forage for the cow/calf operation. In the spring of 2003, the vineyard was started to help support a returning family member and to keep the farm sustainable.

PROJECT DESCRIPTION AND RESULTS
The goal of this project was to research nine recently released varieties of grapes that grow in the upper Midwest and determine if any of them are tolerant to applications of sulfur. Sulfur can be used as an organic fungicide.

We selected nine varieties of grapes that are winter hardy and are recommended for our growing region. Of these nine varieties we wanted to intensely study four of the varieties: Fontenac, LaCrosse, St. Pepin, and Brianna. From all the information we could find, these four varieties seemed to be the most promising for organic grape production. We planted 300 vines of each of the four varieties. Frontenac, Lacrosse and St. Pepin were planted in April of 2004. They were one year, number one grade, bareroot stock. Brianna was planted in May of 2004 after the danger of frost was past. They were potted green tissue cuttings started in a greenhouse, and hardened off for two weeks before planting in the vineyard. All plants were watered and cared for as needed. On the night of July 3, 2004, a wind and hailstorm came and rendered its might. Brianna, being planted as green tissue potted plants sustained major damage and was not able to recover in time to be included in the sulfur study. The rest of the vines were planted as bareroot seedlings and fared the storm with mild to little damage.

Two of the nine varieties looked questionable for organic production. They were Marechal Foch and Traminitte. We planted 150 plants of each of these. They were planted as one year, number one grade, bareroot stock.

Three of the nine varieties that we felt were highly speculative for organic production were de Chaunac, St. Vincent, and Concord. Concord was planted as a benchmark, as the industry relates and describes varietial properties as compared to Concord. (e.g. Lacrosse is harvested three weeks before concord.) All of the varieties were planted in rows spaced eight feet apart with ten feet in between them. All the plants were watered, weeded and maintained to help insure establishment and be ready for the testing in spring and summer of 2005.

Before testing was to begin in the spring of 2005, we visited with Dr. Paul Reed, Professor of Viticulture at the University of Nebraska Lincoln, and he assisted us in setting up our plots. We divided each variety into three groups. The first group was labeled T1, which was the control group, the second group, T2, received half rate applications of sulfur, and the third group, T3 received the full rate (recommended rate) applications of sulfur. Sulfur was applied to the T2 and T3 group at 10 to 14 day intervals to simulate a rational treatment program and as the weather would allow. The following data was recorded for each application

Product used: Micro Sperse Wettable Sulfur – Dow Agro Sciences
EPA Est. No 6325-6A1 particle size 5 microns
Sulfur rates were determined by the label
One-half rate is 3 pounds of product per acre
Full rate is 6 pounds of product per acre Control group is 0 pounds of product per acre
Water was used as the carrier at a rate of 10 gallons per acre

May 15th 1st application:
Vines had two to three inches of growth,
Weather was partly cloudy, temp 65 degrees F, slight breeze, AM application
.30 inch of rain 24 hours after treatment
No signs of sulfur damage the following week, visibly can see more sulfur on the vines sprayed with full rate than those with half rate

May 28th 2nd application:
Vines are growing rapidly
Weather was sunny 75 degrees F, NW wind 15mph, PM application
No signs of sulfur damage the following week

June 6th 3rd application:
Vines beginning to bloom
Weather was sunny 90 degrees F, SW wind 15-20 mph, AM application
Temperatures moderated the following week
No signs of sulfur damage the following week

June 15th 4th application:
Vines growing vigorously and in full bloom
Weather was sunny and HOT, one week of 90 degree F plus temperatures before any precipitation, AM application
Concord showing slight burning of leaves around edges, some slight to moderate leaf discoloration
Little or no signs of sulfur damaged noted in the other varieties.

June 28th 5th application:
Vines continue to grow vigorously, fruit pruning, and vine training
Weather was sunny and hot - 12 days of 90 degree F plus temperatures following application
Concords showing sulfur burns, moderate discoloration of leaves, and burning around edges. Surprisingly, no signs of sulfur damage were noted in the other varieties.

The results were very surprising to us. Through our research and various conversations we were expecting to kill some varieties with the sulfur treatments, and have some degree of sulfur damage on all of the cultivars. The study called for three application of sulfur, however we made a total of five applications since we saw little to no signs of burning, and had nothing to measure. The evaluation criteria we had developed were to measure the effects of sulfur by measuring the leaf area of the burns, and rate the health and vigor of the vines. However after a total of five applications of sulfur, no damage was evident on the cultivars except Concord, which rendered our evaluation criteria ineffective.

Concord is known to be sulfur sensitive, and we were expecting major damage, however the signs of sensitivity did not appear before the temperatures reached 85 degrees, and then they were only slight. It wasn’t until the temperature was sustained above 90 degrees F that moderate damage occurred. Despite conventional wisdom, it appears that sulfur can easily be apart of any vineyards spray program and can be a significant player in an organically certified fungicide program for Frontenac, LaCrosse, St. Pepin, deChaunac, Foch, Traminitte, and St. Vincent grapes throughout the growing season. It is our findings that sulfur can be used on Concords at least through early summer or until temperatures sustain 85 degrees.

PROJECT IMPACTS
This project has had and will continue to have impacts on the grape growing industry for years to come. First it dispels the myth that an organic certified sulfur will burn your vines and result in serious injure to your vineyard. Secondly it will help growers begin to question the infallible word of the chemical companies, and thirdly it will encourage further experimentation with growing grapes organically, since an organic fungicide does exist.

OUTREACH
Outreach is a very important part of the grant process. Our research project will be useless unless we can get the results out. We were able to partner with the University of Nebraska at Lincoln Viticulture Department, specifically Paul Reed with this project. Paul is the lone Viticulturist for Nebraska – his insight and contribution to this project insured that the research was conducted in a professional manner. It also helps spread the word, since Paul coordinates and conducts many field days throughout the state of Nebraska, and has connections to the entire Midwest region.

The advertising for the field day was done through the Nebraska Sustainable Agricultural Society, the Nebraska Winery and Grape Growers Association and through a UNL press release, which was sent to 4,600 newspapers across Nebraska and the Midwest. Local newspapers, The Cedar County News, The Press & Dakota, and The Norfolk Daily News all ran articles as well as the press release. Other papers ran the press release, however we don’t know all of the ones that did.

The field day itself was held in conjunction with UNL Viticulture department, Cuthills Vineyards, and Nissen Brothers Vineyards. A segment was dedicated to the USDA SARE program, and Paul Reed was the field day speaker. Over 30 fellow grape growers attended the field day with all the participants originating with in a 150-mile radius of the Nissen Brothers Vineyard. Handouts were distributed and the participants walked the vineyard exploring the sulfur damage first hand.