Organic hazelnuts can fetch a premium price but growing them without conventional tools also leaves farmers prone to unforeseen risks, according to experts.
Farmers who cultivate hazelnuts organically — or aspire to do so — learned about dealing with the challenges during an Aug. 15 tour of operations near Lebanon and Scio, Ore., organized by the Organic Hazelnut Growers Association.
Without access to most chemical sprays, organic growers have to be creative in battling the multitude of pests and diseases that can afflict the crop, according to speakers.
“You really can’t just do it for the return. It’s a different system of farming if you’re not used to it,” said Drew Katz, transition coordinator for Oregon Tilth, an organic certifier.
One scourge facing organically grown hazelnut trees is Eastern Filbert Blight, a fungal pathogen that conventional growers can fight with systemic fungicides.
Organic farmers can treat their orchards with copper but the substance must be re-applied after rain, requiring multiple applications during the storm season.
Copper can also build up in the soil to the point that it’s toxic to the trees, said Nik Wiman, an Oregon State University orchard specialist. “It can hurt plant growth in the long term.”
Keeping the orchard floor clean in preparation for harvest is also more labor-intensive without the “chemical mow” offered by herbicides, requiring the planting of cover crops as well as mowing and tillage.
Sharp-point fluvellin is a problem weed that can wrap around components of harvesting equipment and has spread through an organic orchard owned by Chess Ag Full Harvest Partners, an investment firm.
Don Hatai, the company’s farm manager, said he’s thinking about planting perennial grasses to “shade out” the weed, but may need to switch back to conventional treatments to control it.
In general, it’s advisable to establish an orchard block with conventional methods before transitioning it to organic production, Hatai said. “You need to get that tree to grow.”
For example, there’s no organic spray to control flathead borers, which tend to feed on younger trees, he said. Once they reach about five years, though, the insect doesn’t inflict as much damage.
Disrupting the reproduction of filbertworms — which eat kernels — with pheromone treatments can control their populations in organic orchards.
However, mating disruption is most effective at keeping the number of insects low, rather than treating an orchard that is already teeming with them.
“You can’t manage a big population,” Wiman said.
Organic farmers can spray for filbertworms with Entrust, a biopesticide, which has a “synergistic effect” when combined with neem oil, he said. The worry is that growers are becoming too reliant on the chemical, threatening its effectiveness.
To transition to organic production, an orchard cannot be treated with a prohibited substance for three years.
Farmers who have already transitioned their land to organic production must plant new orchards with organically grown seedlings, unless they’re not available, said Katz.
If growers can demonstrate they can’t obtain the variety, quantity or quality of organic trees they need, they can then plant conventional stock, he said.
Apart from agronomic considerations, processing is another complication for organic hazelnut growers.
The options for “custom processing” are currently limited due to the small volume of organic hazelnuts, which is why the Organic Hazelnut Growers Association is looking at options for a dedicated facility.
To maintain her crop’s organic status, farmer Linda Perrine must use an accredited organic pasteurizer, processor and commercial kitchen.
While a pound of her hazelnut kernels sell for up to $11 wholesale and $15 retail, the expense of producing an organic crop is considerably greater, she said. “The broader public doesn’t understand why there is so much cost difference.”