What Fruit and Vegetable Research is Happening at UMN in 2019?

Between professors, graduate students, staff, and Extension educators, numerous people at UMN work hard every day to conduct research that helps make growing fruits and vegetables in Minnesota more sustainable and successful for farmers. We want to make sure that you know about this research and can apply what we learn to your farm.

Steve Poppe maintains bell pepper research
plots at the West Central Research and
Outreach Center in 2018.
Photo: Annie Klodd.

Below are just some of the research projects going on in 2019. Many of these projects are done to address needs raised by growers, and funded in large part because of input by growers on research needs and priorities. We also benefited from letters of support from several growers - Thank you!

Please keep an eye out for the results of this work in future editions of the Fruit and Vegetable News, at workshops hosted by our partner organizations, and at winter conferences such as the annual Sustainable Farming Association, MN Organic, MN Fruit and Vegetable Association, and MOSES.

Dr. Vince Fritz and Charlie Rohwer have a number of interesting projects in the works at the Southern Research and Outreach Center (SROC) in Waseca:

• Effects of planting time and pinching on Brussels sprout shape and yield
• Determining pre-sprout treatments and harvest dates to produce high-tunnel ginger
• Nitrogen requirements for summer broccoli following a spring pea/oat cover crop
• Raised bed and population effects on carrot shape and yield
• Working with growers and brewers to breed new hops for our region

A spring pea/oat cover crop before broccoli
at the SROC in Waseca. Photo: Annie Klodd

The Grossman Lab, led by Dr. Julie Grossman, researches ways in which they can better manage plant-soil-microbe relationships. Current projects include: 

• Nitrogen management with cover crops in high tunnels
• Identifying summer cover crop opportunities, including seeding systems and pollinator forage potential
• Better understanding soil rhizobia as related to nitrogen fixation

The Rogers Lab, led by Dr. Mary Rogers, is currently conducting the following projects related to organic fruit and vegetable production: 

• Investigating augmentative releases of pupal parasitoids for biocontrol for spotted-wing drosophila management in high tunnel raspberries (partnership w/Hutchison lab)
• Investigating the efficacy of botanical-based repellents to lower spotted-wing drosophila infestation in small fruit
• Furthering investigation on physical exclusion of spotted-wing drosophila from primocane raspberries using tunnels (partnership w/Hutchison lab)
• Assessing the impact of high tunnels and plastic coverings on insect herbivory on brassica crops in organic systems 
• Investigating ecosystem services and population structure of beneficial insects in urban agriculture (project led by Dr. Nick Jelinski in soil, water, & climate)

The Hoover Lab, led by Dr. Emily Hoover, is conducting several projects including but not limited to grit weeding and kiwiberry development: 

Grit Weeding: They are starting the second year of a 2-year study on grit weeding in perennial fruit crops, funded by the Minnesota Department of Agriculture. Grit weeding is a practice in which an abrasive material, in this case ground corn cobs, is blasted by compressed air at weed seedlings. Preliminary data is showing effective control of early season annual weeds in apples, grapes, and raspberries. This coming year will focus on refining treatment timing and establishing practical recommendations for growers. Keep an eye out for presentations and hands-on demonstrations around the state.

Dr. Matt Clark and Anna Underhill,
M.S. graduate, process grapevine samples for
research in 2018. Photo: Annie Klodd

Kiwiberry: They are starting the second year of a 2-year study focused on kiwiberries. This research, funded by the Minnesota Department of Agriculture, is examining several production traits and factors for commercial kiwiberry production in Minnesota.

Factors being studied include optimum harvest and postharvest periods, traits affecting consumer appeal, and consumer preferences for kiwiberry varieties adapted to Minnesota. The 2019 field season will focus on repeating harvest and data collection for vines that survived the winter. Stay tuned to learn about preliminary results from the first year of harvest. 

The Tong lab, led by Dr. Cindy Tong, is in Year 2 of a project to produce romaine lettuce and white cauliflower with acceptable flavor in late July through early August. This is a collaborative project between University of Minnesota researchers and Shared Ground farmers. At Shared Ground farms, they are doing an experiment comparing flavor of 2 varieties under three different transplant dates, to see which transplant dates yield the best flavor for each variety. At the SROC, and on the St. Paul campus, Cindy's group is testing the flavor effect of netted shade for romaine lettuce and IR-blocking shade for cauliflower, when compared to no-shade treatments.

Annie Klodd and Rod Elmstrand will compare which
jack pumpkin varieties grow best in low-till and no-till soil.
Photo: Annie Klodd.

Annie Klodd, Extension Educator, is evaluating which jack-o-lantern pumpkin varieties grow best on no-till fields and following a rye cover crop. This project will be conducted at Rod's Berry Farm in collaboration with Rod Elmstrand. She is also working with Dr. Matt Clark and Dr. Bob Blanchette to investigate the impact of grapevine trunk diseases on Minnesota vineyards, and developing recommendations for grape growers to manage trunk disease.

The Hutchison lab, led by Dr. Bill Hutchison, will be implementing the following recently funded research for Invasive Insect Pests of Fruit & Vegetable Crops:

• "Rapid Response to Japanese Beetle as a New Pest of Wine Grapes & Raspberry." Rapid Agricultural Response Fund, UMN CFANS. With Dr. Matt Clark, Horticulture
• "Early Warning Forecast Models for the Invasive Japanese Beetle in Minnesota Specialty Crops." USDA-MDA Specialty Crops Program
• "Early Detection, Forecasting and Management of Brown Marmorated Stinkbug." MN Invasive Terrestrial Plants & Pest Center (MITPPC, UMN, LCCMR). With Drs. Peter Snyder & Tracey Twine: Soil, Water & Climate.
• "Management strategies for the invasive spotted wing drosophila," MN Invasive Terrestrial Plants & Pest Center (MITPPC, UMN, LCCMR). With Dr. Mary Rogers, Horticulture

The Clark lab, led by Dr. Matt Clark, develops new cold hardy grape varieties and studies the best methods for producing high quality grapes and wine in the upper Midwest. Some current projects include:

• Terroir: How soils effect cold hardy grapes and wine. The UMN along with Harlene Hatterman-Valenti at North Dakota State University will be sampling Brianna and Marquette from distinct soil types across both states and making wine to determine how soil is impacting viticultural traits like cluster size and shape, fruit quality, and wine quality. We will use industry sensory panels to provide feedback on wine quality. (Funded by Minnesota Dept of Agriculture Specialty Crop Block Grant)
• Evaluation of Elmer Swenson Breeding lines at the Horst Rechelbacher Foundation property in Osecola, WI: This collection was obtained from Seed Savers Exchange (Deorah, IA) in order to have a final evaluation of fruit quality and resistance traits that may be useful in breeding. Approximately 140 vines were planted in 2018 and this will be the first year of screening for insect pests and diseases. 
• Development and Evaluation of Cold Hardy Table Grapes: This project will focus on developing methods of screening table grape for fruit quality and storage traits. Traits of interest include berry color, seedlessness, size and shape. Texture and flavors are also important in table grapes, and new methods need to be developed for the cold-hardy germplasm. Currently, the program screens wine grapes and table grapes similarly which does not capture the unique variation in the table grape materials.

Julie Weisenhorn, Extension Educator, runs the Pollinators for Food (P4F) project. In 2019, she is trialing interplanting design of pollinator attractive annual flowers and bell peppers to determine any effect on harvest. This is the second year of P4F. The first year showed positive results at plots the North Central Research and Outreach Center and at the MN Landscape Arboretum on pepper harvest when planted and open to insect pollination. Collaborators include Dr. Vince Fritz, Annie Klodd, Extension Master Gardeners, UMN PlantED, and Pillsbury United Communities. Funded by the Horst Rechelbacher Foundation. 

Julie Weisenhorn sets up a Pollinators for Food
research plot at the Minnesota Landscape Arboretum.
Photo: Annie Klodd.

Authors: Annie Klodd, Charlie Rohwer, Ann Pfeiffer, Mary Rogers, Cindy Tong, Bill Hutchison, and Emily Tepe, and Matt Clark