Commercialization of Hazelnuts for Growers in the Upper Midwest

Project Overview

Project Type: Research and Education
Funds awarded in 2015: $198,569.00
Projected End Date: 12/31/2018
Grant Recipient: University of Wisconsin
Region: North Central
State: Wisconsin
Project Coordinator:
Jason Fischbach
Bayfield County UW-Extension

Annual Reports

Information Products


  • Nuts: hazelnuts


  • Crop Production: agroforestry, alley cropping, crop improvement and selection, food product quality/safety, plant breeding and genetics, windbreaks
  • Education and Training: extension, participatory research


    The overall purpose of our project was to advance the hazelnut industry in the Upper Midwest through a series of targeted research projects.  Our objectives were to: 1) Advance our long-term effort to develop improved germplasm for growers through establishment of replicated germplasm trials evaluating the performance of our top selections across a range of environments, 2) Better understand the phenolic content of hazelnut involucres, shells, and leaves as possible co-products of post-harvest processing, 3) Develop chemical fingerprinting tools for flavor compounds as a tool to identify superior genotypes for flavor and to assess the impact of post-harvest handling practices on flavor, and 4) To optimize cracking procedures to maximize whole kernel recovery rates. 

    We have completed work analyzing the phenolic and antioxidant content of the leaves, involucres, and nuts of American and Hybrid hazelnuts and have published the results in the American Journal of Essential Oils and Natural Products.  We have completed exploratory work identifying anti-quality flavor compounds (bitterness) in hazelnut kernels and will be completing work to track the changes in these compounds in storage outside the time period of this grant project.  We completed the 2016 and 2017 harvest and data analysis, identified the top 12 plants for propagation and commercial release, and established replicated performance trials with these selections at 6 locations in the Upper Midwest (two each in IA, MN, and WI)  Work is continuing to develop the field-ready propagules from these 12 plants through micropropagation, but progress has been slow and delayed our goal of planting at least 10 on-farm trials.  We have completed development of EMC (Equilibrium Moisture Content) curves in order to optimize cracking and dry-down procedures.  We completed work to evaluate the effect of moisture content on cracking and have finished quantifying deformation forces and cracking characteristics. The results of this cracking analysis have been submitted for publication in the journal of Transactions of the American Society of Agricultural and Biological Engineers.   We continue to provide updates to our stakeholders and growers via a newsletter, field days, and conferences.

    Project objectives:

    Outcome/Objective 1: On-Farm Evaluation of Select Hazelnut Genotypes

    Achieving Objective 1 of this project will take all three years. The first year will finalize selection of the top genotypes and put those genotypes through micro-propagation.  Years 2 and 3 will focus on establishment of the replicated performance trials.

    Outcome/Objective 2: Optimizing Post-Harvest Handling for Processing

    The first step in this objective is to develop EMC curves for the hazelnuts in order to identify optimal cracking moisture and dry down procedures.

    Outcome/Objective 3: Optimizing Post-Harvest Handling for Flavor

    The next step is to implement the dry-down and storage trials to determine optimal procedures for protecting hazelnut flavor.

    Outcome/Objective 4: Screening Hazelnuts for Phenolic Content and Novel Compounds

    The purpose of this objective is to screen hazelnut kernel, shell, and involucre for phenolic content for possible identification of novel phenolics with commercial potential.

    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.