Grape Harvest 2022
The challenge of summarizing the grape harvest in Iowa is that grapes are grown in a wide geographic range throughout the state. In many of states, grape production tends to be more concentrated in smaller regions such as the Finger Lakes in New York, or the Leelanau and Old Mission Peninsulas in Michigan. In those situations, most growers have very common weather experiences. Driving around Iowa this year, it was clear that was not the case.A few things stand out in 2022, one of them being the variable precipitation in the state. One positive of that is the lack of moisture in many parts of the state seemed to reduce the prevalence of harvest rots, except for some vineyards having some phomopsis fruit rot.
Phomopsis fruit rot generally infects the berries around bloom but does not rot the fruit until harvest.In some of these cases harvest occurred earlier than would be ideal to save the fruit from shattering. Some growers reported starting harvest around a week later than typical, but by the end of the harvest many seemed to be caught up to average. If you look at the growing degree days from 2022, we were pretty were close to average. The weather started out cool in April but warmer temps the rest of the summer got growing degree days back on track to average.
Reports on yield and quality were variable. Some growers had excellent sugar levels and yields, while others had reduced yields at lower sugar levels than last year. One common comment I have heard is that growers reported a wide harvest window. The lack of rain, fruit rots, and slowly changing fruit pH allowed growers a wide range of when to harvest.In our plots we had the same experiences.If you would like to share you experiences or have any questions, feel free to contact me.
Randall Vos
Phone: 641-660-5710
Email: rjvos@iastate.edu
2022 Crush-ISU Winery
This year saw the second commercial harvest for the ISU Winery as well as several research winemaking projects. Two student workers-Emma Frederick and Drew Tuttle and Randall Vos were instrumental during the grape processing activities.
The winery space was used to process grapes starting August 26 with Dr. Watrelot’s group processing a large quantity of Marquette for research projects.
For research winemaking, the MGWII crushed ~500 lbs of La Crescent which had 3 vineyard levels of treatment (no treatment, mild combing/leaf thinning, rigorous combing/leaf thinning) and 3 harvest timepoints (early, mid, late). This project will be featured in a conference presentation at the Iowa Specialty Producers Conference in Feb. 2023, so stay tuned.
For commercial winemaking we crushed a total of 3600 lbs which is about half the amount from last year (7000 lbs). Due to decreased yields from the ISU Horticulture research farm, we sourced grapes from a winery this year, and we were very thankful for the donation from Tassel Ridge Winery for both Marquette and St. Pepin grapes. We’re pleased with the potential of the wines, and excited to continue working on them.
Erin Norton
515-294-1555
elnorton@iastate.edu