University of Oregon - Hallett Lab

Our pigs spent autumn under the canopy of oaks and hazelnuts in constant pursuit of falling nuts. We did this to explore the potential for pigs to interrupt the life cycle of our hazelnut’s most feared (and effective) pest—Filbert Worm. These worms are native to Oregon and hatch as moths in early summer to lay their eggs near nuts before their hard shell has time to develop. The worm burrows into the nut and eats the kernel all summer long before falling to the ground in October. Assuming the worm isn’t removed from the ground, it will transform into a moth the following year and repeat the process. Filbert worms are a major problem in most Oregon orchards, and they are usually combated with pesticide. If a farmer’s orchard neighbors a stand of oaks, they are often advised to remove the native host of filbert worm: acorns.

In partnering with the University of Oregon, we spent 2018 moving our pigs through different oak and hazelnut paddocks, making sure to leave control areas untouched. We found that pigs no doubt have a strong preference for both hazelnuts and acorns. We’re won’t know the full results of the project until filbert worm moths are caught in 2019, but we sure don’t see a lot of nuts laying on the ground.

Project summary:

"The spillover of pests from wildlands to farmland creates conflict between habitat conservation and agricultural production. This is the case in the Pacific Northwest; where Oregon white oaks harbor the filbertworm moth, the key economic pest for hazelnuts. These oaks are dispersed throughout a matrix of private agricultural land and comprise one of the most imperiled habitats in Oregon – with less than 5% remaining in the state. Furthermore, the Willamette Valley accounts for almost all the hazelnuts grown nationwide and pest pressure incentivizes landowners to clear oaks from their property to reduce crop damage and pesticide cost.

A growing number of landowners are recognizing the need to conserve oak habitat and are looking for ways to adaptively manage filbertworm within the landscape. Agroforestry practices such as silvopastures, where animals graze within forested areas, is a promising tool for disrupting the life cycle of agricultural pests and can help align conservation principles with economic goals. Likewise, domestic hogs have historically grazed oak habitat in Spain and Portugal, creating some of the most desired ham in the world. If prescribed hog-grazing of oak habitat in the Willamette Valley is carefully managed, it could have significant economic and ecological potential for diversifying farms.

With this in mind, we set out to see if prescribed hog-grazing reduces filbertworm pest pressure over the course of two years. Between 2018 and 2020, hogs grazed oak woodlands at My Brother’s Farm in October, when acorns infested with the filbertworm larvae fall to the ground. To minimize the effects of grazing on the understory vegetation and soil, the hogs were rotated through 2-acre paddocks every 4-5 days. To measure the population of filbertworm throughout Spring and Summer, we used ground emergence traps and commercial sticky traps in the oak canopy.

We found that hogs were extremely effective at removing infested acorns while having an insignificant change in understory vegetation. Additionally, the emerging filbertworm populations in the grazed paddocks diverged from the control with near-zero emerging in 2020. These results, along with an increased demand for nature-friendly pork and a decreased spillover potential, are a promising step towards resolving the conflict between oak conservation and hazelnut production in the Pacific Northwest. Although hog-grazing may not be practical in some cases, prescribed burns, and alternative grazers such as goats, could be additional tools for adaptively managing filbertworm and other pests in the agricultural-wildland matrix."

Big Leaf Maple Project with Oregon State University

The farm is involved in a project with Oregon State University that is exploring the viability of producing maple water & maple syrup from Big Leaf Maple in the Willamette Valley. Big Leaf Maple sap does not have as high of a sugar content as the traditional Sugar Maple from the Northeast, but they produce tons of maple water! When the season turns cold the taps start to flow. We have been collecting maple water from trees on the farm, but the project extends to multiple sites from Portland area to the surrounding Eugene area. Much of the maple water that is collected will be run through a reverse osmosis machine to make a more concentrated solution. Thereafter we can boil it in the evaporator until it reaches syrup concentration at 66.9 Brix (% sugar). The project is aimed at creating maple syrup and other maple water products. Maple water is an isotonic beverage, similar to coconut water with a lot less food miles attached for locals.

Sustainable Agriculture Research and Education

Potential for Shake and Catch Harvesting of Hazelnuts

Research funded by the Western SARE Farmer/Rancher Grant Program is helping us look at alternative harvesting options for our hazelnuts. Conventionally, hazelnuts are harvested by sweeping them off of the orchard floor every fall. This “sweep harvest” method necessitates keeping orchard floors very flat and free of vegetation/debris that may interfere with harvest.

Keeping orchard floors “clean” is achieved through frequent flail mowing, leveling, and herbicide applications, which can lead to soil degradation and biodiversity decline. Additionally, because sweep harvesting cannot begin until all nuts have fallen from the tree, harvest is often conducted after the onset of the fall rains, which can lead to additional compaction and difficulties separating the nuts from debris and mud.

Shake & Catch harvesting could allow for a whole host of environmental benefits, as well as increase the economic viability of small to mid-size hazelnut orchards. With shake and catch harvesting techniques, nuts are harvested straight from the tree by shaking the trunk, causing nuts to fall onto an inverted umbrella and into a tote. Deep-rooted cover crops could be grown to maximize their soil building potential, and our pigs and bison could be integrated after the harvest to help control disease and maintain fertility.

In order to test the viability of shake and catch harvesting, the project will compare yield and timing of “shake and catch harvesting” vs “sweep harvesting.”  Stay tuned!