Hybrid Hazelnuts in the Midwest

Hybrid Hazelnuts in the Midwest

Overview

Hazelnuts, sometimes called filberts, are the fruit produced by the various species of the genus Corylus. A member of the birch family, the hazelnut is deciduous, growing in shrubby clusters approximately one to five meters in height depending on the species. Male flowers are in the form of long, pendulous stalks called catkins (8-10cm long) while female flowers are inconspicuously contained within a scaly bud. The acorn-like nut is the resulting fruit. Enclosed within two bracts forming a husk-like structure, the nuts are one to two centimeters long in varieties native to North America (C. americana and C. cornuta). These species are prized for their sweet taste, may be ground into flour to make a cake-like bread, and were used by Native Americans to flavor soups.While similar in flavor to native North American varieties, the European hazelnut (C. avellana L.) dominates world commercial production due to its slightly larger-sized nuts. The European hazelnut requires very specific temperate climatic conditions (generally mild, humid winters and cool summers), limiting its production to regions like the Black Sea region of Turkey, Italy, and the Pacific Northwest of the United States. (7) (8)

Uses

Hazelnuts may be eaten raw or may be added to cereals, cookies, breads and other staples to enhance flavor. They may also be pressed into cooking oils and are sometimes used as a flavoring for coffees, syrups and beer. Non-food uses for hazelnuts include massage oils, essential oils, biodiesel, mulch and livestock feed (using the leftover meal after oil extraction). Grown as an agroforestry crop, hazelnuts also offer several ecological and economic advantages (see below). (9)

World Production

According to FAO production data from 2007, 567,265 hectares of hazelnuts were cultivated resulting in 776,890 tons of hazelnuts harvested. This represents a positive trend over the past ten years, as acreage and yield have grown by 13.9% and 19.2% respectively. The top two hazelnut producing countries, Italy and Turkey, produce over 80% of the world’s hazelnuts, with Turkey making up the bulk of that number. The United States is the third largest producer (about 4% annually), and other significant producers include Azerbaijan, Spain, Iron, Georgia and China. (10) European hazelnuts (C. avellana) grown in orchards in Oregon’s Willamette Valley account for roughly 99% of total U.S. production (approximately 15,000 hectares). This results in an estimated economic impact of $75 million. (11)

The Advantages of Hybrids for U.S. Production

Two particular problems underscore the value of cultivating hybrid hazelnuts. First, while C. avellana is prized for its larger nuts, it is not cold-tolerant, requiring instead a humid, temperate environment which significantly limits its potential range within the U.S. Mehlenbacher (1991) noted that “Inadequate cold hardiness is a major factor limiting the expansion of commercial production into northern and inland areas” and contended that a dearth of public breeding programs is a result of increased hardiness being unnecessary where hazelnuts are currently cultivated, and an aversion to encouraging competition from new areas. While there is significant hardy germplasm within the species C. Avellana itself, the beaked hazel, C. Cornuta, has a much more northerly range, and can tolerate temperatures down to -50°C. Thus, in the middle of the Twentieth Century, the beaked hazel was hybridized with the European hazel to combine the hardiness of the wild species with the large nut size of the cultivated species with the intended use as windbreaks on Canadian prairies. (12)

Second, the European hazelnut (C. avellana) is highly susceptible to the fungal disease Eastern Filbert Blight (EFB) which has been a significant problem in Oregon hazelnut orchards. (12) Although American hazelnut (C. americana) is the natural host of the disease, it suffers relatively little if infected, while EFB can be devastating to the non-native C. avellana. Early attempts to establish European hazelnuts in the Eastern United States were thwarted by EFB. When susceptible trees are infected, perennial cankers girdle scaffold limbs, nut yields decline sharply, and the trees generally die as the cankers spread to the main trunk.(12)It has been determined that C. avellana X C. americana hybrids can exhibit extremely high levels of resistance to EFB (13), however these hybrid cultivars have had little commercial significance. (12)

Over the past few decades, however, breeders (particularly the National Arbor Day Foundation’s Hazelnut Research Field in Nebraska and Badgersett Research Corporation in Minnesota) have worked to cross the European hazelnut with both the American hazelnut and the beaked hazelnut creating commercially viable, cold hardy, EFB resistant cultivars suitable for the Midwest. (5)(14) These cultivars retain commercially attractive traits (100-300% larger nuts than wild varieties, thinner shells, with most kernels within commercial processing range) and have also proven to be very drought resistant. (14) Cultivating hybrid hazelnuts in the Midwest may result in a host of environmental and economic benefits for the region.

CultivationSpecifics for Hybrid Hazelnuts in the Midwest

Establishment: Since hybrid hazelnut trees may be productive for fifty years or more, it is important to select an appropriate site suitable for production and/or environmental goals. Hazelnuts may be grown as an orchard, as a windbreak or snow fence, as riparian forest buffers, in an alley cropping method with annual crops grown between rows, or on odd plots of land not suitable for row cropping. (5) For production plantings, plants should be spaced six to nine feet apart with roughly 15 feet between rows; to develop more quickly closed hedgerows for wind breaks or snow fences plants may be placed as little as four feet apart. (15) Prior to planting, phosphorous and potassium should be amended to levels for other fruit crops, and lime should be added if pH is below 5.6. Perennial weeds should be removed with a burn-down glyphosate spray or with repeated tillage. Most planting of hybrid hazelnuts occurs by hand and is best conducted when the weather is cool and moist. When planting, it is important to dig holes just deep enough to accommodate the root ball plus half an inch, no deeper, to prevent the seedlings from sinking as the soil settles. (15)

Maintenance: During establishment, a weed-free radius of one to one and a half feet should be maintained, however after two to three years, plants successfully compete against weeds on their own. Mowing between rows is often the only weed abatement strategy necessary. Although drought-resistant, hybrid hazelnuts benefit from a half inch of water weekly if this has not been supplied by rainfall. If phosphorous and potassium are accounted for before planting, nitrogen is the element of most importance while growing hazelnuts. Fertilizer is generally not required for the first two years of growth, however after this point, applications based on bush size and leaf nitrogen content can help growth and production. Some sources recommend that applications take place between May and August to prevent leaching (15), however others advise that a fall application yield consistently better crops.(5) Fortunately, hybrid hazelnuts in the Midwest have no current insect or disease problems of significant concern, however herbivory at the hands of deer, mice and rodents should be guarded against, especially during establishment. (15)

Harvesting: Hazelnuts often start producing nuts in their fourth year after establishment, however may not mature into full production until year nine or later. As soon as nuts become loose in their husks they should be harvested to stave off predation. Harvest generally occurs from mid-August to mid-September in Minnesota, and slightly earlier in Iowa. While most hazelnuts in the Midwest are currently harvested by hand, an unmodified blueberry picker has been proven to be a viable mechanized alternative. After harvest, nuts need to post-ripen for a week or two in humid conditions if husks were still green at time of harvest. If husks were beginning to brown when harvested, they should be dried completely by hanging in onion bags in a dried location or putting them in a crop drier at a low temperature. (15)

Hazelnuts as an Environmentally Beneficial Agroforestry Crop

Hazelnuts are considered to be an environmentally beneficial agroforestry crop, especially in the row crop dominated Midwest. (1)Agroforestry can be summarized by the notion that “trees and shrubs are planted in a specific place and design to capitalize on positive biological interactions, to do a specific job, and to diversify income sources for farmers.” (1)Strategically using agroforestry crops such as hazelnuts can help rowcrop farmers mitigate erosion and flooding at a local level, and can help lessen non-point source pollution by intercepting surface runoff and subsurface flow. In fact, certain tree/shrub riparian buffer designs have been shown to reduce nitrates and agrochemical pollutants moving through the soil rooting zone by 80 to 90 percent. (2) The hypoxic dead zone at the mouth of Mississippi River (thought to be caused by nitrogen leaching from Midwestern farms (3)) is often cited as reason for the Midwest to more aggressively pursue agroforestry technologies. (1)The biology and structureof hybrid hazelnut bushes make them well suited to provide several particular environmental benefits:

Low input requirements: Enormous root systems allow hybrid hazelnuts to weather droughts that would destroy perennial crops, resulting in less resource-intensive cultivation. (4) If rain is scarce, irrigation of one half inch per week is sufficient (see above). (15) Hazelnuts readily out-compete weeds once established, requiring no herbicide application. Modest application of nitrogen fertilizer may, however, benefit production. (15)

European hazelnuts cultivated in Oregon are susceptible to pests such as the filbertworm, filbert weevil, filbert leafroller and hazelnut aphid (a recently invasive species)(20)in addition to the Eastern Filbert Blight fungus. Although Integrated Pest Management strategies have been implemented in controlling some pestspecies(20), conventional pesticide and fungicide spraying is recommended forOregon hazelnut orchards (21). That hybrid hazelnuts currently face no significant pest problems(15) and are bred to be resistant to EFB obviates the need to spray chemical pesticides or fungicides.

Carbon Sequestration: Because they have extensive root systems, hazelnuts help build soil organic matter therefore sequestering it from the atmosphere. Additionally, hazelnuts have an extensive photosynthetic period from early spring through late fall which results in a long period when carbon dioxide is fixed. (4)

Controlling Soil Erosion: The root system and long-lasting canopy can help reduce erosion on sloping aspects. Dormant vegetation and leaf litter also help limit erosion from raindrop splash as well as from wind during the winter. (4) Consequently, hazelnuts may serve farmers well as wind-breaks between fields or as living snow fences.Additionally, hazelnuts may be employed in the practice of alley cropping whereby annual crops are grown between widely spaced strips of trees or shrubs.(5)Since hazelnuts are a perennial crop and do not require tillage, strategic placement of hazelnutsallows farmers to till less land for row crops, further ameliorating erosion problems.

Riparian Buffer Zone: The USDA and National Resource Conservation Service classify hazelnuts as a riparian buffer zone species, serving as a biofilter that protects lakes and streams from sedimentation, erosion and surface runoff. (4) Hybrid hazelnuts do not suffer from waterlogging or being submerged making them an idea lowland agroforestry species. (6)

Nitrogen Leaching: Below the frost line, the hazelnut tree’s perennial root system is active most of the year. This helps prevent excessive nitrogen leaching, which, in turn reduces the need for upkeep. (4)

Wildlife Habitat: Hazelnuts provide good nutrition and habitat for wildlife. Squirrels, deer, turkey, woodpeckers and pheasants eat the nuts, while ruffed grouse eat the male catkins throughout the winter. (4)

Economic Benefits of Cultivating Hybrid Hazelnuts

One part the economic allure of growing hybrid hazelnuts in the Midwest is the general ease of upkeep and potential for low production costs. (18) After establishment, hybrid hazelnuts readily outcompete weeds, tolerate drought and flooding, return to production just a few years after a fire and survive in soils of various types and pH ranges (5.0-7.5, sometimes higher). (6)(15) Planting hybrid hazelnuts on marginal land not suited for cultivated crops, or on small difficult-to-farm tracts (such as those created by center-pivot irrigation) can allow farmers to reap an income from land that otherwise would have gone unused (or, if cultivated, would be environmentally detrimental). (15)(5) Hazelnuts are sold on two different markets—the in-shell market (nuts that will stay in their shell until cracked by the end consumer) and the kernel market (nuts that will be processed).The in-shell market peaks around the holiday season, and requires large, attractive nuts with thin shells. While current hybrid cultivars may not be suitable for the in-shell market, the remaining 90 to 95% of the hazelnuts grown in the world go to the kernel (de-shelled) market where they are sold to bakers, confectioners and other processors.(13) To avoid confusion, it important to note that producers often sell hazelnuts that are still “in-shell” to processors even though these nuts are ultimately destined for the kernel market where processors subsequently de-shell (and often roast) the nuts. Smaller, rounder nuts are valued in this market (13) for which hybrid cultivars may be better suited. Hybrid bushes start producing nuts after two to four years;without extensive care they can yield one and a half pounds of nuts (in-shell), and up to four pounds for superior plants. While the raw commodity in-shell market for hazelnuts has averaged about $0.85 per pound in recent years (14), it has jumped to a record-breaking $1.10 per pound in the fall of 2011 due to a much smaller and later Turkish crop (16). Hence, cultivating hybrid hazelnuts may be especially economically advantageous when the more disease/cold-susceptible European hazelnut (C. avellana) crops fail. Small hybrid hazelnut growers can realize even greater margins by selling their nuts as a local specialty or as a value-added product such as oil, especially since the hybrids do not yield the large nuts desired for fancy nut mixes on the in-shell market. (14)(15)

Market Growth Potential:

Proponents of growing hybrid hazelnuts in the Midwest point out that only 20% of the hazelnuts consumed in the United States are produced inside the country, resulting in a large un-met demand. (15) Additionally, the United States demand may prove to be untapped and relatively elastic since, according to current estimates, US per capita yearly consumption of hazelnuts is a scant two nuts compared to Europe’s per capita weekly average of one cup. (9)One grower has characterized the possibility for expansion in the hazelnut market in the following way: “…anything that can be done with a soybean could be done with a hazelnut, and more. No one familiar with hazel marketing doubts the ability of the market to absorb additional production, even without development of new products.” (14) Whether or not such exuberance is warranted, there are several indicators that domestic hazelnut demand may well grow in the near future:

Nutrition: Demand may grow as people become more aware of the health benefits of nuts, particularly hazelnuts. Although traditionally perceived by the public as being unhealthy due to high fat content, more recent epidemiological and clinical studies have shown a connection between nut consumption and decreased levels of heart disease. The FDA’s recognition of nuts as a “heart-healthy” food by the FDA is significant in boosting the public image of nuts. Recent research, in fact, suggests that a hazelnut-enriched diet may reduce levels of LDL (“bad”) cholesterol while increasing HDL (“good”) cholesterol. Additionally,the heart-healthy fatty acids in hazelnut oil account for approximately 92% of all fatty acids present, making it more desirable than other vegetable oils in terms of heart health. Hazelnuts (out of all tree nuts) are alsothe superior source of folate, biotin and vitamin E, a fat-soluble antioxidant that protects the body’s cells from damage from free radicals. (17) It is important to note that most of these health claims apply to C. avellana, and that more research will be required to better understand the nutritional benefits of hybrid hazelnuts.

Hazelnuts as Biofuel: With an oil content of approximately 60%, some hybrid hazelnut proponents point to hazelnuts as a potential biofuel crop. (15) Citing that US diesel demand far exceeds current biodiesel production capabilities of vegetable oil and animal fat industries,Xu and Hanna (2008) declare a need for low-input oilseed crops that can be grown on marginal land to meet existing energy demands. Their research shows that oil derived from hybrid hazelnuts shows excellent promise as a feedstock for biofuel production. (18) If biodiesel production from hazelnuts proves economically viable, hybrid hazelnut demand could increase immensely.