Economic Comparison of Mechanical and Hand Pruning of Northern Cold Climate Grape Hybrids in Small Wisconsin Vineyards

Project Overview

Project Type: Farmer/Rancher
Funds awarded in 2012: $21,968.00
Projected End Date: 12/31/2013
Region: North Central
State: Wisconsin
Project Coordinator:
David Danzinger
Danzinger Vineyards

Annual Reports


  • Fruits: grapes


  • Production Systems: general crop production

    Proposal summary:


    David Danzinger began Danzinger Vineyards in partnership with his brother Melvin in 2002. They currently have 14 acres of grapes, all are northern cold climate varieties. The vineyard is located just outside of Alma, Wisconsin overlooking the Mississippi River. David and Melvin were partners in a dairy farm their entire lives following graduation from college. David has his Master's Degree in Agricultural Education and Melvin has his Bachelors of Science Degree in Agronomy, both from the University of Wisconsin-River Falls.  They decided to start a vineyard as the next generation started to take over the management of their dairy farm. A vineyard fits well into Buffalo County with relatively steep soils that are subject to erosion. Danzinger Vineyards sell all of their grapes thr9ugh their own winery. They currently are growing La Crosse, La Crescent, Prairie Star, Saint Croix, Marquette, Frontenac, Frontenac Gris, Blue Bell, Saint Pepin, Brianna, and King of the North varieties.

    Ron Haakenson and his wife Karen, own and operate Whispering Pines Vineyard just south of Westby, Wisconsin in Vernon County. For over 40 years Ron and Karen were successful tobacco growers until the industry started to rapidly decline in the l'!-te 1990's. They knew they had to seek out another source of farm income.  The Haakenson's were selected to be part of the very first grape growing project in Wisconsin by planting a one half acre vineyard in 2001.

    Their vineyard now consists of over 6 acres of cold climate varieties.  The vineyard soil consists of a typical ridge top silt loam soil representative of many Vernon County soils. The Haakensons currently are growing Edelweiss, La Crosse, La Crescent, Prairie Star, Saint Croix, Marquette, and Louis Swenson varieties. Whispering Pines Vineyard contracts their grape to Midwest wineries.

    Daniel and Mellissa Linse farm together with Daniel's parents David and Marge Linse. Their four acre vineyard is located just north of Modena, Wisconsin. The vineyard was planted in 2006 with their second harvest of grapes in 2011.  The vineyard is located on a steep section of the Linse farm. They have Marquette, Frontenac, and Frontenac Gris grapes -- all cold climate varieties that will be part of the project. Besides grapes, the Linses also raise corn, soybeans and turkeys commercially. Daniel is the high school chemistry teacher at Mondovi High School. The Linses sell all of their grapes to other Midwest wineries.


    Most of the land in the Driftless area of Western Wisconsin is highly erodible. Diverse farm enterprises are needed to preserve land, control erosion, and provide economic development in small rural communities found along the Mississippi River. Cold climate hybrid grapes, bred mostly by the University of Minnesota, produce very well and make very acceptable juice, wine and table grapes. The Wisconsin/Midwest grape growing industry is mostly small vineyards hiring local labor and is becoming a strong component of the local food/product movement.

    Hand pruning the vineyard is a very time consuming and physically challenging activity on small vineyards.  The time frame for pruning can be very limited. Many years, heavy snows accumulate in the vineyards and delay the pruning season. Late spring frost damage to the primary buds can severely limit the amount of harvestable fruit from the vines. Delayed pruning can delay the onset of bud break on vines, reducing the chance of late spring frost damage.

    On the Danzinger Vineyard site, it took four people working six days a week, four weeks to prune 12 acres of vines in 2011. This is very difficult, repetitive work and seasonal labor in rural areas can be very difficult to find. This project would compare mechanical pre-pruning to hand pre-pruning. A hand-finish pruning will be used with both systems. It would also compare hand vine pruning versus mechanical vine pruning which is completed throughout the growing season.

    Benefits of these three sites are they are within 85 miles of each other along the Mississippi River, and all three sites grow similar varieties of grapes giving more accurate and reliable data. The project would be designed to measure the following on all three sites:

    • Measure the time required for mechanical pre-pruning with hand pre-pruning.
    • Evaluate the difference of bud break date on hand pre-pruning versus mechanical pre-pruning on cold climate grape varieties. Marquette, Frontenac, La Crosse, La Crescent and Prairie Star varieties will be compared in the project.
    • Evaluate the ripening date on hand pre-pruning versus mechanical pre-pruning on cold climate grape varieties.
    • Evaluate the quality of grapes by measuring sugar, acid, and pH levels at harvest on hand pre­ pruning versus mechanical pre-pruning on cold climate grape varieties.
    • Compare grape yields at harvest time for each variety for hand pre-pruning versus mechanical pre-pruning on cold climate grapes.
    • Compare grape cluster weights and yields for each treatment. Very little cluster weight data is available for cold climate grapes.
    • Evaluate the budgets, including labor differences on hand pre-pruning versus mechanical pre­ pruning.

    Used equipment is not readily available for small scale vineyards in the Midwest. This has been confirmed in an email discussion with Tom Zabedal, Michigan State University Viticulturist. The project leader will continue to search for used equipment in the United States but may have to look to the European used equipment market. The project leader will first attempt to lease the equipment for two years.  Per year lease expenses are estimated to be: $2000 per year for a pre-pruner and $1,000 per year for a finish pruner.  If the equipment cannot be leased, a yearly depreciation expense will be charged against the grant not to exceed the estimated lease amounts


    A 2001 Northeast SARE project titled, "Developing an Efficient Mechanical Pruner for Northeast Vineyards", project leaders were Bob and Dawn Betts was reviewed.  The study looked at building/modifying a pruning machine that would work on larger vineyards in the northeast, mainly New York. Vineyard size was 50 acres or larger and varieties and trellis systems were not suited to the upper Midwest. A major difference was the trellis system in this study is different and requires a different type of mechanical pruner than the trellises used for cold climate grape varieties.

    The Southwest Michigan Research and Extension Center (SWMREC) Report #19 titled, "Consideration for the Mechanical Pruning of Concord Grapevines", 1998 was reviewed. Conclusion of this study was that mechanical pruning was best suited for medium to large vineyards that would tolerate less precise pruning. These were all done on Concord grapes which are not grown commercially in the Upper Midwest.  They are also on larger vineyards and only used mechanical pruning with no hand follow-up pruning.  Concord grapes are grown in the juice industry for yield only, cold climate grapes are grown for quality not quanti

    The final study reviewed was, 'The Challenges of Vineyard Mechanization near the Climatic Limits of Commercial Vine Culture'', Howell, G. Stanley and Paolo Sabbatini, Michigan State University, 2008. This study only looked at Vinifera varieties along with Concord grapes. They also only looked at total mechanization not a combination of mechanical and hand pruning.


    Field days will be held in cooperation with the Wisconsin and Minnesota Grape Growers Associations and University of Wisconsin-Cooperative Extension. Field days will focus on demonstrations, evaluation results as they become available, and economic data for pruning comparisons. Field days will be open to everyone, but special emphasis will be used to publicize them to current grape growers.

    At least one field day will be held each spring to demonstrate the pre-pruning equipment and hand follow-up pruning.  Proper pruning techniques will be shown for the different varieties that are located at the vineyards.

    A summer field day will also be held each summer to demonstrate mechanical vine pruning versus hand vine pruning on different cold climate grape varieties.

    Fact sheets, a DVD, and budgets will be developed in cooperation with UW-Cooperative Extension on the pros and cons of mechanical and hand pruning. Fact sheets, DVD, pictures, and the budget will be available on the Wisconsin and Minnesota Grape Grower and

    UW-Cooperative Extension websites.


    The following will be measured for a two year period:

    1. Time spent pruning in normal pruning months of February through April both hand pre­ pruning and mechanical pre-pruning. Data will be recorded in minutes per vine for all four varieties at all three locations.  A minimum of two replications per treatment will be measured as much as possible depending on the variety and the vineyard layout.
    2. The date of bud break will be measured and recorded for both treatments and all varieties at the three locations. Daily high and low temperatures will also be measured throughout the season at all locations.
    3. Ripening date will be recorded for both treatments and all varieties at all locations.
    4. Grape quality will be determined by measuring the sugar, pH, and acid content of grapes inboth treatments and all varieties at each location. A value per ton will then be assigned to each sample based on winery parameters.
    5. Grape cluster weights and yields will be measured by weighing representative random samples in both treatments and all varieties at all locations.
    6. Data will be incorporated into a spreadsheet to determine any differences measured in

    value and yield for varieties in each treatment and location. These will be compared with labor and machine operating cost to determine the economic viability of mechanical versus hand pruning.

    1. Observational data will also be recorded throughout the growing season on the operation of the equipment on slopes versus level land. Observations will also be recorded on any differences noticed in disease pressure in the different treatment areas of the vineyards.

    Photos and video will be used to record mechanical as well and hand pre-pruning with hand follow-up pruning of the vineyards to be used at field days and in fact sheets that will be developed.


    Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture or SARE.