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

Danzinger Vineyards started in 2003 and has grown to 18 acres of 10,000 cold climate vines. The vineyard has 11 varieties. First planted in 2003 and in a 4-year period planted 8,000 vines. Have 10,000 vines now producing. All major cold climate grape varieties are grown on Vertical Shoot Positioned (VSP) trellising. In 2016 harvested 64 tons of grapes – about 4 ton an acre average or 14 lbs per vine. But varieties varied greatly.

Danzinger Vineyards Grape Varieties

1. Marquette: Likes VSP, Hardy, disease resistance, good chemistry, low yielding (10 lbs.) Phylloxera low problem. Normal spray program – no major disease problems. Middle to early harvest for red grape. pH 3.2, brix 22 (1300)
2. LaCrescent: Struggles with VSP, Vigorous at our site, yields 15 to 20 lbs. With normal spray program it is necessary many years to spray extra late for Downy Mildew. Middle to late harvest but must harvest before berries start dropping. pH 3.1 and brix 21. (1400)
3. Frontena: Likes VSP, Loves our site, 15-20 lbs late harvest. No disease issues with normal spray program. Susceptible to Phylloxera. pH 3.2 and brix 22 (930)
4. Frontenac Gris: Just like Frontenac but harvest a little earlier. pH 3.15, brix 20 (1000)
5. LaCrosse: Struggles on VSP. Vigorous – 20 lbs. Medium harvest date. Must pick when ripe or you will have rot and berry splitting. pH 3.1 and brix 20. (200)
6. Pepin: VSP OK – 10 – 15 lb yield. Needs pollination plant. Disease no problem with normal spray program. Can be used for Ice Wine or Late Harvest Wine. pH 3.1 and brix 23 (450).
7. Croix: Struggles on VSP. Early harvest. Disease no problem on normal spray program. Some Phylloxera issues. Yields 15-20 lbs. Some uneven ripening. pH 3.2, brix 20 (660).
8. Brianna: Likes VSP. Early harvest. Good yield 20 lbs. Must be picked when ripe; has flavor and disease issues if left too long. pH 3.10, Brix 16 – 18 (1000)
9. Frontenac Blanc: Grows much like other Frontenac varieties (1000)
10. King of North: High Wire – juice or wine. Vigorous growth, no disease issues on normal spray program. High Acid Grapey. High yield 30 lbs. Raccoons can smell it and like it. (200)
11. Itasca: Latest release from University of Minnesota. Lower acid white wine grape (1200)

These vines, with the exception of King of North, are all on Vertical Shoot Positioned (VSP) trellising. The posts are treated wood with seven high tensile catch wires. Rows are 10 feet apart with posts in row at 24 feet with 3 vines planted between each set of posts. No rows are longer than 425 feet and they are planted on contour.

Our goal of this trial was to see if mechanical pruning would work on Cold Climate Varieties.

We started with a Pre-Pruner that is used in the Northwest United States. This unit works fine and cuts pruning labor by at least 50%. We then decided to see what other things we could do to reduce labor.

The following is a list of practices we are using that work in our Cold Climate Hybrid Grape Vineyard.

1. Pre-prune with a machine
2. Finish hand pruning with hand electric pruner
3. Shred vines and leave in Vineyard
4. Use power brush to rake vines out of row
5. Use Tapener Hand Tie gun to tie up vines
6. Use mechanical hedger to trim vines at least twice in growing season
7. Spray under the vine in row with ATV mounted sprayer
8. Mow with a 7-foot rear discharge mower as needed
9. Spray vines with an air blast sprayer that has had a tower built on it for grape spraying
10. Use mechanical leaf puller to remove extra leaves at least once in season
11. Net the whole vineyard to keep the birds out
12. Harvest by hand picking into small totes and loading into Macro bins
13. Haul Macro Bins to winery with tractor and use dump to put in de-stemmer

Most of these practices are standard in established grape growing areas. In Wisconsin, most of this was not available new or used when we started. Now some local dealers are selling this equipment.

It is our experience that practices that work in other parts of the world for growing grapes can be used in Wisconsin on the Cold Climate Hybrid Grapes. The biggest challenges are weather (humidity) and small size of vineyards.

In the future, we will be trying machine picking of our grapes. Cost of the machine is by far the biggest problem with this.

If we were to make a recommendation to a person wanting to grow grapes commercially, we would want to see 100 acres of grapes to be able to capture the advantages of machines.

I would like to thank Carl Duely, University of Wisconsin Extension Agent for his help with the Power Point.

The attached 3 Power Points have been presented at the Wisconsin Grape Growers Conference and Cold Climate Grape Growers Conference. Also there is an attachment with more details on Vineyard Mechanization including details of equipment shown in Power Points, Youtube video links, and Equipment websites.

Danzinger-Vineyard-automation

Danzinger-Vineyard-crop-protection1

Danzinger-Vineyard-harvesting

Power-Points-Vineyard-Mechanization4

We found that the equipment is very expensive and ended up renting equipment to make our budget reach. We ended up spending all of the grant money.

Thank you for the opportunity to do this project.

Sincerely,

David Danzinger

Danzinger Vineyards.