Eastern filbert blight is an ongoing and costly problem for hazelnut growers, but researchers at the Oregon State Extension are researching newer and more efficient ways to combat it. At the Nut Growers Society’s Winter Meeting, Jay Pscheidt spoke with Matthew Malcolm at Malcolm Media Ag Publishing and shared their findings on drenching. Watch this quick video and read more in Pacific Nut Producer Magazine.
Please thank this video’s sponsor George Packing Company for their industry support.
Oregon is renowned for producing some of the highest quality hazelnuts in the world, thanks to its ideal climate and rich volcanic soils. The state ranks No. 1 in the United States in hazelnuts, producing 99% of the hazelnuts grown in the United States. About 1,000 Oregon farm families grow hazelnuts on almost 97,000 acres. The farmgate value of Oregon’s hazelnut harvest has averaged over $120 million annually in recent years.
Oregon State University (OSU), through its Agricultural Experiment Station and Extension Service, plays a crucial role in supporting Oregon hazelnut growers. Investments in OSU research and development help improve hazelnut production practices, leading to higher yields and better-quality nuts. This, in turn, enhances the economic viability of hazelnut farming.
New strains of Eastern Filbert Blight (EFB) are infecting hazelnut trees with the Gasaway resistance gene in Oregon and Washington. Genetic analysis shows these strains differ from those in the eastern United States and are evolving regionally. Affected cultivars include Jefferson, McDonald and Yamhill, with infections reported in several areas.
OSU fungicide research and breeding programs for quantitative resistance are ongoing. Despite the challenge, new promising hazelnut varieties are in development, and OSU Extension provides resources and guidance to hazelnut growers on how to manage the disease. This includes scouting for cankers, pruning infected wood, implementing fungicide spray programs and submitting samples for testing.
In addition to breeding new varieties, OSU conducts hazelnut research that focuses on improving tree health, pest and disease management and enhancing yield and quality. OSU collaborates with industry partners, such as Ferrero, to fund research projects aimed at addressing key challenges faced by hazelnut growers. These partnerships help ensure the sustainability and profitability of the hazelnut industry.
Here are some key initiatives:
OSU’s hazelnut research and Extension programs provide invaluable support to the state’s hazelnut industry. By developing disease-resistant cultivars and implementing advanced agricultural practices, OSU ensures higher yields, improved kernel quality and sustainable farming methods.
These initiatives not only bolster Oregon’s position as the leading hazelnut producer in the United States but also contribute to the economic vitality and environmental sustainability of the region. — By Nik Wiman, Jay Pscheidt and Marcelo Moretti, Oregon State University Extension
In addition to good news of higher prices and a new hazelnut variety release from Oregon State University, hazelnut growers in attendance at the Nut Growers Society Winter Meeting were also discussing and expressing much concern over a new strain of Eastern Filbert Blight (EFB). Now spreading around the Willamette Valley of Oregon, this new strain appears to be no respecter of the long trusted EFB resistant varieties growers have been investing in. Pacific Nut Producer Editor Matthew Malcolm discussed this issue with the new Nut Growers Society President, Matt Miller, who happened to be among the first to discover this new EFB strain. Watch Miller’s interview and read more about it in Pacific Nut Producer Magazine.
Please thank this video’s sponsor George Packing Company for their industry support.
The hazelnut breeding program at Oregon State University (OSU) has been doing a great job over the years developing new blight resistant hazelnut varieties better suited for todays growing industry in the Pacific Northwest. Back at the Nut Growers Society’s Annual Meeting in Corvallis, Becky McCluskey from the OSU Department of Horticulture showcased some of these varieties. Watch this brief video as she talks about the strengths and characteristics of each variety and read more about it in Pacific Nut Producer Magazine. Don’t currently receive this monthly publication? Subscribe for FREE at https://malcolmmedia.com/pacific-nut-producer-magazine-subscriptions/.
With Eastern Filbert Blight taking a major toll on older hazelnut orchards in the Pacific Northwest, many growers are looking to replant their blocks with new blight resistant varieties. One of the newest of these varieties released by Oregon State University’s hazelnut breeding program is known as PollyO. Check out this brief interview with plant breeder Shawn Mehlenbacher to learn more about this new variety. Read more about growing hazelnuts in Pacific Nut Producer Magazine. Don’t currently receive it? Subscribe for FREE today Here
Announcement from Oregon State University:
Ziram 76 DF at 3 to 8 lb/A. Do not use after May. Group M3 fungicide. 48-hr reentry.
Ziram 76 DF (from United Phosphorus, Inc) was registered for use on hazelnuts on December 12, 2017. Growers must have the supplemental label on hand as well as the label from the product container before use. This material has been very effective on eastern filbert blight. Use this contact only material much like you would any of the chlorothalonil products such as Bravo or Echo. It does not have systemic activity and must be reapplied after significant shoot growth. As always, use at bud break and then every two weeks for two months for best control of EFB.
Testing has shown good efficacy but many of them were done during low disease pressure years. Rates at 1.5 lb/100 gal water resulted in an average of 88% control in two trials. Rates at 3 to 6 lb/100 gallons water have been 100% effective so far. Use of surfactants is recommended for improved handling if not efficacy. Tank mixes with other fungicides is allowed. Application by air is NOT allowed.
We expect more test result in the fall of 2018 when testing was done at high disease pressure. Results are expected to be less than 100% effective but still significant enough to recommend its use.
Strategies for Using Fungicides for Management of Eastern Filbert Blight
Fungicides are best used to protect susceptible tissue in the spring at bud break and for the next 8 weeks. Most fungicides will last 2 weeks before another application is needed. This means a total of 4 applications starting with the first at bud break. Although hazelnuts are still susceptible after this period, additional applications have not resulted in significantly better disease control.
Due to fungicide resistance issues and resulting label requirements, you may not be able to use the same fungicide for all 4 applications. Since the EFB fungus has a long 2-year life cycle the resistance risk is already low relative to other diseases (such as powdery mildew). Strategies to minimize this risk further include alternating and/or tank mixing fungicides with different modes of action. The modes of action for fungicides have been categorized, grouped and assigned numbers such as “group M5”.
Alternating fungicides with different modes of action has been effective to manage EFB. Research has not detected any one alternating strategy as better than any other strategy. We have 5 fungicide groups to choose from including groups 3, 11, M5, M3 and M1. It is suggested that the first application be chorothalonil or Ziram (group M5 or M3) followed by your choice of a group 3 or 11 fungicide. Each of the next two applications would be different from the last one. An example of this program might be to start with Bravo (group M5) at bud break, followed by Gem (group 11) two weeks later, then Tilt (group 3) two weeks after that and ending with Cabrio (group 11). Use of multi-site products such as chlorothalonil (M5), Ziram (M3) or copper-based (M1) products for all 4 applications would also be acceptable.
Do not just alternate fungicides with different trade names as they might have the same mode of action. Some fungicide premixes already are a combination of two fungicides with different modes of action, generally a group 3 and 11 fungicide. These products cannot be used for every application as they do not allow more than 2 sequential applications before switching to a different product with a different mode of action. If you use these premixes you must use an M5, M3 or M1 fungicide in the rotation. An example of this program might be to start with Bravo (M5) at bud break, followed by Stratego (3 + 11) or QuiltXcel (3 + 11) 2 weeks later, then the same product 2 weeks after that but ending with Bravo.
You can make your own tank mixes. Since this can be expensive growers have asked about reducing the rate of each product in the tank. Research to date has shown that a half rate of Echo 90DF (group M5) tank mixed with either Tilt (group 3) or Cabrio (group 11) is effective to manage EFB. Combining fungicide resistance theory and research on EFB in Oregon suggests we should use a half rate of chlorothalonil tank mixed with a full rate of a group 3 fungicide or a half rate of a group 11 fungicide. An example of this program might be:
1st Application – A full rate of Bravo (M5) at bud break.
2nd Application 2 weeks later – A mix of Cabrio (11) plus Echo 90DF (M5) each at half rates.
3rd Application 2 weeks later – A mix of Tilt (3) at full rate plus Echo 90 DF (M5) at half rate.
4th Application 2 weeks later – A mix of Cabrio (11) plus Echo 90DF (M5) each at half rates.
Research has indicated that the addition of a surfactant will provide better disease control than using a fungicide alone. Numerous products can break the surface tension of water to get better coverage of plant tissue. They also can help keep the fungicide solution in contact with the plant, reducing wash off during rain events. Unless otherwise stated on the label, it is recommended to add a surfactant with a fungicide. Copper-based products have traditionally been applied with horticultural mineral oil. Newer fungicides may be mixed with silicone-based or non-ionic surfactants. Be careful as several fungicides may already come formulated with a surfactant and specifically say NOT to add these products. For example, do not add a surfactant to Bravo, Echo or Quadris Top.