Hazelnut Research and Breeding at Rutgers

Wild American Hazelnut.

Hazelnuts, also known as filberts, are currently only produced commercially in the United States in the Willamette Valley of Oregon. However, research and breeding at Rutgers is changing this scenario. Hazelnuts, compared to other species, are a very low-input crop, needing very little to no supplemental irrigation, pesticide or fungicides. They can be grown on a diversity of soil types, including those that are less than ideal. Hazelnuts are widely adapted, and depending on the cultivar, can be very cold hardy. In regions such as New Jersey, the Mid-Atlantic and much of the fruit belt of the eastern U.S. and southern Canada, many hazelnuts would thrive. However, the presence of a disease called Eastern Filbert Blight has made growing hazelnuts as a commercial venture in this region nearly impossible; that is, until only very recently.

Eastern Filbert Blight.
Eastern Filbert Blight, a destructive disease of hazelnut.

Eastern Filbert Blight is a fungal disease that causes stem cankers, branch die-back and eventual death of susceptible hazelnuts. Unlike many other plant pathogens that cause economic damage to agriculture in the U.S., eastern filbert blight is found naturally occurring in our forests associated with our native hazelnut, Corylus americana, which is very tolerant of the disease. Corylus americana is not grown commercially, due to its tiny, thick shelled nuts and spreading growth habit. Its European relative, Corylus avellana, is the species grown commercially, as it produces large nuts with thin shells and high quality kernels. Unfortunately, the European species is generally highly susceptible to the disease.

New Eastern Filbert Blight resistant hazelnut.
New Eastern Filbert Blight resistant hazelnut developed at Rutgers.

Hazelnut research and breeding at Rutgers was initiated in 1996. Working since that time in close collaboration with hazelnut researchers at Oregon State University, has lead to the development of adapted and productive plants that are highly resistant to eastern filbert blight, while producing excellent quality nuts. Our approach to developing resistant plants includes using sources of resistance found within the European species in our breeding program, as well as creating hybrids between better adapted wild species to develop advanced generation plants that are disease resistant, very cold hardy, as well as having improved nut quality and yield.

We are now in the initial phases of multi-location testing of our first generation of disease resistant plants, supported by a USDA Specialty Crops Grant, a Northeast SARE partnership grant and the New Jersey Agricultural Experiment Station. We are confident by the end of this decade, due to our breeding and research, there will be small to medium scale orchards of hazelnuts being grown for nut production in New Jersey, the surrounding states, as well as southern Ontario. Further progress in developing wider-adapted hazelnuts is being made through our close involvement in the Hybrid Hazelnut Consortium, consisting of Rutgers, Oregon State University, the University of Nebraska, Lincoln, and the Arbor Day Foundation.

Nut clusters of purple-leaf ornamental hazelnut.
Nut clusters of purple-leaf ornamental hazelnut developed at Rutgers.

In addition to hazelnuts for nut production, we are also developing a new line of disease resistant ornamental hazelnuts. These include plants with attractive purple leaves and bright fall color, as well as those with contorted and weeping branches. The fall color comes from our native hazelnut and the purple leaves from the European species. These plants also produce nuts, making them edible landscape plants.


If you are interested in learning more about our hazelnut breeding program, including testing of experimental lines in the near future, please contact:

Thomas Molnar
Assistant Professor, Dept. of Plant Biology
Email: thomas.molnar@rutgers.edu